224c700a1f
Also check in work in progress for blend modes, round rects, and a placeholder for pictures. One minor include change to add a parameter name for SkBlendMode function. TBR=reed@google.com R=caryclark@google.com Docs-Preview: https://skia.org/?cl=134200 Bug: skia:6898 Change-Id: I5d2a9221d61edb32d9c7edbb3193401605b2b513 Reviewed-on: https://skia-review.googlesource.com/134200 Reviewed-by: Cary Clark <caryclark@google.com> Reviewed-by: Cary Clark <caryclark@skia.org> Commit-Queue: Cary Clark <caryclark@skia.org> Auto-Submit: Cary Clark <caryclark@skia.org>
5922 lines
182 KiB
Plaintext
5922 lines
182 KiB
Plaintext
#Topic Path
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#Alias Path_Reference ##
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#Alias Paths ##
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Path contains Lines and Curves which can be stroked or filled. Contour is
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composed of a series of connected Lines and Curves. Path may contain zero,
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one, or more Contours.
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Each Line and Curve are described by Verb, Points, and optional Conic_Weight.
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Each pair of connected Lines and Curves share common Point; for instance, Path
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containing two connected Lines are described the Verb sequence:
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SkPath::kMove_Verb, SkPath::kLine_Verb, SkPath::kLine_Verb; and a Point sequence
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with three entries, sharing
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the middle entry as the end of the first Line and the start of the second Line.
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Path components Arc, Rect, Round_Rect, Circle, and Oval are composed of
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Lines and Curves with as many Verbs and Points required
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for an exact description. Once added to Path, these components may lose their
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identity; although Path can be inspected to determine if it describes a single
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Rect, Oval, Round_Rect, and so on.
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#Example
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#Height 192
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#Description
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Path contains three Contours: Line, Circle, and Quad. Line is stroked but
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not filled. Circle is stroked and filled; Circle stroke forms a loop. Quad
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is stroked and filled, but since it is not closed, Quad does not stroke a loop.
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##
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void draw(SkCanvas* canvas) {
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SkPaint paint;
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paint.setAntiAlias(true);
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SkPath path;
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path.moveTo(124, 108);
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path.lineTo(172, 24);
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path.addCircle(50, 50, 30);
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path.moveTo(36, 148);
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path.quadTo(66, 188, 120, 136);
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canvas->drawPath(path, paint);
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paint.setStyle(SkPaint::kStroke_Style);
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paint.setColor(SK_ColorBLUE);
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paint.setStrokeWidth(3);
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canvas->drawPath(path, paint);
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}
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##
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Path contains a Fill_Type which determines whether overlapping Contours
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form fills or holes. Fill_Type also determines whether area inside or outside
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Lines and Curves is filled.
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#Example
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#Height 192
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#Description
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Path is drawn filled, then stroked, then stroked and filled.
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##
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void draw(SkCanvas* canvas) {
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SkPaint paint;
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paint.setAntiAlias(true);
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SkPath path;
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path.moveTo(36, 48);
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path.quadTo(66, 88, 120, 36);
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canvas->drawPath(path, paint);
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paint.setStyle(SkPaint::kStroke_Style);
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paint.setColor(SK_ColorBLUE);
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paint.setStrokeWidth(8);
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canvas->translate(0, 50);
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canvas->drawPath(path, paint);
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paint.setStyle(SkPaint::kStrokeAndFill_Style);
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paint.setColor(SK_ColorRED);
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canvas->translate(0, 50);
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canvas->drawPath(path, paint);
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}
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##
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Path contents are never shared. Copying Path by value effectively creates
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a new Path independent of the original. Internally, the copy does not duplicate
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its contents until it is edited, to reduce memory use and improve performance.
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#Subtopic Contour
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#Alias Contours ##
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#Line # loop of lines and curves ##
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Contour contains one or more Verbs, and as many Points as
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are required to satisfy Verb_Array. First Verb in Path is always
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SkPath::kMove_Verb; each SkPath::kMove_Verb that follows starts a new Contour.
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#Example
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#Description
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Each SkPath::moveTo starts a new Contour, and content after SkPath::close()
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also starts a new Contour. Since SkPath::conicTo is not preceded by
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SkPath::moveTo, the first Point of the third Contour starts at the last Point
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of the second Contour.
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##
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#Height 192
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SkPaint paint;
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paint.setAntiAlias(true);
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canvas->drawString("1st contour", 150, 100, paint);
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canvas->drawString("2nd contour", 130, 160, paint);
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canvas->drawString("3rd contour", 40, 30, paint);
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paint.setStyle(SkPaint::kStroke_Style);
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SkPath path;
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path.moveTo(124, 108);
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path.lineTo(172, 24);
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path.moveTo(36, 148);
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path.quadTo(66, 188, 120, 136);
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path.close();
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path.conicTo(70, 20, 110, 40, 0.6f);
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canvas->drawPath(path, paint);
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##
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If final Verb in Contour is SkPath::kClose_Verb, Line connects Last_Point in
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Contour with first Point. A closed Contour, stroked, draws
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Paint_Stroke_Join at Last_Point and first Point. Without SkPath::kClose_Verb
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as final Verb, Last_Point and first Point are not connected; Contour
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remains open. An open Contour, stroked, draws Paint_Stroke_Cap at
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Last_Point and first Point.
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#Example
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#Height 160
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#Description
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Path is drawn stroked, with an open Contour and a closed Contour.
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##
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void draw(SkCanvas* canvas) {
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SkPaint paint;
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paint.setAntiAlias(true);
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paint.setStyle(SkPaint::kStroke_Style);
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paint.setStrokeWidth(8);
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SkPath path;
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path.moveTo(36, 48);
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path.quadTo(66, 88, 120, 36);
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canvas->drawPath(path, paint);
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path.close();
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canvas->translate(0, 50);
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canvas->drawPath(path, paint);
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}
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##
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#Subtopic Zero_Length
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#Alias Zero_Length_Contour ##
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#Line # consideration when contour has no length ##
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Contour length is distance traveled from first Point to Last_Point,
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plus, if Contour is closed, distance from Last_Point to first Point.
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Even if Contour length is zero, stroked Lines are drawn if Paint_Stroke_Cap
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makes them visible.
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#Example
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#Height 64
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SkPaint paint;
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paint.setAntiAlias(true);
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paint.setStyle(SkPaint::kStroke_Style);
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paint.setStrokeWidth(8);
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paint.setStrokeCap(SkPaint::kRound_Cap);
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SkPath path;
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path.moveTo(36, 48);
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path.lineTo(36, 48);
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canvas->drawPath(path, paint);
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path.reset();
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paint.setStrokeCap(SkPaint::kSquare_Cap);
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path.moveTo(56, 48);
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path.close();
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canvas->drawPath(path, paint);
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##
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#Subtopic Zero_Length ##
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#Subtopic Contour ##
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# ------------------------------------------------------------------------------
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#Class SkPath
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Paths contain geometry. Paths may be empty, or contain one or more Verbs that
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outline a figure. Path always starts with a move verb to a Cartesian_Coordinate,
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and may be followed by additional verbs that add lines or curves.
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Adding a close verb makes the geometry into a continuous loop, a closed contour.
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Paths may contain any number of contours, each beginning with a move verb.
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Path contours may contain only a move verb, or may also contain lines,
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Quadratic_Beziers, Conics, and Cubic_Beziers. Path contours may be open or
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closed.
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When used to draw a filled area, Path describes whether the fill is inside or
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outside the geometry. Path also describes the winding rule used to fill
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overlapping contours.
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Internally, Path lazily computes metrics likes bounds and convexity. Call
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SkPath::updateBoundsCache to make Path thread safe.
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#Subtopic Overview
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#Populate
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##
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#Subtopic Related_Function
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#Populate
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##
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#Subtopic Constant
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#Populate
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##
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#Subtopic Class
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#Populate
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##
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#Subtopic Constructor
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#Populate
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##
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#Subtopic Operator
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#Populate
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##
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#Subtopic Member_Function
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#Populate
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##
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#Subtopic Verb
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#Alias Verbs ##
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#Line # line and curve type ##
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#Enum Verb
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#Line # controls how Path Points are interpreted ##
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#Code
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enum Verb {
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kMove_Verb,
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kLine_Verb,
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kQuad_Verb,
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kConic_Verb,
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kCubic_Verb,
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kClose_Verb,
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kDone_Verb,
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};
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##
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Verb instructs Path how to interpret one or more Point and optional Conic_Weight;
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manage Contour, and terminate Path.
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#Const kMove_Verb 0
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#Line # starts new Contour at next Point ##
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Consecutive kMove_Verb are preserved but all but the last kMove_Verb is
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ignored. kMove_Verb after other Verbs implicitly closes the previous Contour
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if SkPaint::kFill_Style is set when drawn; otherwise, stroke is drawn open.
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kMove_Verb as the last Verb is preserved but ignored.
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##
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#Const kLine_Verb 1
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#Line # adds Line from Last_Point to next Point ##
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Line is a straight segment from Point to Point. Consecutive kLine_Verb
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extend Contour. kLine_Verb at same position as prior kMove_Verb is
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preserved, and draws Point if SkPaint::kStroke_Style is set, and
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SkPaint::Cap is SkPaint::kSquare_Cap or SkPaint::kRound_Cap. kLine_Verb
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at same position as prior line or curve Verb is preserved but is ignored.
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##
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#Const kQuad_Verb 2
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#Line # adds Quad from Last_Point ##
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Adds Quad from Last_Point, using control Point, and end Point.
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Quad is a parabolic section within tangents from Last_Point to control Point,
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and control Point to end Point.
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##
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#Const kConic_Verb 3
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#Line # adds Conic from Last_Point ##
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Adds Conic from Last_Point, using control Point, end Point, and Conic_Weight.
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Conic is a elliptical, parabolic, or hyperbolic section within tangents
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from Last_Point to control Point, and control Point to end Point, constrained
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by Conic_Weight. Conic_Weight less than one is elliptical; equal to one is
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parabolic (and identical to Quad); greater than one hyperbolic.
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##
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#Const kCubic_Verb 4
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#Line # adds Cubic from Last_Point ##
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Adds Cubic from Last_Point, using two control Points, and end Point.
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Cubic is a third-order Bezier_Curve section within tangents from Last_Point
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to first control Point, and from second control Point to end Point.
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##
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#Const kClose_Verb 5
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#Line # closes Contour ##
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Closes Contour, connecting Last_Point to kMove_Verb Point. Consecutive
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kClose_Verb are preserved but only first has an effect. kClose_Verb after
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kMove_Verb has no effect.
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##
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#Const kDone_Verb 6
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#Line # terminates Path ##
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Not in Verb_Array, but returned by Path iterator.
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##
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Each Verb has zero or more Points stored in Path.
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Path iterator returns complete curve descriptions, duplicating shared Points
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for consecutive entries.
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#Table
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#Legend
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# Verb # Allocated Points # Iterated Points # Weights ##
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##
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# kMove_Verb # 1 # 1 # 0 ##
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# kLine_Verb # 1 # 2 # 0 ##
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# kQuad_Verb # 2 # 3 # 0 ##
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# kConic_Verb # 2 # 3 # 1 ##
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# kCubic_Verb # 3 # 4 # 0 ##
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# kClose_Verb # 0 # 1 # 0 ##
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# kDone_Verb # -- # 0 # 0 ##
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##
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#Example
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void draw(SkCanvas* canvas) {
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SkPath path;
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path.lineTo(20, 20);
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path.quadTo(-10, -10, 30, 30);
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path.close();
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path.cubicTo(1, 2, 3, 4, 5, 6);
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path.conicTo(0, 0, 0, 0, 2);
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uint8_t verbs[7];
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int count = path.getVerbs(verbs, (int) SK_ARRAY_COUNT(verbs));
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const char* verbStr[] = { "Move", "Line", "Quad", "Conic", "Cubic", "Close" };
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SkDebugf("verb count: %d\nverbs: ", count);
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for (int i = 0; i < count; ++i) {
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SkDebugf("k%s_Verb ", verbStr[verbs[i]]);
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}
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SkDebugf("\n");
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}
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#StdOut
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verb count: 7
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verbs: kMove_Verb kLine_Verb kQuad_Verb kClose_Verb kMove_Verb kCubic_Verb kConic_Verb
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##
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##
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#Enum Verb ##
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#Subtopic Verb ##
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# ------------------------------------------------------------------------------
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#Subtopic Direction
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#Line # contour orientation, clockwise or counterclockwise ##
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#Alias Directions ##
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#Enum Direction
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#Line # sets Contour clockwise or counterclockwise ##
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#Code
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enum Direction {
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kCW_Direction,
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kCCW_Direction,
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};
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##
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Direction describes whether Contour is clockwise or counterclockwise.
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When Path contains multiple overlapping Contours, Direction together with
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Fill_Type determines whether overlaps are filled or form holes.
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Direction also determines how Contour is measured. For instance, dashing
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measures along Path to determine where to start and stop stroke; Direction
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will change dashed results as it steps clockwise or counterclockwise.
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Closed Contours like Rect, Round_Rect, Circle, and Oval added with
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kCW_Direction travel clockwise; the same added with kCCW_Direction
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travel counterclockwise.
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#Const kCW_Direction 0
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#Line # contour travels clockwise ##
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##
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#Const kCCW_Direction 1
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#Line # contour travels counterclockwise ##
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##
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#Example
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#Height 100
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void draw(SkCanvas* canvas) {
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const SkPoint arrow[] = { {40, -5}, {45, 0}, {40, 5} };
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const SkRect rect = {10, 10, 90, 90};
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SkPaint rectPaint;
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rectPaint.setAntiAlias(true);
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SkPaint textPaint(rectPaint);
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textPaint.setTextAlign(SkPaint::kCenter_Align);
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rectPaint.setStyle(SkPaint::kStroke_Style);
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SkPaint arrowPaint(rectPaint);
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SkPath arrowPath;
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arrowPath.addPoly(arrow, SK_ARRAY_COUNT(arrow), true);
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arrowPaint.setPathEffect(SkPath1DPathEffect::Make(arrowPath, 320, 0,
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SkPath1DPathEffect::kRotate_Style));
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for (auto direction : { SkPath::kCW_Direction, SkPath::kCCW_Direction } ) {
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canvas->drawRect(rect, rectPaint);
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for (unsigned start : { 0, 1, 2, 3 } ) {
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SkPath path;
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path.addRect(rect, direction, start);
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canvas->drawPath(path, arrowPaint);
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}
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canvas->drawString(SkPath::kCW_Direction == direction ? "CW" : "CCW", rect.centerX(),
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rect.centerY(), textPaint);
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canvas->translate(120, 0);
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}
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}
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##
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#SeeAlso arcTo rArcTo isRect isNestedFillRects addRect addOval
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#Enum Direction ##
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#Subtopic Direction ##
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# ------------------------------------------------------------------------------
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#Method SkPath()
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#Line # constructs with default values ##
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By default, Path has no Verbs, no Points, and no Weights.
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Fill_Type is set to kWinding_FillType.
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#Return empty Path ##
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#Example
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SkPath path;
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SkDebugf("path is " "%s" "empty", path.isEmpty() ? "" : "not ");
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#StdOut
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path is empty
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##
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##
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#SeeAlso reset rewind
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##
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# ------------------------------------------------------------------------------
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#Method SkPath(const SkPath& path)
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#Line # makes a shallow copy ##
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Copy constructor makes two paths identical by value. Internally, path and
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the returned result share pointer values. The underlying Verb_Array, Point_Array
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and Weights are copied when modified.
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Creating a Path copy is very efficient and never allocates memory.
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Paths are always copied by value from the interface; the underlying shared
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pointers are not exposed.
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#Param path Path to copy by value ##
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#Return copy of Path ##
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#Example
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#Description
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Modifying one path does not effect another, even if they started as copies
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of each other.
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##
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SkPath path;
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path.lineTo(20, 20);
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SkPath path2(path);
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path2.close();
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SkDebugf("path verbs: %d\n", path.countVerbs());
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SkDebugf("path2 verbs: %d\n", path2.countVerbs());
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path.reset();
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SkDebugf("after reset\n" "path verbs: %d\n", path.countVerbs());
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SkDebugf("path2 verbs: %d\n", path2.countVerbs());
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#StdOut
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path verbs: 2
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path2 verbs: 3
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after reset
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path verbs: 0
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path2 verbs: 3
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##
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##
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#SeeAlso operator=(const SkPath& path)
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##
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# ------------------------------------------------------------------------------
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#Method ~SkPath()
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#Line # decreases Reference_Count of owned objects ##
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Releases ownership of any shared data and deletes data if Path is sole owner.
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#Example
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#Description
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delete calls Path Destructor, but copy of original in path2 is unaffected.
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##
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void draw(SkCanvas* canvas) {
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SkPath* path = new SkPath();
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path->lineTo(20, 20);
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SkPath path2(*path);
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delete path;
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SkDebugf("path2 is " "%s" "empty", path2.isEmpty() ? "" : "not ");
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}
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##
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#SeeAlso SkPath() SkPath(const SkPath& path) operator=(const SkPath& path)
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##
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# ------------------------------------------------------------------------------
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#Method SkPath& operator=(const SkPath& path)
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#Line # makes a shallow copy ##
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Path assignment makes two paths identical by value. Internally, assignment
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shares pointer values. The underlying Verb_Array, Point_Array and Weights
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are copied when modified.
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Copying Paths by assignment is very efficient and never allocates memory.
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Paths are always copied by value from the interface; the underlying shared
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pointers are not exposed.
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#Param path Verb_Array, Point_Array, Weights, and Fill_Type to copy ##
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#Return Path copied by value ##
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#Example
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SkPath path1;
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path1.addRect({10, 20, 30, 40});
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SkPath path2 = path1;
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const SkRect& b1 = path1.getBounds();
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SkDebugf("path1 bounds = %g, %g, %g, %g\n", b1.fLeft, b1.fTop, b1.fRight, b1.fBottom);
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|
const SkRect& b2 = path2.getBounds();
|
|
SkDebugf("path2 bounds = %g, %g, %g, %g\n", b2.fLeft, b2.fTop, b2.fRight, b2.fBottom);
|
|
#StdOut
|
|
path1 bounds = 10, 20, 30, 40
|
|
path2 bounds = 10, 20, 30, 40
|
|
#StdOut ##
|
|
##
|
|
|
|
#SeeAlso swap() SkPath(const SkPath& path)
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method bool operator==(const SkPath& a, const SkPath& b)
|
|
|
|
#Line # compares paths for equality ##
|
|
Compares a and b; returns true if Fill_Type, Verb_Array, Point_Array, and Weights
|
|
are equivalent.
|
|
|
|
#Param a Path to compare ##
|
|
#Param b Path to compare ##
|
|
|
|
#Return true if Path pair are equivalent ##
|
|
|
|
#Example
|
|
#Description
|
|
Rewind removes Verb_Array but leaves storage; since storage is not compared,
|
|
Path pair are equivalent.
|
|
##
|
|
void draw(SkCanvas* canvas) {
|
|
auto debugster = [](const char* prefix, const SkPath& a, const SkPath& b) -> void {
|
|
SkDebugf("%s one %c= two\n", prefix, a == b ? '=' : '!');
|
|
};
|
|
SkPath one;
|
|
SkPath two;
|
|
debugster("empty", one, two);
|
|
one.moveTo(0, 0);
|
|
debugster("moveTo", one, two);
|
|
one.rewind();
|
|
debugster("rewind", one, two);
|
|
one.moveTo(0, 0);
|
|
one.reset();
|
|
debugster("reset", one, two);
|
|
}
|
|
#StdOut
|
|
empty one == two
|
|
moveTo one != two
|
|
rewind one == two
|
|
reset one == two
|
|
##
|
|
##
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method bool operator!=(const SkPath& a, const SkPath& b)
|
|
|
|
#Line # compares paths for inequality ##
|
|
Compares a and b; returns true if Fill_Type, Verb_Array, Point_Array, and Weights
|
|
are not equivalent.
|
|
|
|
#Param a Path to compare ##
|
|
#Param b Path to compare ##
|
|
|
|
#Return true if Path pair are not equivalent ##
|
|
|
|
#Example
|
|
#Description
|
|
Path pair are equal though their convexity is not equal.
|
|
##
|
|
void draw(SkCanvas* canvas) {
|
|
auto debugster = [](const char* prefix, const SkPath& a, const SkPath& b) -> void {
|
|
SkDebugf("%s one %c= two\n", prefix, a != b ? '!' : '=');
|
|
};
|
|
SkPath one;
|
|
SkPath two;
|
|
debugster("empty", one, two);
|
|
one.addRect({10, 20, 30, 40});
|
|
two.addRect({10, 20, 30, 40});
|
|
debugster("addRect", one, two);
|
|
one.setConvexity(SkPath::kConcave_Convexity);
|
|
debugster("setConvexity", one, two);
|
|
SkDebugf("convexity %c=\n", one.getConvexity() == two.getConvexity() ? '=' : '!');
|
|
}
|
|
#StdOut
|
|
empty one == two
|
|
addRect one == two
|
|
setConvexity one == two
|
|
convexity !=
|
|
##
|
|
##
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Subtopic Property
|
|
#Populate
|
|
#Line # metrics and attributes ##
|
|
##
|
|
|
|
#Method bool isInterpolatable(const SkPath& compare) const
|
|
#In Property
|
|
#In Interpolate
|
|
#Line # returns if pair contains equal counts of Verb_Array and Weights ##
|
|
Return true if Paths contain equal Verbs and equal Weights.
|
|
If Paths contain one or more Conics, the Weights must match.
|
|
|
|
conicTo may add different Verbs depending on Conic_Weight, so it is not
|
|
trivial to interpolate a pair of Paths containing Conics with different
|
|
Conic_Weight values.
|
|
|
|
#Param compare Path to compare ##
|
|
|
|
#Return true if Paths Verb_Array and Weights are equivalent ##
|
|
|
|
#Example
|
|
SkPath path, path2;
|
|
path.moveTo(20, 20);
|
|
path.lineTo(40, 40);
|
|
path.lineTo(20, 20);
|
|
path.lineTo(40, 40);
|
|
path.close();
|
|
path2.addRect({20, 20, 40, 40});
|
|
SkDebugf("paths are " "%s" "interpolatable", path.isInterpolatable(path2) ? "" : "not ");
|
|
#StdOut
|
|
paths are interpolatable
|
|
##
|
|
##
|
|
|
|
#SeeAlso isInterpolatable
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Subtopic Interpolate
|
|
#Populate
|
|
#Line # weighted average of Path pair ##
|
|
##
|
|
|
|
#Method bool interpolate(const SkPath& ending, SkScalar weight, SkPath* out) const
|
|
#In Interpolate
|
|
#Line # interpolates between Path pair ##
|
|
Interpolate between Paths with Point_Array of equal size.
|
|
Copy Verb_Array and Weights to out, and set out Point_Array to a weighted
|
|
average of this Point_Array and ending Point_Array, using the formula:
|
|
#Formula
|
|
(Path Point * weight) + ending Point * (1 - weight)
|
|
##
|
|
.
|
|
|
|
weight is most useful when between zero (ending Point_Array) and
|
|
one (this Point_Array); will work with values outside of this
|
|
range.
|
|
|
|
interpolate() returns false and leaves out unchanged if Point_Array is not
|
|
the same size as ending Point_Array. Call isInterpolatable to check Path
|
|
compatibility prior to calling interpolate().
|
|
|
|
#Param ending Point_Array averaged with this Point_Array ##
|
|
#Param weight contribution of this Point_Array, and
|
|
one minus contribution of ending Point_Array
|
|
##
|
|
#Param out Path replaced by interpolated averages ##
|
|
|
|
#Return true if Paths contain same number of Points ##
|
|
|
|
#Example
|
|
#Height 60
|
|
void draw(SkCanvas* canvas) {
|
|
SkPaint paint;
|
|
paint.setAntiAlias(true);
|
|
paint.setStyle(SkPaint::kStroke_Style);
|
|
SkPath path, path2;
|
|
path.moveTo(20, 20);
|
|
path.lineTo(40, 40);
|
|
path.lineTo(20, 40);
|
|
path.lineTo(40, 20);
|
|
path.close();
|
|
path2.addRect({20, 20, 40, 40});
|
|
for (SkScalar i = 0; i <= 1; i += 1.f / 6) {
|
|
SkPath interp;
|
|
path.interpolate(path2, i, &interp);
|
|
canvas->drawPath(interp, paint);
|
|
canvas->translate(30, 0);
|
|
}
|
|
}
|
|
##
|
|
|
|
#SeeAlso isInterpolatable
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method bool unique() const
|
|
#Deprecated soon
|
|
Only valid for Android framework.
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
#Subtopic Fill_Type
|
|
#Line # fill rule, normal and inverted ##
|
|
|
|
#Enum FillType
|
|
#Line # sets winding rule and inverse fill ##
|
|
|
|
#Code
|
|
enum FillType {
|
|
kWinding_FillType,
|
|
kEvenOdd_FillType,
|
|
kInverseWinding_FillType,
|
|
kInverseEvenOdd_FillType,
|
|
};
|
|
##
|
|
|
|
Fill_Type selects the rule used to fill Path. Path set to kWinding_FillType
|
|
fills if the sum of Contour edges is not zero, where clockwise edges add one, and
|
|
counterclockwise edges subtract one. Path set to kEvenOdd_FillType fills if the
|
|
number of Contour edges is odd. Each Fill_Type has an inverse variant that
|
|
reverses the rule:
|
|
kInverseWinding_FillType fills where the sum of Contour edges is zero;
|
|
kInverseEvenOdd_FillType fills where the number of Contour edges is even.
|
|
|
|
#Example
|
|
#Height 100
|
|
#Description
|
|
The top row has two clockwise rectangles. The second row has one clockwise and
|
|
one counterclockwise rectangle. The even-odd variants draw the same. The
|
|
winding variants draw the top rectangle overlap, which has a winding of 2, the
|
|
same as the outer parts of the top rectangles, which have a winding of 1.
|
|
##
|
|
void draw(SkCanvas* canvas) {
|
|
SkPath path;
|
|
path.addRect({10, 10, 30, 30}, SkPath::kCW_Direction);
|
|
path.addRect({20, 20, 40, 40}, SkPath::kCW_Direction);
|
|
path.addRect({10, 60, 30, 80}, SkPath::kCW_Direction);
|
|
path.addRect({20, 70, 40, 90}, SkPath::kCCW_Direction);
|
|
SkPaint strokePaint;
|
|
strokePaint.setStyle(SkPaint::kStroke_Style);
|
|
SkRect clipRect = {0, 0, 51, 100};
|
|
canvas->drawPath(path, strokePaint);
|
|
SkPaint fillPaint;
|
|
for (auto fillType : { SkPath::kWinding_FillType, SkPath::kEvenOdd_FillType,
|
|
SkPath::kInverseWinding_FillType, SkPath::kInverseEvenOdd_FillType } ) {
|
|
canvas->translate(51, 0);
|
|
canvas->save();
|
|
canvas->clipRect(clipRect);
|
|
path.setFillType(fillType);
|
|
canvas->drawPath(path, fillPaint);
|
|
canvas->restore();
|
|
}
|
|
}
|
|
##
|
|
|
|
#Const kWinding_FillType 0
|
|
#Line # is enclosed by a non-zero sum of Contour Directions ##
|
|
##
|
|
#Const kEvenOdd_FillType 1
|
|
#Line # is enclosed by an odd number of Contours ##
|
|
##
|
|
#Const kInverseWinding_FillType 2
|
|
#Line # is enclosed by a zero sum of Contour Directions ##
|
|
##
|
|
#Const kInverseEvenOdd_FillType 3
|
|
#Line # is enclosed by an even number of Contours ##
|
|
##
|
|
|
|
#Example
|
|
#Height 230
|
|
void draw(SkCanvas* canvas) {
|
|
SkPath path;
|
|
path.addRect({20, 10, 80, 70}, SkPath::kCW_Direction);
|
|
path.addRect({40, 30, 100, 90}, SkPath::kCW_Direction);
|
|
SkPaint strokePaint;
|
|
strokePaint.setStyle(SkPaint::kStroke_Style);
|
|
SkRect clipRect = {0, 0, 128, 128};
|
|
canvas->drawPath(path, strokePaint);
|
|
canvas->drawLine({0, 50}, {120, 50}, strokePaint);
|
|
SkPaint textPaint;
|
|
textPaint.setAntiAlias(true);
|
|
textPaint.setTextAlign(SkPaint::kCenter_Align);
|
|
SkScalar textHPos[] = { 10, 30, 60, 90, 110 };
|
|
canvas->drawPosTextH("01210", 5, textHPos, 48, textPaint);
|
|
textPaint.setTextSize(18);
|
|
canvas->translate(0, 128);
|
|
canvas->scale(.5f, .5f);
|
|
canvas->drawString("inverse", 384, 150, textPaint);
|
|
SkPaint fillPaint;
|
|
for (auto fillType : { SkPath::kWinding_FillType, SkPath::kEvenOdd_FillType,
|
|
SkPath::kInverseWinding_FillType, SkPath::kInverseEvenOdd_FillType } ) {
|
|
canvas->save();
|
|
canvas->clipRect(clipRect);
|
|
path.setFillType(fillType);
|
|
canvas->drawPath(path, fillPaint);
|
|
canvas->restore();
|
|
canvas->drawString(fillType & 1 ? "even-odd" : "winding", 64, 170, textPaint);
|
|
canvas->translate(128, 0);
|
|
}
|
|
}
|
|
##
|
|
|
|
#SeeAlso SkPaint::Style Direction getFillType setFillType
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method FillType getFillType() const
|
|
|
|
#In Fill_Type
|
|
#Line # returns Fill_Type: winding, even-odd, inverse ##
|
|
Returns FillType, the rule used to fill Path. FillType of a new Path is
|
|
kWinding_FillType.
