15fa138f22
git-svn-id: http://skia.googlecode.com/svn/trunk@3861 2bbb7eff-a529-9590-31e7-b0007b416f81
1747 lines
60 KiB
C++
1747 lines
60 KiB
C++
/*
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* Copyright 2012 Google Inc.
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*
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* Use of this source code is governed by a BSD-style license that can be
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* found in the LICENSE file.
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*/
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#include "CurveIntersection.h"
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#include "Intersections.h"
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#include "LineIntersection.h"
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#include "SkPath.h"
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#include "SkRect.h"
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#include "SkTArray.h"
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#include "SkTDArray.h"
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#include "ShapeOps.h"
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#include "TSearch.h"
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#include <algorithm> // used for std::min
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#undef SkASSERT
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#define SkASSERT(cond) while (!(cond)) { sk_throw(); }
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// Terminology:
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// A Path contains one of more Contours
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// A Contour is made up of Segment array
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// A Segment is described by a Verb and a Point array
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// A Verb is one of Line, Quad(ratic), and Cubic
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// A Segment contains a Span array
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// A Span is describes a portion of a Segment using starting and ending T
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// T values range from 0 to 1, where 0 is the first Point in the Segment
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// FIXME: remove once debugging is complete
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#if 0 // set to 1 for no debugging whatsoever
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//const bool gxRunTestsInOneThread = false;
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#define DEBUG_ADD_INTERSECTING_TS 0
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#define DEBUG_BRIDGE 0
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#define DEBUG_DUMP 0
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#else
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//const bool gRunTestsInOneThread = true;
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#define DEBUG_ADD_INTERSECTING_TS 1
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#define DEBUG_BRIDGE 1
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#define DEBUG_DUMP 1
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#endif
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#if DEBUG_DUMP
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static const char* kLVerbStr[] = {"", "line", "quad", "cubic"};
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static const char* kUVerbStr[] = {"", "Line", "Quad", "Cubic"};
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static int gContourID;
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static int gSegmentID;
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#endif
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static int LineIntersect(const SkPoint a[2], const SkPoint b[2],
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Intersections& intersections) {
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const _Line aLine = {{a[0].fX, a[0].fY}, {a[1].fX, a[1].fY}};
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const _Line bLine = {{b[0].fX, b[0].fY}, {b[1].fX, b[1].fY}};
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return intersect(aLine, bLine, intersections.fT[0], intersections.fT[1]);
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}
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static int QuadLineIntersect(const SkPoint a[3], const SkPoint b[2],
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Intersections& intersections) {
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const Quadratic aQuad = {{a[0].fX, a[0].fY}, {a[1].fX, a[1].fY}, {a[2].fX, a[2].fY}};
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const _Line bLine = {{b[0].fX, b[0].fY}, {b[1].fX, b[1].fY}};
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intersect(aQuad, bLine, intersections);
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return intersections.fUsed;
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}
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static int CubicLineIntersect(const SkPoint a[2], const SkPoint b[3],
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Intersections& intersections) {
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const Cubic aCubic = {{a[0].fX, a[0].fY}, {a[1].fX, a[1].fY}, {a[2].fX, a[2].fY},
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{a[3].fX, a[3].fY}};
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const _Line bLine = {{b[0].fX, b[0].fY}, {b[1].fX, b[1].fY}};
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return intersect(aCubic, bLine, intersections.fT[0], intersections.fT[1]);
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}
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static int QuadIntersect(const SkPoint a[3], const SkPoint b[3],
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Intersections& intersections) {
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const Quadratic aQuad = {{a[0].fX, a[0].fY}, {a[1].fX, a[1].fY}, {a[2].fX, a[2].fY}};
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const Quadratic bQuad = {{b[0].fX, b[0].fY}, {b[1].fX, b[1].fY}, {b[2].fX, b[2].fY}};
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intersect(aQuad, bQuad, intersections);
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return intersections.fUsed;
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}
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static int CubicIntersect(const SkPoint a[4], const SkPoint b[4],
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Intersections& intersections) {
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const Cubic aCubic = {{a[0].fX, a[0].fY}, {a[1].fX, a[1].fY}, {a[2].fX, a[2].fY},
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{a[3].fX, a[3].fY}};
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const Cubic bCubic = {{b[0].fX, b[0].fY}, {b[1].fX, b[1].fY}, {b[2].fX, b[2].fY},
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{b[3].fX, b[3].fY}};
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intersect(aCubic, bCubic, intersections);
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return intersections.fUsed;
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}
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static int HLineIntersect(const SkPoint a[2], SkScalar left, SkScalar right,
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SkScalar y, bool flipped, Intersections& intersections) {
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const _Line aLine = {{a[0].fX, a[0].fY}, {a[1].fX, a[1].fY}};
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return horizontalIntersect(aLine, left, right, y, flipped, intersections);
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}
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static int VLineIntersect(const SkPoint a[2], SkScalar left, SkScalar right,
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SkScalar y, bool flipped, Intersections& intersections) {
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const _Line aLine = {{a[0].fX, a[0].fY}, {a[1].fX, a[1].fY}};