|
|
|
|
#Return one of: kWinding_FillType, kEvenOdd_FillType, kInverseWinding_FillType,
|
|
kInverseEvenOdd_FillType
|
|
##
|
|
|
|
#Example
|
|
SkPath path;
|
|
SkDebugf("default path fill type is %s\n",
|
|
path.getFillType() == SkPath::kWinding_FillType ? "kWinding_FillType" :
|
|
path.getFillType() == SkPath::kEvenOdd_FillType ? "kEvenOdd_FillType" :
|
|
path.getFillType() == SkPath::kInverseWinding_FillType ? "kInverseWinding_FillType" :
|
|
"kInverseEvenOdd_FillType");
|
|
#StdOut
|
|
default path fill type is kWinding_FillType
|
|
##
|
|
##
|
|
|
|
#SeeAlso FillType setFillType isInverseFillType
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method void setFillType(FillType ft)
|
|
|
|
#In Fill_Type
|
|
#Line # sets Fill_Type: winding, even-odd, inverse ##
|
|
Sets FillType, the rule used to fill Path. While there is no check
|
|
that ft is legal, values outside of FillType are not supported.
|
|
|
|
#Param ft one of: kWinding_FillType, kEvenOdd_FillType, kInverseWinding_FillType,
|
|
kInverseEvenOdd_FillType
|
|
##
|
|
|
|
#Example
|
|
#Description
|
|
If empty Path is set to inverse FillType, it fills all pixels.
|
|
##
|
|
#Height 64
|
|
SkPath path;
|
|
path.setFillType(SkPath::kInverseWinding_FillType);
|
|
SkPaint paint;
|
|
paint.setColor(SK_ColorBLUE);
|
|
canvas->drawPath(path, paint);
|
|
##
|
|
|
|
#SeeAlso FillType getFillType toggleInverseFillType
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method bool isInverseFillType() const
|
|
|
|
#In Fill_Type
|
|
#Line # returns if Fill_Type fills outside geometry ##
|
|
Returns if FillType describes area outside Path geometry. The inverse fill area
|
|
extends indefinitely.
|
|
|
|
#Return true if FillType is kInverseWinding_FillType or kInverseEvenOdd_FillType ##
|
|
|
|
#Example
|
|
SkPath path;
|
|
SkDebugf("default path fill type is inverse: %s\n",
|
|
path.isInverseFillType() ? "true" : "false");
|
|
#StdOut
|
|
default path fill type is inverse: false
|
|
##
|
|
##
|
|
|
|
#SeeAlso FillType getFillType setFillType toggleInverseFillType
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method void toggleInverseFillType()
|
|
|
|
#In Fill_Type
|
|
#Line # toggles Fill_Type between inside and outside geometry ##
|
|
Replace FillType with its inverse. The inverse of FillType describes the area
|
|
unmodified by the original FillType.
|
|
|
|
#Table
|
|
#Legend
|
|
# FillType # toggled FillType ##
|
|
##
|
|
# kWinding_FillType # kInverseWinding_FillType ##
|
|
# kEvenOdd_FillType # kInverseEvenOdd_FillType ##
|
|
# kInverseWinding_FillType # kWinding_FillType ##
|
|
# kInverseEvenOdd_FillType # kEvenOdd_FillType ##
|
|
##
|
|
|
|
#Example
|
|
#Description
|
|
Path drawn normally and through its inverse touches every pixel once.
|
|
##
|
|
#Height 100
|
|
SkPath path;
|
|
SkPaint paint;
|
|
paint.setColor(SK_ColorRED);
|
|
paint.setTextSize(80);
|
|
paint.getTextPath("ABC", 3, 20, 80, &path);
|
|
canvas->drawPath(path, paint);
|
|
path.toggleInverseFillType();
|
|
paint.setColor(SK_ColorGREEN);
|
|
canvas->drawPath(path, paint);
|
|
##
|
|
|
|
#SeeAlso FillType getFillType setFillType isInverseFillType
|
|
|
|
##
|
|
|
|
#Subtopic Fill_Type ##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Subtopic Convexity
|
|
#Line # if Path is concave or convex ##
|
|
|
|
#Enum Convexity
|
|
#Line # returns if Path is convex or concave ##
|
|
|
|
#Code
|
|
enum Convexity : uint8_t {
|
|
kUnknown_Convexity,
|
|
kConvex_Convexity,
|
|
kConcave_Convexity,
|
|
};
|
|
##
|
|
|
|
Path is convex if it contains one Contour and Contour loops no more than
|
|
360 degrees, and Contour angles all have same Direction. Convex Path
|
|
may have better performance and require fewer resources on GPU_Surface.
|
|
|
|
Path is concave when either at least one Direction change is clockwise and
|
|
another is counterclockwise, or the sum of the changes in Direction is not 360
|
|
degrees.
|
|
|
|
Initially Path Convexity is kUnknown_Convexity. Path Convexity is computed
|
|
if needed by destination Surface.
|
|
|
|
#Const kUnknown_Convexity 0
|
|
#Line # indicates Convexity has not been determined ##
|
|
##
|
|
#Const kConvex_Convexity 1
|
|
#Line # one Contour made of a simple geometry without indentations ##
|
|
##
|
|
#Const kConcave_Convexity 2
|
|
#Line # more than one Contour, or a geometry with indentations ##
|
|
##
|
|
|
|
#Example
|
|
void draw(SkCanvas* canvas) {
|
|
SkPaint paint;
|
|
SkPoint quad[] = {{70, 70}, {20, 20}, {120, 20}, {120, 120}};
|
|
const char* labels[] = { "unknown", "convex", "concave" };
|
|
for (SkScalar x : { 40, 100 } ) {
|
|
SkPath path;
|
|
quad[0].fX = x;
|
|
path.addPoly(quad, SK_ARRAY_COUNT(quad), true);
|
|
canvas->drawPath(path, paint);
|
|
canvas->drawString(labels[(int) path.getConvexity()], 30, 100, paint);
|
|
canvas->translate(100, 100);
|
|
}
|
|
}
|
|
##
|
|
|
|
#SeeAlso Contour Direction getConvexity getConvexityOrUnknown setConvexity isConvex
|
|
|
|
#Enum Convexity ##
|
|
|
|
#Method Convexity getConvexity() const
|
|
|
|
#In Convexity
|
|
#Line # returns geometry convexity, computing if necessary ##
|
|
Computes Convexity if required, and returns stored value.
|
|
Convexity is computed if stored value is kUnknown_Convexity,
|
|
or if Path has been altered since Convexity was computed or set.
|
|
|
|
#Return computed or stored Convexity ##
|
|
|
|
#Example
|
|
void draw(SkCanvas* canvas) {
|
|
auto debugster = [](const char* prefix, const SkPath& path) -> void {
|
|
SkDebugf("%s path convexity is %s\n", prefix,
|
|
SkPath::kUnknown_Convexity == path.getConvexity() ? "unknown" :
|
|
SkPath::kConvex_Convexity == path.getConvexity() ? "convex" : "concave"); };
|
|
SkPath path;
|
|
debugster("initial", path);
|
|
path.lineTo(50, 0);
|
|
debugster("first line", path);
|
|
path.lineTo(50, 50);
|
|
debugster("second line", path);
|
|
path.lineTo(100, 50);
|
|
debugster("third line", path);
|
|
}
|
|
##
|
|
|
|
#SeeAlso Convexity Contour Direction getConvexityOrUnknown setConvexity isConvex
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method Convexity getConvexityOrUnknown() const
|
|
|
|
#In Convexity
|
|
#Line # returns geometry convexity if known ##
|
|
Returns last computed Convexity, or kUnknown_Convexity if
|
|
Path has been altered since Convexity was computed or set.
|
|
|
|
#Return stored Convexity ##
|
|
|
|
#Example
|
|
#Description
|
|
Convexity is unknown unless getConvexity is called without a subsequent call
|
|
that alters the path.
|
|
##
|
|
void draw(SkCanvas* canvas) {
|
|
auto debugster = [](const char* prefix, const SkPath& path) -> void {
|
|
SkDebugf("%s path convexity is %s\n", prefix,
|
|
SkPath::kUnknown_Convexity == path.getConvexityOrUnknown() ? "unknown" :
|
|
SkPath::kConvex_Convexity == path.getConvexityOrUnknown() ? "convex" : "concave"); };
|
|
SkPath path;
|
|
debugster("initial", path);
|
|
path.lineTo(50, 0);
|
|
debugster("first line", path);
|
|
path.getConvexity();
|
|
path.lineTo(50, 50);
|
|
debugster("second line", path);
|
|
path.lineTo(100, 50);
|
|
path.getConvexity();
|
|
debugster("third line", path);
|
|
}
|
|
##
|
|
|
|
#SeeAlso Convexity Contour Direction getConvexity setConvexity isConvex
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method void setConvexity(Convexity convexity)
|
|
|
|
#In Convexity
|
|
#Line # sets if geometry is convex to avoid future computation ##
|
|
Stores convexity so that it is later returned by getConvexity or getConvexityOrUnknown.
|
|
convexity may differ from getConvexity, although setting an incorrect value may
|
|
cause incorrect or inefficient drawing.
|
|
|
|
If convexity is kUnknown_Convexity: getConvexity will
|
|
compute Convexity, and getConvexityOrUnknown will return kUnknown_Convexity.
|
|
|
|
If convexity is kConvex_Convexity or kConcave_Convexity, getConvexity
|
|
and getConvexityOrUnknown will return convexity until the path is
|
|
altered.
|
|
|
|
#Param convexity one of: kUnknown_Convexity, kConvex_Convexity, or kConcave_Convexity ##
|
|
|
|
#Example
|
|
void draw(SkCanvas* canvas) {
|
|
auto debugster = [](const char* prefix, const SkPath& path) -> void {
|
|
SkDebugf("%s path convexity is %s\n", prefix,
|
|
SkPath::kUnknown_Convexity == path.getConvexity() ? "unknown" :
|
|
SkPath::kConvex_Convexity == path.getConvexity() ? "convex" : "concave"); };
|
|
SkPoint quad[] = {{70, 70}, {20, 20}, {120, 20}, {120, 120}};
|
|
SkPath path;
|
|
path.addPoly(quad, SK_ARRAY_COUNT(quad), true);
|
|
debugster("initial", path);
|
|
path.setConvexity(SkPath::kConcave_Convexity);
|
|
debugster("after forcing concave", path);
|
|
path.setConvexity(SkPath::kUnknown_Convexity);
|
|
debugster("after forcing unknown", path);
|
|
}
|
|
##
|
|
|
|
#SeeAlso Convexity Contour Direction getConvexity getConvexityOrUnknown isConvex
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method bool isConvex() const
|
|
|
|
#In Convexity
|
|
#Line # returns if geometry is convex ##
|
|
Computes Convexity if required, and returns true if value is kConvex_Convexity.
|
|
If setConvexity was called with kConvex_Convexity or kConcave_Convexity, and
|
|
the path has not been altered, Convexity is not recomputed.
|
|
|
|
#Return true if Convexity stored or computed is kConvex_Convexity ##
|
|
|
|
#Example
|
|
#Description
|
|
Concave shape is erroneously considered convex after a forced call to
|
|
setConvexity.
|
|
##
|
|
void draw(SkCanvas* canvas) {
|
|
SkPaint paint;
|
|
SkPoint quad[] = {{70, 70}, {20, 20}, {120, 20}, {120, 120}};
|
|
for (SkScalar x : { 40, 100 } ) {
|
|
SkPath path;
|
|
quad[0].fX = x;
|
|
path.addPoly(quad, SK_ARRAY_COUNT(quad), true);
|
|
path.setConvexity(SkPath::kConvex_Convexity);
|
|
canvas->drawPath(path, paint);
|
|
canvas->drawString(path.isConvex() ? "convex" : "not convex", 30, 100, paint);
|
|
canvas->translate(100, 100);
|
|
}
|
|
}
|
|
##
|
|
|
|
#SeeAlso Convexity Contour Direction getConvexity getConvexityOrUnknown setConvexity
|
|
|
|
##
|
|
|
|
#Subtopic Convexity ##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method bool isOval(SkRect* bounds) const
|
|
#In Property
|
|
#Line # returns if describes Oval ##
|
|
|
|
Returns true if this path is recognized as an oval or circle.
|
|
|
|
bounds receives bounds of Oval.
|
|
|
|
bounds is unmodified if Oval is not found.
|
|
|
|
#Param bounds storage for bounding Rect of Oval; may be nullptr ##
|
|
|
|
#Return true if Path is recognized as an oval or circle ##
|
|
|
|
#Example
|
|
void draw(SkCanvas* canvas) {
|
|
SkPaint paint;
|
|
SkPath path;
|
|
path.addOval({20, 20, 220, 220});
|
|
SkRect bounds;
|
|
if (path.isOval(&bounds)) {
|
|
paint.setColor(0xFF9FBFFF);
|
|
canvas->drawRect(bounds, paint);
|
|
}
|
|
paint.setColor(0x3f000000);
|
|
canvas->drawPath(path, paint);
|
|
}
|
|
##
|
|
|
|
#SeeAlso Oval addCircle addOval
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method bool isRRect(SkRRect* rrect) const
|
|
#In Property
|
|
#Line # returns if describes Round_Rect ##
|
|
|
|
Returns true if this path is recognized as a SkRRect (but not an oval/circle or rect).
|
|
|
|
rrect receives bounds of Round_Rect.
|
|
|
|
rrect is unmodified if Round_Rect is not found.
|
|
|
|
#Param rrect storage for bounding Rect of Round_Rect; may be nullptr ##
|
|
|
|
#Return true if Path contains only Round_Rect ##
|
|
|
|
#Example
|
|
#Description
|
|
Draw rounded rectangle and its bounds.
|
|
##
|
|
void draw(SkCanvas* canvas) {
|
|
SkPaint paint;
|
|
SkPath path;
|
|
path.addRRect(SkRRect::MakeRectXY({20, 20, 220, 220}, 30, 50));
|
|
SkRRect rrect;
|
|
if (path.isRRect(&rrect)) {
|
|
const SkRect& bounds = rrect.rect();
|
|
paint.setColor(0xFF9FBFFF);
|
|
canvas->drawRect(bounds, paint);
|
|
}
|
|
paint.setColor(0x3f000000);
|
|
canvas->drawPath(path, paint);
|
|
}
|
|
##
|
|
|
|
#SeeAlso Round_Rect addRoundRect addRRect
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method void reset()
|
|
#In Constructor
|
|
#Line # removes Verb_Array, Point_Array, and Weights; frees memory ##
|
|
Sets Path to its initial state.
|
|
Removes Verb_Array, Point_Array, and Weights, and sets FillType to kWinding_FillType.
|
|
Internal storage associated with Path is released.
|
|
|
|
#Example
|
|
SkPath path1, path2;
|
|
path1.setFillType(SkPath::kInverseWinding_FillType);
|
|
path1.addRect({10, 20, 30, 40});
|
|
SkDebugf("path1 %c= path2\n", path1 == path2 ? '=' : '!');
|
|
path1.reset();
|
|
SkDebugf("path1 %c= path2\n", path1 == path2 ? '=' : '!');
|
|
##
|
|
|
|
#SeeAlso rewind()
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method void rewind()
|
|
#In Constructor
|
|
#Line # removes Verb_Array, Point_Array, and Weights, keeping memory ##
|
|
Sets Path to its initial state, preserving internal storage.
|
|
Removes Verb_Array, Point_Array, and Weights, and sets FillType to kWinding_FillType.
|
|
Internal storage associated with Path is retained.
|
|
|
|
Use rewind() instead of reset() if Path storage will be reused and performance
|
|
is critical.
|
|
|
|
#Example
|
|
#Description
|
|
Although path1 retains its internal storage, it is indistinguishable from
|
|
a newly initialized path.
|
|
##
|
|
SkPath path1, path2;
|
|
path1.setFillType(SkPath::kInverseWinding_FillType);
|
|
path1.addRect({10, 20, 30, 40});
|
|
SkDebugf("path1 %c= path2\n", path1 == path2 ? '=' : '!');
|
|
path1.rewind();
|
|
SkDebugf("path1 %c= path2\n", path1 == path2 ? '=' : '!');
|
|
##
|
|
|
|
#SeeAlso reset()
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method bool isEmpty() const
|
|
#In Property
|
|
#Line # returns if verb count is zero ##
|
|
Empty Path may have FillType but has no SkPoint, Verb, or Conic_Weight.
|
|
SkPath() constructs empty Path; reset() and (rewind) make Path empty.
|
|
|
|
#Return true if the path contains no Verb array ##
|
|
|
|
#Example
|
|
void draw(SkCanvas* canvas) {
|
|
auto debugster = [](const char* prefix, const SkPath& path) -> void {
|
|
SkDebugf("%s path is %s" "empty\n", prefix, path.isEmpty() ? "" : "not ");
|
|
};
|
|
SkPath path;
|
|
debugster("initial", path);
|
|
path.moveTo(0, 0);
|
|
debugster("after moveTo", path);
|
|
path.rewind();
|
|
debugster("after rewind", path);
|
|
path.lineTo(0, 0);
|
|
debugster("after lineTo", path);
|
|
path.reset();
|
|
debugster("after reset", path);
|
|
}
|
|
#StdOut
|
|
initial path is empty
|
|
after moveTo path is not empty
|
|
after rewind path is empty
|
|
after lineTo path is not empty
|
|
after reset path is empty
|
|
##
|
|
##
|
|
|
|
#SeeAlso SkPath() reset() rewind()
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method bool isLastContourClosed() const
|
|
#In Property
|
|
#Line # returns if final Contour forms a loop ##
|
|
Contour is closed if Path Verb array was last modified by close(). When stroked,
|
|
closed Contour draws Paint_Stroke_Join instead of Paint_Stroke_Cap at first and last Point.
|
|
|
|
#Return true if the last Contour ends with a kClose_Verb ##
|
|
|
|
#Example
|
|
#Description
|
|
close() has no effect if Path is empty; isLastContourClosed() returns
|
|
false until Path has geometry followed by close().
|
|
##
|
|
void draw(SkCanvas* canvas) {
|
|
auto debugster = [](const char* prefix, const SkPath& path) -> void {
|
|
SkDebugf("%s last contour is %s" "closed\n", prefix,
|
|
path.isLastContourClosed() ? "" : "not ");
|
|
};
|
|
SkPath path;
|
|
debugster("initial", path);
|
|
path.close();
|
|
debugster("after close", path);
|
|
path.lineTo(0, 0);
|
|
debugster("after lineTo", path);
|
|
path.close();
|
|
debugster("after close", path);
|
|
}
|
|
#StdOut
|
|
initial last contour is not closed
|
|
after close last contour is not closed
|
|
after lineTo last contour is not closed
|
|
after close last contour is closed
|
|
##
|
|
##
|
|
|
|
#SeeAlso close()
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method bool isFinite() const
|
|
#In Property
|
|
#Line # returns if all Point values are finite ##
|
|
Returns true for finite Point array values between negative SK_ScalarMax and
|
|
positive SK_ScalarMax. Returns false for any Point array value of
|
|
SK_ScalarInfinity, SK_ScalarNegativeInfinity, or SK_ScalarNaN.
|
|
|
|
#Return true if all Point values are finite ##
|
|
|
|
#Example
|
|
void draw(SkCanvas* canvas) {
|
|
auto debugster = [](const char* prefix, const SkPath& path) -> void {
|
|
SkDebugf("%s path is %s" "finite\n", prefix, path.isFinite() ? "" : "not ");
|
|
};
|
|
SkPath path;
|
|
debugster("initial", path);
|
|
path.lineTo(SK_ScalarMax, SK_ScalarMax);
|
|
debugster("after line", path);
|
|
SkMatrix matrix;
|
|
matrix.setScale(2, 2);
|
|
path.transform(matrix);
|
|
debugster("after scale", path);
|
|
}
|
|
#StdOut
|
|
initial path is finite
|
|
after line path is finite
|
|
after scale path is not finite
|
|
##
|
|
##
|
|
|
|
#SeeAlso SkScalar
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method bool isVolatile() const
|
|
#In Property
|
|
#In Volatile
|
|
#Line # returns if Device should not cache ##
|
|
Returns true if the path is volatile; it will not be altered or discarded
|
|
by the caller after it is drawn. Paths by default have volatile set false, allowing
|
|
Surface to attach a cache of data which speeds repeated drawing. If true, Surface
|
|
may not speed repeated drawing.
|
|
|
|
#Return true if caller will alter Path after drawing ##
|
|
|
|
#Example
|
|
SkPath path;
|
|
SkDebugf("volatile by default is %s\n", path.isVolatile() ? "true" : "false");
|
|
#StdOut
|
|
volatile by default is false
|
|
##
|
|
##
|
|
|
|
#SeeAlso setIsVolatile
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
#Subtopic Volatile
|
|
#Populate
|
|
#Line # caching attribute ##
|
|
##
|
|
|
|
#Method void setIsVolatile(bool isVolatile)
|
|
#In Volatile
|
|
#Line # sets if Device should not cache ##
|
|
Specify whether Path is volatile; whether it will be altered or discarded
|
|
by the caller after it is drawn. Paths by default have volatile set false, allowing
|
|
Device to attach a cache of data which speeds repeated drawing.
|
|
|
|
Mark temporary paths, discarded or modified after use, as volatile
|
|
to inform Device that the path need not be cached.
|
|
|
|
Mark animating Path volatile to improve performance.
|
|
Mark unchanging Path non-volatile to improve repeated rendering.
|
|
|
|
Raster_Surface Path draws are affected by volatile for some shadows.
|
|
GPU_Surface Path draws are affected by volatile for some shadows and concave geometries.
|
|
|
|
#Param isVolatile true if caller will alter Path after drawing ##
|
|
|
|
#Example
|
|
#Height 50
|
|
#Width 50
|
|
SkPaint paint;
|
|
paint.setStyle(SkPaint::kStroke_Style);
|
|
SkPath path;
|
|
path.setIsVolatile(true);
|
|
path.lineTo(40, 40);
|
|
canvas->drawPath(path, paint);
|
|
path.rewind();
|
|
path.moveTo(0, 40);
|
|
path.lineTo(40, 0);
|
|
canvas->drawPath(path, paint);
|
|
##
|
|
|
|
#ToDo tie example to bench to show how volatile affects speed or dm to show resource usage ##
|
|
|
|
#SeeAlso isVolatile
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method static bool IsLineDegenerate(const SkPoint& p1, const SkPoint& p2, bool exact)
|
|
#In Property
|
|
#Line # returns if Line is very small ##
|
|
Test if Line between Point pair is degenerate.
|
|
Line with no length or that moves a very short distance is degenerate; it is
|
|
treated as a point.
|
|
|
|
exact changes the equality test. If true, returns true only if p1 equals p2.
|
|
If false, returns true if p1 equals or nearly equals p2.
|
|
|
|
#Param p1 line start point ##
|
|
#Param p2 line end point ##
|
|
#Param exact if false, allow nearly equals ##
|
|
|
|
#Return true if Line is degenerate; its length is effectively zero ##
|
|
|
|
#Example
|
|
#Description
|
|
As single precision floats, 100 and 100.000001 have the same bit representation,
|
|
and are exactly equal. 100 and 100.0001 have different bit representations, and
|
|
are not exactly equal, but are nearly equal.
|
|
##
|
|
void draw(SkCanvas* canvas) {
|
|
SkPoint points[] = { {100, 100}, {100.000001f, 100.000001f}, {100.0001f, 100.0001f} };
|
|
for (size_t i = 0; i < SK_ARRAY_COUNT(points) - 1; ++i) {
|
|
for (bool exact : { false, true } ) {
|
|
SkDebugf("line from (%1.8g,%1.8g) to (%1.8g,%1.8g) is %s" "degenerate, %s\n",
|
|
points[i].fX, points[i].fY, points[i + 1].fX, points[i + 1].fY,
|
|
SkPath::IsLineDegenerate(points[i], points[i + 1], exact)
|
|
? "" : "not ", exact ? "exactly" : "nearly");
|
|
}
|
|
}
|
|
}
|
|
#StdOut
|
|
line from (100,100) to (100,100) is degenerate, nearly
|
|
line from (100,100) to (100,100) is degenerate, exactly
|
|
line from (100,100) to (100.0001,100.0001) is degenerate, nearly
|
|
line from (100,100) to (100.0001,100.0001) is not degenerate, exactly
|
|
#StdOut ##
|
|
##
|
|
|
|
#SeeAlso IsQuadDegenerate IsCubicDegenerate
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method static bool IsQuadDegenerate(const SkPoint& p1, const SkPoint& p2,
|
|
const SkPoint& p3, bool exact)
|
|
#In Property
|
|
#Line # returns if Quad is very small ##
|
|
|
|
Test if Quad is degenerate.
|
|
Quad with no length or that moves a very short distance is degenerate; it is
|
|
treated as a point.
|
|
|
|
#Param p1 Quad start point ##
|
|
#Param p2 Quad control point ##
|
|
#Param p3 Quad end point ##
|
|
#Param exact if true, returns true only if p1, p2, and p3 are equal;
|
|
if false, returns true if p1, p2, and p3 are equal or nearly equal
|
|
##
|
|
|
|
#Return true if Quad is degenerate; its length is effectively zero ##
|
|
|
|
#Example
|
|
#Description
|
|
As single precision floats: 100, 100.00001, and 100.00002 have different bit representations
|
|
but nearly the same value. Translating all three by 1000 gives them the same bit representation;
|
|
the fractional portion of the number can not be represented by the float and is lost.
|
|
##
|
|
void draw(SkCanvas* canvas) {
|
|
auto debugster = [](const SkPath& path, bool exact) -> void {
|
|
SkDebugf("quad (%1.8g,%1.8g), (%1.8g,%1.8g), (%1.8g,%1.8g) is %s" "degenerate, %s\n",
|
|
path.getPoint(0).fX, path.getPoint(0).fY, path.getPoint(1).fX,
|
|
path.getPoint(1).fY, path.getPoint(2).fX, path.getPoint(2).fY,
|
|
SkPath::IsQuadDegenerate(path.getPoint(0), path.getPoint(1), path.getPoint(2), exact) ?
|
|
"" : "not ", exact ? "exactly" : "nearly");
|
|
};
|
|
SkPath path, offset;
|
|
path.moveTo({100, 100});
|
|
path.quadTo({100.00001f, 100.00001f}, {100.00002f, 100.00002f});
|
|
offset.addPath(path, 1000, 1000);
|
|
for (bool exact : { false, true } ) {
|
|
debugster(path, exact);
|
|
debugster(offset, exact);
|
|
}
|
|
}
|
|
#StdOut
|
|
quad (100,100), (100.00001,100.00001), (100.00002,100.00002) is degenerate, nearly
|
|
quad (1100,1100), (1100,1100), (1100,1100) is degenerate, nearly
|
|
quad (100,100), (100.00001,100.00001), (100.00002,100.00002) is not degenerate, exactly
|
|
quad (1100,1100), (1100,1100), (1100,1100) is degenerate, exactly
|
|
#StdOut ##
|
|
##
|
|
|
|
#SeeAlso IsLineDegenerate IsCubicDegenerate
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method static bool IsCubicDegenerate(const SkPoint& p1, const SkPoint& p2,
|
|
const SkPoint& p3, const SkPoint& p4, bool exact)
|
|
#In Property
|
|
#Line # returns if Cubic is very small ##
|
|
|
|
Test if Cubic is degenerate.
|
|
Cubic with no length or that moves a very short distance is degenerate; it is
|
|
treated as a point.
|
|
|
|
#Param p1 Cubic start point ##
|
|
#Param p2 Cubic control point 1 ##
|
|
#Param p3 Cubic control point 2 ##
|
|
#Param p4 Cubic end point ##
|
|
#Param exact if true, returns true only if p1, p2, p3, and p4 are equal;
|
|
if false, returns true if p1, p2, p3, and p4 are equal or nearly equal
|
|
##
|
|
|
|
#Return true if Cubic is degenerate; its length is effectively zero ##
|
|
|
|
#Example
|
|
void draw(SkCanvas* canvas) {
|
|
SkPoint points[] = {{1, 0}, {0, 0}, {0, 0}, {0, 0}};
|
|
SkScalar step = 1;
|
|
SkScalar prior, length = 0, degenerate = 0;
|
|
do {
|
|
prior = points[0].fX;
|
|
step /= 2;
|
|
if (SkPath::IsCubicDegenerate(points[0], points[1], points[2], points[3], false)) {
|
|
degenerate = prior;
|
|
points[0].fX += step;
|
|
} else {
|
|
length = prior;
|
|
points[0].fX -= step;
|
|
}
|
|
} while (prior != points[0].fX);
|
|
SkDebugf("%1.8g is degenerate\n", degenerate);
|
|
SkDebugf("%1.8g is length\n", length);
|
|
}
|
|
#StdOut
|
|
0.00024414062 is degenerate
|
|
0.00024414065 is length
|
|
#StdOut ##
|
|
##
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method bool isLine(SkPoint line[2]) const
|
|
#In Property
|
|
#Line # returns if describes Line ##
|
|
Returns true if Path contains only one Line;
|
|
Path_Verb array has two entries: kMove_Verb, kLine_Verb.
|
|
If Path contains one Line and line is not nullptr, line is set to
|
|
Line start point and Line end point.
|
|
Returns false if Path is not one Line; line is unaltered.
|
|
|
|
#Param line storage for Line. May be nullptr ##
|
|
|
|
#Return true if Path contains exactly one Line ##
|
|
|
|
#Example
|
|
void draw(SkCanvas* canvas) {
|
|
auto debugster = [](const char* prefix, const SkPath& path) -> void {
|
|
SkPoint line[2];
|
|
if (path.isLine(line)) {
|
|
SkDebugf("%s is line (%1.8g,%1.8g) (%1.8g,%1.8g)\n", prefix,
|
|
line[0].fX, line[0].fY, line[1].fX, line[1].fY);
|
|
} else {
|
|
SkDebugf("%s is not line\n", prefix);
|
|
}
|
|
};
|
|
SkPath path;
|
|
debugster("empty", path);
|
|
path.lineTo(0, 0);
|
|
debugster("zero line", path);
|
|
path.rewind();
|
|
path.moveTo(10, 10);
|
|
path.lineTo(20, 20);
|
|
debugster("line", path);
|
|
path.moveTo(20, 20);
|
|
debugster("second move", path);
|
|
}
|
|
#StdOut
|
|
empty is not line
|
|
zero line is line (0,0) (0,0)
|
|
line is line (10,10) (20,20)
|
|
second move is not line
|
|
##
|
|
##
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Subtopic Point_Array
|
|
#Line # end points and control points for lines and curves ##
|
|
#Substitute SkPoint array
|
|
|
|
Point_Array contains Points satisfying the allocated Points for
|
|
each Verb in Verb_Array. For instance, Path containing one Contour with Line
|
|
and Quad is described by Verb_Array: Verb::kMoveTo, Verb::kLineTo, Verb::kQuadTo; and
|
|
one Point for move, one Point for Line, two Points for Quad; totaling four Points.
|
|
|
|
Point_Array may be read directly from Path with getPoints, or inspected with
|
|
getPoint, with Iter, or with RawIter.
|
|
|
|
#Method int getPoints(SkPoint points[], int max) const
|
|
|
|
#In Point_Array
|
|
#Line # returns Point_Array ##
|
|
Returns number of points in Path. Up to max points are copied.
|
|
points may be nullptr; then, max must be zero.
|
|
If max is greater than number of points, excess points storage is unaltered.
|
|
|
|
#Param points storage for Path Point array. May be nullptr ##
|
|
#Param max maximum to copy; must be greater than or equal to zero ##
|
|
|
|
#Return Path Point array length ##
|
|
|
|
#Example
|
|
void draw(SkCanvas* canvas) {
|
|
auto debugster = [](const char* prefix, const SkPath& path, SkPoint* points, int max) -> void {
|
|
int count = path.getPoints(points, max);
|
|
SkDebugf("%s point count: %d ", prefix, count);
|
|
for (int i = 0; i < SkTMin(count, max) && points; ++i) {
|
|
SkDebugf("(%1.8g,%1.8g) ", points[i].fX, points[i].fY);
|
|
}
|
|
SkDebugf("\n");
|
|
};
|
|
SkPath path;
|
|
path.lineTo(20, 20);
|
|
path.lineTo(-10, -10);
|
|
SkPoint points[3];
|
|
debugster("no points", path, nullptr, 0);
|
|
debugster("zero max", path, points, 0);
|
|
debugster("too small", path, points, 2);
|
|
debugster("just right", path, points, path.countPoints());
|
|
}
|
|
#StdOut
|
|
no points point count: 3
|
|
zero max point count: 3
|
|
too small point count: 3 (0,0) (20,20)
|
|
just right point count: 3 (0,0) (20,20) (-10,-10)
|
|
##
|
|
##
|
|
|
|
#SeeAlso countPoints getPoint
|
|
##
|
|
|
|
#Method int countPoints() const
|
|
|
|
#In Point_Array
|
|
#Line # returns Point_Array length ##
|
|
Returns the number of points in Path.
|
|
Point count is initially zero.
|
|
|
|
#Return Path Point array length ##
|
|
|
|
#Example
|
|
void draw(SkCanvas* canvas) {
|
|
auto debugster = [](const char* prefix, const SkPath& path) -> void {
|
|
SkDebugf("%s point count: %d\n", prefix, path.countPoints());
|
|
};
|
|
SkPath path;
|
|
debugster("empty", path);
|
|
path.lineTo(0, 0);
|
|
debugster("zero line", path);
|
|
path.rewind();
|
|
path.moveTo(10, 10);
|
|
path.lineTo(20, 20);
|
|
debugster("line", path);
|
|
path.moveTo(20, 20);
|
|
debugster("second move", path);
|
|
}
|
|
#StdOut
|
|
empty point count: 0
|
|
zero line point count: 2
|
|
line point count: 2
|
|
second move point count: 3
|
|
##
|
|
##
|
|
|
|
#SeeAlso getPoints
|
|
##
|
|
|
|
#Method SkPoint getPoint(int index) const
|
|
|
|
#In Point_Array
|
|
#Line # returns entry from Point_Array ##
|
|
Returns Point at index in Point_Array. Valid range for index is
|
|
0 to countPoints - 1.
|
|
Returns (0, 0) if index is out of range.
|
|
|
|
#Param index Point array element selector ##
|
|
|
|
#Return Point array value or (0, 0) ##
|
|
|
|
#Example
|
|
void draw(SkCanvas* canvas) {
|
|
SkPath path;
|
|
path.lineTo(20, 20);
|
|
path.offset(-10, -10);
|
|
for (int i= 0; i < path.countPoints(); ++i) {
|
|
SkDebugf("point %d: (%1.8g,%1.8g)\n", i, path.getPoint(i).fX, path.getPoint(i).fY);
|
|
}
|
|
}
|
|
#StdOut
|
|
point 0: (-10,-10)
|
|
point 1: (10,10)
|
|
##
|
|
##
|
|
|
|
#SeeAlso countPoints getPoints
|
|
##
|
|
|
|
|
|
#Subtopic Point_Array ##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
#Subtopic Verb_Array
|
|
#Line # line and curve type for points ##
|
|
|
|
Verb_Array always starts with kMove_Verb.
|
|
If kClose_Verb is not the last entry, it is always followed by kMove_Verb;
|
|
the quantity of kMove_Verb equals the Contour count.
|
|
Verb_Array does not include or count kDone_Verb; it is a convenience
|
|
returned when iterating through Verb_Array.
|
|
|
|
Verb_Array may be read directly from Path with getVerbs, or inspected with Iter,
|
|
or with RawIter.
|
|
|
|
#Method int countVerbs() const
|
|
|
|
#In Verb_Array
|
|
#Line # returns Verb_Array length ##
|
|
Returns the number of Verbs: kMove_Verb, kLine_Verb, kQuad_Verb, kConic_Verb,
|
|
kCubic_Verb, and kClose_Verb; added to Path.
|
|
|
|
#Return length of Verb_Array ##
|
|
|
|
#Example
|
|
SkPath path;
|
|
SkDebugf("empty verb count: %d\n", path.countVerbs());
|
|
path.addRoundRect({10, 20, 30, 40}, 5, 5);
|
|
SkDebugf("round rect verb count: %d\n", path.countVerbs());
|
|
#StdOut
|
|
empty verb count: 0
|
|
round rect verb count: 10
|
|
##
|
|
##
|
|
|
|
#SeeAlso getVerbs Iter RawIter
|
|
|
|
##
|
|
|
|
#Method int getVerbs(uint8_t verbs[], int max) const
|
|
|
|
#In Verb_Array
|
|
#Line # returns Verb_Array ##
|
|
Returns the number of verbs in the path. Up to max verbs are copied. The
|
|
verbs are copied as one byte per verb.
|
|
|
|
#Param verbs storage for verbs, may be nullptr ##
|
|
#Param max maximum number to copy into verbs ##
|
|
|
|
#Return the actual number of verbs in the path ##
|
|
|
|
#Example
|
|
void draw(SkCanvas* canvas) {
|
|
auto debugster = [](const char* prefix, const SkPath& path, uint8_t* verbs, int max) -> void {
|
|
int count = path.getVerbs(verbs, max);
|
|
SkDebugf("%s verb count: %d ", prefix, count);
|
|
const char* verbStr[] = { "move", "line", "quad", "conic", "cubic", "close" };
|
|
for (int i = 0; i < SkTMin(count, max) && verbs; ++i) {
|
|
SkDebugf("%s ", verbStr[verbs[i]]);
|
|
}
|
|
SkDebugf("\n");
|
|
};
|
|
SkPath path;
|
|
path.lineTo(20, 20);
|
|
path.lineTo(-10, -10);
|
|
uint8_t verbs[3];
|
|
debugster("no verbs", path, nullptr, 0);
|
|
debugster("zero max", path, verbs, 0);
|
|
debugster("too small", path, verbs, 2);
|
|
debugster("just right", path, verbs, path.countVerbs());
|
|
}
|
|
#StdOut
|
|
no verbs verb count: 3
|
|
zero max verb count: 3
|
|
too small verb count: 3 move line
|
|
just right verb count: 3 move line line
|
|
##
|
|
##
|
|
|
|
#SeeAlso countVerbs getPoints Iter RawIter
|
|
##
|
|
|
|
#Subtopic Verb_Array ##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method void swap(SkPath& other)
|
|
#In Operator
|
|
#Line # exchanges Path pair ##
|
|
Exchanges the Verb_Array, Point_Array, Weights, and Fill_Type with other.
|
|
Cached state is also exchanged. swap() internally exchanges pointers, so
|
|
it is lightweight and does not allocate memory.
|
|
|
|
swap() usage has largely been replaced by operator=(const SkPath& path).
|
|
Paths do not copy their content on assignment until they are written to,
|
|
making assignment as efficient as swap().
|
|
|
|
#Param other Path exchanged by value ##
|
|
|
|
#Example
|
|
SkPath path1, path2;
|
|
path1.addRect({10, 20, 30, 40});
|
|
path1.swap(path2);
|
|
const SkRect& b1 = path1.getBounds();
|
|
SkDebugf("path1 bounds = %g, %g, %g, %g\n", b1.fLeft, b1.fTop, b1.fRight, b1.fBottom);
|
|
const SkRect& b2 = path2.getBounds();
|
|
SkDebugf("path2 bounds = %g, %g, %g, %g\n", b2.fLeft, b2.fTop, b2.fRight, b2.fBottom);
|
|
#StdOut
|
|
path1 bounds = 0, 0, 0, 0
|
|
path2 bounds = 10, 20, 30, 40
|
|
#StdOut ##
|
|
##
|
|
|
|
#SeeAlso operator=(const SkPath& path)
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method const SkRect& getBounds() const
|
|
#In Property
|
|
#Line # returns maximum and minimum of Point_Array ##
|
|
Returns minimum and maximum axes values of Point_Array.
|
|
Returns (0, 0, 0, 0) if Path contains no points. Returned bounds width and height may
|
|
be larger or smaller than area affected when Path is drawn.
|
|
|
|
Rect returned includes all Points added to Path, including Points associated with
|
|
kMove_Verb that define empty Contours.
|
|
|
|
#Return bounds of all Points in Point_Array ##
|
|
|
|
#Example
|
|
#Description
|
|
Bounds of upright Circle can be predicted from center and radius.
|
|
Bounds of rotated Circle includes control Points outside of filled area.
|
|
##
|
|
auto debugster = [](const char* prefix, const SkPath& path) -> void {
|
|
const SkRect& bounds = path.getBounds();
|
|
SkDebugf("%s bounds = %g, %g, %g, %g\n", prefix,
|
|
bounds.fLeft, bounds.fTop, bounds.fRight, bounds.fBottom);
|
|
};
|
|
SkPath path;
|
|
debugster("empty", path);
|
|
path.addCircle(50, 45, 25);
|
|
debugster("circle", path);
|
|
SkMatrix matrix;
|
|
matrix.setRotate(45, 50, 45);
|
|
path.transform(matrix);
|
|
debugster("rotated circle", path);
|
|
#StdOut
|
|
empty bounds = 0, 0, 0, 0
|
|
circle bounds = 25, 20, 75, 70
|
|
rotated circle bounds = 14.6447, 9.64466, 85.3553, 80.3553
|
|
##
|
|
##
|
|
|
|
#SeeAlso computeTightBounds updateBoundsCache
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
#Subtopic Utility
|
|
#Populate
|
|
#Line # rarely called management functions ##
|
|
##
|
|
|
|
#Method void updateBoundsCache() const
|
|
#In Utility
|
|
#Line # refreshes result of getBounds ##
|
|
Update internal bounds so that subsequent calls to getBounds are instantaneous.
|
|
Unaltered copies of Path may also access cached bounds through getBounds.
|
|
|
|
For now, identical to calling getBounds and ignoring the returned value.
|
|
|
|
Call to prepare Path subsequently drawn from multiple threads,
|
|
to avoid a race condition where each draw separately computes the bounds.
|
|
|
|
#Example
|
|
double times[2] = { 0, 0 };
|
|
for (int i = 0; i < 10000; ++i) {
|
|
SkPath path;
|
|
for (int j = 1; j < 100; ++ j) {
|
|
path.addCircle(50 + j, 45 + j, 25 + j);
|
|
}
|
|
if (1 & i) {
|
|
path.updateBoundsCache();
|
|
}
|
|
double start = SkTime::GetNSecs();
|
|
(void) path.getBounds();
|
|
times[1 & i] += SkTime::GetNSecs() - start;
|
|
}
|
|
SkDebugf("uncached avg: %g ms\n", times[0] * 1e-6);
|
|
SkDebugf("cached avg: %g ms\n", times[1] * 1e-6);
|
|
#StdOut
|
|
#Volatile
|
|
uncached avg: 0.18048 ms
|
|
cached avg: 0.182784 ms
|
|
##
|
|
##
|
|
|
|
#SeeAlso getBounds
|
|
#ToDo the results don't make sense, need to profile to figure this out ##
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method SkRect computeTightBounds() const
|
|
#In Property
|
|
#Line # returns extent of geometry ##
|
|
Returns minimum and maximum axes values of the lines and curves in Path.
|
|
Returns (0, 0, 0, 0) if Path contains no points.
|
|
Returned bounds width and height may be larger or smaller than area affected
|
|
when Path is drawn.
|
|
|
|
Includes Points associated with kMove_Verb that define empty
|
|
Contours.
|
|
|
|
Behaves identically to getBounds when Path contains
|
|
only lines. If Path contains curves, computed bounds includes
|
|
the maximum extent of the Quad, Conic, or Cubic; is slower than getBounds;
|
|
and unlike getBounds, does not cache the result.
|
|
|
|
#Return tight bounds of curves in Path ##
|
|
|
|
#Example
|
|
auto debugster = [](const char* prefix, const SkPath& path) -> void {
|
|
const SkRect& bounds = path.computeTightBounds();
|
|
SkDebugf("%s bounds = %g, %g, %g, %g\n", prefix,
|
|
bounds.fLeft, bounds.fTop, bounds.fRight, bounds.fBottom);
|
|
};
|
|
SkPath path;
|
|
debugster("empty", path);
|
|
path.addCircle(50, 45, 25);
|
|
debugster("circle", path);
|
|
SkMatrix matrix;
|
|
matrix.setRotate(45, 50, 45);
|
|
path.transform(matrix);
|
|
debugster("rotated circle", path);
|
|
#StdOut
|
|
empty bounds = 0, 0, 0, 0
|
|
circle bounds = 25, 20, 75, 70
|
|
rotated circle bounds = 25, 20, 75, 70
|
|
##
|
|
##
|
|
|
|
#SeeAlso getBounds
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method bool conservativelyContainsRect(const SkRect& rect) const
|
|
#In Property
|
|
#Line # returns true if Rect may be inside ##
|
|
Returns true if rect is contained by Path.
|
|
May return false when rect is contained by Path.
|
|
|
|
For now, only returns true if Path has one Contour and is convex.
|
|
rect may share points and edges with Path and be contained.
|
|
Returns true if rect is empty, that is, it has zero width or height; and
|
|
the Point or Line described by rect is contained by Path.
|
|
|
|
#Param rect Rect, Line, or Point checked for containment ##
|
|
|
|
#Return true if rect is contained ##
|
|
|
|
#Example
|
|
#Height 140
|
|
#Description
|
|
Rect is drawn in blue if it is contained by red Path.
|
|
##
|
|
void draw(SkCanvas* canvas) {
|
|
SkPath path;
|
|
path.addRoundRect({10, 20, 54, 120}, 10, 20);
|
|
SkRect tests[] = {
|
|
{ 10, 40, 54, 80 },
|
|
{ 25, 20, 39, 120 },
|
|
{ 15, 25, 49, 115 },
|
|
{ 13, 27, 51, 113 },
|
|
};
|
|
for (unsigned i = 0; i < SK_ARRAY_COUNT(tests); ++i) {
|
|
SkPaint paint;
|
|
paint.setColor(SK_ColorRED);
|
|
canvas->drawPath(path, paint);
|
|
bool rectInPath = path.conservativelyContainsRect(tests[i]);
|
|
paint.setColor(rectInPath ? SK_ColorBLUE : SK_ColorBLACK);
|
|
canvas->drawRect(tests[i], paint);
|
|
canvas->translate(64, 0);
|
|
}
|
|
}
|
|
##
|
|
|
|
#SeeAlso contains Op Rect Convexity
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method void incReserve(unsigned extraPtCount)
|
|
#In Utility
|
|
#Line # reserves space for additional data ##
|
|
grows Path Verb_Array and Point_Array to contain extraPtCount additional Points.
|
|
May improve performance and use less memory by
|
|
reducing the number and size of allocations when creating Path.
|
|
|
|
#Param extraPtCount number of additional Points to allocate ##
|
|
|
|
#Example
|
|
#Height 192
|
|
void draw(SkCanvas* canvas) {
|
|
auto addPoly = [](int sides, SkScalar size, SkPath* path) -> void {
|
|
path->moveTo(size, 0);
|
|
for (int i = 1; i < sides; i++) {
|
|
SkScalar c, s = SkScalarSinCos(SK_ScalarPI * 2 * i / sides, &c);
|
|
path->lineTo(c * size, s * size);
|
|
}
|
|
path->close();
|
|
};
|
|
SkPath path;
|
|
path.incReserve(3 + 4 + 5 + 6 + 7 + 8 + 9);
|
|
for (int sides = 3; sides < 10; ++sides) {
|
|
addPoly(sides, sides, &path);
|
|
}
|
|
SkMatrix matrix;
|
|
matrix.setScale(10, 10, -10, -10);
|
|
path.transform(matrix);
|
|
SkPaint paint;
|
|
paint.setStyle(SkPaint::kStroke_Style);
|
|
canvas->drawPath(path, paint);
|
|
}
|
|
##
|
|
|
|
#SeeAlso Point_Array
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
#Subtopic Build
|
|
#Populate
|
|
#Line # adds points and verbs to path ##
|
|
##
|
|
|
|
#Method void moveTo(SkScalar x, SkScalar y)
|
|
#In Build
|
|
#Line # starts Contour ##
|
|
Adds beginning of Contour at Point (x, y).
|
|
|
|
#Param x x-axis value of Contour start ##
|
|
#Param y y-axis value of Contour start ##
|
|
|
|
#Example
|
|
#Width 140
|
|
#Height 100
|
|
void draw(SkCanvas* canvas) {
|
|
SkRect rect = { 20, 20, 120, 80 };
|
|
SkPath path;
|
|
path.addRect(rect);
|
|
path.moveTo(rect.fLeft, rect.fTop);
|
|
path.lineTo(rect.fRight, rect.fBottom);
|
|
path.moveTo(rect.fLeft, rect.fBottom);
|
|
path.lineTo(rect.fRight, rect.fTop);
|
|
SkPaint paint;
|
|
paint.setStyle(SkPaint::kStroke_Style);
|
|
canvas->drawPath(path, paint);
|
|
}
|
|
##
|
|
|
|
#SeeAlso Contour lineTo rMoveTo quadTo conicTo cubicTo close()
|
|
|
|
##
|
|
|
|
#Method void moveTo(const SkPoint& p)
|
|
|
|
Adds beginning of Contour at Point p.
|
|
|
|
#Param p contour start ##
|
|
|
|
#Example
|
|
#Width 128
|
|
#Height 128
|
|
void draw(SkCanvas* canvas) {
|
|
SkPoint data[][3] = {{{30,40},{60,60},{90,30}}, {{30,120},{60,100},{90,120}},
|
|
{{60,100},{60,40},{70,30}}, {{60,40},{50,20},{70,30}}};
|
|
SkPath path;
|
|
for (unsigned i = 0; i < SK_ARRAY_COUNT(data); ++i) {
|
|
path.moveTo(data[i][0]);
|
|
path.lineTo(data[i][1]);
|
|
path.lineTo(data[i][2]);
|
|
}
|
|
SkPaint paint;
|
|
paint.setStyle(SkPaint::kStroke_Style);
|
|
canvas->drawPath(path, paint);
|
|
}
|
|
##
|
|
|
|
#SeeAlso Contour lineTo rMoveTo quadTo conicTo cubicTo close()
|
|
|
|
##
|
|
|
|
#Method void rMoveTo(SkScalar dx, SkScalar dy)
|
|
#In Build
|
|
#Line # starts Contour relative to Last_Point ##
|
|
Adds beginning of Contour relative to Last_Point.
|
|
If Path is empty, starts Contour at (dx, dy).
|
|
Otherwise, start Contour at Last_Point offset by (dx, dy).
|
|
Function name stands for "relative move to".
|
|
|
|
#Param dx offset from Last_Point to Contour start on x-axis ##
|
|
#Param dy offset from Last_Point to Contour start on y-axis ##
|
|
|
|
#Example
|
|
#Height 100
|
|
SkPath path;
|
|
path.addRect({20, 20, 80, 80}, SkPath::kCW_Direction, 2);
|
|
path.rMoveTo(25, 2);
|
|
SkVector arrow[] = {{0, -4}, {-20, 0}, {0, -3}, {-5, 5}, {5, 5}, {0, -3}, {20, 0}};
|
|
for (unsigned i = 0; i < SK_ARRAY_COUNT(arrow); ++i) {
|
|
path.rLineTo(arrow[i].fX, arrow[i].fY);
|
|
}
|
|
SkPaint paint;
|
|
canvas->drawPath(path, paint);
|
|
SkPoint lastPt;
|
|
path.getLastPt(&lastPt);
|
|
canvas->drawString("start", lastPt.fX, lastPt.fY, paint);
|
|
##
|
|
|
|
#SeeAlso Contour lineTo moveTo quadTo conicTo cubicTo close()
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method void lineTo(SkScalar x, SkScalar y)
|
|
#In Build
|
|
#Line # appends Line ##
|
|
Adds Line from Last_Point to (x, y). If Path is empty, or last Verb is
|
|
kClose_Verb, Last_Point is set to (0, 0) before adding Line.
|
|
|
|
lineTo appends kMove_Verb to Verb_Array and (0, 0) to Point_Array, if needed.
|
|
lineTo then appends kLine_Verb to Verb_Array and (x, y) to Point_Array.
|
|
|
|
#Param x end of added Line in x ##
|
|
#Param y end of added Line in y ##
|
|
|
|
#Example
|
|
#Height 100
|
|
###$
|
|
void draw(SkCanvas* canvas) {
|
|
SkPaint paint;
|
|
paint.setAntiAlias(true);
|
|
paint.setTextSize(72);
|
|
canvas->drawString("#", 120, 80, paint);
|
|
paint.setStyle(SkPaint::kStroke_Style);
|
|
paint.setStrokeWidth(5);
|
|
SkPath path;
|
|
SkPoint hash[] = {{58, 28}, {43, 80}, {37, 45}, {85, 45}};
|
|
SkVector offsets[] = {{0, 0}, {17, 0}, {0, 0}, {-5, 17}};
|
|
unsigned o = 0;
|
|
for (unsigned i = 0; i < SK_ARRAY_COUNT(hash); i += 2) {
|
|
for (unsigned j = 0; j < 2; o++, j++) {
|
|
path.moveTo(hash[i].fX + offsets[o].fX, hash[i].fY + offsets[o].fY);
|
|
path.lineTo(hash[i + 1].fX + offsets[o].fX, hash[i + 1].fY + offsets[o].fY);
|
|
}
|
|
}
|
|
canvas->drawPath(path, paint);
|
|
}
|
|
$$$#
|
|
##
|
|
|
|
#SeeAlso Contour moveTo rLineTo addRect
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method void lineTo(const SkPoint& p)
|
|
|
|
Adds Line from Last_Point to Point p. If Path is empty, or last Verb is
|
|
kClose_Verb, Last_Point is set to (0, 0) before adding Line.
|
|
|
|
lineTo first appends kMove_Verb to Verb_Array and (0, 0) to Point_Array, if needed.
|
|
lineTo then appends kLine_Verb to Verb_Array and Point p to Point_Array.
|
|
|
|
#Param p end Point of added Line ##
|
|
|
|
#Example
|
|
#Height 100
|
|
SkPath path;
|
|
SkVector oxo[] = {{25, 25}, {35, 35}, {25, 35}, {35, 25},
|
|
{40, 20}, {40, 80}, {60, 20}, {60, 80},
|
|
{20, 40}, {80, 40}, {20, 60}, {80, 60}};
|
|
for (unsigned i = 0; i < SK_ARRAY_COUNT(oxo); i += 2) {
|
|
path.moveTo(oxo[i]);
|
|
path.lineTo(oxo[i + 1]);
|
|
}
|
|
SkPaint paint;
|
|
paint.setStyle(SkPaint::kStroke_Style);
|
|
canvas->drawPath(path, paint);
|
|
##
|
|
|
|
#SeeAlso Contour moveTo rLineTo addRect
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method void rLineTo(SkScalar dx, SkScalar dy)
|
|
#In Build
|
|
#Line # appends Line relative to Last_Point ##
|
|
Adds Line from Last_Point to Vector (dx, dy). If Path is empty, or last Verb is
|
|
kClose_Verb, Last_Point is set to (0, 0) before adding Line.
|
|
|
|
Appends kMove_Verb to Verb_Array and (0, 0) to Point_Array, if needed;
|
|
then appends kLine_Verb to Verb_Array and Line end to Point_Array.
|
|
Line end is Last_Point plus Vector (dx, dy).
|
|
Function name stands for "relative line to".
|
|
|
|
#Param dx offset from Last_Point to Line end on x-axis ##
|
|
#Param dy offset from Last_Point to Line end on y-axis ##
|
|
|
|
#Example
|
|
#Height 128
|
|
void draw(SkCanvas* canvas) {
|
|
SkPaint paint;
|
|
paint.setAntiAlias(true);
|
|
paint.setStyle(SkPaint::kStroke_Style);
|
|
SkPath path;
|
|
path.moveTo(10, 98);
|
|
SkScalar x = 0, y = 0;
|
|
for (int i = 10; i < 100; i += 5) {
|
|
x += i * ((i & 2) - 1);
|
|
y += i * (((i + 1) & 2) - 1);
|
|
path.rLineTo(x, y);
|
|
|
|
}
|
|
canvas->drawPath(path, paint);
|
|
}
|
|
##
|
|
|
|
#SeeAlso Contour moveTo lineTo addRect
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
#Subtopic Quad
|
|
#Alias Quad ##
|
|
#Alias Quads ##
|
|
#Alias Quadratic_Bezier ##
|
|
#Alias Quadratic_Beziers ##
|
|
#Line # curve described by second-order polynomial ##
|
|
|
|
Quad describes a quadratic Bezier, a second-order curve identical to a section
|
|
of a parabola. Quad begins at a start Point, curves towards a control Point,
|
|
and then curves to an end Point.
|
|
|
|
#Example
|
|
#Height 110
|
|
void draw(SkCanvas* canvas) {
|
|
SkPaint paint;
|
|
paint.setAntiAlias(true);
|
|
paint.setStyle(SkPaint::kStroke_Style);
|
|
SkPoint quadPts[] = {{20, 90}, {120, 10}, {220, 90}};
|
|
canvas->drawLine(quadPts[0], quadPts[1], paint);
|
|
canvas->drawLine(quadPts[1], quadPts[2], paint);
|
|
SkPath path;
|
|
path.moveTo(quadPts[0]);
|
|
path.quadTo(quadPts[1], quadPts[2]);
|
|
paint.setStrokeWidth(3);
|
|
canvas->drawPath(path, paint);
|
|
}
|
|
##
|
|
|
|
Quad is a special case of Conic where Conic_Weight is set to one.
|
|
|
|
Quad is always contained by the triangle connecting its three Points. Quad
|
|
begins tangent to the line between start Point and control Point, and ends
|
|
tangent to the line between control Point and end Point.
|
|
|
|
#Example
|
|
#Height 160
|
|
void draw(SkCanvas* canvas) {
|
|
SkPaint paint;
|
|
paint.setAntiAlias(true);
|
|
paint.setStyle(SkPaint::kStroke_Style);
|
|
SkPoint quadPts[] = {{20, 150}, {120, 10}, {220, 150}};
|
|
SkColor colors[] = { 0xff88ff00, 0xff0088bb, 0xff6600cc, 0xffbb3377 };
|
|
for (unsigned i = 0; i < SK_ARRAY_COUNT(colors); ++i) {
|
|
paint.setColor(0x7fffffff & colors[i]);
|
|
paint.setStrokeWidth(1);
|
|
canvas->drawLine(quadPts[0], quadPts[1], paint);
|
|
canvas->drawLine(quadPts[1], quadPts[2], paint);
|
|
SkPath path;
|
|
path.moveTo(quadPts[0]);
|
|
path.quadTo(quadPts[1], quadPts[2]);
|
|
paint.setStrokeWidth(3);
|
|
paint.setColor(colors[i]);
|
|
canvas->drawPath(path, paint);
|
|
quadPts[1].fY += 30;
|
|
}
|
|
}
|
|
##
|
|
|
|
#Method void quadTo(SkScalar x1, SkScalar y1, SkScalar x2, SkScalar y2)
|
|
|
|
#In Quad
|
|
#Line # appends Quad ##
|
|
Adds Quad from Last_Point towards (x1, y1), to (x2, y2).
|
|
If Path is empty, or last Verb is kClose_Verb, Last_Point is set to (0, 0)
|
|
before adding Quad.
|
|
|
|
Appends kMove_Verb to Verb_Array and (0, 0) to Point_Array, if needed;
|
|
then appends kQuad_Verb to Verb_Array; and (x1, y1), (x2, y2)
|
|
to Point_Array.