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return verticalIntersect(aLine, left, right, y, flipped, intersections);
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}
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static int HQuadIntersect(const SkPoint a[3], SkScalar left, SkScalar right,
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SkScalar y, bool flipped, Intersections& intersections) {
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const Quadratic aQuad = {{a[0].fX, a[0].fY}, {a[1].fX, a[1].fY}, {a[2].fX, a[2].fY}};
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return horizontalIntersect(aQuad, left, right, y, flipped, intersections);
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}
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static int VQuadIntersect(const SkPoint a[3], SkScalar left, SkScalar right,
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SkScalar y, bool flipped, Intersections& intersections) {
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const Quadratic aQuad = {{a[0].fX, a[0].fY}, {a[1].fX, a[1].fY}, {a[2].fX, a[2].fY}};
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return verticalIntersect(aQuad, left, right, y, flipped, intersections);
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}
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static int HCubicIntersect(const SkPoint a[4], SkScalar left, SkScalar right,
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SkScalar y, bool flipped, Intersections& intersections) {
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const Cubic aCubic = {{a[0].fX, a[0].fY}, {a[1].fX, a[1].fY}, {a[2].fX, a[2].fY},
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{a[3].fX, a[3].fY}};
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return horizontalIntersect(aCubic, left, right, y, flipped, intersections);
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}
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static int VCubicIntersect(const SkPoint a[4], SkScalar left, SkScalar right,
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SkScalar y, bool flipped, Intersections& intersections) {
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const Cubic aCubic = {{a[0].fX, a[0].fY}, {a[1].fX, a[1].fY}, {a[2].fX, a[2].fY},
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{a[3].fX, a[3].fY}};
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return verticalIntersect(aCubic, left, right, y, flipped, intersections);
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}
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static void LineXYAtT(const SkPoint a[2], double t, SkPoint* out) {
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const _Line line = {{a[0].fX, a[0].fY}, {a[1].fX, a[1].fY}};
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double x, y;
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xy_at_t(line, t, x, y);
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out->fX = SkDoubleToScalar(x);
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out->fY = SkDoubleToScalar(y);
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}
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static void QuadXYAtT(const SkPoint a[3], double t, SkPoint* out) {
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const Quadratic quad = {{a[0].fX, a[0].fY}, {a[1].fX, a[1].fY}, {a[2].fX, a[2].fY}};
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double x, y;
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xy_at_t(quad, t, x, y);
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out->fX = SkDoubleToScalar(x);
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out->fY = SkDoubleToScalar(y);
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}
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static void CubicXYAtT(const SkPoint a[4], double t, SkPoint* out) {
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const Cubic cubic = {{a[0].fX, a[0].fY}, {a[1].fX, a[1].fY}, {a[2].fX, a[2].fY},
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{a[3].fX, a[3].fY}};
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double x, y;
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xy_at_t(cubic, t, x, y);
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out->fX = SkDoubleToScalar(x);
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out->fY = SkDoubleToScalar(y);
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}
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static void (* const SegmentXYAtT[])(const SkPoint [], double , SkPoint* ) = {
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NULL,
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LineXYAtT,
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QuadXYAtT,
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CubicXYAtT
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};
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static SkScalar LineXAtT(const SkPoint a[2], double t) {
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const _Line aLine = {{a[0].fX, a[0].fY}, {a[1].fX, a[1].fY}};
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double x;
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xy_at_t(aLine, t, x, *(double*) 0);
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return SkDoubleToScalar(x);
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}
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static SkScalar QuadXAtT(const SkPoint a[3], double t) {
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const Quadratic quad = {{a[0].fX, a[0].fY}, {a[1].fX, a[1].fY}, {a[2].fX, a[2].fY}};
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double x;
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xy_at_t(quad, t, x, *(double*) 0);
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return SkDoubleToScalar(x);
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}
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static SkScalar CubicXAtT(const SkPoint a[4], double t) {
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const Cubic cubic = {{a[0].fX, a[0].fY}, {a[1].fX, a[1].fY}, {a[2].fX, a[2].fY},
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{a[3].fX, a[3].fY}};
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double x;
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xy_at_t(cubic, t, x, *(double*) 0);
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return SkDoubleToScalar(x);
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}
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static SkScalar (* const SegmentXAtT[])(const SkPoint [], double ) = {
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NULL,
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LineXAtT,
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QuadXAtT,
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CubicXAtT
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};
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static SkScalar LineYAtT(const SkPoint a[2], double t) {
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const _Line aLine = {{a[0].fX, a[0].fY}, {a[1].fX, a[1].fY}};
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double y;
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xy_at_t(aLine, t, *(double*) 0, y);
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return SkDoubleToScalar(y);
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}
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static SkScalar QuadYAtT(const SkPoint a[3], double t) {
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const Quadratic quad = {{a[0].fX, a[0].fY}, {a[1].fX, a[1].fY}, {a[2].fX, a[2].fY}};
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double y;
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xy_at_t(quad, t, *(double*) 0, y);
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return SkDoubleToScalar(y);
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}
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static SkScalar CubicYAtT(const SkPoint a[4], double t) {
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const Cubic cubic = {{a[0].fX, a[0].fY}, {a[1].fX, a[1].fY}, {a[2].fX, a[2].fY},
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{a[3].fX, a[3].fY}};