|
|
|
|
#Param x1 control Point of Quad in x ##
|
|
#Param y1 control Point of Quad in y ##
|
|
#Param x2 end Point of Quad in x ##
|
|
#Param y2 end Point of Quad in y ##
|
|
|
|
#Example
|
|
void draw(SkCanvas* canvas) {
|
|
SkPaint paint;
|
|
paint.setAntiAlias(true);
|
|
paint.setStyle(SkPaint::kStroke_Style);
|
|
SkPath path;
|
|
path.moveTo(0, -10);
|
|
for (int i = 0; i < 128; i += 16) {
|
|
path.quadTo( 10 + i, -10 - i, 10 + i, 0);
|
|
path.quadTo( 14 + i, 14 + i, 0, 14 + i);
|
|
path.quadTo(-18 - i, 18 + i, -18 - i, 0);
|
|
path.quadTo(-22 - i, -22 - i, 0, -22 - i);
|
|
}
|
|
path.offset(128, 128);
|
|
canvas->drawPath(path, paint);
|
|
}
|
|
##
|
|
|
|
#SeeAlso Contour moveTo conicTo rQuadTo
|
|
|
|
##
|
|
|
|
#Method void quadTo(const SkPoint& p1, const SkPoint& p2)
|
|
#In Build
|
|
#In Quad
|
|
Adds Quad from Last_Point towards Point p1, to Point p2.
|
|
If Path is empty, or last Verb is kClose_Verb, Last_Point is set to (0, 0)
|
|
before adding Quad.
|
|
|
|
Appends kMove_Verb to Verb_Array and (0, 0) to Point_Array, if needed;
|
|
then appends kQuad_Verb to Verb_Array; and Points p1, p2
|
|
to Point_Array.
|
|
|
|
#Param p1 control Point of added Quad ##
|
|
#Param p2 end Point of added Quad ##
|
|
|
|
#Example
|
|
void draw(SkCanvas* canvas) {
|
|
SkPaint paint;
|
|
paint.setStyle(SkPaint::kStroke_Style);
|
|
paint.setAntiAlias(true);
|
|
SkPath path;
|
|
SkPoint pts[] = {{128, 10}, {10, 214}, {236, 214}};
|
|
path.moveTo(pts[1]);
|
|
for (int i = 0; i < 3; ++i) {
|
|
path.quadTo(pts[i % 3], pts[(i + 2) % 3]);
|
|
}
|
|
canvas->drawPath(path, paint);
|
|
}
|
|
##
|
|
|
|
#SeeAlso Contour moveTo conicTo rQuadTo
|
|
|
|
##
|
|
|
|
#Method void rQuadTo(SkScalar dx1, SkScalar dy1, SkScalar dx2, SkScalar dy2)
|
|
#In Build
|
|
#In Quad
|
|
#Line # appends Quad relative to Last_Point ##
|
|
Adds Quad from Last_Point towards Vector (dx1, dy1), to Vector (dx2, dy2).
|
|
If Path is empty, or last Verb
|
|
is kClose_Verb, Last_Point is set to (0, 0) before adding Quad.
|
|
|
|
Appends kMove_Verb to Verb_Array and (0, 0) to Point_Array,
|
|
if needed; then appends kQuad_Verb to Verb_Array; and appends Quad
|
|
control and Quad end to Point_Array.
|
|
Quad control is Last_Point plus Vector (dx1, dy1).
|
|
Quad end is Last_Point plus Vector (dx2, dy2).
|
|
Function name stands for "relative quad to".
|
|
|
|
#Param dx1 offset from Last_Point to Quad control on x-axis ##
|
|
#Param dy1 offset from Last_Point to Quad control on y-axis ##
|
|
#Param dx2 offset from Last_Point to Quad end on x-axis ##
|
|
#Param dy2 offset from Last_Point to Quad end on y-axis ##
|
|
|
|
#Example
|
|
void draw(SkCanvas* canvas) {
|
|
SkPaint paint;
|
|
paint.setAntiAlias(true);
|
|
SkPath path;
|
|
path.moveTo(128, 20);
|
|
path.rQuadTo(-6, 10, -7, 10);
|
|
for (int i = 1; i < 32; i += 4) {
|
|
path.rQuadTo(10 + i, 10 + i, 10 + i * 4, 10);
|
|
path.rQuadTo(-10 - i, 10 + i, -10 - (i + 2) * 4, 10);
|
|
}
|
|
path.quadTo(92, 220, 128, 215);
|
|
canvas->drawPath(path, paint);
|
|
}
|
|
##
|
|
|
|
#SeeAlso Contour moveTo conicTo quadTo
|
|
|
|
##
|
|
|
|
#Subtopic Quad ##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Subtopic Conic
|
|
#Line # conic section defined by three points and a weight ##
|
|
#Alias Conics ##
|
|
|
|
Conic describes a conical section: a piece of an ellipse, or a piece of a
|
|
parabola, or a piece of a hyperbola. Conic begins at a start Point,
|
|
curves towards a control Point, and then curves to an end Point. The influence
|
|
of the control Point is determined by Conic_Weight.
|
|
|
|
Each Conic in Path adds two Points and one Conic_Weight. Conic_Weights in Path
|
|
may be inspected with Iter, or with RawIter.
|
|
|
|
#Subtopic Weight
|
|
#Alias Conic_Weights ##
|
|
#Alias Weights ##
|
|
#Line # strength of Conic control Point ##
|
|
|
|
Weight determines both the strength of the control Point and the type of Conic.
|
|
Weight varies from zero to infinity. At zero, Weight causes the control Point to
|
|
have no effect; Conic is identical to a line segment from start Point to end
|
|
point. If Weight is less than one, Conic follows an elliptical arc.
|
|
If Weight is exactly one, then Conic is identical to Quad; Conic follows a
|
|
parabolic arc. If Weight is greater than one, Conic follows a hyperbolic
|
|
arc. If Weight is infinity, Conic is identical to two line segments, connecting
|
|
start Point to control Point, and control Point to end Point.
|
|
|
|
#Example
|
|
#Description
|
|
When Conic_Weight is one, Quad is added to path; the two are identical.
|
|
##
|
|
void draw(SkCanvas* canvas) {
|
|
const char* verbNames[] = { "move", "line", "quad", "conic", "cubic", "close", "done" };
|
|
const int pointCount[] = { 1 , 2 , 3 , 3 , 4 , 1 , 0 };
|
|
SkPath path;
|
|
path.conicTo(20, 30, 50, 60, 1);
|
|
SkPath::Iter iter(path, false);
|
|
SkPath::Verb verb;
|
|
do {
|
|
SkPoint points[4];
|
|
verb = iter.next(points);
|
|
SkDebugf("%s ", verbNames[(int) verb]);
|
|
for (int i = 0; i < pointCount[(int) verb]; ++i) {
|
|
SkDebugf("{%g, %g}, ", points[i].fX, points[i].fY);
|
|
}
|
|
if (SkPath::kConic_Verb == verb) {
|
|
SkDebugf("weight = %g", iter.conicWeight());
|
|
}
|
|
SkDebugf("\n");
|
|
} while (SkPath::kDone_Verb != verb);
|
|
}
|
|
#StdOut
|
|
move {0, 0},
|
|
quad {0, 0}, {20, 30}, {50, 60},
|
|
done
|
|
##
|
|
##
|
|
|
|
If weight is less than one, Conic is an elliptical segment.
|
|
|
|
#Example
|
|
#Description
|
|
A 90 degree circular arc has the weight
|
|
#Formula
|
|
1 / sqrt(2)
|
|
##
|
|
.
|
|
##
|
|
void draw(SkCanvas* canvas) {
|
|
const char* verbNames[] = { "move", "line", "quad", "conic", "cubic", "close", "done" };
|
|
const int pointCount[] = { 1 , 2 , 3 , 3 , 4 , 1 , 0 };
|
|
SkPath path;
|
|
path.arcTo(20, 0, 20, 20, 20);
|
|
SkPath::Iter iter(path, false);
|
|
SkPath::Verb verb;
|
|
do {
|
|
SkPoint points[4];
|
|
verb = iter.next(points);
|
|
SkDebugf("%s ", verbNames[(int) verb]);
|
|
for (int i = 0; i < pointCount[(int) verb]; ++i) {
|
|
SkDebugf("{%g, %g}, ", points[i].fX, points[i].fY);
|
|
}
|
|
if (SkPath::kConic_Verb == verb) {
|
|
SkDebugf("weight = %g", iter.conicWeight());
|
|
}
|
|
SkDebugf("\n");
|
|
} while (SkPath::kDone_Verb != verb);
|
|
}
|
|
#StdOut
|
|
move {0, 0},
|
|
conic {0, 0}, {20, 0}, {20, 20}, weight = 0.707107
|
|
done
|
|
##
|
|
##
|
|
|
|
If weight is greater than one, Conic is a hyperbolic segment. As weight gets large,
|
|
a hyperbolic segment can be approximated by straight lines connecting the
|
|
control Point with the end Points.
|
|
|
|
#Example
|
|
void draw(SkCanvas* canvas) {
|
|
const char* verbNames[] = { "move", "line", "quad", "conic", "cubic", "close", "done" };
|
|
const int pointCount[] = { 1 , 2 , 3 , 3 , 4 , 1 , 0 };
|
|
SkPath path;
|
|
path.conicTo(20, 0, 20, 20, SK_ScalarInfinity);
|
|
SkPath::Iter iter(path, false);
|
|
SkPath::Verb verb;
|
|
do {
|
|
SkPoint points[4];
|
|
verb = iter.next(points);
|
|
SkDebugf("%s ", verbNames[(int) verb]);
|
|
for (int i = 0; i < pointCount[(int) verb]; ++i) {
|
|
SkDebugf("{%g, %g}, ", points[i].fX, points[i].fY);
|
|
}
|
|
if (SkPath::kConic_Verb == verb) {
|
|
SkDebugf("weight = %g", iter.conicWeight());
|
|
}
|
|
SkDebugf("\n");
|
|
} while (SkPath::kDone_Verb != verb);
|
|
}
|
|
#StdOut
|
|
move {0, 0},
|
|
line {0, 0}, {20, 0},
|
|
line {20, 0}, {20, 20},
|
|
done
|
|
##
|
|
##
|
|
|
|
#Subtopic Weight ##
|
|
|
|
#Method void conicTo(SkScalar x1, SkScalar y1, SkScalar x2, SkScalar y2,
|
|
SkScalar w)
|
|
#In Conic
|
|
#In Build
|
|
#Line # appends Conic ##
|
|
|
|
Adds Conic from Last_Point towards (x1, y1), to (x2, y2), weighted by w.
|
|
If Path is empty, or last Verb is kClose_Verb, Last_Point is set to (0, 0)
|
|
before adding Conic.
|
|
|
|
Appends kMove_Verb to Verb_Array and (0, 0) to Point_Array, if needed.
|
|
|
|
If w is finite and not one, appends kConic_Verb to Verb_Array;
|
|
and (x1, y1), (x2, y2) to Point_Array; and w to Conic_Weights.
|
|
|
|
If w is one, appends kQuad_Verb to Verb_Array, and
|
|
(x1, y1), (x2, y2) to Point_Array.
|
|
|
|
If w is not finite, appends kLine_Verb twice to Verb_Array, and
|
|
(x1, y1), (x2, y2) to Point_Array.
|
|
|
|
#Param x1 control Point of Conic in x ##
|
|
#Param y1 control Point of Conic in y ##
|
|
#Param x2 end Point of Conic in x ##
|
|
#Param y2 end Point of Conic in y ##
|
|
#Param w weight of added Conic ##
|
|
|
|
#Example
|
|
#Height 160
|
|
#Description
|
|
As weight increases, curve is pulled towards control point.
|
|
The bottom two curves are elliptical; the next is parabolic; the
|
|
top curve is hyperbolic.
|
|
##
|
|
void draw(SkCanvas* canvas) {
|
|
SkPaint paint;
|
|
paint.setAntiAlias(true);
|
|
paint.setStyle(SkPaint::kStroke_Style);
|
|
SkPoint conicPts[] = {{20, 150}, {120, 10}, {220, 150}};
|
|
canvas->drawLine(conicPts[0], conicPts[1], paint);
|
|
canvas->drawLine(conicPts[1], conicPts[2], paint);
|
|
SkColor colors[] = { 0xff88ff00, 0xff0088bb, 0xff6600cc, 0xffbb3377 };
|
|
paint.setStrokeWidth(3);
|
|
SkScalar weight = 0.5f;
|
|
for (unsigned i = 0; i < SK_ARRAY_COUNT(colors); ++i) {
|
|
SkPath path;
|
|
path.moveTo(conicPts[0]);
|
|
path.conicTo(conicPts[1], conicPts[2], weight);
|
|
paint.setColor(colors[i]);
|
|
canvas->drawPath(path, paint);
|
|
weight += 0.25f;
|
|
}
|
|
}
|
|
##
|
|
|
|
#SeeAlso rConicTo arcTo addArc quadTo
|
|
|
|
##
|
|
|
|
#Method void conicTo(const SkPoint& p1, const SkPoint& p2, SkScalar w)
|
|
#In Build
|
|
#In Conic
|
|
Adds Conic from Last_Point towards Point p1, to Point p2, weighted by w.
|
|
If Path is empty, or last Verb is kClose_Verb, Last_Point is set to (0, 0)
|
|
before adding Conic.
|
|
|
|
Appends kMove_Verb to Verb_Array and (0, 0) to Point_Array, if needed.
|
|
|
|
If w is finite and not one, appends kConic_Verb to Verb_Array;
|
|
and Points p1, p2 to Point_Array; and w to Conic_Weights.
|
|
|
|
If w is one, appends kQuad_Verb to Verb_Array, and Points p1, p2
|
|
to Point_Array.
|
|
|
|
If w is not finite, appends kLine_Verb twice to Verb_Array, and
|
|
Points p1, p2 to Point_Array.
|
|
|
|
#Param p1 control Point of added Conic ##
|
|
#Param p2 end Point of added Conic ##
|
|
#Param w weight of added Conic ##
|
|
|
|
#Example
|
|
#Height 128
|
|
#Description
|
|
Conics and arcs use identical representations. As the arc sweep increases
|
|
the Conic_Weight also increases, but remains smaller than one.
|
|
##
|
|
void draw(SkCanvas* canvas) {
|
|
SkPaint paint;
|
|
paint.setAntiAlias(true);
|
|
paint.setStyle(SkPaint::kStroke_Style);
|
|
SkRect oval = {0, 20, 120, 140};
|
|
SkPath path;
|
|
for (int i = 0; i < 4; ++i) {
|
|
path.moveTo(oval.centerX(), oval.fTop);
|
|
path.arcTo(oval, -90, 90 - 20 * i, false);
|
|
oval.inset(15, 15);
|
|
}
|
|
path.offset(100, 0);
|
|
SkScalar conicWeights[] = { 0.707107f, 0.819152f, 0.906308f, 0.965926f };
|
|
SkPoint conicPts[][3] = { { {40, 20}, {100, 20}, {100, 80} },
|
|
{ {40, 35}, {71.509f, 35}, {82.286f, 64.6091f} },
|
|
{ {40, 50}, {53.9892f, 50}, {62.981f, 60.7164f} },
|
|
{ {40, 65}, {44.0192f, 65}, {47.5f, 67.0096f} } };
|
|
for (int i = 0; i < 4; ++i) {
|
|
path.moveTo(conicPts[i][0]);
|
|
path.conicTo(conicPts[i][1], conicPts[i][2], conicWeights[i]);
|
|
}
|
|
canvas->drawPath(path, paint);
|
|
}
|
|
##
|
|
|
|
#SeeAlso rConicTo arcTo addArc quadTo
|
|
|
|
##
|
|
|
|
#Method void rConicTo(SkScalar dx1, SkScalar dy1, SkScalar dx2, SkScalar dy2,
|
|
SkScalar w)
|
|
#In Build
|
|
#In Conic
|
|
#Line # appends Conic relative to Last_Point ##
|
|
|
|
Adds Conic from Last_Point towards Vector (dx1, dy1), to Vector (dx2, dy2),
|
|
weighted by w. If Path is empty, or last Verb
|
|
is kClose_Verb, Last_Point is set to (0, 0) before adding Conic.
|
|
|
|
Appends kMove_Verb to Verb_Array and (0, 0) to Point_Array,
|
|
if needed.
|
|
|
|
If w is finite and not one, next appends kConic_Verb to Verb_Array,
|
|
and w is recorded as Conic_Weight; otherwise, if w is one, appends
|
|
kQuad_Verb to Verb_Array; or if w is not finite, appends kLine_Verb
|
|
twice to Verb_Array.
|
|
|
|
In all cases appends Points control and end to Point_Array.
|
|
control is Last_Point plus Vector (dx1, dy1).
|
|
end is Last_Point plus Vector (dx2, dy2).
|
|
|
|
Function name stands for "relative conic to".
|
|
|
|
#Param dx1 offset from Last_Point to Conic control on x-axis ##
|
|
#Param dy1 offset from Last_Point to Conic control on y-axis ##
|
|
#Param dx2 offset from Last_Point to Conic end on x-axis ##
|
|
#Param dy2 offset from Last_Point to Conic end on y-axis ##
|
|
#Param w weight of added Conic ##
|
|
|
|
#Example
|
|
#Height 140
|
|
void draw(SkCanvas* canvas) {
|
|
SkPaint paint;
|
|
paint.setAntiAlias(true);
|
|
paint.setStyle(SkPaint::kStroke_Style);
|
|
SkPath path;
|
|
path.moveTo(20, 80);
|
|
path.rConicTo( 60, 0, 60, 60, 0.707107f);
|
|
path.rConicTo( 0, -60, 60, -60, 0.707107f);
|
|
path.rConicTo(-60, 0, -60, -60, 0.707107f);
|
|
path.rConicTo( 0, 60, -60, 60, 0.707107f);
|
|
canvas->drawPath(path, paint);
|
|
}
|
|
##
|
|
|
|
#SeeAlso conicTo arcTo addArc quadTo
|
|
|
|
##
|
|
|
|
#Subtopic Conic ##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
#Subtopic Cubic
|
|
#Alias Cubic ##
|
|
#Alias Cubics ##
|
|
#Alias Cubic_Bezier ##
|
|
#Alias Cubic_Beziers ##
|
|
#Line # curve described by third-order polynomial ##
|
|
|
|
Cubic describes a Bezier_Curve segment described by a third-order polynomial.
|
|
Cubic begins at a start Point, curving towards the first control Point;
|
|
and curves from the end Point towards the second control Point.
|
|
|
|
#Example
|
|
#Height 160
|
|
void draw(SkCanvas* canvas) {
|
|
SkPaint paint;
|
|
paint.setAntiAlias(true);
|
|
paint.setStyle(SkPaint::kStroke_Style);
|
|
SkPoint cubicPts[] = {{20, 150}, {90, 10}, {160, 150}, {230, 10}};
|
|
SkColor colors[] = { 0xff88ff00, 0xff0088bb, 0xff6600cc, 0xffbb3377 };
|
|
for (unsigned i = 0; i < SK_ARRAY_COUNT(colors); ++i) {
|
|
paint.setColor(0x7fffffff & colors[i]);
|
|
paint.setStrokeWidth(1);
|
|
for (unsigned j = 0; j < 3; ++j) {
|
|
canvas->drawLine(cubicPts[j], cubicPts[j + 1], paint);
|
|
}
|
|
SkPath path;
|
|
path.moveTo(cubicPts[0]);
|
|
path.cubicTo(cubicPts[1], cubicPts[2], cubicPts[3]);
|
|
paint.setStrokeWidth(3);
|
|
paint.setColor(colors[i]);
|
|
canvas->drawPath(path, paint);
|
|
cubicPts[1].fY += 30;
|
|
cubicPts[2].fX += 30;
|
|
}
|
|
}
|
|
##
|
|
|
|
#Method void cubicTo(SkScalar x1, SkScalar y1, SkScalar x2, SkScalar y2,
|
|
SkScalar x3, SkScalar y3)
|
|
#In Build
|
|
#In Cubic
|
|
#Line # appends Cubic ##
|
|
|
|
Adds Cubic from Last_Point towards (x1, y1), then towards (x2, y2), ending at
|
|
(x3, y3). If Path is empty, or last Verb is kClose_Verb, Last_Point is set to
|
|
(0, 0) before adding Cubic.
|
|
|
|
Appends kMove_Verb to Verb_Array and (0, 0) to Point_Array, if needed;
|
|
then appends kCubic_Verb to Verb_Array; and (x1, y1), (x2, y2), (x3, y3)
|
|
to Point_Array.
|
|
|
|
#Param x1 first control Point of Cubic in x ##
|
|
#Param y1 first control Point of Cubic in y ##
|
|
#Param x2 second control Point of Cubic in x ##
|
|
#Param y2 second control Point of Cubic in y ##
|
|
#Param x3 end Point of Cubic in x ##
|
|
#Param y3 end Point of Cubic in y ##
|
|
|
|
#Example
|
|
void draw(SkCanvas* canvas) {
|
|
SkPaint paint;
|
|
paint.setAntiAlias(true);
|
|
paint.setStyle(SkPaint::kStroke_Style);
|
|
SkPath path;
|
|
path.moveTo(0, -10);
|
|
for (int i = 0; i < 128; i += 16) {
|
|
SkScalar c = i * 0.5f;
|
|
path.cubicTo( 10 + c, -10 - i, 10 + i, -10 - c, 10 + i, 0);
|
|
path.cubicTo( 14 + i, 14 + c, 14 + c, 14 + i, 0, 14 + i);
|
|
path.cubicTo(-18 - c, 18 + i, -18 - i, 18 + c, -18 - i, 0);
|
|
path.cubicTo(-22 - i, -22 - c, -22 - c, -22 - i, 0, -22 - i);
|
|
}
|
|
path.offset(128, 128);
|
|
canvas->drawPath(path, paint);
|
|
}
|
|
##
|
|
|
|
#SeeAlso Contour moveTo rCubicTo quadTo
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method void cubicTo(const SkPoint& p1, const SkPoint& p2, const SkPoint& p3)
|
|
|
|
#In Build
|
|
#In Cubic
|
|
Adds Cubic from Last_Point towards Point p1, then towards Point p2, ending at
|
|
Point p3. If Path is empty, or last Verb is kClose_Verb, Last_Point is set to
|
|
(0, 0) before adding Cubic.
|
|
|
|
Appends kMove_Verb to Verb_Array and (0, 0) to Point_Array, if needed;
|
|
then appends kCubic_Verb to Verb_Array; and Points p1, p2, p3
|
|
to Point_Array.
|
|
|
|
#Param p1 first control Point of Cubic ##
|
|
#Param p2 second control Point of Cubic ##
|
|
#Param p3 end Point of Cubic ##
|
|
|
|
#Example
|
|
#Height 84
|
|
SkPaint paint;
|
|
paint.setAntiAlias(true);
|
|
paint.setStyle(SkPaint::kStroke_Style);
|
|
SkPoint pts[] = { {20, 20}, {300, 80}, {-140, 90}, {220, 10} };
|
|
SkPath path;
|
|
path.moveTo(pts[0]);
|
|
path.cubicTo(pts[1], pts[2], pts[3]);
|
|
canvas->drawPath(path, paint);
|
|
##
|
|
|
|
#SeeAlso Contour moveTo rCubicTo quadTo
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method void rCubicTo(SkScalar x1, SkScalar y1, SkScalar x2, SkScalar y2,
|
|
SkScalar x3, SkScalar y3)
|
|
#In Build
|
|
#In Cubic
|
|
#Line # appends Cubic relative to Last_Point ##
|
|
|
|
Adds Cubic from Last_Point towards Vector (dx1, dy1), then towards
|
|
Vector (dx2, dy2), to Vector (dx3, dy3).
|
|
If Path is empty, or last Verb
|
|
is kClose_Verb, Last_Point is set to (0, 0) before adding Cubic.
|
|
|
|
Appends kMove_Verb to Verb_Array and (0, 0) to Point_Array,
|
|
if needed; then appends kCubic_Verb to Verb_Array; and appends Cubic
|
|
control and Cubic end to Point_Array.
|
|
Cubic control is Last_Point plus Vector (dx1, dy1).
|
|
Cubic end is Last_Point plus Vector (dx2, dy2).
|
|
Function name stands for "relative cubic to".
|
|
|
|
#Param x1 offset from Last_Point to first Cubic control on x-axis ##
|
|
#Param y1 offset from Last_Point to first Cubic control on y-axis ##
|
|
#Param x2 offset from Last_Point to second Cubic control on x-axis ##
|
|
#Param y2 offset from Last_Point to second Cubic control on y-axis ##
|
|
#Param x3 offset from Last_Point to Cubic end on x-axis ##
|
|
#Param y3 offset from Last_Point to Cubic end on y-axis ##
|
|
|
|
#Example
|
|
void draw(SkCanvas* canvas) {
|
|
SkPaint paint;
|
|
paint.setAntiAlias(true);
|
|
paint.setStyle(SkPaint::kStroke_Style);
|
|
SkPath path;
|
|
path.moveTo(24, 108);
|
|
for (int i = 0; i < 16; i++) {
|
|
SkScalar sx, sy;
|
|
sx = SkScalarSinCos(i * SK_ScalarPI / 8, &sy);
|
|
path.rCubicTo(40 * sx, 4 * sy, 4 * sx, 40 * sy, 40 * sx, 40 * sy);
|
|
}
|
|
canvas->drawPath(path, paint);
|
|
}
|
|
##
|
|
|
|
#SeeAlso Contour moveTo cubicTo quadTo
|
|
|
|
##
|
|
|
|
#Subtopic Cubic ##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Subtopic Arc
|
|
#Line # part of Oval or Circle ##
|
|
Arc can be constructed in a number of ways. Arc may be described by part of Oval and angles,
|
|
by start point and end point, and by radius and tangent lines. Each construction has advantages,
|
|
and some constructions correspond to Arc drawing in graphics standards.
|
|
|
|
All Arc draws are implemented by one or more Conic draws. When Conic_Weight is less than one,
|
|
Conic describes an Arc of some Oval or Circle.
|
|
|
|
arcTo(const SkRect& oval, SkScalar startAngle, SkScalar sweepAngle, bool forceMoveTo)
|
|
describes Arc as a piece of Oval, beginning at start angle, sweeping clockwise or counterclockwise,
|
|
which may continue Contour or start a new one. This construction is similar to PostScript and
|
|
HTML_Canvas arcs. Variation addArc always starts new Contour. Canvas::drawArc draws without
|
|
requiring Path.
|
|
|
|
arcTo(SkScalar x1, SkScalar y1, SkScalar x2, SkScalar y2, SkScalar radius)
|
|
describes Arc as tangent to the line (x0, y0), (x1, y1) and tangent to the line (x1, y1), (x2, y2)
|
|
where (x0, y0) is the last Point added to Path. This construction is similar to PostScript and
|
|
HTML_Canvas arcs.
|
|
|
|
arcTo(SkScalar rx, SkScalar ry, SkScalar xAxisRotate, ArcSize largeArc, Direction sweep,
|
|
SkScalar x, SkScalar y)
|
|
describes Arc as part of Oval with radii (rx, ry), beginning at
|
|
last Point added to Path and ending at (x, y). More than one Arc satisfies this criteria,
|
|
so additional values choose a single solution. This construction is similar to SVG arcs.
|
|
|
|
conicTo describes Arc of less than 180 degrees as a pair of tangent lines and Conic_Weight.
|
|
conicTo can represent any Arc with a sweep less than 180 degrees at any rotation. All arcTo
|
|
constructions are converted to Conic data when added to Path.
|
|
|
|
#ToDo allow example to hide source and not be exposed as fiddle since markdown / html can't
|
|
do the kind of table shown in the illustration.
|
|
example is spaced correctly on fiddle but spacing is too wide on pc
|
|
##
|
|
|
|
#Example
|
|
#Height 300
|
|
#Width 600
|
|
#Description
|
|
#List
|
|
# <sup>1</sup> arcTo(const SkRect& oval, SkScalar startAngle, SkScalar sweepAngle, bool forceMoveTo) ##
|
|
# <sup>2</sup> parameter sets force MoveTo ##
|
|
# <sup>3</sup> start angle must be multiple of 90 degrees ##
|
|
# <sup>4</sup> arcTo(SkScalar x1, SkScalar y1, SkScalar x2, SkScalar y2, SkScalar radius) ##
|
|
# <sup>5</sup> arcTo(SkScalar rx, SkScalar ry, SkScalar xAxisRotate, ArcSize largeArc,
|
|
Direction sweep, SkScalar x, SkScalar y) ##
|
|
#List ##
|
|
#Description ##
|
|
#Function
|
|
###$
|
|
struct data {
|
|
const char* name;
|
|
char super;
|
|
int yn[10];
|
|
};
|
|
|
|
const data dataSet[] = {
|
|
{ "arcTo sweep", '1', {1, 3, 1, 0, 0, 0, 0, 1, 0, 0 }},
|
|
{ "drawArc", 0, {1, -1, 1, 1, 1, 1, 1, 0, 0, 0 }},
|
|
{ "addArc", 0, {1, 1, 1, 4, 0, 1, 1, 1, 0, 0 }},
|
|
{ "arcTo tangents", '4', {0, 0, 0, 0, 0, 0, 0, 1, 1, 0 }},
|
|
{ "arcTo radii", '5', {1, 0, 1, 0, 0, 0, 0, 1, 1, 0 }},
|
|
{ "conicTo", 0, {1, 1, 0, 0, 0, 0, 0, 1, 1, 1 }}
|
|
};
|
|
|
|
#define __degree_symbol__ "\xC2" "\xB0"
|
|
|
|
const char* headers[] = {
|
|
"Oval part",
|
|
"force moveTo",
|
|
"can draw 180" __degree_symbol__,
|
|
"can draw 360" __degree_symbol__,
|
|
"can draw greater than 360" __degree_symbol__,
|
|
"ignored if radius is zero",
|
|
"ignored if sweep is zero",
|
|
"requires Path",
|
|
"describes rotation",
|
|
"describes perspective",
|
|
};
|
|
|
|
const char* yna[] = {
|
|
"n/a",
|
|
"no",
|
|
"yes"
|
|
};
|
|
$$$#
|
|
##
|
|
void draw(SkCanvas* canvas) {
|
|
SkPaint lp;
|
|
lp.setAntiAlias(true);
|
|
SkPaint tp(lp);
|
|
SkPaint sp(tp);
|
|
SkPaint bp(tp);
|
|
bp.setFakeBoldText(true);
|
|
sp.setTextSize(10);
|
|
lp.setColor(SK_ColorGRAY);
|
|
canvas->translate(0, 32);
|
|
const int tl = 115;
|
|
for (unsigned col = 0; col <= SK_ARRAY_COUNT(headers); ++col) {
|
|
canvas->drawLine(tl + col * 35, 100, tl + col * 35, 250, lp);
|
|
if (0 == col) {
|
|
continue;
|
|
}
|
|
canvas->drawLine(tl + col * 35, 100, tl + 100 + col * 35, 0, lp);
|
|
SkPath path;
|
|
path.moveTo(tl - 3 + col * 35, 103);
|
|
path.lineTo(tl + 124 + col * 35, -24);
|
|
canvas->drawTextOnPathHV(headers[col -1], strlen(headers[col -1]), path, 0, -9, bp);
|
|
}
|
|
for (unsigned row = 0; row <= SK_ARRAY_COUNT(dataSet); ++row) {
|
|
if (0 == row) {
|
|
canvas->drawLine(tl, 100, tl + 350, 100, lp);
|
|
} else {
|
|
canvas->drawLine(5, 100 + row * 25, tl + 350, 100 + row * 25, lp);
|
|
}
|
|
if (row == SK_ARRAY_COUNT(dataSet)) {
|
|
break;
|
|
}
|
|
canvas->drawString(dataSet[row].name, 5, 117 + row * 25, bp);
|
|
if (dataSet[row].super) {
|
|
SkScalar width = bp.measureText(dataSet[row].name, strlen(dataSet[row].name));
|
|
canvas->drawText(&dataSet[row].super, 1, 8 + width, 112 + row * 25, sp);
|
|
}
|
|
for (unsigned col = 0; col < SK_ARRAY_COUNT(headers); ++col) {
|
|
int val = dataSet[row].yn[col];
|
|
canvas->drawString(yna[SkTMin(2, val + 1)], tl + 5 + col * 35, 117 + row * 25, tp);
|
|
if (val > 1) {
|
|
char supe = '0' + val - 1;
|
|
canvas->drawText(&supe, 1, tl + 25 + col * 35, 112 + row * 25, sp);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
#Example ##
|
|
|
|
#Example
|
|
#Height 128
|
|
#Description
|
|
#ToDo make this a list or table ##
|
|
1 describes an arc from an oval, a starting angle, and a sweep angle.
|
|
2 is similar to 1, but does not require building a path to draw.
|
|
3 is similar to 1, but always begins new Contour.
|
|
4 describes an arc from a pair of tangent lines and a radius.
|
|
5 describes an arc from Oval center, arc start Point and arc end Point.
|
|
6 describes an arc from a pair of tangent lines and a Conic_Weight.
|
|
##
|
|
void draw(SkCanvas* canvas) {
|
|
SkRect oval = {8, 8, 56, 56};
|
|
SkPaint ovalPaint;
|
|
ovalPaint.setAntiAlias(true);
|
|
SkPaint textPaint(ovalPaint);
|
|
ovalPaint.setStyle(SkPaint::kStroke_Style);
|
|
SkPaint arcPaint(ovalPaint);
|
|
arcPaint.setStrokeWidth(5);
|
|
arcPaint.setColor(SK_ColorBLUE);
|
|
canvas->translate(-64, 0);
|
|
for (char arcStyle = '1'; arcStyle <= '6'; ++arcStyle) {
|
|
'4' == arcStyle ? canvas->translate(-96, 55) : canvas->translate(64, 0);
|
|
canvas->drawText(&arcStyle, 1, 30, 36, textPaint);
|
|
canvas->drawOval(oval, ovalPaint);
|
|
SkPath path;
|
|
path.moveTo({56, 32});
|
|
switch (arcStyle) {
|
|
case '1':
|
|
path.arcTo(oval, 0, 90, false);
|
|
break;
|
|
case '2':
|
|
canvas->drawArc(oval, 0, 90, false, arcPaint);
|
|
continue;
|
|
case '3':
|
|
path.addArc(oval, 0, 90);
|
|
break;
|
|
case '4':
|
|
path.arcTo({56, 56}, {32, 56}, 24);
|
|
break;
|
|
case '5':
|
|
path.arcTo({24, 24}, 0, SkPath::kSmall_ArcSize, SkPath::kCW_Direction, {32, 56});
|
|
break;
|
|
case '6':
|
|
path.conicTo({56, 56}, {32, 56}, SK_ScalarRoot2Over2);
|
|
break;
|
|
}
|
|
canvas->drawPath(path, arcPaint);
|
|
}
|
|
}
|
|
#Example ##
|
|
|
|
|
|
#Method void arcTo(const SkRect& oval, SkScalar startAngle, SkScalar sweepAngle, bool forceMoveTo)
|
|
#In Build
|
|
#In Arc
|
|
#Line # appends Arc ##
|
|
Append Arc to Path. Arc added is part of ellipse
|
|
bounded by oval, from startAngle through sweepAngle. Both startAngle and
|
|
sweepAngle are measured in degrees, where zero degrees is aligned with the
|
|
positive x-axis, and positive sweeps extends Arc clockwise.
|
|
|
|
arcTo adds Line connecting Path last Point to initial Arc Point if forceMoveTo
|
|
is false and Path is not empty. Otherwise, added Contour begins with first point
|
|
of Arc. Angles greater than -360 and less than 360 are treated modulo 360.
|
|
|
|
#Param oval bounds of ellipse containing Arc ##
|
|
#Param startAngle starting angle of Arc in degrees ##
|
|
#Param sweepAngle sweep, in degrees. Positive is clockwise; treated modulo 360 ##
|
|
#Param forceMoveTo true to start a new contour with Arc ##
|
|
|
|
#Example
|
|
#Height 200
|
|
#Description
|
|
arcTo continues a previous contour when forceMoveTo is false and when Path
|
|
is not empty.
|
|
##
|
|
void draw(SkCanvas* canvas) {
|
|
SkPaint paint;
|
|
SkPath path;
|
|
paint.setStyle(SkPaint::kStroke_Style);
|
|
paint.setStrokeWidth(4);
|
|
path.moveTo(0, 0);
|
|
path.arcTo({20, 20, 120, 120}, -90, 90, false);
|
|
canvas->drawPath(path, paint);
|
|
path.rewind();
|
|
path.arcTo({120, 20, 220, 120}, -90, 90, false);
|
|
canvas->drawPath(path, paint);
|
|
path.rewind();
|
|
path.moveTo(0, 0);
|
|
path.arcTo({20, 120, 120, 220}, -90, 90, true);
|
|
canvas->drawPath(path, paint);
|
|
}
|
|
##
|
|
|
|
#SeeAlso addArc SkCanvas::drawArc conicTo
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method void arcTo(SkScalar x1, SkScalar y1, SkScalar x2, SkScalar y2, SkScalar radius)
|
|
#In Build
|
|
#In Arc
|
|
Append Arc to Path, after appending Line if needed. Arc is implemented by Conic
|
|
weighted to describe part of Circle. Arc is contained by tangent from
|
|
last Path point (x0, y0) to (x1, y1), and tangent from (x1, y1) to (x2, y2). Arc
|
|
is part of Circle sized to radius, positioned so it touches both tangent lines.
|
|
|
|
#ToDo allow example to hide source and not be exposed as fiddle ##
|
|
|
|
#Example
|
|
#Height 226
|
|
void draw(SkCanvas* canvas) {
|
|
SkPaint tangentPaint;
|
|
tangentPaint.setAntiAlias(true);
|
|
SkPaint textPaint(tangentPaint);
|
|
tangentPaint.setStyle(SkPaint::kStroke_Style);
|
|
tangentPaint.setColor(SK_ColorGRAY);
|
|
SkPaint arcPaint(tangentPaint);
|
|
arcPaint.setStrokeWidth(5);
|
|
arcPaint.setColor(SK_ColorBLUE);
|
|
SkPath path;
|
|
SkPoint pts[] = { {56, 20}, {200, 20}, {90, 190} };
|
|
SkScalar radius = 50;
|
|
path.moveTo(pts[0]);
|
|
path.arcTo(pts[1], pts[2], radius);
|
|
canvas->drawLine(pts[0], pts[1], tangentPaint);
|
|
canvas->drawLine(pts[1], pts[2], tangentPaint);
|
|
SkPoint lastPt;
|
|
(void) path.getLastPt(&lastPt);
|
|
SkVector radial = pts[2] - pts[1];
|
|
radial.setLength(radius);
|
|
SkPoint center = { lastPt.fX - radial.fY, lastPt.fY + radial.fX };
|
|
canvas->drawCircle(center, radius, tangentPaint);
|
|
canvas->drawLine(lastPt, center, tangentPaint);
|
|
radial = pts[1] - pts[0];
|
|
radial.setLength(radius);
|
|
SkPoint arcStart = { center.fX + radial.fY, center.fY - radial.fX };
|
|
canvas->drawLine(center, arcStart, tangentPaint);
|
|
canvas->drawPath(path, arcPaint);
|
|
textPaint.setTextAlign(SkPaint::kRight_Align);
|
|
canvas->drawString("(x0, y0)", pts[0].fX - 5, pts[0].fY, textPaint);
|
|
textPaint.setTextAlign(SkPaint::kLeft_Align);
|
|
canvas->drawString("(x1, y1)", pts[1].fX + 5, pts[1].fY, textPaint);
|
|
textPaint.setTextAlign(SkPaint::kCenter_Align);
|
|
canvas->drawString("(x2, y2)", pts[2].fX, pts[2].fY + 15, textPaint);
|
|
textPaint.setTextAlign(SkPaint::kRight_Align);
|
|
canvas->drawString("radius", center.fX + 15, center.fY + 25, textPaint);
|
|
canvas->drawString("radius", center.fX - 3, center.fY - 16, textPaint);
|
|
}
|
|
##
|
|
|
|
If last Path Point does not start Arc, arcTo appends connecting Line to Path.
|
|
The length of Vector from (x1, y1) to (x2, y2) does not affect Arc.
|
|
|
|
#Example
|
|
#Height 128
|
|
void draw(SkCanvas* canvas) {
|
|
SkPaint tangentPaint;
|
|
tangentPaint.setAntiAlias(true);
|
|
SkPaint textPaint(tangentPaint);
|
|
tangentPaint.setStyle(SkPaint::kStroke_Style);
|
|
tangentPaint.setColor(SK_ColorGRAY);
|
|
SkPaint arcPaint(tangentPaint);
|
|
arcPaint.setStrokeWidth(5);
|
|
arcPaint.setColor(SK_ColorBLUE);
|
|
SkPath path;
|
|
SkPoint pts[] = { {156, 20}, {200, 20}, {170, 50} };
|
|
SkScalar radius = 50;
|
|
path.moveTo(pts[0]);
|
|
path.arcTo(pts[1], pts[2], radius);
|
|
canvas->drawLine(pts[0], pts[1], tangentPaint);
|
|
canvas->drawLine(pts[1], pts[2], tangentPaint);
|
|
SkPoint lastPt;
|
|
(void) path.getLastPt(&lastPt);
|
|
SkVector radial = pts[2] - pts[1];
|
|
radial.setLength(radius);
|
|
SkPoint center = { lastPt.fX - radial.fY, lastPt.fY + radial.fX };
|
|
canvas->drawLine(lastPt, center, tangentPaint);
|
|
radial = pts[1] - pts[0];
|
|
radial.setLength(radius);
|
|
SkPoint arcStart = { center.fX + radial.fY, center.fY - radial.fX };
|
|
canvas->drawLine(center, arcStart, tangentPaint);
|
|
canvas->drawPath(path, arcPaint);
|
|
textPaint.setTextAlign(SkPaint::kCenter_Align);
|
|
canvas->drawString("(x0, y0)", pts[0].fX, pts[0].fY - 7, textPaint);
|
|
textPaint.setTextAlign(SkPaint::kLeft_Align);
|
|
canvas->drawString("(x1, y1)", pts[1].fX + 5, pts[1].fY, textPaint);
|
|
textPaint.setTextAlign(SkPaint::kCenter_Align);
|
|
canvas->drawString("(x2, y2)", pts[2].fX, pts[2].fY + 15, textPaint);
|
|
textPaint.setTextAlign(SkPaint::kRight_Align);
|
|
canvas->drawString("radius", center.fX + 15, center.fY + 25, textPaint);
|
|
canvas->drawString("radius", center.fX - 5, center.fY - 20, textPaint);
|
|
}
|
|
##
|
|
|
|
Arc sweep is always less than 180 degrees. If radius is zero, or if
|
|
tangents are nearly parallel, arcTo appends Line from last Path Point to (x1, y1).
|
|
|
|
arcTo appends at most one Line and one Conic.
|
|
arcTo implements the functionality of PostScript_Arct and HTML_Canvas_ArcTo.
|
|
|
|
#Param x1 x-axis value common to pair of tangents ##
|
|
#Param y1 y-axis value common to pair of tangents ##
|
|
#Param x2 x-axis value end of second tangent ##
|
|
#Param y2 y-axis value end of second tangent ##
|
|
#Param radius distance from Arc to Circle center ##
|
|
|
|
#Example
|
|
#Description
|
|
arcTo is represented by Line and circular Conic in Path.
|
|
##
|
|
void draw(SkCanvas* canvas) {
|
|
SkPath path;
|
|
path.moveTo({156, 20});
|
|
path.arcTo(200, 20, 170, 50, 50);
|
|
SkPath::Iter iter(path, false);
|
|
SkPoint p[4];
|
|
SkPath::Verb verb;
|
|
while (SkPath::kDone_Verb != (verb = iter.next(p))) {
|
|
switch (verb) {
|
|
case SkPath::kMove_Verb:
|
|
SkDebugf("move to (%g,%g)\n", p[0].fX, p[0].fY);
|
|
break;
|
|
case SkPath::kLine_Verb:
|
|
SkDebugf("line (%g,%g),(%g,%g)\n", p[0].fX, p[0].fY, p[1].fX, p[1].fY);
|
|
break;
|
|
case SkPath::kConic_Verb:
|
|
SkDebugf("conic (%g,%g),(%g,%g),(%g,%g) weight %g\n",
|
|
p[0].fX, p[0].fY, p[1].fX, p[1].fY, p[2].fX, p[2].fY, iter.conicWeight());
|
|
break;
|
|
default:
|
|
SkDebugf("unexpected verb\n");
|
|
}
|
|
}
|
|
}
|
|
#StdOut
|
|
move to (156,20)
|
|
line (156,20),(79.2893,20)
|
|
conic (79.2893,20),(200,20),(114.645,105.355) weight 0.382683
|
|
##
|
|
##
|
|
|
|
#SeeAlso conicTo
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method void arcTo(const SkPoint p1, const SkPoint p2, SkScalar radius)
|
|
#In Build
|
|
#In Arc
|
|
Append Arc to Path, after appending Line if needed. Arc is implemented by Conic
|
|
weighted to describe part of Circle. Arc is contained by tangent from
|
|
last Path point to p1, and tangent from p1 to p2. Arc
|
|
is part of Circle sized to radius, positioned so it touches both tangent lines.
|
|
|
|
If last Path Point does not start Arc, arcTo appends connecting Line to Path.
|
|
The length of Vector from p1 to p2 does not affect Arc.
|
|
|
|
Arc sweep is always less than 180 degrees. If radius is zero, or if
|
|
tangents are nearly parallel, arcTo appends Line from last Path Point to p1.
|
|
|
|
arcTo appends at most one Line and one Conic.
|
|
arcTo implements the functionality of PostScript_Arct and HTML_Canvas_ArcTo.
|
|
|
|
#Param p1 Point common to pair of tangents ##
|
|
#Param p2 end of second tangent ##
|
|
#Param radius distance from Arc to Circle center ##
|
|
|
|
#Example
|
|
#Description
|
|
Because tangent lines are parallel, arcTo appends line from last Path Point to
|
|
p1, but does not append a circular Conic.
|
|
##
|
|
void draw(SkCanvas* canvas) {
|
|
SkPath path;
|
|
path.moveTo({156, 20});
|
|
path.arcTo({200, 20}, {170, 20}, 50);
|
|
SkPath::Iter iter(path, false);
|
|
SkPoint p[4];
|
|
SkPath::Verb verb;
|
|
while (SkPath::kDone_Verb != (verb = iter.next(p))) {
|
|
switch (verb) {
|
|
case SkPath::kMove_Verb:
|
|
SkDebugf("move to (%g,%g)\n", p[0].fX, p[0].fY);
|
|
break;
|
|
case SkPath::kLine_Verb:
|
|
SkDebugf("line (%g,%g),(%g,%g)\n", p[0].fX, p[0].fY, p[1].fX, p[1].fY);
|
|
break;
|
|
case SkPath::kConic_Verb:
|
|
SkDebugf("conic (%g,%g),(%g,%g),(%g,%g) weight %g\n",
|
|
p[0].fX, p[0].fY, p[1].fX, p[1].fY, p[2].fX, p[2].fY, iter.conicWeight());
|
|
break;
|
|
default:
|
|
SkDebugf("unexpected verb\n");
|
|
}
|
|
}
|
|
}
|
|
#StdOut
|
|
move to (156,20)
|
|
line (156,20),(200,20)
|
|
##
|
|
##
|
|
|
|
#SeeAlso conicTo
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Enum ArcSize
|
|
#Line # used by arcTo variation ##
|
|
|
|
#Code
|
|
enum ArcSize {
|
|
kSmall_ArcSize,
|
|
kLarge_ArcSize,
|
|
};
|
|
##
|
|
|
|
Four Oval parts with radii (rx, ry) start at last Path Point and ends at (x, y).
|
|
ArcSize and Direction select one of the four Oval parts.
|
|
|
|
#Const kSmall_ArcSize 0
|
|
#Line # smaller of Arc pair ##
|
|
##
|
|
#Const kLarge_ArcSize 1
|
|
#Line # larger of Arc pair ##
|
|
##
|
|
|
|
#Example
|
|
#Height 160
|
|
#Description
|
|
Arc begins at top of Oval pair and ends at bottom. Arc can take four routes to get there.
|
|
Two routes are large, and two routes are counterclockwise. The one route both large
|
|
and counterclockwise is blue.
|
|
##
|
|
void draw(SkCanvas* canvas) {
|
|
SkPaint paint;
|
|
paint.setAntiAlias(true);
|
|
paint.setStyle(SkPaint::kStroke_Style);
|
|
for (auto sweep: { SkPath::kCW_Direction, SkPath::kCCW_Direction } ) {
|
|
for (auto arcSize : { SkPath::kSmall_ArcSize, SkPath::kLarge_ArcSize } ) {
|
|
SkPath path;
|
|
path.moveTo({120, 50});
|
|
path.arcTo(70, 40, 30, arcSize, sweep, 156, 100);
|
|
if (SkPath::kCCW_Direction == sweep && SkPath::kLarge_ArcSize == arcSize) {
|
|
paint.setColor(SK_ColorBLUE);
|
|
paint.setStrokeWidth(3);
|
|
}
|
|
canvas->drawPath(path, paint);
|
|
}
|
|
}
|
|
}
|
|
##
|
|
|
|
#SeeAlso arcTo Direction
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method void arcTo(SkScalar rx, SkScalar ry, SkScalar xAxisRotate, ArcSize largeArc,
|
|
Direction sweep, SkScalar x, SkScalar y)
|
|
#In Build
|
|
#In Arc
|
|
|
|
Append Arc to Path. Arc is implemented by one or more Conics weighted to
|
|
describe part of Oval with radii (rx, ry) rotated by xAxisRotate degrees. Arc
|
|
curves from last Path Point to (x, y), choosing one of four possible routes:
|
|
clockwise or counterclockwise, and smaller or larger.
|
|
|
|
Arc sweep is always less than 360 degrees. arcTo appends Line to (x, y) if
|
|
either radii are zero, or if last Path Point equals (x, y). arcTo scales radii
|
|
(rx, ry) to fit last Path Point and (x, y) if both are greater than zero but
|
|
too small.
|
|
|
|
arcTo appends up to four Conic curves.
|
|
arcTo implements the functionality of SVG_Arc, although SVG "sweep-flag" value
|
|
is opposite the integer value of sweep; SVG "sweep-flag" uses 1 for clockwise,
|
|
while kCW_Direction cast to int is zero.
|
|
|
|
#Param rx radius in x before x-axis rotation ##
|
|
#Param ry radius in y before x-axis rotation ##
|
|
#Param xAxisRotate x-axis rotation in degrees; positive values are clockwise ##
|
|
#Param largeArc chooses smaller or larger Arc ##
|
|
#Param sweep chooses clockwise or counterclockwise Arc ##
|
|
#Param x end of Arc ##
|
|
#Param y end of Arc ##
|
|
|
|
#Example
|
|
#Height 160
|
|
void draw(SkCanvas* canvas) {
|
|
SkPaint paint;
|
|
paint.setAntiAlias(true);
|
|
paint.setStyle(SkPaint::kStroke_Style);
|
|
for (auto sweep: { SkPath::kCW_Direction, SkPath::kCCW_Direction } ) {
|
|
for (auto arcSize : { SkPath::kSmall_ArcSize, SkPath::kLarge_ArcSize } ) {
|
|
SkPath path;
|
|
path.moveTo({120, 50});
|
|
path.arcTo(70, 40, 30, arcSize, sweep, 120.1, 50);
|
|
if (SkPath::kCCW_Direction == sweep && SkPath::kLarge_ArcSize == arcSize) {
|
|
paint.setColor(SK_ColorBLUE);
|
|
paint.setStrokeWidth(3);
|
|
}
|
|
canvas->drawPath(path, paint);
|
|
}
|
|
}
|
|
}
|
|
##
|
|
|
|
#SeeAlso rArcTo ArcSize Direction
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method void arcTo(const SkPoint r, SkScalar xAxisRotate, ArcSize largeArc, Direction sweep,
|
|
const SkPoint xy)
|
|
#In Build
|
|
#In Arc
|
|
|
|
Append Arc to Path. Arc is implemented by one or more Conic weighted to describe part of Oval
|
|
with radii (r.fX, r.fY) rotated by xAxisRotate degrees. Arc curves from last Path Point to
|
|
(xy.fX, xy.fY), choosing one of four possible routes: clockwise or counterclockwise,
|
|
and smaller or larger.
|
|
|
|
Arc sweep is always less than 360 degrees. arcTo appends Line to xy if either radii are zero,
|
|
or if last Path Point equals (x, y). arcTo scales radii r to fit last Path Point and
|
|
xy if both are greater than zero but too small to describe an arc.
|
|
|
|
arcTo appends up to four Conic curves.
|
|
arcTo implements the functionality of SVG_Arc, although SVG "sweep-flag" value is
|
|
opposite the integer value of sweep; SVG "sweep-flag" uses 1 for clockwise, while
|
|
kCW_Direction cast to int is zero.
|
|
|
|
#Param r radii on axes before x-axis rotation ##
|
|
#Param xAxisRotate x-axis rotation in degrees; positive values are clockwise ##
|
|
#Param largeArc chooses smaller or larger Arc ##
|
|
#Param sweep chooses clockwise or counterclockwise Arc ##
|
|
#Param xy end of Arc ##
|
|
|
|
#Example
|
|
#Height 108
|
|
void draw(SkCanvas* canvas) {
|
|
SkPaint paint;
|
|
SkPath path;
|
|
const SkPoint starts[] = {{20, 20}, {120, 20}, {70, 60}};
|
|
for (auto start : starts) {
|
|
path.moveTo(start.fX, start.fY);
|
|
path.rArcTo(20, 20, 0, SkPath::kSmall_ArcSize, SkPath::kCCW_Direction, 60, 0);
|
|
}
|
|
canvas->drawPath(path, paint);
|
|
}
|
|
##
|
|
|
|
#SeeAlso rArcTo ArcSize Direction
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method void rArcTo(SkScalar rx, SkScalar ry, SkScalar xAxisRotate, ArcSize largeArc,
|
|
Direction sweep, SkScalar dx, SkScalar dy)
|
|
#In Build
|
|
#In Arc
|
|
#Line # appends Arc relative to Last_Point ##
|
|
|
|
Append Arc to Path, relative to last Path Point. Arc is implemented by one or
|
|
more Conic, weighted to describe part of Oval with radii (rx, ry) rotated by
|
|
xAxisRotate degrees. Arc curves from last Path Point (x0, y0) to end Point:
|
|
|
|
#Formula
|
|
(x0 + dx, y0 + dy)
|
|
##
|
|
, choosing one of four possible routes: clockwise or
|
|
counterclockwise, and smaller or larger. If Path is empty, the start Arc Point
|
|
is (0, 0).
|
|
|
|
Arc sweep is always less than 360 degrees. arcTo appends Line to end Point
|
|
if either radii are zero, or if last Path Point equals end Point.
|
|
arcTo scales radii (rx, ry) to fit last Path Point and end Point if both are
|
|
greater than zero but too small to describe an arc.
|
|
|
|
arcTo appends up to four Conic curves.
|
|
arcTo implements the functionality of SVG_Arc, although SVG "sweep-flag" value is
|
|
opposite the integer value of sweep; SVG "sweep-flag" uses 1 for clockwise, while
|
|
kCW_Direction cast to int is zero.
|
|
|
|
#Param rx radius before x-axis rotation ##
|
|
#Param ry radius before x-axis rotation ##
|
|
#Param xAxisRotate x-axis rotation in degrees; positive values are clockwise ##
|
|
#Param largeArc chooses smaller or larger Arc ##
|
|
#Param sweep chooses clockwise or counterclockwise Arc ##
|
|
#Param dx x-axis offset end of Arc from last Path Point ##
|
|
#Param dy y-axis offset end of Arc from last Path Point ##
|
|
|
|
#Example
|
|
#Height 108
|
|
void draw(SkCanvas* canvas) {
|
|
SkPaint paint;
|
|
SkPath path;
|
|
const SkPoint starts[] = {{20, 20}, {120, 20}, {70, 60}};
|
|
for (auto start : starts) {
|
|
path.moveTo(start.fX, start.fY);
|
|
path.rArcTo(20, 20, 0, SkPath::kSmall_ArcSize, SkPath::kCCW_Direction, 60, 0);
|
|
}
|
|
canvas->drawPath(path, paint);
|
|
}
|
|
##
|
|
|
|
#SeeAlso arcTo ArcSize Direction
|
|
|
|
##
|
|
|
|
#Subtopic Arc ##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method void close()
|
|
#In Build
|
|
#Line # makes last Contour a loop ##
|
|
Append kClose_Verb to Path. A closed Contour connects the first and last Point
|
|
with Line, forming a continuous loop. Open and closed Contour draw the same
|
|
with SkPaint::kFill_Style. With SkPaint::kStroke_Style, open Contour draws
|
|
Paint_Stroke_Cap at Contour start and end; closed Contour draws
|
|
Paint_Stroke_Join at Contour start and end.
|
|
|
|
close() has no effect if Path is empty or last Path Verb is kClose_Verb.
|
|
|
|
#Example
|
|
void draw(SkCanvas* canvas) {
|
|
SkPaint paint;
|
|
paint.setStrokeWidth(15);
|
|
paint.setStrokeCap(SkPaint::kRound_Cap);
|
|
SkPath path;
|
|
const SkPoint points[] = {{20, 20}, {70, 20}, {40, 90}};
|
|
path.addPoly(points, SK_ARRAY_COUNT(points), false);
|
|
for (int loop = 0; loop < 2; ++loop) {
|
|
for (auto style : {SkPaint::kStroke_Style, SkPaint::kFill_Style,
|
|
SkPaint::kStrokeAndFill_Style} ) {
|
|
paint.setStyle(style);
|
|
canvas->drawPath(path, paint);
|
|
canvas->translate(85, 0);
|
|
}
|
|
path.close();
|
|
canvas->translate(-255, 128);
|
|
}
|
|
}
|
|
##
|
|
|
|
#SeeAlso
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method static bool IsInverseFillType(FillType fill)
|
|
#In Property
|
|
#Line # returns if Fill_Type represents outside geometry ##
|
|
Returns true if fill is inverted and Path with fill represents area outside
|
|
of its geometric bounds.
|
|
|
|
#Table
|
|
#Legend
|
|
# FillType # is inverse ##
|
|
##
|
|
# kWinding_FillType # false ##
|
|
# kEvenOdd_FillType # false ##
|
|
# kInverseWinding_FillType # true ##
|
|
# kInverseEvenOdd_FillType # true ##
|
|
##
|
|
|
|
#Param fill one of: kWinding_FillType, kEvenOdd_FillType,
|
|
kInverseWinding_FillType, kInverseEvenOdd_FillType
|
|
##
|
|
|
|
#Return true if Path fills outside its bounds ##
|
|
|
|
#Example
|
|
#Function
|
|
###$
|
|
#define nameValue(fill) { SkPath::fill, #fill }
|
|
|
|
$$$#
|
|
##
|
|
void draw(SkCanvas* canvas) {
|
|
struct {
|
|
SkPath::FillType fill;
|
|
const char* name;
|
|
} fills[] = {
|
|
nameValue(kWinding_FillType),
|
|
nameValue(kEvenOdd_FillType),
|
|
nameValue(kInverseWinding_FillType),
|
|
nameValue(kInverseEvenOdd_FillType),
|
|
};
|
|
for (auto fill: fills ) {
|
|
SkDebugf("IsInverseFillType(%s) == %s\n", fill.name, SkPath::IsInverseFillType(fill.fill) ?