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double y;
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xy_at_t(cubic, t, *(double*) 0, y);
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return SkDoubleToScalar(y);
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}
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static SkScalar (* const SegmentYAtT[])(const SkPoint [], double ) = {
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NULL,
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LineYAtT,
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QuadYAtT,
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CubicYAtT
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};
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static void LineSubDivide(const SkPoint a[2], double startT, double endT,
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SkPoint sub[2]) {
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const _Line aLine = {{a[0].fX, a[0].fY}, {a[1].fX, a[1].fY}};
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_Line dst;
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sub_divide(aLine, startT, endT, dst);
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sub[0].fX = SkDoubleToScalar(dst[0].x);
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sub[0].fY = SkDoubleToScalar(dst[0].y);
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sub[1].fX = SkDoubleToScalar(dst[1].x);
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sub[1].fY = SkDoubleToScalar(dst[1].y);
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}
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static void QuadSubDivide(const SkPoint a[3], double startT, double endT,
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SkPoint sub[3]) {
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const Quadratic aQuad = {{a[0].fX, a[0].fY}, {a[1].fX, a[1].fY},
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{a[2].fX, a[2].fY}};
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Quadratic dst;
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sub_divide(aQuad, startT, endT, dst);
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sub[0].fX = SkDoubleToScalar(dst[0].x);
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sub[0].fY = SkDoubleToScalar(dst[0].y);
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sub[1].fX = SkDoubleToScalar(dst[1].x);
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sub[1].fY = SkDoubleToScalar(dst[1].y);
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sub[2].fX = SkDoubleToScalar(dst[2].x);
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sub[2].fY = SkDoubleToScalar(dst[2].y);
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}
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static void CubicSubDivide(const SkPoint a[4], double startT, double endT,
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SkPoint sub[4]) {
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const Cubic aCubic = {{a[0].fX, a[0].fY}, {a[1].fX, a[1].fY},
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{a[2].fX, a[2].fY}, {a[3].fX, a[3].fY}};
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Cubic dst;
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sub_divide(aCubic, startT, endT, dst);
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sub[0].fX = SkDoubleToScalar(dst[0].x);
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sub[0].fY = SkDoubleToScalar(dst[0].y);
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sub[1].fX = SkDoubleToScalar(dst[1].x);
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sub[1].fY = SkDoubleToScalar(dst[1].y);
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sub[2].fX = SkDoubleToScalar(dst[2].x);
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sub[2].fY = SkDoubleToScalar(dst[2].y);
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sub[3].fX = SkDoubleToScalar(dst[3].x);
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sub[3].fY = SkDoubleToScalar(dst[3].y);
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}
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static void QuadSubBounds(const SkPoint a[3], double startT, double endT,
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SkRect& bounds) {
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SkPoint dst[3];
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QuadSubDivide(a, startT, endT, dst);
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bounds.fLeft = bounds.fRight = dst[0].fX;
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bounds.fTop = bounds.fBottom = dst[0].fY;
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for (int index = 1; index < 3; ++index) {
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bounds.growToInclude(dst[index].fX, dst[index].fY);
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}
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}
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static void CubicSubBounds(const SkPoint a[4], double startT, double endT,
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SkRect& bounds) {
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SkPoint dst[4];
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CubicSubDivide(a, startT, endT, dst);
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bounds.fLeft = bounds.fRight = dst[0].fX;
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bounds.fTop = bounds.fBottom = dst[0].fY;
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for (int index = 1; index < 4; ++index) {
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bounds.growToInclude(dst[index].fX, dst[index].fY);
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}
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}
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static SkPath::Verb QuadReduceOrder(const SkPoint a[3],
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SkTDArray<SkPoint>& reducePts) {
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const Quadratic aQuad = {{a[0].fX, a[0].fY}, {a[1].fX, a[1].fY},
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{a[2].fX, a[2].fY}};
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Quadratic dst;
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int order = reduceOrder(aQuad, dst);
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for (int index = 0; index < order; ++index) {
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SkPoint* pt = reducePts.append();
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pt->fX = SkDoubleToScalar(dst[index].x);
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pt->fY = SkDoubleToScalar(dst[index].y);
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}
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return (SkPath::Verb) (order - 1);
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}
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static SkPath::Verb CubicReduceOrder(const SkPoint a[4],
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SkTDArray<SkPoint>& reducePts) {
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const Cubic aCubic = {{a[0].fX, a[0].fY}, {a[1].fX, a[1].fY},
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{a[2].fX, a[2].fY}, {a[3].fX, a[3].fY}};
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Cubic dst;
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int order = reduceOrder(aCubic, dst, kReduceOrder_QuadraticsAllowed);
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for (int index = 0; index < order; ++index) {
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SkPoint* pt = reducePts.append();
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pt->fX = SkDoubleToScalar(dst[index].x);
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pt->fY = SkDoubleToScalar(dst[index].y);
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}
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return (SkPath::Verb) (order - 1);
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}
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static bool QuadIsLinear(const SkPoint a[3]) {