|
|
"true" : "false");
|
|
}
|
|
}
|
|
#StdOut
|
|
IsInverseFillType(kWinding_FillType) == false
|
|
IsInverseFillType(kEvenOdd_FillType) == false
|
|
IsInverseFillType(kInverseWinding_FillType) == true
|
|
IsInverseFillType(kInverseEvenOdd_FillType) == true
|
|
##
|
|
##
|
|
|
|
#SeeAlso FillType getFillType setFillType ConvertToNonInverseFillType
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method static FillType ConvertToNonInverseFillType(FillType fill)
|
|
#In Utility
|
|
#Line # returns Fill_Type representing inside geometry ##
|
|
Returns equivalent Fill_Type representing Path fill inside its bounds.
|
|
.
|
|
|
|
#Table
|
|
#Legend
|
|
# FillType # inside FillType ##
|
|
##
|
|
# kWinding_FillType # kWinding_FillType ##
|
|
# kEvenOdd_FillType # kEvenOdd_FillType ##
|
|
# kInverseWinding_FillType # kWinding_FillType ##
|
|
# kInverseEvenOdd_FillType # kEvenOdd_FillType ##
|
|
##
|
|
|
|
#Param fill one of: kWinding_FillType, kEvenOdd_FillType,
|
|
kInverseWinding_FillType, kInverseEvenOdd_FillType
|
|
##
|
|
|
|
#Return fill, or kWinding_FillType or kEvenOdd_FillType if fill is inverted ##
|
|
|
|
#Example
|
|
#Function
|
|
###$
|
|
#define nameValue(fill) { SkPath::fill, #fill }
|
|
|
|
$$$#
|
|
##
|
|
void draw(SkCanvas* canvas) {
|
|
struct {
|
|
SkPath::FillType fill;
|
|
const char* name;
|
|
} fills[] = {
|
|
nameValue(kWinding_FillType),
|
|
nameValue(kEvenOdd_FillType),
|
|
nameValue(kInverseWinding_FillType),
|
|
nameValue(kInverseEvenOdd_FillType),
|
|
};
|
|
for (unsigned i = 0; i < SK_ARRAY_COUNT(fills); ++i) {
|
|
if (fills[i].fill != (SkPath::FillType) i) {
|
|
SkDebugf("fills array order does not match FillType enum order");
|
|
break;
|
|
}
|
|
SkDebugf("ConvertToNonInverseFillType(%s) == %s\n", fills[i].name,
|
|
fills[(int) SkPath::ConvertToNonInverseFillType(fills[i].fill)].name);
|
|
}
|
|
}
|
|
#StdOut
|
|
ConvertToNonInverseFillType(kWinding_FillType) == kWinding_FillType
|
|
ConvertToNonInverseFillType(kEvenOdd_FillType) == kEvenOdd_FillType
|
|
ConvertToNonInverseFillType(kInverseWinding_FillType) == kWinding_FillType
|
|
ConvertToNonInverseFillType(kInverseEvenOdd_FillType) == kEvenOdd_FillType
|
|
##
|
|
##
|
|
|
|
#SeeAlso FillType getFillType setFillType IsInverseFillType
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method static int ConvertConicToQuads(const SkPoint& p0, const SkPoint& p1, const SkPoint& p2,
|
|
SkScalar w, SkPoint pts[], int pow2)
|
|
#In Utility
|
|
#Line # approximates Conic with Quad array ##
|
|
|
|
Approximates Conic with Quad array. Conic is constructed from start Point p0,
|
|
control Point p1, end Point p2, and weight w.
|
|
Quad array is stored in pts; this storage is supplied by caller.
|
|
Maximum Quad count is 2 to the pow2.
|
|
Every third point in array shares last Point of previous Quad and first Point of
|
|
next Quad. Maximum pts storage size is given by:
|
|
#Formula
|
|
(1 + 2 * (1 << pow2)) * sizeof(SkPoint)
|
|
##
|
|
.
|
|
|
|
Returns Quad count used the approximation, which may be smaller
|
|
than the number requested.
|
|
|
|
Conic_Weight determines the amount of influence Conic control point has on the curve.
|
|
w less than one represents an elliptical section. w greater than one represents
|
|
a hyperbolic section. w equal to one represents a parabolic section.
|
|
|
|
Two Quad curves are sufficient to approximate an elliptical Conic with a sweep
|
|
of up to 90 degrees; in this case, set pow2 to one.
|
|
|
|
#Param p0 Conic start Point ##
|
|
#Param p1 Conic control Point ##
|
|
#Param p2 Conic end Point ##
|
|
#Param w Conic weight ##
|
|
#Param pts storage for Quad array ##
|
|
#Param pow2 Quad count, as power of two, normally 0 to 5 (1 to 32 Quad curves) ##
|
|
|
|
#Return number of Quad curves written to pts ##
|
|
|
|
#Example
|
|
#Description
|
|
A pair of Quad curves are drawn in red on top of the elliptical Conic curve in black.
|
|
The middle curve is nearly circular. The top-right curve is parabolic, which can
|
|
be drawn exactly with a single Quad.
|
|
##
|
|
void draw(SkCanvas* canvas) {
|
|
SkPaint conicPaint;
|
|
conicPaint.setAntiAlias(true);
|
|
conicPaint.setStyle(SkPaint::kStroke_Style);
|
|
SkPaint quadPaint(conicPaint);
|
|
quadPaint.setColor(SK_ColorRED);
|
|
SkPoint conic[] = { {20, 170}, {80, 170}, {80, 230} };
|
|
for (auto weight : { .25f, .5f, .707f, .85f, 1.f } ) {
|
|
SkPoint quads[5];
|
|
SkPath::ConvertConicToQuads(conic[0], conic[1], conic[2], weight, quads, 1);
|
|
SkPath path;
|
|
path.moveTo(conic[0]);
|
|
path.conicTo(conic[1], conic[2], weight);
|
|
canvas->drawPath(path, conicPaint);
|
|
path.rewind();
|
|
path.moveTo(quads[0]);
|
|
path.quadTo(quads[1], quads[2]);
|
|
path.quadTo(quads[3], quads[4]);
|
|
canvas->drawPath(path, quadPaint);
|
|
canvas->translate(50, -50);
|
|
}
|
|
}
|
|
##
|
|
|
|
#SeeAlso Conic Quad
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method bool isRect(SkRect* rect, bool* isClosed = nullptr, Direction* direction = nullptr) const
|
|
#In Property
|
|
#Line # returns if describes Rect ##
|
|
Returns true if Path is equivalent to Rect when filled.
|
|
If false: rect, isClosed, and direction are unchanged.
|
|
If true: rect, isClosed, and direction are written to if not nullptr.
|
|
|
|
rect may be smaller than the Path bounds. Path bounds may include kMove_Verb points
|
|
that do not alter the area drawn by the returned rect.
|
|
|
|
#Param rect storage for bounds of Rect; may be nullptr ##
|
|
#Param isClosed storage set to true if Path is closed; may be nullptr ##
|
|
#Param direction storage set to Rect direction; may be nullptr ##
|
|
|
|
#Return true if Path contains Rect ##
|
|
|
|
#Example
|
|
#Description
|
|
After addRect, isRect returns true. Following moveTo permits isRect to return true, but
|
|
following lineTo does not. addPoly returns true even though rect is not closed, and one
|
|
side of rect is made up of consecutive line segments.
|
|
##
|
|
void draw(SkCanvas* canvas) {
|
|
auto debugster = [](const char* prefix, const SkPath& path) -> void {
|
|
SkRect rect;
|
|
SkPath::Direction direction;
|
|
bool isClosed;
|
|
path.isRect(&rect, &isClosed, &direction) ?
|
|
SkDebugf("%s is rect (%g, %g, %g, %g); is %s" "closed; direction %s\n", prefix,
|
|
rect.fLeft, rect.fTop, rect.fRight, rect.fBottom, isClosed ? "" : "not ",
|
|
SkPath::kCW_Direction == direction ? "CW" : "CCW") :
|
|
SkDebugf("%s is not rect\n", prefix);
|
|
};
|
|
SkPath path;
|
|
debugster("empty", path);
|
|
path.addRect({10, 20, 30, 40});
|
|
debugster("addRect", path);
|
|
path.moveTo(60, 70);
|
|
debugster("moveTo", path);
|
|
path.lineTo(60, 70);
|
|
debugster("lineTo", path);
|
|
path.reset();
|
|
const SkPoint pts[] = { {0, 0}, {0, 80}, {80, 80}, {80, 0}, {40, 0}, {20, 0} };
|
|
path.addPoly(pts, SK_ARRAY_COUNT(pts), false);
|
|
debugster("addPoly", path);
|
|
}
|
|
#StdOut
|
|
empty is not rect
|
|
addRect is rect (10, 20, 30, 40); is closed; direction CW
|
|
moveTo is rect (10, 20, 30, 40); is closed; direction CW
|
|
lineTo is not rect
|
|
addPoly is rect (0, 0, 80, 80); is not closed; direction CCW
|
|
##
|
|
##
|
|
|
|
#SeeAlso computeTightBounds conservativelyContainsRect getBounds isConvex isLastContourClosed isNestedFillRects
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method bool isNestedFillRects(SkRect rect[2], Direction dirs[2] = nullptr) const
|
|
#In Property
|
|
#Line # returns if describes Rect pair, one inside the other ##
|
|
Returns true if Path is equivalent to nested Rect pair when filled.
|
|
If false, rect and dirs are unchanged.
|
|
If true, rect and dirs are written to if not nullptr:
|
|
setting rect[0] to outer Rect, and rect[1] to inner Rect;
|
|
setting dirs[0] to Direction of outer Rect, and dirs[1] to Direction of inner
|
|
Rect.
|
|
|
|
#Param rect storage for Rect pair; may be nullptr ##
|
|
#Param dirs storage for Direction pair; may be nullptr ##
|
|
|
|
#Return true if Path contains nested Rect pair ##
|
|
|
|
#Example
|
|
void draw(SkCanvas* canvas) {
|
|
SkPaint paint;
|
|
paint.setStyle(SkPaint::kStroke_Style);
|
|
paint.setStrokeWidth(5);
|
|
SkPath path;
|
|
path.addRect({10, 20, 30, 40});
|
|
paint.getFillPath(path, &path);
|
|
SkRect rects[2];
|
|
SkPath::Direction directions[2];
|
|
if (path.isNestedFillRects(rects, directions)) {
|
|
for (int i = 0; i < 2; ++i) {
|
|
SkDebugf("%s (%g, %g, %g, %g); direction %s\n", i ? "inner" : "outer",
|
|
rects[i].fLeft, rects[i].fTop, rects[i].fRight, rects[i].fBottom,
|
|
SkPath::kCW_Direction == directions[i] ? "CW" : "CCW");
|
|
}
|
|
} else {
|
|
SkDebugf("is not nested rectangles\n");
|
|
}
|
|
}
|
|
#StdOut
|
|
outer (7.5, 17.5, 32.5, 42.5); direction CW
|
|
inner (12.5, 22.5, 27.5, 37.5); direction CCW
|
|
##
|
|
##
|
|
|
|
#SeeAlso computeTightBounds conservativelyContainsRect getBounds isConvex isLastContourClosed isRect
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method void addRect(const SkRect& rect, Direction dir = kCW_Direction)
|
|
#In Build
|
|
#Line # adds one Contour containing Rect ##
|
|
Add Rect to Path, appending kMove_Verb, three kLine_Verb, and kClose_Verb,
|
|
starting with top-left corner of Rect; followed by top-right, bottom-right,
|
|
and bottom-left if dir is kCW_Direction; or followed by bottom-left,
|
|
bottom-right, and top-right if dir is kCCW_Direction.
|
|
|
|
#Param rect Rect to add as a closed contour ##
|
|
#Param dir Direction to wind added contour ##
|
|
|
|
#Example
|
|
#Description
|
|
The left Rect dashes starting at the top-left corner, to the right.
|
|
The right Rect dashes starting at the top-left corner, towards the bottom.
|
|
##
|
|
#Height 128
|
|
void draw(SkCanvas* canvas) {
|
|
SkPaint paint;
|
|
paint.setStrokeWidth(15);
|
|
paint.setStrokeCap(SkPaint::kSquare_Cap);
|
|
float intervals[] = { 5, 21.75f };
|
|
paint.setStyle(SkPaint::kStroke_Style);
|
|
paint.setPathEffect(SkDashPathEffect::Make(intervals, SK_ARRAY_COUNT(intervals), 0));
|
|
SkPath path;
|
|
path.addRect({20, 20, 100, 100}, SkPath::kCW_Direction);
|
|
canvas->drawPath(path, paint);
|
|
path.rewind();
|
|
path.addRect({140, 20, 220, 100}, SkPath::kCCW_Direction);
|
|
canvas->drawPath(path, paint);
|
|
}
|
|
##
|
|
|
|
#SeeAlso SkCanvas::drawRect Direction
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method void addRect(const SkRect& rect, Direction dir, unsigned start)
|
|
|
|
Add Rect to Path, appending kMove_Verb, three kLine_Verb, and kClose_Verb.
|
|
If dir is kCW_Direction, Rect corners are added clockwise; if dir is
|
|
kCCW_Direction, Rect corners are added counterclockwise.
|
|
start determines the first corner added.
|
|
|
|
#Table
|
|
#Legend
|
|
# start # first corner ##
|
|
#Legend ##
|
|
# 0 # top-left ##
|
|
# 1 # top-right ##
|
|
# 2 # bottom-right ##
|
|
# 3 # bottom-left ##
|
|
#Table ##
|
|
|
|
#Param rect Rect to add as a closed contour ##
|
|
#Param dir Direction to wind added contour ##
|
|
#Param start initial corner of Rect to add ##
|
|
|
|
#Example
|
|
#Height 128
|
|
#Description
|
|
The arrow is just after the initial corner and points towards the next
|
|
corner appended to Path.
|
|
##
|
|
void draw(SkCanvas* canvas) {
|
|
const SkPoint arrow[] = { {5, -5}, {15, -5}, {20, 0}, {15, 5}, {5, 5}, {10, 0} };
|
|
const SkRect rect = {10, 10, 54, 54};
|
|
SkPaint rectPaint;
|
|
rectPaint.setAntiAlias(true);
|
|
rectPaint.setStyle(SkPaint::kStroke_Style);
|
|
SkPaint arrowPaint(rectPaint);
|
|
SkPath arrowPath;
|
|
arrowPath.addPoly(arrow, SK_ARRAY_COUNT(arrow), true);
|
|
arrowPaint.setPathEffect(SkPath1DPathEffect::Make(arrowPath, 176, 0,
|
|
SkPath1DPathEffect::kRotate_Style));
|
|
for (auto direction : { SkPath::kCW_Direction, SkPath::kCCW_Direction } ) {
|
|
for (unsigned start : { 0, 1, 2, 3 } ) {
|
|
SkPath path;
|
|
path.addRect(rect, direction, start);
|
|
canvas->drawPath(path, rectPaint);
|
|
canvas->drawPath(path, arrowPaint);
|
|
canvas->translate(64, 0);
|
|
}
|
|
canvas->translate(-256, 64);
|
|
}
|
|
}
|
|
##
|
|
|
|
#SeeAlso SkCanvas::drawRect Direction
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method void addRect(SkScalar left, SkScalar top, SkScalar right, SkScalar bottom,
|
|
Direction dir = kCW_Direction)
|
|
|
|
Add Rect (left, top, right, bottom) to Path,
|
|
appending kMove_Verb, three kLine_Verb, and kClose_Verb,
|
|
starting with top-left corner of Rect; followed by top-right, bottom-right,
|
|
and bottom-left if dir is kCW_Direction; or followed by bottom-left,
|
|
bottom-right, and top-right if dir is kCCW_Direction.
|
|
|
|
#Param left smaller x-axis value of Rect ##
|
|
#Param top smaller y-axis value of Rect ##
|
|
#Param right larger x-axis value of Rect ##
|
|
#Param bottom larger y-axis value of Rect ##
|
|
#Param dir Direction to wind added contour ##
|
|
|
|
#Example
|
|
#Description
|
|
The left Rect dashes start at the top-left corner, and continue to the right.
|
|
The right Rect dashes start at the top-left corner, and continue down.
|
|
##
|
|
#Height 128
|
|
void draw(SkCanvas* canvas) {
|
|
SkPaint paint;
|
|
paint.setStrokeWidth(15);
|
|
paint.setStrokeCap(SkPaint::kSquare_Cap);
|
|
float intervals[] = { 5, 21.75f };
|
|
paint.setStyle(SkPaint::kStroke_Style);
|
|
paint.setPathEffect(SkDashPathEffect::Make(intervals, SK_ARRAY_COUNT(intervals), 0));
|
|
for (auto direction : { SkPath::kCW_Direction, SkPath::kCCW_Direction } ) {
|
|
SkPath path;
|
|
path.addRect(20, 20, 100, 100, direction);
|
|
canvas->drawPath(path, paint);
|
|
canvas->translate(128, 0);
|
|
}
|
|
}
|
|
##
|
|
|
|
#SeeAlso SkCanvas::drawRect Direction
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method void addOval(const SkRect& oval, Direction dir = kCW_Direction)
|
|
#In Build
|
|
#Line # adds one Contour containing Oval ##
|
|
Add Oval to path, appending kMove_Verb, four kConic_Verb, and kClose_Verb.
|
|
Oval is upright ellipse bounded by Rect oval with radii equal to half oval width
|
|
and half oval height. Oval begins at (oval.fRight, oval.centerY()) and continues
|
|
clockwise if dir is kCW_Direction, counterclockwise if dir is kCCW_Direction.
|
|
|
|
#Param oval bounds of ellipse added ##
|
|
#Param dir Direction to wind ellipse ##
|
|
|
|
#Example
|
|
#Height 120
|
|
SkPaint paint;
|
|
SkPath oval;
|
|
oval.addOval({20, 20, 160, 80});
|
|
canvas->drawPath(oval, paint);
|
|
##
|
|
|
|
#SeeAlso SkCanvas::drawOval Direction Oval
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method void addOval(const SkRect& oval, Direction dir, unsigned start)
|
|
|
|
Add Oval to Path, appending kMove_Verb, four kConic_Verb, and kClose_Verb.
|
|
Oval is upright ellipse bounded by Rect oval with radii equal to half oval width
|
|
and half oval height. Oval begins at start and continues
|
|
clockwise if dir is kCW_Direction, counterclockwise if dir is kCCW_Direction.
|
|
|
|
#Table
|
|
#Legend
|
|
# start # Point ##
|
|
#Legend ##
|
|
# 0 # oval.centerX(), oval.fTop ##
|
|
# 1 # oval.fRight, oval.centerY() ##
|
|
# 2 # oval.centerX(), oval.fBottom ##
|
|
# 3 # oval.fLeft, oval.centerY() ##
|
|
#Table ##
|
|
|
|
#Param oval bounds of ellipse added ##
|
|
#Param dir Direction to wind ellipse ##
|
|
#Param start index of initial point of ellipse ##
|
|
|
|
#Example
|
|
#Height 160
|
|
void draw(SkCanvas* canvas) {
|
|
const SkPoint arrow[] = { {0, -5}, {10, 0}, {0, 5} };
|
|
const SkRect rect = {10, 10, 54, 54};
|
|
SkPaint ovalPaint;
|
|
ovalPaint.setAntiAlias(true);
|
|
SkPaint textPaint(ovalPaint);
|
|
textPaint.setTextAlign(SkPaint::kCenter_Align);
|
|
ovalPaint.setStyle(SkPaint::kStroke_Style);
|
|
SkPaint arrowPaint(ovalPaint);
|
|
SkPath arrowPath;
|
|
arrowPath.addPoly(arrow, SK_ARRAY_COUNT(arrow), true);
|
|
arrowPaint.setPathEffect(SkPath1DPathEffect::Make(arrowPath, 176, 0,
|
|
SkPath1DPathEffect::kRotate_Style));
|
|
for (auto direction : { SkPath::kCW_Direction, SkPath::kCCW_Direction } ) {
|
|
for (unsigned start : { 0, 1, 2, 3 } ) {
|
|
SkPath path;
|
|
path.addOval(rect, direction, start);
|
|
canvas->drawPath(path, ovalPaint);
|
|
canvas->drawPath(path, arrowPaint);
|
|
canvas->drawText(&"0123"[start], 1, rect.centerX(), rect.centerY() + 5, textPaint);
|
|
canvas->translate(64, 0);
|
|
}
|
|
canvas->translate(-256, 72);
|
|
canvas->drawString(SkPath::kCW_Direction == direction ? "clockwise" : "counterclockwise",
|
|
128, 0, textPaint);
|
|
}
|
|
}
|
|
##
|
|
|
|
#SeeAlso SkCanvas::drawOval Direction Oval
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method void addCircle(SkScalar x, SkScalar y, SkScalar radius,
|
|
Direction dir = kCW_Direction)
|
|
#In Build
|
|
#Line # adds one Contour containing Circle ##
|
|
|
|
Add Circle centered at (x, y) of size radius to Path, appending kMove_Verb,
|
|
four kConic_Verb, and kClose_Verb. Circle begins at:
|
|
#Formula
|
|
(x + radius, y)
|
|
##
|
|
, continuing
|
|
clockwise if dir is kCW_Direction, and counterclockwise if dir is kCCW_Direction.
|
|
|
|
Has no effect if radius is zero or negative.
|
|
|
|
#Param x center of Circle ##
|
|
#Param y center of Circle ##
|
|
#Param radius distance from center to edge ##
|
|
#Param dir Direction to wind Circle ##
|
|
|
|
#Example
|
|
void draw(SkCanvas* canvas) {
|
|
SkPaint paint;
|
|
paint.setAntiAlias(true);
|
|
paint.setStyle(SkPaint::kStroke_Style);
|
|
paint.setStrokeWidth(10);
|
|
for (int size = 10; size < 300; size += 20) {
|
|
SkPath path;
|
|
path.addCircle(128, 128, size, SkPath::kCW_Direction);
|
|
canvas->drawPath(path, paint);
|
|
}
|
|
}
|
|
##
|
|
|
|
#SeeAlso SkCanvas::drawCircle Direction Circle
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method void addArc(const SkRect& oval, SkScalar startAngle, SkScalar sweepAngle)
|
|
#In Build
|
|
#Line # adds one Contour containing Arc ##
|
|
Append Arc to Path, as the start of new Contour. Arc added is part of ellipse
|
|
bounded by oval, from startAngle through sweepAngle. Both startAngle and
|
|
sweepAngle are measured in degrees, where zero degrees is aligned with the
|
|
positive x-axis, and positive sweeps extends Arc clockwise.
|
|
|
|
If sweepAngle <= -360, or sweepAngle >= 360; and startAngle modulo 90 is nearly
|
|
zero, append Oval instead of Arc. Otherwise, sweepAngle values are treated
|
|
modulo 360, and Arc may or may not draw depending on numeric rounding.
|
|
|
|
#Param oval bounds of ellipse containing Arc ##
|
|
#Param startAngle starting angle of Arc in degrees ##
|
|
#Param sweepAngle sweep, in degrees. Positive is clockwise; treated modulo 360 ##
|
|
|
|
#Example
|
|
#Description
|
|
The middle row of the left and right columns draw differently from the entries
|
|
above and below because sweepAngle is outside of the range of +/-360,
|
|
and startAngle modulo 90 is not zero.
|
|
##
|
|
void draw(SkCanvas* canvas) {
|
|
SkPaint paint;
|
|
for (auto start : { 0, 90, 135, 180, 270 } ) {
|
|
for (auto sweep : { -450.f, -180.f, -90.f, 90.f, 180.f, 360.1f } ) {
|
|
SkPath path;
|
|
path.addArc({10, 10, 35, 45}, start, sweep);
|
|
canvas->drawPath(path, paint);
|
|
canvas->translate(252 / 6, 0);
|
|
}
|
|
canvas->translate(-252, 255 / 5);
|
|
}
|
|
}
|
|
##
|
|
|
|
#SeeAlso Arc arcTo SkCanvas::drawArc
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method void addRoundRect(const SkRect& rect, SkScalar rx, SkScalar ry,
|
|
Direction dir = kCW_Direction)
|
|
#In Build
|
|
#Line # adds one Contour containing Round_Rect with common corner radii ##
|
|
|
|
Append Round_Rect to Path, creating a new closed Contour. Round_Rect has bounds
|
|
equal to rect; each corner is 90 degrees of an ellipse with radii (rx, ry). If
|
|
dir is kCW_Direction, Round_Rect starts at top-left of the lower-left corner and
|
|
winds clockwise. If dir is kCCW_Direction, Round_Rect starts at the bottom-left
|
|
of the upper-left corner and winds counterclockwise.
|
|
|
|
If either rx or ry is too large, rx and ry are scaled uniformly until the
|
|
corners fit. If rx or ry is less than or equal to zero, addRoundRect appends
|
|
Rect rect to Path.
|
|
|
|
After appending, Path may be empty, or may contain: Rect, Oval, or RoundRect.
|
|
|
|
#Param rect bounds of Round_Rect ##
|
|
#Param rx x-axis radius of rounded corners on the Round_Rect ##
|
|
#Param ry y-axis radius of rounded corners on the Round_Rect ##
|
|
#Param dir Direction to wind Round_Rect ##
|
|
|
|
#Example
|
|
#Description
|
|
If either radius is zero, path contains Rect and is drawn red.
|
|
If sides are only radii, path contains Oval and is drawn blue.
|
|
All remaining path draws are convex, and are drawn in gray; no
|
|
paths constructed from addRoundRect are concave, so none are
|
|
drawn in green.
|
|
##
|
|
void draw(SkCanvas* canvas) {
|
|
SkPaint paint;
|
|
paint.setAntiAlias(true);
|
|
for (auto xradius : { 0, 7, 13, 20 } ) {
|
|
for (auto yradius : { 0, 9, 18, 40 } ) {
|
|
SkPath path;
|
|
path.addRoundRect({10, 10, 36, 46}, xradius, yradius);
|
|
paint.setColor(path.isRect(nullptr) ? SK_ColorRED : path.isOval(nullptr) ?
|
|
SK_ColorBLUE : path.isConvex() ? SK_ColorGRAY : SK_ColorGREEN);
|
|
canvas->drawPath(path, paint);
|
|
canvas->translate(64, 0);
|
|
}
|
|
canvas->translate(-256, 64);
|
|
}
|
|
}
|
|
##
|
|
|
|
#SeeAlso addRRect SkCanvas::drawRoundRect
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method void addRoundRect(const SkRect& rect, const SkScalar radii[],
|
|
Direction dir = kCW_Direction)
|
|
|
|
Append Round_Rect to Path, creating a new closed Contour. Round_Rect has bounds
|
|
equal to rect; each corner is 90 degrees of an ellipse with radii from the
|
|
array.
|
|
|
|
#Table
|
|
#Legend
|
|
# radii index # location ##
|
|
#Legend ##
|
|
# 0 # x-axis radius of top-left corner ##
|
|
# 1 # y-axis radius of top-left corner ##
|
|
# 2 # x-axis radius of top-right corner ##
|
|
# 3 # y-axis radius of top-right corner ##
|
|
# 4 # x-axis radius of bottom-right corner ##
|
|
# 5 # y-axis radius of bottom-right corner ##
|
|
# 6 # x-axis radius of bottom-left corner ##
|
|
# 7 # y-axis radius of bottom-left corner ##
|
|
#Table ##
|
|
|
|
If dir is kCW_Direction, Round_Rect starts at top-left of the lower-left corner
|
|
and winds clockwise. If dir is kCCW_Direction, Round_Rect starts at the
|
|
bottom-left of the upper-left corner and winds counterclockwise.
|
|
|
|
If both radii on any side of rect exceed its length, all radii are scaled
|
|
uniformly until the corners fit. If either radius of a corner is less than or
|
|
equal to zero, both are treated as zero.
|
|
|
|
After appending, Path may be empty, or may contain: Rect, Oval, or RoundRect.
|
|
|
|
#Param rect bounds of Round_Rect ##
|
|
#Param radii array of 8 SkScalar values, a radius pair for each corner ##
|
|
#Param dir Direction to wind Round_Rect ##
|
|
|
|
#Example
|
|
void draw(SkCanvas* canvas) {
|
|
SkPaint paint;
|
|
paint.setAntiAlias(true);
|
|
SkScalar radii[] = { 80, 100, 0, 0, 40, 60, 0, 0 };
|
|
SkPath path;
|
|
SkMatrix rotate90;
|
|
rotate90.setRotate(90, 128, 128);
|
|
for (int i = 0; i < 4; ++i) {
|
|
path.addRoundRect({10, 10, 110, 110}, radii);
|
|
path.transform(rotate90);
|
|
}
|
|
canvas->drawPath(path, paint);
|
|
}
|
|
##
|
|
|
|
#SeeAlso addRRect SkCanvas::drawRoundRect
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method void addRRect(const SkRRect& rrect, Direction dir = kCW_Direction)
|
|
#In Build
|
|
#Line # adds one Contour containing Round_Rect ##
|
|
Add rrect to Path, creating a new closed Contour. If
|
|
dir is kCW_Direction, rrect starts at top-left of the lower-left corner and
|
|
winds clockwise. If dir is kCCW_Direction, rrect starts at the bottom-left
|
|
of the upper-left corner and winds counterclockwise.
|
|
|
|
After appending, Path may be empty, or may contain: Rect, Oval, or Round_Rect.
|
|
|
|
#Param rrect bounds and radii of rounded rectangle ##
|
|
#Param dir Direction to wind Round_Rect ##
|
|
|
|
#Example
|
|
void draw(SkCanvas* canvas) {
|
|
SkPaint paint;
|
|
paint.setAntiAlias(true);
|
|
SkRRect rrect;
|
|
SkVector radii[] = {{50, 50}, {0, 0}, {0, 0}, {50, 50}};
|
|
rrect.setRectRadii({10, 10, 110, 110}, radii);
|
|
SkPath path;
|
|
SkMatrix rotate90;
|
|
rotate90.setRotate(90, 128, 128);
|
|
for (int i = 0; i < 4; ++i) {
|
|
path.addRRect(rrect);
|
|
path.transform(rotate90);
|
|
}
|
|
canvas->drawPath(path, paint);
|
|
}
|
|
##
|
|
|
|
#SeeAlso addRoundRect SkCanvas::drawRRect
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method void addRRect(const SkRRect& rrect, Direction dir, unsigned start)
|
|
|
|
Add rrect to Path, creating a new closed Contour. If dir is kCW_Direction, rrect
|
|
winds clockwise; if dir is kCCW_Direction, rrect winds counterclockwise.
|
|
start determines the first point of rrect to add.
|
|
|
|
#Table
|
|
#Legend
|
|
# start # location ##
|
|
#Legend ##
|
|
# 0 # right of top-left corner ##
|
|
# 1 # left of top-right corner ##
|
|
# 2 # bottom of top-right corner ##
|
|
# 3 # top of bottom-right corner ##
|
|
# 4 # left of bottom-right corner ##
|
|
# 5 # right of bottom-left corner ##
|
|
# 6 # top of bottom-left corner ##
|
|
# 7 # bottom of top-left corner ##
|
|
#Table ##
|
|
|
|
After appending, Path may be empty, or may contain: Rect, Oval, or Round_Rect.
|
|
|
|
#Param rrect bounds and radii of rounded rectangle ##
|
|
#Param dir Direction to wind Round_Rect ##
|
|
#Param start index of initial point of Round_Rect ##
|
|
|
|
#Example
|
|
void draw(SkCanvas* canvas) {
|
|
SkPaint paint;
|
|
paint.setAntiAlias(true);
|
|
SkRRect rrect;
|
|
rrect.setRectXY({40, 40, 215, 215}, 50, 50);
|
|
SkPath path;
|
|
path.addRRect(rrect);
|
|
canvas->drawPath(path, paint);
|
|
for (int start = 0; start < 8; ++start) {
|
|
SkPath textPath;
|
|
textPath.addRRect(rrect, SkPath::kCW_Direction, start);
|
|
canvas->drawTextOnPathHV(&"01234567"[start], 1, textPath, 0, -5, paint);
|
|
}
|
|
}
|
|
##
|
|
|
|
#SeeAlso addRoundRect SkCanvas::drawRRect
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method void addPoly(const SkPoint pts[], int count, bool close)
|
|
#In Build
|
|
#Line # adds one Contour containing connected lines ##
|
|
Add Contour created from Line array, adding (count - 1) Line segments.
|
|
Contour added starts at pts[0], then adds a line for every additional Point
|
|
in pts array. If close is true,appends kClose_Verb to Path, connecting
|
|
pts[count - 1] and pts[0].
|
|
|
|
If count is zero, append kMove_Verb to path.
|
|
Has no effect if count is less than one.
|
|
|
|
#Param pts array of Line sharing end and start Point ##
|
|
#Param count length of Point array ##
|
|
#Param close true to add Line connecting Contour end and start ##
|
|
|
|
#Example
|
|
void draw(SkCanvas* canvas) {
|
|
SkPaint paint;
|
|
paint.setStrokeWidth(15);
|
|
paint.setStrokeCap(SkPaint::kRound_Cap);
|
|
const SkPoint points[] = {{20, 20}, {70, 20}, {40, 90}};
|
|
for (bool close : { false, true } ) {
|
|
SkPath path;
|
|
path.addPoly(points, SK_ARRAY_COUNT(points), close);
|
|
for (auto style : {SkPaint::kStroke_Style, SkPaint::kFill_Style,
|
|
SkPaint::kStrokeAndFill_Style} ) {
|
|
paint.setStyle(style);
|
|
canvas->drawPath(path, paint);
|
|
canvas->translate(85, 0);
|
|
}
|
|
canvas->translate(-255, 128);
|
|
}
|
|
}
|
|
##
|
|
|
|
#SeeAlso SkCanvas::drawPoints
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Enum AddPathMode
|
|
#Line # sets addPath options ##
|
|
|
|
#Code
|
|
enum AddPathMode {
|
|
kAppend_AddPathMode,
|
|
kExtend_AddPathMode,
|
|
};
|
|
##
|
|
|
|
AddPathMode chooses how addPath appends. Adding one Path to another can extend
|
|
the last Contour or start a new Contour.
|
|
|
|
#Const kAppend_AddPathMode
|
|
#Line # appended to destination unaltered ##
|
|
Path Verbs, Points, and Conic_Weights are appended to destination unaltered.
|
|
Since Path Verb_Array begins with kMove_Verb if src is not empty, this
|
|
starts a new Contour.
|
|
##
|
|
#Const kExtend_AddPathMode
|
|
#Line # add line if prior Contour is not closed ##
|
|
If destination is closed or empty, start a new Contour. If destination
|
|
is not empty, add Line from Last_Point to added Path first Point. Skip added
|
|
Path initial kMove_Verb, then append remining Verbs, Points, and Conic_Weights.
|
|
##
|
|
|
|
#Example
|
|
#Description
|
|
test is built from path, open on the top row, and closed on the bottom row.
|
|
The left column uses kAppend_AddPathMode; the right uses kExtend_AddPathMode.
|
|
The top right composition is made up of one contour; the other three have two.
|
|
##
|
|
#Height 180
|
|
SkPath path, path2;
|
|
path.moveTo(20, 20);
|
|
path.lineTo(20, 40);
|
|
path.lineTo(40, 20);
|
|
path2.moveTo(60, 60);
|
|
path2.lineTo(80, 60);
|
|
path2.lineTo(80, 40);
|
|
SkPaint paint;
|
|
paint.setStyle(SkPaint::kStroke_Style);
|
|
for (int i = 0; i < 2; i++) {
|
|
for (auto addPathMode : { SkPath::kAppend_AddPathMode, SkPath::kExtend_AddPathMode } ) {
|
|
SkPath test(path);
|
|
test.addPath(path2, addPathMode);
|
|
canvas->drawPath(test, paint);
|
|
canvas->translate(100, 0);
|
|
}
|
|
canvas->translate(-200, 100);
|
|
path.close();
|
|
}
|
|
##
|
|
|
|
#SeeAlso addPath reverseAddPath
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method void addPath(const SkPath& src, SkScalar dx, SkScalar dy,
|
|
AddPathMode mode = kAppend_AddPathMode)
|
|
#In Build
|
|
#Line # adds contents of Path ##
|
|
|
|
Append src to Path, offset by (dx, dy).
|
|
|
|
If mode is kAppend_AddPathMode, src Verb_Array, Point_Array, and Conic_Weights are
|
|
added unaltered. If mode is kExtend_AddPathMode, add Line before appending
|
|
Verbs, Points, and Conic_Weights.
|
|
|
|
#Param src Path Verbs, Points, and Conic_Weights to add ##
|
|
#Param dx offset added to src Point_Array x-axis coordinates ##
|
|
#Param dy offset added to src Point_Array y-axis coordinates ##
|
|
#Param mode kAppend_AddPathMode or kExtend_AddPathMode ##
|
|
|
|
#Example
|
|
#Height 180
|
|
SkPaint paint;
|
|
paint.setTextSize(128);
|
|
paint.setFakeBoldText(true);
|
|
SkPath dest, text;
|
|
paint.getTextPath("O", 1, 50, 120, &text);
|
|
for (int i = 0; i < 3; i++) {
|
|
dest.addPath(text, i * 20, i * 20);
|
|
}
|
|
Simplify(dest, &dest);
|
|
paint.setStyle(SkPaint::kStroke_Style);
|
|
paint.setStrokeWidth(3);
|
|
canvas->drawPath(dest, paint);
|
|
##
|
|
|
|
#SeeAlso AddPathMode offset reverseAddPath
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method void addPath(const SkPath& src, AddPathMode mode = kAppend_AddPathMode)
|
|
|
|
Append src to Path.
|
|
|
|
If mode is kAppend_AddPathMode, src Verb_Array, Point_Array, and Conic_Weights are
|
|
added unaltered. If mode is kExtend_AddPathMode, add Line before appending
|
|
Verbs, Points, and Conic_Weights.
|
|
|
|
#Param src Path Verbs, Points, and Conic_Weights to add ##
|
|
#Param mode kAppend_AddPathMode or kExtend_AddPathMode ##
|
|
|
|
#Example
|
|
#Height 80
|
|
SkPaint paint;
|
|
paint.setStyle(SkPaint::kStroke_Style);
|
|
SkPath dest, path;
|
|
path.addOval({-80, 20, 0, 60}, SkPath::kCW_Direction, 1);
|
|
for (int i = 0; i < 2; i++) {
|
|
dest.addPath(path, SkPath::kExtend_AddPathMode);
|
|
dest.offset(100, 0);
|
|
}
|
|
canvas->drawPath(dest, paint);
|
|
##
|
|
|
|
#SeeAlso AddPathMode reverseAddPath
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method void addPath(const SkPath& src, const SkMatrix& matrix, AddPathMode mode = kAppend_AddPathMode)
|
|
|
|
Append src to Path, transformed by matrix. Transformed curves may have different
|
|
Verbs, Points, and Conic_Weights.
|
|
|
|
If mode is kAppend_AddPathMode, src Verb_Array, Point_Array, and Conic_Weights are
|
|
added unaltered. If mode is kExtend_AddPathMode, add Line before appending
|
|
Verbs, Points, and Conic_Weights.
|
|
|
|
#Param src Path Verbs, Points, and Conic_Weights to add ##
|
|
#Param matrix transform applied to src ##
|
|
#Param mode kAppend_AddPathMode or kExtend_AddPathMode ##
|
|
|
|
#Example
|
|
#Height 160
|
|
SkPaint paint;
|
|
paint.setStyle(SkPaint::kStroke_Style);
|
|
SkPath dest, path;
|
|
path.addOval({20, 20, 200, 120}, SkPath::kCW_Direction, 1);
|
|
for (int i = 0; i < 6; i++) {
|
|
SkMatrix matrix;
|
|
matrix.reset();
|
|
matrix.setPerspX(i / 400.f);
|
|
dest.addPath(path, matrix);
|
|
}
|
|
canvas->drawPath(dest, paint);
|
|
##
|
|
|
|
#SeeAlso AddPathMode transform offset reverseAddPath
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method void reverseAddPath(const SkPath& src)
|
|
#In Build
|
|
#Line # adds contents of Path back to front ##
|
|
Append src to Path, from back to front.
|
|
Reversed src always appends a new Contour to Path.
|
|
|
|
#Param src Path Verbs, Points, and Conic_Weights to add ##
|
|
|
|
#Example
|
|
#Height 200
|
|
SkPath path;
|
|
path.moveTo(20, 20);
|
|
path.lineTo(20, 40);
|
|
path.lineTo(40, 20);
|
|
SkPaint paint;
|
|
paint.setStyle(SkPaint::kStroke_Style);
|
|
for (int i = 0; i < 2; i++) {
|
|
SkPath path2;
|
|
path2.moveTo(60, 60);
|
|
path2.lineTo(80, 60);
|
|
path2.lineTo(80, 40);
|
|
for (int j = 0; j < 2; j++) {
|
|
SkPath test(path);
|
|
test.reverseAddPath(path2);
|
|
canvas->drawPath(test, paint);
|
|
canvas->translate(100, 0);
|
|
path2.close();
|
|
}
|
|
canvas->translate(-200, 100);
|
|
path.close();
|
|
}
|
|
##
|
|
|
|
#SeeAlso AddPathMode transform offset addPath
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method void offset(SkScalar dx, SkScalar dy, SkPath* dst) const
|
|
#In Transform
|
|
#Line # translates Point_Array ##
|
|
Offset Point_Array by (dx, dy). Offset Path replaces dst.
|
|
If dst is nullptr, Path is replaced by offset data.
|
|
|
|
#Param dx offset added to Point_Array x-axis coordinates ##
|
|
#Param dy offset added to Point_Array y-axis coordinates ##
|
|
#Param dst overwritten, translated copy of Path; may be nullptr ##
|
|
|
|
#Example
|
|
#Height 60
|
|
SkPath pattern;
|
|
pattern.moveTo(20, 20);
|
|
pattern.lineTo(20, 40);
|
|
pattern.lineTo(40, 20);
|
|
SkPaint paint;
|
|
paint.setStyle(SkPaint::kStroke_Style);
|
|
for (int i = 0; i < 10; i++) {
|
|
SkPath path;
|
|
pattern.offset(20 * i, 0, &path);
|
|
canvas->drawPath(path, paint);
|
|
}
|
|
##
|
|
|
|
#SeeAlso addPath transform
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
#Subtopic Transform
|
|
#Populate
|
|
#Line # modify all points ##
|
|
##
|
|
|
|
#Method void offset(SkScalar dx, SkScalar dy)
|
|
#In Transform
|
|
Offset Point_Array by (dx, dy). Path is replaced by offset data.
|
|
|
|
#Param dx offset added to Point_Array x-axis coordinates ##
|
|
#Param dy offset added to Point_Array y-axis coordinates ##
|
|
|
|
#Example
|
|
#Height 60
|
|
SkPath path;
|
|
path.moveTo(20, 20);
|
|
path.lineTo(20, 40);
|
|
path.lineTo(40, 20);
|
|
SkPaint paint;
|
|
paint.setStyle(SkPaint::kStroke_Style);
|
|
for (int i = 0; i < 10; i++) {
|
|
canvas->drawPath(path, paint);
|
|
path.offset(20, 0);
|
|
}
|
|
##
|
|
|
|
#SeeAlso addPath transform SkCanvas::translate()
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method void transform(const SkMatrix& matrix, SkPath* dst) const
|
|
#In Transform
|
|
#Line # applies Matrix to Point_Array and Weights ##
|
|
Transform Verb_Array, Point_Array, and weight by matrix.
|
|
transform may change Verbs and increase their number.
|
|
Transformed Path replaces dst; if dst is nullptr, original data
|
|
is replaced.
|
|
|
|
#Param matrix Matrix to apply to Path ##
|
|
#Param dst overwritten, transformed copy of Path; may be nullptr ##
|
|
|
|
#Example
|
|
#Height 200
|
|
SkPath pattern;
|
|
pattern.moveTo(100, 100);
|
|
pattern.lineTo(100, 20);
|
|
pattern.lineTo(20, 100);
|
|
SkPaint paint;
|
|
paint.setStyle(SkPaint::kStroke_Style);
|
|
for (int i = 0; i < 10; i++) {
|
|
SkPath path;
|
|
SkMatrix matrix;
|
|
matrix.setRotate(36 * i, 100, 100);
|
|
pattern.transform(matrix, &path);
|
|
canvas->drawPath(path, paint);
|
|
}
|
|
##
|
|
|
|
#SeeAlso addPath offset SkCanvas::concat() SkMatrix
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method void transform(const SkMatrix& matrix)
|
|
|
|
Transform Verb_Array, Point_Array, and weight by matrix.
|
|
transform may change Verbs and increase their number.
|
|
Path is replaced by transformed data.
|
|
|
|
#Param matrix Matrix to apply to Path ##
|
|
|
|
#Example
|
|
#Height 200
|
|
SkPath path;
|
|
path.moveTo(100, 100);
|
|
path.quadTo(100, 20, 20, 100);
|
|
SkPaint paint;
|
|
paint.setStyle(SkPaint::kStroke_Style);
|
|
for (int i = 0; i < 10; i++) {
|
|
SkMatrix matrix;
|
|
matrix.setRotate(36, 100, 100);
|
|
path.transform(matrix);
|
|
canvas->drawPath(path, paint);
|
|
}
|
|
##
|
|
|
|
#SeeAlso addPath offset SkCanvas::concat() SkMatrix
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Subtopic Last_Point
|
|
#Line # final Point in Contour ##
|
|
|
|
Path is defined cumulatively, often by adding a segment to the end of last
|
|
Contour. Last_Point of Contour is shared as first Point of added Line or Curve.
|
|
Last_Point can be read and written directly with getLastPt and setLastPt.
|
|
|
|
#Method bool getLastPt(SkPoint* lastPt) const
|
|
#In Property
|
|
#In Last_Point
|
|
#Line # returns Last_Point ##
|
|
Returns Last_Point on Path in lastPt. Returns false if Point_Array is empty,
|
|
storing (0, 0) if lastPt is not nullptr.
|
|
|
|
#Param lastPt storage for final Point in Point_Array; may be nullptr ##
|
|
|
|
#Return true if Point_Array contains one or more Points ##
|
|
|
|
#Example
|
|
SkPath path;
|
|
path.moveTo(100, 100);
|
|
path.quadTo(100, 20, 20, 100);
|
|
SkMatrix matrix;
|
|
matrix.setRotate(36, 100, 100);
|
|
path.transform(matrix);
|
|
SkPoint last;
|
|
path.getLastPt(&last);
|
|
SkDebugf("last point: %g, %g\n", last.fX, last.fY);
|
|
#StdOut
|
|
last point: 35.2786, 52.9772
|
|
##
|
|
##
|
|
|
|
#SeeAlso setLastPt
|
|
|
|
##
|
|
|
|
#Method void setLastPt(SkScalar x, SkScalar y)
|
|
#In Utility
|
|
#In Last_Point
|
|
#Line # replaces Last_Point ##
|
|
Set Last_Point to (x, y). If Point_Array is empty, append kMove_Verb to
|
|
Verb_Array and append (x, y) to Point_Array.
|
|
|
|
#Param x set x-axis value of Last_Point ##
|
|
#Param y set y-axis value of Last_Point ##
|
|
|
|
#Example
|
|
#Height 128
|
|
SkPaint paint;
|
|
paint.setTextSize(128);
|
|
SkPath path;
|
|
paint.getTextPath("@", 1, 60, 100, &path);
|
|
path.setLastPt(20, 120);
|
|
canvas->drawPath(path, paint);
|
|
##
|
|
|
|
#SeeAlso getLastPt
|
|
|
|
##
|
|
|
|
#Method void setLastPt(const SkPoint& p)
|
|
|
|
Set the last point on the path. If Point_Array is empty, append kMove_Verb to
|
|
Verb_Array and append p to Point_Array.
|
|
|
|
#Param p set value of Last_Point ##
|
|
|
|
#Example
|
|
#Height 128
|
|
SkPaint paint;
|
|
paint.setTextSize(128);
|
|
SkPath path, path2;
|
|
paint.getTextPath("A", 1, 60, 100, &path);
|
|
paint.getTextPath("Z", 1, 60, 100, &path2);
|
|
SkPoint pt, pt2;
|
|
path.getLastPt(&pt);
|
|
path2.getLastPt(&pt2);
|
|
path.setLastPt(pt2);
|
|
path2.setLastPt(pt);
|
|
canvas->drawPath(path, paint);
|
|
canvas->drawPath(path2, paint);
|
|
##
|
|
|
|
#SeeAlso getLastPt
|
|
|
|
##
|
|
|
|
#Subtopic Last_Point ##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Enum SegmentMask
|
|
#Line # returns Verb types in Path ##
|
|
|
|
#Code
|
|
enum SegmentMask {
|
|
kLine_SegmentMask = 1 << 0,
|
|
kQuad_SegmentMask = 1 << 1,
|
|
kConic_SegmentMask = 1 << 2,
|
|
kCubic_SegmentMask = 1 << 3,
|
|
};
|
|
##
|
|
|
|
SegmentMask constants correspond to each drawing Verb type in Path; for
|
|
instance, if Path only contains Lines, only the kLine_SegmentMask bit is set.
|
|
|
|
#Bug 6785
|
|
#Const kLine_SegmentMask 1
|
|
#Line # contains one or more Lines ##
|
|
Set if Verb_Array contains kLine_Verb.
|
|
##
|
|
#Const kQuad_SegmentMask 2
|
|
#Line # contains one or more Quads ##
|
|
Set if Verb_Array contains kQuad_Verb. Note that conicTo may add a Quad.
|
|
##
|
|
#Const kConic_SegmentMask 4
|
|
#Line # contains one or more Conics ##
|
|
Set if Verb_Array contains kConic_Verb.
|
|
##
|
|
#Const kCubic_SegmentMask 8
|
|
#Line # contains one or more Cubics ##
|
|
Set if Verb_Array contains kCubic_Verb.
|
|
##
|
|
|
|
#Example
|
|
#Description
|
|
When conicTo has a weight of one, Quad is added to Path.
|
|
##
|
|
SkPath path;
|
|
path.conicTo(10, 10, 20, 30, 1);
|
|
SkDebugf("Path kConic_SegmentMask is %s\n", path.getSegmentMasks() &
|
|
SkPath::kConic_SegmentMask ? "set" : "clear");
|
|
SkDebugf("Path kQuad_SegmentMask is %s\n", path.getSegmentMasks() &
|
|
SkPath::kQuad_SegmentMask ? "set" : "clear");
|
|
#StdOut
|
|
Path kConic_SegmentMask is clear
|
|
Path kQuad_SegmentMask is set
|
|
##
|
|
##
|
|
|
|
#SeeAlso getSegmentMasks Verb
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method uint32_t getSegmentMasks() const
|
|
#In Utility
|
|
#In Property
|
|
#Line # returns types in Verb_Array ##
|
|
Returns a mask, where each set bit corresponds to a SegmentMask constant
|
|
if Path contains one or more Verbs of that type.
|
|
Returns zero if Path contains no Lines, or Curves: Quads, Conics, or Cubics.
|
|
|
|
getSegmentMasks() returns a cached result; it is very fast.
|
|
|
|
#Return SegmentMask bits or zero ##
|
|
|
|
#Example
|
|
SkPath path;
|
|
path.quadTo(20, 30, 40, 50);
|
|
path.close();
|
|
const char* masks[] = { "line", "quad", "conic", "cubic" };
|
|
int index = 0;
|
|
for (auto mask : { SkPath::kLine_SegmentMask, SkPath::kQuad_SegmentMask,
|
|
SkPath::kConic_SegmentMask, SkPath::kCubic_SegmentMask } ) {
|
|
if (mask & path.getSegmentMasks()) {
|
|
SkDebugf("mask %s set\n", masks[index]);
|
|
}
|
|
++index;
|
|
}
|
|
#StdOut
|
|
mask quad set
|
|
##
|
|
##
|
|
|
|
#SeeAlso getSegmentMasks Verb
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method bool contains(SkScalar x, SkScalar y) const
|
|
#In Property
|
|
#Line # returns if Point is in fill area ##
|
|
Returns true if the point (x, y) is contained by Path, taking into
|
|
account FillType.
|
|
|
|
#Table
|
|
#Legend
|
|
# FillType # contains() returns true if Point is enclosed by ##
|
|
##
|
|
# kWinding_FillType # a non-zero sum of Contour Directions. ##
|
|
# kEvenOdd_FillType # an odd number of Contours. ##
|
|
# kInverseWinding_FillType # a zero sum of Contour Directions. ##
|
|
# kInverseEvenOdd_FillType # and even number of Contours. ##
|
|
##
|
|
|
|
#Param x x-axis value of containment test ##
|
|
#Param y y-axis value of containment test ##
|
|
|
|
#Return true if Point is in Path ##
|
|
|
|
#Example
|
|
SkPath path;
|
|
SkPaint paint;
|
|
paint.setTextSize(256);
|
|
paint.getTextPath("&", 1, 30, 220, &path);
|
|
for (int y = 2; y < 256; y += 9) {
|
|
for (int x = 2; x < 256; x += 9) {
|
|
int coverage = 0;
|
|
for (int iy = -4; iy <= 4; iy += 2) {
|
|
for (int ix = -4; ix <= 4; ix += 2) {
|
|
coverage += path.contains(x + ix, y + iy);
|
|
}
|
|
}
|
|
paint.setColor(SkColorSetARGB(0x5f, 0xff * coverage / 25, 0, 0xff * (25 - coverage) / 25));
|
|
canvas->drawCircle(x, y, 8, paint);
|
|
}
|
|
}
|
|
##
|
|
|
|
#SeeAlso conservativelyContainsRect Fill_Type Op
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method void dump(SkWStream* stream, bool forceClose, bool dumpAsHex) const
|
|
#In Utility
|
|
#Line # sends text representation using floats to standard output ##
|
|
Writes text representation of Path to stream. If stream is nullptr, writes to
|
|
standard output. Set forceClose to true to get edges used to fill Path.
|
|
Set dumpAsHex true to generate exact binary representations
|
|
of floating point numbers used in Point_Array and Conic_Weights.
|
|
|
|
#Param stream writable WStream receiving Path text representation; may be nullptr ##
|
|
#Param forceClose true if missing kClose_Verb is output ##
|
|
#Param dumpAsHex true if SkScalar values are written as hexadecimal ##
|
|
|
|
#Example
|
|
SkPath path;
|
|
path.quadTo(20, 30, 40, 50);
|
|
for (bool forceClose : { false, true } ) {
|
|
for (bool dumpAsHex : { false, true } ) {
|
|
path.dump(nullptr, forceClose, dumpAsHex);
|
|
SkDebugf("\n");
|
|
}
|
|
}
|
|
#StdOut
|
|
path.setFillType(SkPath::kWinding_FillType);
|
|
path.moveTo(0, 0);
|
|
path.quadTo(20, 30, 40, 50);
|
|
|
|
path.setFillType(SkPath::kWinding_FillType);
|
|
path.moveTo(SkBits2Float(0x00000000), SkBits2Float(0x00000000)); // 0, 0
|
|
path.quadTo(SkBits2Float(0x41a00000), SkBits2Float(0x41f00000), SkBits2Float(0x42200000), SkBits2Float(0x42480000)); // 20, 30, 40, 50
|
|
|
|
path.setFillType(SkPath::kWinding_FillType);
|
|
path.moveTo(0, 0);
|
|
path.quadTo(20, 30, 40, 50);
|
|
path.lineTo(0, 0);
|
|
path.close();
|
|
|
|
path.setFillType(SkPath::kWinding_FillType);
|
|
path.moveTo(SkBits2Float(0x00000000), SkBits2Float(0x00000000)); // 0, 0
|
|
path.quadTo(SkBits2Float(0x41a00000), SkBits2Float(0x41f00000), SkBits2Float(0x42200000), SkBits2Float(0x42480000)); // 20, 30, 40, 50
|
|
path.lineTo(SkBits2Float(0x00000000), SkBits2Float(0x00000000)); // 0, 0
|
|
path.close();
|
|
##
|
|
##
|
|
|
|
#SeeAlso SkRect::dump() SkRRect::dump() SkPathMeasure::dump()
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method void dump() const
|
|
|
|
Writes text representation of Path to standard output. The representation may be
|
|
directly compiled as C++ code. Floating point values are written
|
|
with limited precision; it may not be possible to reconstruct original Path
|
|
from output.
|
|
|
|
#Example
|
|
SkPath path, copy;
|
|
path.lineTo(6.f / 7, 2.f / 3);
|
|
path.dump();
|
|
copy.setFillType(SkPath::kWinding_FillType);
|
|
copy.moveTo(0, 0);
|
|
copy.lineTo(0.857143f, 0.666667f);
|
|
SkDebugf("path is " "%s" "equal to copy\n", path == copy ? "" : "not ");
|
|
#StdOut
|
|
path.setFillType(SkPath::kWinding_FillType);
|
|
path.moveTo(0, 0);
|
|
path.lineTo(0.857143f, 0.666667f);
|
|
path is not equal to copy
|
|
##
|
|
##
|
|
|
|
#SeeAlso dumpHex SkRect::dump() SkRRect::dump() SkPathMeasure::dump() writeToMemory
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method void dumpHex() const
|
|
#In Utility
|
|
#Line # sends text representation using hexadecimal to standard output ##
|
|
Writes text representation of Path to standard output. The representation may be
|
|
directly compiled as C++ code. Floating point values are written
|
|
in hexadecimal to preserve their exact bit pattern. The output reconstructs the
|
|
original Path.
|
|
|
|
Use instead of dump() when submitting
|
|
#A bug reports against Skia # https://bug.skia.org ##
|
|
.
|
|
|
|
#Example
|
|
SkPath path, copy;
|
|
path.lineTo(6.f / 7, 2.f / 3);
|
|
path.dumpHex();
|
|
copy.setFillType(SkPath::kWinding_FillType);
|
|
copy.moveTo(SkBits2Float(0x00000000), SkBits2Float(0x00000000)); // 0, 0
|
|
copy.lineTo(SkBits2Float(0x3f5b6db7), SkBits2Float(0x3f2aaaab)); // 0.857143f, 0.666667f
|
|
SkDebugf("path is " "%s" "equal to copy\n", path == copy ? "" : "not ");
|
|
#StdOut
|
|
path.setFillType(SkPath::kWinding_FillType);
|
|
path.moveTo(SkBits2Float(0x00000000), SkBits2Float(0x00000000)); // 0, 0
|
|
path.lineTo(SkBits2Float(0x3f5b6db7), SkBits2Float(0x3f2aaaab)); // 0.857143f, 0.666667f
|
|
path is equal to copy
|
|
##
|
|
##
|
|
|
|
#SeeAlso dump SkRect::dumpHex SkRRect::dumpHex writeToMemory
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method size_t writeToMemory(void* buffer) const
|
|
#In Utility
|
|
#Line # copies data to buffer ##
|
|
Writes Path to buffer, returning the number of bytes written.
|
|
Pass nullptr to obtain the storage size.
|
|
|
|
Writes Fill_Type, Verb_Array, Point_Array, Conic_Weight, and
|
|
additionally writes computed information like Convexity and bounds.
|
|
|
|
Use only be used in concert with readFromMemory;
|
|
the format used for Path in memory is not guaranteed.
|
|
|
|
#Param buffer storage for Path; may be nullptr ##
|
|
|
|
#Return size of storage required for Path; always a multiple of 4 ##
|
|
|
|
#Example
|
|
void draw(SkCanvas* canvas) {
|
|
SkPath path, copy;
|
|
path.lineTo(6.f / 7, 2.f / 3);
|
|
size_t size = path.writeToMemory(nullptr);
|
|
SkTDArray<char> storage;
|
|
storage.setCount(size);
|
|
path.writeToMemory(storage.begin());
|
|
copy.readFromMemory(storage.begin(), size);
|
|
SkDebugf("path is " "%s" "equal to copy\n", path == copy ? "" : "not ");
|
|
}
|
|
#StdOut
|
|
path is equal to copy
|
|
##
|
|
##
|
|
|
|
#SeeAlso serialize readFromMemory dump dumpHex
|
|
|
|
##
|
|
|
|
#Method sk_sp<SkData> serialize() const
|
|
#In Utility
|
|
#Line # copies data to buffer ##
|
|
Write Path to buffer, returning the buffer written to, wrapped in Data.