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const Quadratic aQuad = {{a[0].fX, a[0].fY}, {a[1].fX, a[1].fY},
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{a[2].fX, a[2].fY}};
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return isLinear(aQuad, 0, 2);
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}
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static bool CubicIsLinear(const SkPoint a[4]) {
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const Cubic aCubic = {{a[0].fX, a[0].fY}, {a[1].fX, a[1].fY},
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{a[2].fX, a[2].fY}, {a[3].fX, a[3].fY}};
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return isLinear(aCubic, 0, 3);
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}
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static SkScalar LineLeftMost(const SkPoint a[2], double startT, double endT) {
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const _Line aLine = {{a[0].fX, a[0].fY}, {a[1].fX, a[1].fY}};
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double x[2];
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xy_at_t(aLine, startT, x[0], *(double*) 0);
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xy_at_t(aLine, endT, x[0], *(double*) 0);
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return startT < endT ? startT : endT;
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}
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static SkScalar QuadLeftMost(const SkPoint a[3], double startT, double endT) {
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const Quadratic aQuad = {{a[0].fX, a[0].fY}, {a[1].fX, a[1].fY},
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{a[2].fX, a[2].fY}};
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return leftMostT(aQuad, startT, endT);
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}
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static SkScalar CubicLeftMost(const SkPoint a[4], double startT, double endT) {
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const Cubic aCubic = {{a[0].fX, a[0].fY}, {a[1].fX, a[1].fY},
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{a[2].fX, a[2].fY}, {a[3].fX, a[3].fY}};
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return leftMostT(aCubic, startT, endT);
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}
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static SkScalar (* const SegmentLeftMost[])(const SkPoint [], double , double) = {
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NULL,
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LineLeftMost,
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QuadLeftMost,
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CubicLeftMost
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};
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static bool IsCoincident(const SkPoint a[2], const SkPoint& above,
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const SkPoint& below) {
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const _Line aLine = {{a[0].fX, a[0].fY}, {a[1].fX, a[1].fY}};
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const _Line bLine = {{above.fX, above.fY}, {below.fX, below.fY}};
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return implicit_matches_ulps(aLine, bLine, 32);
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}
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// sorting angles
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// given angles of {dx dy ddx ddy dddx dddy} sort them
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class Angle {
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public:
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bool operator<(const Angle& rh) const {
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if ((dy < 0) ^ (rh.dy < 0)) {
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return dy < 0;
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}
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SkScalar cmp = dx * rh.dy - rh.dx * dy;
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if (cmp) {
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return cmp < 0;
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}
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if ((ddy < 0) ^ (rh.ddy < 0)) {
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return ddy < 0;
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}
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cmp = ddx * rh.ddy - rh.ddx * ddy;
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if (cmp) {
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return cmp < 0;
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}
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if ((dddy < 0) ^ (rh.dddy < 0)) {
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return ddy < 0;
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}
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return dddx * rh.dddy < rh.dddx * dddy;
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}
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void set(SkPoint* pts, SkPath::Verb verb) {
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dx = pts[1].fX - pts[0].fX; // b - a
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dy = pts[1].fY - pts[0].fY;
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if (verb == SkPath::kLine_Verb) {
|
|
ddx = ddy = dddx = dddy = 0;
|
|
return;
|
|
}
|
|
ddx = pts[2].fX - pts[1].fX - dx; // a - 2b + c
|
|
ddy = pts[2].fY - pts[2].fY - dy;
|
|
if (verb == SkPath::kQuad_Verb) {
|
|
dddx = dddy = 0;
|
|
return;
|
|
}
|
|
dddx = pts[3].fX + 3 * (pts[1].fX - pts[2].fX) - pts[0].fX;
|
|
dddy = pts[3].fY + 3 * (pts[1].fY - pts[2].fY) - pts[0].fY;
|
|
}
|
|
|
|
private:
|
|
SkScalar dx;
|
|
SkScalar dy;
|
|
SkScalar ddx;
|
|
SkScalar ddy;
|
|
SkScalar dddx;
|
|
SkScalar dddy;
|
|
};
|
|
|
|
// Bounds, unlike Rect, does not consider a vertical line to be empty.
|
|
struct Bounds : public SkRect {
|
|
static bool Intersects(const Bounds& a, const Bounds& b) {
|
|
return a.fLeft <= b.fRight && b.fLeft <= a.fRight &&
|
|
a.fTop <= b.fBottom && b.fTop <= a.fBottom;
|
|
}
|
|
|
|
bool isEmpty() {
|
|
return fLeft > fRight || fTop > fBottom
|
|
|| fLeft == fRight && fTop == fBottom
|
|
|| isnan(fLeft) || isnan(fRight)
|
|
|| isnan(fTop) || isnan(fBottom);
|
|
}
|
|
|
|
void setCubicBounds(const SkPoint a[4]) {
|
|
_Rect dRect;
|
|
Cubic cubic = {{a[0].fX, a[0].fY}, {a[1].fX, a[1].fY},
|
|
{a[2].fX, a[2].fY}, {a[3].fX, a[3].fY}};
|
|
dRect.setBounds(cubic);
|
|
set(dRect.left, dRect.top, dRect.right, dRect.bottom);
|
|
}
|
|
|
|
void setQuadBounds(const SkPoint a[3]) {
|
|
const Quadratic quad = {{a[0].fX, a[0].fY}, {a[1].fX, a[1].fY},
|
|
{a[2].fX, a[2].fY}};
|
|
_Rect dRect;
|
|
dRect.setBounds(quad);
|
|
set(dRect.left, dRect.top, dRect.right, dRect.bottom);
|
|
}
|
|
};
|
|
|
|
class Segment;
|
|
|
|
struct Span {
|
|
double fT;
|
|
Segment* fOther;
|
|
double fOtherT;
|
|
int fWinding; // accumulated from contours surrounding this one
|
|
// OPTIMIZATION: done needs only 2 bits (values are -1, 0, 1)
|
|
int fDone; // set when t to t+fDone is processed
|
|
// OPTIMIZATION: done needs only 2 bits (values are -1, 0, 1)
|
|
int fCoincident; // -1 start of coincidence, 0 no coincidence, 1 end
|
|
};
|
|
|
|
class Segment {
|
|
public:
|
|
Segment() {
|
|
#if DEBUG_DUMP
|
|
fID = ++gSegmentID;
|
|
#endif
|
|
}
|
|
|
|
void addAngle(SkTDArray<Angle>& angles, double start, double end) {
|
|
// FIXME complete this
|
|
// start here;
|
|
}
|
|
|
|
bool addCubic(const SkPoint pts[4]) {
|
|
fPts = pts;
|
|
fVerb = SkPath::kCubic_Verb;
|
|
fBounds.setCubicBounds(pts);
|
|
}
|
|
|
|
bool addLine(const SkPoint pts[2]) {
|
|
fPts = pts;
|
|
fVerb = SkPath::kLine_Verb;
|
|
fBounds.set(pts, 2);
|
|
}
|
|
|
|
// add 2 to edge or out of range values to get T extremes
|
|
void addOtherT(int index, double other) {
|
|
fTs[index].fOtherT = other;
|
|
}
|
|
|
|
bool addQuad(const SkPoint pts[3]) {
|
|
fPts = pts;
|
|
fVerb = SkPath::kQuad_Verb;
|
|
fBounds.setQuadBounds(pts);
|
|
}
|
|
|
|
int addT(double newT, Segment& other, int coincident) {
|
|
// FIXME: in the pathological case where there is a ton of intercepts,
|
|
// binary search?
|
|
int insertedAt = -1;
|
|
Span* span;
|
|
size_t tCount = fTs.count();
|
|
double delta;
|
|
for (size_t idx2 = 0; idx2 < tCount; ++idx2) {
|
|
// OPTIMIZATION: if there are three or more identical Ts, then
|
|
// the fourth and following could be further insertion-sorted so
|
|
// that all the edges are clockwise or counterclockwise.
|
|
// This could later limit segment tests to the two adjacent
|
|
// neighbors, although it doesn't help with determining which
|
|
// circular direction to go in.
|
|
if (newT <= fTs[idx2].fT) {
|
|
insertedAt = idx2;
|
|
span = fTs.insert(idx2);
|
|
goto finish;
|
|
}
|
|
}
|
|
insertedAt = tCount;
|
|
span = fTs.append();
|
|
finish:
|
|
span->fT = newT;
|
|
span->fOther = &other;
|
|
span->fWinding = 1;
|
|
span->fDone = 0;
|
|
span->fCoincident = coincident;
|
|
fCoincident |= coincident;
|
|
return insertedAt;
|
|
}
|
|
|
|
const Bounds& bounds() const {
|
|
return fBounds;
|
|
}
|
|
|
|
bool done() const {
|
|
return fDone;
|
|
}
|
|
|
|
int findCoincidentEnd(int start) const {
|
|
int tCount = fTs.count();
|
|
SkASSERT(start < tCount);
|
|
const Span& span = fTs[start];
|
|
SkASSERT(span.fCoincident);
|
|
for (int index = start + 1; index < tCount; ++index) {
|
|
const Span& match = fTs[index];
|
|
if (match.fOther == span.fOther) {
|
|
SkASSERT(match.fCoincident);
|
|
return index;
|
|
}
|
|
}
|
|
SkASSERT(0); // should never get here
|
|
return -1;
|
|
}
|
|
|
|
// start is the index of the beginning T of this edge
|
|
// it is guaranteed to have an end which describes a non-zero length (?)
|
|
// winding -1 means ccw, 1 means cw
|
|
// step is in/out -1 or 1
|
|
// spanIndex is returned
|
|
Segment* findNext(int start, int winding, int& step, int& spanIndex) {
|
|
SkASSERT(step == 1 || step == -1);
|
|
int count = fTs.count();
|
|
SkASSERT(step > 0 ? start < count - 1 : start > 0);
|
|
Span* startSpan = &fTs[start];
|
|
// FIXME:
|
|
// since Ts can be stepped either way, done markers must be careful
|
|
// not to assume that segment was only ascending in T. This shouldn't
|
|
// be a problem unless pathologically a segment can be partially
|
|
// ascending and partially descending -- maybe quads/cubic can do this?
|
|
startSpan->fDone = step;
|
|
SkPoint startLoc; // OPTIMIZATION: store this in the t span?
|
|
xyAtT(startSpan->fT, &startLoc);
|
|
SkPoint endLoc;
|
|
Span* endSpan;
|
|
int end = nextSpan(start, step, startLoc, startSpan, &endLoc, &endSpan);
|
|
|
|
// if we hit the end looking for span end, is that always an error?
|
|
SkASSERT(step > 0 ? end + 1 < count : end - 1 >= 0);
|
|
|
|
// preflight for coincidence -- if present, it may change winding
|
|
// considerations and whether reversed edges can be followed
|
|
bool foundCoincident = false;
|
|
int last = lastSpan(end, step, &startLoc, startSpan, foundCoincident);
|
|
|
|
// Discard opposing direction candidates if no coincidence was found.