|
|
|
|
serialize() writes Fill_Type, Verb_Array, Point_Array, Conic_Weight, and
|
|
additionally writes computed information like Convexity and bounds.
|
|
|
|
serialize() should only be used in concert with readFromMemory.
|
|
The format used for Path in memory is not guaranteed.
|
|
|
|
#Return Path data wrapped in Data buffer ##
|
|
|
|
#Example
|
|
void draw(SkCanvas* canvas) {
|
|
SkPath path, copy;
|
|
path.lineTo(6.f / 7, 2.f / 3);
|
|
sk_sp<SkData> data = path.serialize();
|
|
copy.readFromMemory(data->data(), data->size());
|
|
SkDebugf("path is " "%s" "equal to copy\n", path == copy ? "" : "not ");
|
|
}
|
|
#StdOut
|
|
path is equal to copy
|
|
##
|
|
##
|
|
|
|
#SeeAlso writeToMemory readFromMemory dump dumpHex
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method size_t readFromMemory(const void* buffer, size_t length)
|
|
#In Utility
|
|
#Line # initializes from buffer ##
|
|
Initializes Path from buffer of size length. Returns zero if the buffer is
|
|
data is inconsistent, or the length is too small.
|
|
|
|
Reads Fill_Type, Verb_Array, Point_Array, Conic_Weight, and
|
|
additionally reads computed information like Convexity and bounds.
|
|
|
|
Used only in concert with writeToMemory;
|
|
the format used for Path in memory is not guaranteed.
|
|
|
|
#Param buffer storage for Path ##
|
|
#Param length buffer size in bytes; must be multiple of 4 ##
|
|
|
|
#Return number of bytes read, or zero on failure ##
|
|
|
|
#Example
|
|
void draw(SkCanvas* canvas) {
|
|
SkPath path, copy;
|
|
path.lineTo(6.f / 7, 2.f / 3);
|
|
size_t size = path.writeToMemory(nullptr);
|
|
SkTDArray<char> storage;
|
|
storage.setCount(size);
|
|
path.writeToMemory(storage.begin());
|
|
size_t wrongSize = size - 4;
|
|
size_t bytesRead = copy.readFromMemory(storage.begin(), wrongSize);
|
|
SkDebugf("length = %u; returned by readFromMemory = %u\n", wrongSize, bytesRead);
|
|
size_t largerSize = size + 4;
|
|
bytesRead = copy.readFromMemory(storage.begin(), largerSize);
|
|
SkDebugf("length = %u; returned by readFromMemory = %u\n", largerSize, bytesRead);
|
|
}
|
|
#StdOut
|
|
length = 32; returned by readFromMemory = 0
|
|
length = 40; returned by readFromMemory = 36
|
|
##
|
|
##
|
|
|
|
#SeeAlso writeToMemory
|
|
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
#Subtopic Generation_ID
|
|
#Alias Generation_IDs ##
|
|
#Line # value reflecting contents change ##
|
|
Generation_ID provides a quick way to check if Verb_Array, Point_Array, or
|
|
Conic_Weight has changed. Generation_ID is not a hash; identical Paths will
|
|
not necessarily have matching Generation_IDs.
|
|
|
|
Empty Paths have a Generation_ID of one.
|
|
|
|
#Method uint32_t getGenerationID() const
|
|
|
|
#In Generation_ID
|
|
#Line # returns unique ID ##
|
|
Returns a non-zero, globally unique value. A different value is returned
|
|
if Verb_Array, Point_Array, or Conic_Weight changes.
|
|
|
|
Setting Fill_Type does not change Generation_ID.
|
|
|
|
Each time the path is modified, a different Generation_ID will be returned.
|
|
|
|
#Bug 1762
|
|
Fill_Type does affect Generation_ID on Android framework.
|
|
|
|
#Return non-zero, globally unique value ##
|
|
|
|
#Example
|
|
SkPath path;
|
|
SkDebugf("empty genID = %u\n", path.getGenerationID());
|
|
path.lineTo(1, 2);
|
|
SkDebugf("1st lineTo genID = %u\n", path.getGenerationID());
|
|
path.rewind();
|
|
SkDebugf("empty genID = %u\n", path.getGenerationID());
|
|
path.lineTo(1, 2);
|
|
SkDebugf("2nd lineTo genID = %u\n", path.getGenerationID());
|
|
#StdOut
|
|
empty genID = 1
|
|
1st lineTo genID = 2
|
|
empty genID = 1
|
|
2nd lineTo genID = 3
|
|
##
|
|
##
|
|
|
|
#SeeAlso operator==(const SkPath& a, const SkPath& b)
|
|
|
|
##
|
|
|
|
#Subtopic ##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Method bool isValid() const
|
|
#In Property
|
|
#In Utility
|
|
#Line # returns if data is internally consistent ##
|
|
Returns if Path data is consistent. Corrupt Path data is detected if
|
|
internal values are out of range or internal storage does not match
|
|
array dimensions.
|
|
|
|
#Return true if Path data is consistent ##
|
|
|
|
#NoExample
|
|
##
|
|
|
|
##
|
|
|
|
#Method bool pathRefIsValid() const
|
|
#Deprecated soon
|
|
##
|
|
|
|
# ------------------------------------------------------------------------------
|
|
|
|
#Class Iter
|
|
#Line # data iterator ##
|
|
|
|
#Code
|
|
class Iter {
|
|
public:
|
|
Iter();
|
|
Iter(const SkPath& path, bool forceClose);
|
|
void setPath(const SkPath& path, bool forceClose);
|
|
Verb next(SkPoint pts[4], bool doConsumeDegenerates = true, bool exact = false);
|
|
SkScalar conicWeight() const;
|
|
bool isCloseLine() const;
|
|
bool isClosedContour() const;
|
|
};
|
|
##
|
|
|
|
Iterates through Verb_Array, and associated Point_Array and Conic_Weight.
|
|
Provides options to treat open Contours as closed, and to ignore
|
|
degenerate data.
|
|
|
|
#Example
|
|
#Height 128
|
|
#Description
|
|
Ignoring the actual Verbs and replacing them with Quads rounds the
|
|
path of the glyph.
|
|
##
|
|
void draw(SkCanvas* canvas) {
|
|
SkPaint paint;
|
|
paint.setAntiAlias(true);
|
|
paint.setTextSize(256);
|
|
SkPath asterisk, path;
|
|
paint.getTextPath("*", 1, 50, 192, &asterisk);
|
|
SkPath::Iter iter(asterisk, true);
|
|
SkPoint start[4], pts[4];
|
|
iter.next(start); // skip moveTo
|
|
iter.next(start); // first quadTo
|
|
path.moveTo((start[0] + start[1]) * 0.5f);
|
|
while (SkPath::kClose_Verb != iter.next(pts)) {
|
|
path.quadTo(pts[0], (pts[0] + pts[1]) * 0.5f);
|
|
}
|
|
path.quadTo(start[0], (start[0] + start[1]) * 0.5f);
|
|
canvas->drawPath(path, paint);
|
|
}
|
|
##
|
|
|
|
#SeeAlso RawIter
|
|
|
|
#Method Iter()
|
|
#Line # constructs Path iterator ##
|
|
Initializes Iter with an empty Path. next() on Iter returns kDone_Verb.
|
|
Call setPath to initialize Iter at a later time.
|
|
|
|
#Return Iter of empty Path ##
|
|
|
|
#Example
|
|
void draw(SkCanvas* canvas) {
|
|
SkPath::Iter iter;
|
|
SkPoint points[4];
|
|
SkDebugf("iter is " "%s" "done\n", SkPath::kDone_Verb == iter.next(points) ? "" : "not ");
|
|
SkPath path;
|
|
iter.setPath(path, false);
|
|
SkDebugf("iter is " "%s" "done\n", SkPath::kDone_Verb == iter.next(points) ? "" : "not ");
|
|
}
|
|
#StdOut
|
|
iter is done
|
|
iter is done
|
|
##
|
|
##
|
|
|
|
#SeeAlso setPath
|
|
|
|
##
|
|
|
|
#Method Iter(const SkPath& path, bool forceClose)
|
|
|
|
Sets Iter to return elements of Verb_Array, Point_Array, and Conic_Weight in path.
|
|
If forceClose is true, Iter will add kLine_Verb and kClose_Verb after each
|
|
open Contour. path is not altered.
|
|
|
|
#Param path Path to iterate ##
|
|
#Param forceClose true if open Contours generate kClose_Verb ##
|
|
|
|
#Return Iter of path ##
|
|
|
|
#Example
|
|
void draw(SkCanvas* canvas) {
|
|
auto debugster = [](const char* prefix, SkPath::Iter& iter) -> void {
|
|
SkDebugf("%s:\n", prefix);
|
|
const char* verbStr[] = { "Move", "Line", "Quad", "Conic", "Cubic", "Close", "Done" };
|
|
const int pointCount[] = { 1 , 2 , 3 , 3 , 4 , 1 , 0 };
|
|
SkPath::Verb verb;
|
|
do {
|
|
SkPoint points[4];
|
|
verb = iter.next(points);
|
|
SkDebugf("k%s_Verb ", verbStr[(int) verb]);
|
|
for (int i = 0; i < pointCount[(int) verb]; ++i) {
|
|
SkDebugf("{%g, %g}, ", points[i].fX, points[i].fY);
|
|
}
|
|
if (SkPath::kConic_Verb == verb) {
|
|
SkDebugf("weight = %g", iter.conicWeight());
|
|
}
|
|
SkDebugf("\n");
|
|
} while (SkPath::kDone_Verb != verb);
|
|
SkDebugf("\n");
|
|
};
|
|
|
|
SkPath path;
|
|
path.quadTo(10, 20, 30, 40);
|
|
SkPath::Iter openIter(path, false);
|
|
debugster("open", openIter);
|
|
SkPath::Iter closedIter(path, true);
|
|
debugster("closed", closedIter);
|
|
}
|
|
#StdOut
|
|
open:
|
|
kMove_Verb {0, 0},
|
|
kQuad_Verb {0, 0}, {10, 20}, {30, 40},
|
|
kDone_Verb
|
|
|
|
closed:
|
|
kMove_Verb {0, 0},
|
|
kQuad_Verb {0, 0}, {10, 20}, {30, 40},
|
|
kLine_Verb {30, 40}, {0, 0},
|
|
kClose_Verb {0, 0},
|
|
kDone_Verb
|
|
##
|
|
##
|
|
|
|
#SeeAlso setPath
|
|
|
|
##
|
|
|
|
#Method void setPath(const SkPath& path, bool forceClose)
|
|
|
|
Sets Iter to return elements of Verb_Array, Point_Array, and Conic_Weight in path.
|
|
If forceClose is true, Iter will add kLine_Verb and kClose_Verb after each
|
|
open Contour. path is not altered.
|
|
|
|
#Param path Path to iterate ##
|
|
#Param forceClose true if open Contours generate kClose_Verb ##
|
|
|
|
#Example
|
|
void draw(SkCanvas* canvas) {
|
|
auto debugster = [](const char* prefix, SkPath::Iter& iter) -> void {
|
|
SkDebugf("%s:\n", prefix);
|
|
const char* verbStr[] = { "Move", "Line", "Quad", "Conic", "Cubic", "Close", "Done" };
|
|
const int pointCount[] = { 1 , 2 , 3 , 3 , 4 , 1 , 0 };
|
|
SkPath::Verb verb;
|
|
do {
|
|
SkPoint points[4];
|
|
verb = iter.next(points);
|
|
SkDebugf("k%s_Verb ", verbStr[(int) verb]);
|
|
for (int i = 0; i < pointCount[(int) verb]; ++i) {
|
|
SkDebugf("{%g, %g}, ", points[i].fX, points[i].fY);
|
|
}
|
|
if (SkPath::kConic_Verb == verb) {
|
|
SkDebugf("weight = %g", iter.conicWeight());
|
|
}
|
|
SkDebugf("\n");
|
|
} while (SkPath::kDone_Verb != verb);
|
|
SkDebugf("\n");
|
|
};
|
|
|
|
SkPath path;
|
|
path.quadTo(10, 20, 30, 40);
|
|
SkPath::Iter iter(path, false);
|
|
debugster("quad open", iter);
|
|
SkPath path2;
|
|
path2.conicTo(1, 2, 3, 4, .5f);
|
|
iter.setPath(path2, true);
|
|
debugster("conic closed", iter);
|
|
}
|
|
#StdOut
|
|
quad open:
|
|
kMove_Verb {0, 0},
|
|
kQuad_Verb {0, 0}, {10, 20}, {30, 40},
|
|
kDone_Verb
|
|
|
|
conic closed:
|
|
kMove_Verb {0, 0},
|
|
kConic_Verb {0, 0}, {1, 2}, {3, 4}, weight = 0.5
|
|
kLine_Verb {3, 4}, {0, 0},
|
|
kClose_Verb {0, 0},
|
|
kDone_Verb
|
|
##
|
|
##
|
|
|
|
#SeeAlso Iter(const SkPath& path, bool forceClose)
|
|
|
|
##
|
|
|
|
#Method Verb next(SkPoint pts[4], bool doConsumeDegenerates = true, bool exact = false)
|
|
|
|
Returns next Verb in Verb_Array, and advances Iter.
|
|
When Verb_Array is exhausted, returns kDone_Verb.
|
|
|
|
Zero to four Points are stored in pts, depending on the returned Verb.
|
|
|
|
If doConsumeDegenerates is true, skip consecutive kMove_Verb entries, returning
|
|
only the last in the series; and skip very small Lines, Quads, and Conics; and
|
|
skip kClose_Verb following kMove_Verb.
|
|
if doConsumeDegenerates is true and exact is true, only skip Lines, Quads, and
|
|
Conics with zero lengths.
|
|
|
|
#Param pts storage for Point data describing returned Verb ##
|
|
#Param doConsumeDegenerates if true, skip degenerate Verbs ##
|
|
#Param exact skip zero length curves ##
|
|
|
|
#Return next Verb from Verb_Array ##
|
|
|
|
#Example
|
|
#Description
|
|
skip degenerate skips the first in a kMove_Verb pair, the kMove_Verb
|
|
followed by the kClose_Verb, the zero length Line and the very small Line.
|
|
|
|
skip degenerate if exact skips the same as skip degenerate, but shows
|
|
the very small Line.
|
|
|
|
skip none shows all of the Verbs and Points in Path.
|
|
##
|
|
void draw(SkCanvas* canvas) {
|
|
auto debugster = [](const char* prefix, const SkPath& path, bool degen, bool exact) -> void {
|
|
SkPath::Iter iter(path, false);
|
|
SkDebugf("%s:\n", prefix);
|
|
const char* verbStr[] = { "Move", "Line", "Quad", "Conic", "Cubic", "Close", "Done" };
|
|
const int pointCount[] = { 1 , 2 , 3 , 3 , 4 , 1 , 0 };
|
|
SkPath::Verb verb;
|
|
do {
|
|
SkPoint points[4];
|
|
verb = iter.next(points, degen, exact);
|
|
SkDebugf("k%s_Verb ", verbStr[(int) verb]);
|
|
for (int i = 0; i < pointCount[(int) verb]; ++i) {
|
|
SkDebugf("{%1.8g, %1.8g}, ", points[i].fX, points[i].fY);
|
|
}
|
|
SkDebugf("\n");
|
|
} while (SkPath::kDone_Verb != verb);
|
|
SkDebugf("\n");
|
|
};
|
|
|
|
SkPath path;
|
|
path.moveTo(10, 10);
|
|
path.moveTo(20, 20);
|
|
path.quadTo(10, 20, 30, 40);
|
|
path.moveTo(1, 1);
|
|
path.close();
|
|
path.moveTo(30, 30);
|
|
path.lineTo(30, 30);
|
|
path.moveTo(30, 30);
|
|
path.lineTo(30.00001f, 30);
|
|
debugster("skip degenerate", path, true, false);
|
|
debugster("skip degenerate if exact", path, true, true);
|
|
debugster("skip none", path, false, false);
|
|
}
|
|
#StdOut
|
|
skip degenerate:
|
|
kMove_Verb {20, 20},
|
|
kQuad_Verb {20, 20}, {10, 20}, {30, 40},
|
|
kDone_Verb
|
|
|
|
skip degenerate if exact:
|
|
kMove_Verb {20, 20},
|
|
kQuad_Verb {20, 20}, {10, 20}, {30, 40},
|
|
kMove_Verb {30, 30},
|
|
kLine_Verb {30, 30}, {30.00001, 30},
|
|
kDone_Verb
|
|
|
|
skip none:
|
|
kMove_Verb {10, 10},
|
|
kMove_Verb {20, 20},
|
|
kQuad_Verb {20, 20}, {10, 20}, {30, 40},
|
|
kMove_Verb {1, 1},
|
|
kClose_Verb {1, 1},
|
|
kMove_Verb {30, 30},
|
|
kLine_Verb {30, 30}, {30, 30},
|
|
kMove_Verb {30, 30},
|
|
kLine_Verb {30, 30}, {30.00001, 30},
|
|
kDone_Verb
|
|
##
|
|
##
|
|
|
|
#SeeAlso Verb IsLineDegenerate IsCubicDegenerate IsQuadDegenerate
|
|
|
|
##
|
|
|
|
#Method SkScalar conicWeight() const
|
|
|
|
Returns Conic_Weight if next() returned kConic_Verb.
|
|
|
|
If next() has not been called, or next() did not return kConic_Verb,
|
|
result is undefined.
|
|
|
|
#Return Conic_Weight for Conic Points returned by next() ##
|
|
|
|
#Example
|
|
void draw(SkCanvas* canvas) {
|
|
SkPath path;
|
|
path.conicTo(1, 2, 3, 4, .5f);
|
|
SkPath::Iter iter(path, false);
|
|
SkPoint p[4];
|
|
SkDebugf("first verb is " "%s" "move\n", SkPath::kMove_Verb == iter.next(p) ? "" : "not ");
|
|
SkDebugf("next verb is " "%s" "conic\n", SkPath::kConic_Verb == iter.next(p) ? "" : "not ");
|
|
SkDebugf("conic points: {%g,%g}, {%g,%g}, {%g,%g}\n", p[0].fX, p[0].fY, p[1].fX, p[1].fY,
|
|
p[2].fX, p[2].fY);
|
|
SkDebugf("conic weight: %g\n", iter.conicWeight());
|
|
}
|
|
#StdOut
|
|
first verb is move
|
|
next verb is conic
|
|
conic points: {0,0}, {1,2}, {3,4}
|
|
conic weight: 0.5
|
|
##
|
|
##
|
|
|
|
#SeeAlso Conic_Weight
|
|
|
|
##
|
|
|
|
#Method bool isCloseLine() const
|
|
#Line # returns if Line was generated by kClose_Verb ##
|
|
Returns true if last kLine_Verb returned by next() was generated
|
|
by kClose_Verb. When true, the end point returned by next() is
|
|
also the start point of Contour.
|
|
|
|
If next() has not been called, or next() did not return kLine_Verb,
|
|
result is undefined.
|
|
|
|
#Return true if last kLine_Verb was generated by kClose_Verb ##
|
|
|
|
#Example
|
|
void draw(SkCanvas* canvas) {
|
|
SkPath path;
|
|
path.moveTo(6, 7);
|
|
path.conicTo(1, 2, 3, 4, .5f);
|
|
path.close();
|
|
SkPath::Iter iter(path, false);
|
|
SkPoint p[4];
|
|
SkDebugf("1st verb is " "%s" "move\n", SkPath::kMove_Verb == iter.next(p) ? "" : "not ");
|
|
SkDebugf("moveTo point: {%g,%g}\n", p[0].fX, p[0].fY);
|
|
SkDebugf("2nd verb is " "%s" "conic\n", SkPath::kConic_Verb == iter.next(p) ? "" : "not ");
|
|
SkDebugf("3rd verb is " "%s" "line\n", SkPath::kLine_Verb == iter.next(p) ? "" : "not ");
|
|
SkDebugf("line points: {%g,%g}, {%g,%g}\n", p[0].fX, p[0].fY, p[1].fX, p[1].fY);
|
|
SkDebugf("line " "%s" "generated by close\n", iter.isCloseLine() ? "" : "not ");
|
|
SkDebugf("4th verb is " "%s" "close\n", SkPath::kClose_Verb == iter.next(p) ? "" : "not ");
|
|
}
|
|
#StdOut
|
|
1st verb is move
|
|
moveTo point: {6,7}
|
|
2nd verb is conic
|
|
3rd verb is line
|
|
line points: {3,4}, {6,7}
|
|
line generated by close
|
|
4th verb is close
|
|
##
|
|
##
|
|
|
|
#SeeAlso close()
|
|
##
|
|
|
|
#Method bool isClosedContour() const
|
|
#Line # returns if Contour has kClose_Verb ##
|
|
Returns true if subsequent calls to next() return kClose_Verb before returning
|
|
kMove_Verb. if true, Contour Iter is processing may end with kClose_Verb, or
|
|
Iter may have been initialized with force close set to true.
|
|
|
|
#Return true if Contour is closed ##
|
|
|
|
#Example
|
|
void draw(SkCanvas* canvas) {
|
|
for (bool forceClose : { false, true } ) {
|
|
SkPath path;
|
|
path.conicTo(1, 2, 3, 4, .5f);
|
|
SkPath::Iter iter(path, forceClose);
|
|
SkDebugf("without close(), forceClose is %s: isClosedContour returns %s\n",
|
|
forceClose ? "true " : "false", iter.isClosedContour() ? "true" : "false");
|
|
path.close();
|
|
iter.setPath(path, forceClose);
|
|
SkDebugf("with close(), forceClose is %s: isClosedContour returns %s\n",
|
|
forceClose ? "true " : "false", iter.isClosedContour() ? "true" : "false");
|
|
}
|
|
}
|
|
#StdOut
|
|
without close(), forceClose is false: isClosedContour returns false
|
|
with close(), forceClose is false: isClosedContour returns true
|
|
without close(), forceClose is true : isClosedContour returns true
|
|
with close(), forceClose is true : isClosedContour returns true
|
|
##
|
|
##
|
|
|
|
#SeeAlso Iter(const SkPath& path, bool forceClose)
|
|
|
|
##
|
|
|
|
#Class Iter ##
|
|
|
|
#Class RawIter
|
|
#Line # raw data iterator ##
|
|
|
|
#Code
|
|
class RawIter {
|
|
public:
|
|
RawIter();
|
|
RawIter(const SkPath& path);
|
|
void setPath(const SkPath& path);
|
|
Verb next(SkPoint pts[4]);
|
|
Verb peek() const;
|
|
SkScalar conicWeight() const;
|
|
}
|
|
##
|
|
|
|
Iterates through Verb_Array, and associated Point_Array and Conic_Weight.
|
|
Verb_Array, Point_Array, and Conic_Weight are returned unaltered.
|
|
|
|
#Method RawIter()
|
|
#Line # constructs empty Path iterator ##
|
|
|
|
Initializes RawIter with an empty Path. next() on RawIter returns kDone_Verb.
|
|
Call setPath to initialize SkPath::Iter at a later time.
|
|
|
|
#Return RawIter of empty Path ##
|
|
|
|
#NoExample
|
|
##
|
|
##
|
|
|
|
#Method RawIter(const SkPath& path)
|
|
#Line # constructs with Path to iterate over ##
|
|
|
|
|
|
Sets RawIter to return elements of Verb_Array, Point_Array, and Conic_Weight in path.
|
|
|
|
#Param path Path to iterate ##
|
|
|
|
#Return RawIter of path ##
|
|
|
|
#NoExample
|
|
##
|
|
##
|
|
|
|
#Method void setPath(const SkPath& path)
|
|
#Line # sets Path to iterate over ##
|
|
|
|
Sets SkPath::Iter to return elements of Verb_Array, Point_Array, and Conic_Weight in path.
|
|
|
|
#Param path Path to iterate ##
|
|
|
|
#NoExample
|
|
##
|
|
##
|
|
|
|
#Method Verb next(SkPoint pts[4])
|
|
#Line # returns next Verb and associated Points ##
|
|
Returns next Verb in Verb_Array, and advances RawIter.
|
|
When Verb_Array is exhausted, returns kDone_Verb.
|
|
Zero to four Points are stored in pts, depending on the returned Verb.
|
|
|
|
#Param pts storage for Point data describing returned Verb ##
|
|
|
|
#Return next Verb from Verb_Array ##
|
|
|
|
#Example
|
|
void draw(SkCanvas* canvas) {
|
|
SkPath path;
|
|
path.moveTo(50, 60);
|
|
path.quadTo(10, 20, 30, 40);
|
|
path.close();
|
|
path.lineTo(30, 30);
|
|
path.conicTo(1, 2, 3, 4, .5f);
|
|
path.cubicTo(-1, -2, -3, -4, -5, -6);
|
|
SkPath::RawIter iter(path);
|
|
const char* verbStr[] = { "Move", "Line", "Quad", "Conic", "Cubic", "Close", "Done" };
|
|
const int pointCount[] = { 1 , 2 , 3 , 3 , 4 , 1 , 0 };
|
|
SkPath::Verb verb;
|
|
do {
|
|
SkPoint points[4];
|
|
verb = iter.next(points);
|
|
SkDebugf("k%s_Verb ", verbStr[(int) verb]);
|
|
for (int i = 0; i < pointCount[(int) verb]; ++i) {
|
|
SkDebugf("{%1.8g, %1.8g}, ", points[i].fX, points[i].fY);
|
|
}
|
|
if (SkPath::kConic_Verb == verb) {
|
|
SkDebugf("weight = %g", iter.conicWeight());
|
|
}
|
|
SkDebugf("\n");
|
|
} while (SkPath::kDone_Verb != verb);
|
|
}
|
|
#StdOut
|
|
kMove_Verb {50, 60},
|
|
kQuad_Verb {50, 60}, {10, 20}, {30, 40},
|
|
kClose_Verb {50, 60},
|
|
kMove_Verb {50, 60},
|
|
kLine_Verb {50, 60}, {30, 30},
|
|
kConic_Verb {30, 30}, {1, 2}, {3, 4}, weight = 0.5
|
|
kCubic_Verb {3, 4}, {-1, -2}, {-3, -4}, {-5, -6},
|
|
kDone_Verb
|
|
##
|
|
##
|
|
|
|
#SeeAlso peek()
|
|
|
|
##
|
|
|
|
#Method Verb peek() const
|
|
#Line # returns next Verb ##
|
|
Returns next Verb, but does not advance RawIter.
|
|
|
|
#Return next Verb from Verb_Array ##
|
|
|
|
#Example
|
|
SkPath path;
|
|
path.quadTo(10, 20, 30, 40);
|
|
path.conicTo(1, 2, 3, 4, .5f);
|
|
path.cubicTo(1, 2, 3, 4, .5, 6);
|
|
SkPath::RawIter iter(path);
|
|
SkPath::Verb verb, peek = iter.peek();
|
|
const char* verbStr[] = { "Move", "Line", "Quad", "Conic", "Cubic", "Close", "Done" };
|
|
do {
|
|
SkPoint points[4];
|
|
verb = iter.next(points);
|
|
SkDebugf("peek %s %c= verb %s\n", verbStr[peek], peek == verb ? '=' : '!', verbStr[verb]);
|
|
peek = iter.peek();
|
|
} while (SkPath::kDone_Verb != verb);
|
|
SkDebugf("peek %s %c= verb %s\n", verbStr[peek], peek == verb ? '=' : '!', verbStr[verb]);
|
|
#StdOut
|
|
#Volatile
|
|
peek Move == verb Move
|
|
peek Quad == verb Quad
|
|
peek Conic == verb Conic
|
|
peek Cubic == verb Cubic
|
|
peek Done == verb Done
|
|
peek Done == verb Done
|
|
##
|
|
##
|
|
|
|
#Bug 6832
|
|
StdOut is not really volatile, it just produces the wrong result.
|
|
A simple fix changes the output of hairlines and needs to be
|
|
investigated to see if the change is correct or not.
|
|
see change 21340 (abandoned for now)
|
|
|
|
#SeeAlso next()
|
|
|
|
##
|
|
|
|
#Method SkScalar conicWeight() const
|
|
#Line # returns Conic_Weight ##
|
|
|
|
Returns Conic_Weight if next() returned kConic_Verb.
|
|
|
|
If next() has not been called, or next() did not return kConic_Verb,
|
|
result is undefined.
|
|
|
|
#Return Conic_Weight for Conic Points returned by next() ##
|
|
|
|
#Example
|
|
void draw(SkCanvas* canvas) {
|
|
SkPath path;
|
|
path.conicTo(1, 2, 3, 4, .5f);
|
|
SkPath::RawIter iter(path);
|
|
SkPoint p[4];
|
|
SkDebugf("first verb is " "%s" "move\n", SkPath::kMove_Verb == iter.next(p) ? "" : "not ");
|
|
SkDebugf("next verb is " "%s" "conic\n", SkPath::kConic_Verb == iter.next(p) ? "" : "not ");
|
|
SkDebugf("conic points: {%g,%g}, {%g,%g}, {%g,%g}\n", p[0].fX, p[0].fY, p[1].fX, p[1].fY,
|
|
p[2].fX, p[2].fY);
|
|
SkDebugf("conic weight: %g\n", iter.conicWeight());
|
|
}
|
|
#StdOut
|
|
first verb is move
|
|
next verb is conic
|
|
conic points: {0,0}, {1,2}, {3,4}
|
|
conic weight: 0.5
|
|
##
|
|
##
|
|
|
|
#SeeAlso Conic_Weight
|
|
|
|
##
|
|
|
|
#Class RawIter ##
|
|
|
|
#Class SkPath ##
|
|
|
|
#Topic Path ##
|
|
|