|
|
int candidateCount = abs(last - end);
|
|
if (candidateCount == 1) {
|
|
SkASSERT(!foundCoincident);
|
|
// move in winding direction until edge in correct direction
|
|
// balance wrong direction edges before finding correct one
|
|
// this requres that the intersection is angularly sorted
|
|
// for a single intersection, special case -- choose the opposite
|
|
// edge that steps the same
|
|
Segment* other = endSpan->fOther;
|
|
SkASSERT(!other->fDone);
|
|
spanIndex = other->matchSpan(this, endSpan->fT);
|
|
SkASSERT(step < 0 ? spanIndex > 0 : spanIndex < other->fTs.count() - 1);
|
|
return other;
|
|
}
|
|
|
|
// find the next T that describes a length
|
|
SkTDArray<Angle> angles;
|
|
Segment* segmentCandidate = NULL;
|
|
int spanCandidate = -1;
|
|
int directionCandidate;
|
|
do {
|
|
endSpan = &fTs[end];
|
|
Segment* other = endSpan->fOther;
|
|
if (other->fDone) {
|
|
continue;
|
|
}
|
|
// if there is only one live crossing, and no coincidence, continue
|
|
// in the same direction
|
|
// if there is coincidence, the only choice may be to reverse direction
|
|
// find edge on either side of intersection
|
|
int oCount = other->fTs.count();
|
|
for (int oIndex = 0; oIndex < oCount; ++oIndex) {
|
|
Span& otherSpan = other->fTs[oIndex];
|
|
if (otherSpan.fOther != this) {
|
|
continue;
|
|
}
|
|
if (otherSpan.fOtherT != endSpan->fT) {
|
|
continue;
|
|
}
|
|
// if done == -1, prior span has already been processed
|
|
int next = other->nextSpan(oIndex, step, endLoc, &otherSpan,
|
|
NULL, NULL);
|
|
if (next < 0) {
|
|
continue;
|
|
}
|
|
bool otherIsCoincident;
|
|
last = other->lastSpan(next, step, &endLoc, &otherSpan,
|
|
otherIsCoincident);
|
|
if (step < 0) {
|
|
|
|
if (otherSpan.fDone >= 0 && oIndex > 0) {
|
|
// FIXME: this needs to loop on -- until t && pt are different
|
|
Span& prior = other->fTs[oIndex - 1];
|
|
if (prior.fDone > 0) {
|
|
continue;
|
|
}
|
|
|
|
}
|
|
} else { // step == 1
|
|
if (otherSpan.fDone <= 0 && oIndex < oCount - 1) {
|
|
// FIXME: this needs to loop on ++ until t && pt are different
|
|
Span& next = other->fTs[oIndex + 1];
|
|
if (next.fDone < 0) {
|
|
continue;
|
|
}
|
|
}
|
|
}
|
|
if (!segmentCandidate) {
|
|
segmentCandidate = other;
|
|
spanCandidate = oIndex;
|
|
directionCandidate = step;
|
|
continue;
|
|
}
|
|
// there's two or more matches
|
|
if (spanCandidate >= 0) { // retrieve first stored candidate
|
|
// add edge leading into junction
|
|
addAngle(angles, endSpan->fT, startSpan->fT);
|
|
// add edge leading away from junction
|
|
double nextT = nextSpan(end, step, endLoc, endSpan, NULL,
|
|
NULL);
|
|
if (nextT >= 0) {
|
|
addAngle(angles, endSpan->fT, nextT);
|
|
}
|
|
// add first stored candidate into junction
|
|
segmentCandidate->addAngle(angles,
|
|
segmentCandidate->fTs[spanCandidate - 1].fT,
|
|
segmentCandidate->fTs[spanCandidate].fT);
|
|
// add first stored candidate away from junction
|
|
segmentCandidate->addAngle(angles,
|
|
segmentCandidate->fTs[spanCandidate].fT,
|
|
segmentCandidate->fTs[spanCandidate + 1].fT);
|
|
}
|
|
// add candidate into and away from junction
|
|
|
|
|
|
// start here;
|
|
// more than once viable candidate -- need to
|
|
// measure angles to find best
|
|
// noncoincident quads/cubics may have the same initial angle
|
|
// as lines, so must sort by derivatives as well
|
|
// while we're here, figure out all connections given the
|
|
// initial winding info
|
|
// so the span needs to contain the pairing info found here
|
|
// this should include the winding computed for the edge, and
|
|
// what edge it connects to, and whether it is discarded
|
|
// (maybe discarded == abs(winding) > 1) ?
|
|
// only need derivatives for duration of sorting, add a new struct
|
|
// for pairings, remove extra spans that have zero length and
|
|
// reference an unused other
|
|
// for coincident, the last span on the other may be marked done
|
|
// (always?)
|
|
}
|
|
} while ((end += step) != last);
|
|
// if loop is exhausted, contour may be closed.
|
|
// FIXME: pass in close point so we can check for closure
|
|
|
|
// given a segment, and a sense of where 'inside' is, return the next
|
|
// segment. If this segment has an intersection, or ends in multiple
|
|
// segments, find the mate that continues the outside.
|
|
// note that if there are multiples, but no coincidence, we can limit
|
|
// choices to connections in the correct direction
|
|
|
|
// mark found segments as done
|
|
}
|
|
|
|
void findTooCloseToCall(int winding) {
|
|
int count = fTs.count();
|
|
if (count < 3) { // require t=0, x, 1 at minimum
|
|
return;
|
|
}
|
|
int matchIndex = 0;
|
|
int moCount;
|
|
Span* match;
|
|
Segment* mOther;
|
|
do {
|
|
match = &fTs[matchIndex];
|
|
mOther = match->fOther;
|
|
moCount = mOther->fTs.count();
|
|
} while (moCount >= 3 || ++matchIndex < count - 1); // require t=0, x, 1 at minimum
|
|
SkPoint matchPt;
|
|
// OPTIMIZATION: defer matchPt until qualifying toCount is found?
|
|
xyAtT(match->fT, &matchPt);
|
|
// look for a pair of nearby T values that map to the same (x,y) value
|
|
// if found, see if the pair of other segments share a common point. If
|
|
// so, the span from here to there is coincident.
|
|
for (int index = matchIndex + 1; index < count; ++index) {
|
|
Span* test = &fTs[index];
|
|
Segment* tOther = test->fOther;
|
|
int toCount = tOther->fTs.count();
|
|
if (toCount < 3) { // require t=0, x, 1 at minimum
|
|
continue;
|
|
}
|
|
SkPoint testPt;
|
|
xyAtT(test->fT, &testPt);
|
|
if (matchPt != testPt) {
|
|
matchIndex = index;
|
|
moCount = toCount;
|
|
match = test;
|
|
mOther = tOther;
|
|
matchPt = testPt;
|
|
continue;
|
|
}
|
|
int moStart = -1; // FIXME: initialization is debugging only
|
|
for (int moIndex = 0; moIndex < moCount; ++moIndex) {
|
|
Span& moSpan = mOther->fTs[moIndex];
|
|
if (moSpan.fOther == this) {
|
|
if (moSpan.fOtherT == match->fT) {
|
|
moStart = moIndex;
|
|
}
|
|
continue;
|
|
}
|
|
if (moSpan.fOther != tOther) {
|
|
continue;
|
|
}
|
|
int toStart = -1;
|
|
int toIndex; // FIXME: initialization is debugging only
|
|
bool found = false;
|
|
for (toIndex = 0; toIndex < toCount; ++toIndex) {
|
|
Span& toSpan = tOther->fTs[toIndex];
|
|
if (toSpan.fOther == this) {
|
|
if (toSpan.fOtherT == test->fT) {
|
|
toStart = toIndex;
|
|
}
|
|
continue;
|
|
}
|
|
if (toSpan.fOther == mOther && toSpan.fOtherT
|
|
== moSpan.fT) {
|
|
found = true;
|
|
break;
|
|
}
|
|
}
|
|
if (!found) {
|
|
continue;
|
|
}
|
|
SkASSERT(moStart >= 0);
|
|
SkASSERT(toStart >= 0);
|
|
// test to see if the segment between there and here is linear
|
|
if (!mOther->isLinear(moStart, moIndex)
|
|
|| !tOther->isLinear(toStart, toIndex)) {
|
|
continue;
|
|
}
|
|
mOther->fTs[moStart].fCoincident = -1;
|
|
tOther->fTs[toStart].fCoincident = -1;
|
|
mOther->fTs[moIndex].fCoincident = 1;
|
|
tOther->fTs[toIndex].fCoincident = 1;
|
|
}
|
|
nextStart:
|
|
;
|
|
}
|
|
}
|
|
|
|
int findByT(double t, const Segment* match) const {
|
|
// OPTIMIZATION: bsearch if count is honkin huge
|
|
int count = fTs.count();
|
|
for (int index = 0; index < count; ++index) {
|
|
const Span& span = fTs[index];
|
|
if (t == span.fT && match == span.fOther) {
|
|
return index;
|
|
}
|
|
}
|
|
SkASSERT(0); // should never get here
|
|
return -1;
|
|
}
|
|
|
|
// find the adjacent T that is leftmost, with a point != base
|
|
int findLefty(int tIndex, const SkPoint& base) const {
|
|
int bestTIndex;
|
|
SkPoint test;
|
|
SkScalar bestX = DBL_MAX;
|
|
int testTIndex = tIndex;
|
|
while (--testTIndex >= 0) {
|
|
xyAtT(testTIndex, &test);
|
|
if (test != base) {
|
|
continue;
|
|
}
|
|
bestX = test.fX;
|
|
bestTIndex = testTIndex;
|
|
break;
|
|
}
|
|
int count = fTs.count();
|
|
testTIndex = tIndex;
|
|
while (++testTIndex < count) {
|
|
xyAtT(testTIndex, &test);
|
|
if (test == base) {
|
|
continue;
|
|
}
|
|
return bestX > test.fX ? testTIndex : bestTIndex;
|
|
}
|
|
SkASSERT(0); // can't get here (?)
|
|
return -1;
|
|
}
|
|
|
|
// OPTIMIZATION : for a pair of lines, can we compute points at T (cached)
|
|
// and use more concise logic like the old edge walker code?
|
|
// FIXME: this needs to deal with coincident edges
|
|
const Segment* findTop(int& tIndex) const {
|
|
// iterate through T intersections and return topmost
|
|
// topmost tangent from y-min to first pt is closer to horizontal
|
|
int firstT = 0;
|
|
int lastT = 0;
|
|
SkScalar topY = fPts[0].fY;
|
|
int count = fTs.count();
|
|
int index;
|
|
for (index = 1; index < count; ++index) {
|
|
const Span& span = fTs[index];
|
|
double t = span.fT;
|
|
SkScalar yIntercept = yAtT(t);
|
|
if (topY > yIntercept) {
|
|
topY = yIntercept;
|
|
firstT = lastT = index;
|
|
} else if (topY == yIntercept) {
|
|
lastT = index;
|
|
}
|
|
}
|
|
// if there's only a pair of segments, go with the endpoint chosen above
|
|
if (firstT == lastT && (firstT == 0 || firstT == count - 1)) {
|
|
tIndex = firstT;
|
|
return this;
|
|
}
|
|
// if the topmost T is not on end, or is three-way or more, find left
|
|
SkPoint leftBase;
|
|
xyAtT(firstT, &leftBase);
|
|
int tLeft = findLefty(firstT, leftBase);
|
|
const Segment* leftSegment = this;
|
|
// look for left-ness from tLeft to firstT (matching y of other)
|
|
for (index = firstT; index <= lastT; ++index) {
|
|
const Segment* other = fTs[index].fOther;
|
|
double otherT = fTs[index].fOtherT;
|
|
int otherTIndex = other->findByT(otherT, this);
|
|
// pick companionT closest (but not too close) on either side
|
|
int otherTLeft = other->findLefty(otherTIndex, leftBase);
|
|
// within this span, find highest y
|
|
SkPoint testPt, otherPt;
|
|
testPt.fY = yAtT(tLeft);
|
|
otherPt.fY = other->yAtT(otherTLeft);
|
|
// FIXME: incomplete
|
|
// find the y intercept with the opposite segment
|
|
if (testPt.fY < otherPt.fY) {
|
|
|
|
} else if (testPt.fY > otherPt.fY) {
|
|
|
|
}
|
|
// FIXME: leftMost no good. Use y intercept instead
|
|
#if 0
|
|
SkScalar otherMost = other->leftMost(otherTIndex, otherTLeft);
|
|
if (otherMost < left) {
|
|
leftSegment = other;
|
|
}
|
|
#endif
|
|
}
|
|
return leftSegment;
|
|
}
|
|
|
|
bool intersected() const {
|
|
return fTs.count() > 0;
|
|
}
|
|
|
|
bool isLinear(int start, int end) const {
|
|
if (fVerb == SkPath::kLine_Verb) {
|
|
return true;
|
|
}
|
|
if (fVerb == SkPath::kQuad_Verb) {
|
|
SkPoint qPart[3];
|
|
QuadSubDivide(fPts, fTs[start].fT, fTs[end].fT, qPart);
|
|
return QuadIsLinear(qPart);
|
|
} else {
|
|
SkASSERT(fVerb == SkPath::kCubic_Verb);
|
|
SkPoint cPart[4];
|
|
CubicSubDivide(fPts, fTs[start].fT, fTs[end].fT, cPart);
|
|
return CubicIsLinear(cPart);
|
|
}
|
|
}
|
|
|
|
bool isHorizontal() const {
|
|
return fBounds.fTop == fBounds.fBottom;
|
|
}
|
|
|
|
bool isVertical() const {
|
|
return fBounds.fLeft == fBounds.fRight;
|
|
}
|
|
|
|
int lastSpan(int end, int step, const SkPoint* startLoc,
|
|
const Span* startSpan, bool& coincident) {
|
|
int last = end;
|
|
int count = fTs.count();
|
|
coincident = false;
|
|
SkPoint lastLoc;
|
|
do {
|
|
if (fTs[last].fCoincident == -step) {
|
|
coincident = true;
|
|
}
|
|
if (step > 0 ? ++last < count : --last >= 0) {
|
|
break;
|
|
}
|
|
Span* lastSpan = &fTs[last];
|
|
if (lastSpan->fT == startSpan->fT) {
|
|
continue;
|
|
}
|
|
xyAtT(lastSpan->fT, &lastLoc);
|
|
} while (*startLoc == lastLoc);
|
|
}
|
|
|
|
SkScalar leftMost(int start, int end) const {
|
|
return (*SegmentLeftMost[fVerb])(fPts, fTs[start].fT, fTs[end].fT);
|
|
}
|
|
|
|
int matchSpan(const Segment* match, double matchT)
|
|
{
|
|
int count = fTs.count();
|
|
for (int index = 0; index < count; ++index) {
|
|
Span& span = fTs[index];
|
|
if (span.fOther != match) {
|
|
continue;
|
|
}
|
|
if (span.fOtherT != matchT) {
|
|
continue;
|
|
}
|
|
return index;
|
|
}
|
|
SkASSERT(0); // should never get here
|
|
return -1;
|
|
}
|
|
|
|
int nextSpan(int from, int step, const SkPoint& fromLoc,
|
|
const Span* fromSpan, SkPoint* toLoc, Span** toSpan) {
|
|
int count = fTs.count();
|
|
int to = from;
|
|
while (step > 0 ? ++to < count : --to >= 0) {
|
|
Span* span = &fTs[to];
|
|
if (span->fT == fromSpan->fT) {
|
|
continue;
|
|
}
|
|
SkPoint loc;
|
|
xyAtT(span->fT, &loc);
|
|
if (fromLoc == loc) {
|
|
continue;
|
|
}
|
|
if (toLoc) {
|
|
*toLoc = loc;
|
|
}
|
|
if (toSpan) {
|
|
*toSpan = span;
|
|
}
|
|
return to;
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
const SkPoint* pts() const {
|
|
return fPts;
|
|
}
|
|
|
|
void reset() {
|
|
fPts = NULL;
|
|
fVerb = (SkPath::Verb) -1;
|
|
fBounds.set(SK_ScalarMax, SK_ScalarMax, SK_ScalarMax, SK_ScalarMax);
|
|
fTs.reset();
|
|
fDone = false;
|
|
fCoincident = 0;
|
|
}
|
|
|
|
// OPTIMIZATION: remove this function if it's never called
|
|
double t(int tIndex) const {
|
|
return fTs[tIndex].fT;
|
|
}
|
|
|
|
SkPath::Verb verb() const {
|
|
return fVerb;
|
|
}
|
|
|
|
SkScalar xAtT(double t) const {
|
|
return (*SegmentXAtT[fVerb])(fPts, t);
|
|
}
|
|
|
|
void xyAtT(double t, SkPoint* pt) const {
|
|
(*SegmentXYAtT[fVerb])(fPts, t, pt);
|
|
}
|
|
|
|
SkScalar yAtT(double t) const {
|
|
return (*SegmentYAtT[fVerb])(fPts, t);
|
|
}
|
|
|
|
#if DEBUG_DUMP
|
|
void dump() const {
|
|
const char className[] = "Segment";
|
|
const int tab = 4;
|
|
for (int i = 0; i < fTs.count(); ++i) {
|
|
SkPoint out;
|
|
(*SegmentXYAtT[fVerb])(fPts, t(i), &out);
|
|
SkDebugf("%*s [%d] %s.fTs[%d]=%1.9g (%1.9g,%1.9g) other=%d"
|
|
" otherT=%1.9g winding=%d\n",
|
|
tab + sizeof(className), className, fID,
|
|
kLVerbStr[fVerb], i, fTs[i].fT, out.fX, out.fY,
|
|
fTs[i].fOther->fID, fTs[i].fOtherT, fTs[i].fWinding);
|
|
}
|
|
SkDebugf("%*s [%d] fBounds=(l:%1.9g, t:%1.9g r:%1.9g, b:%1.9g)",
|
|
tab + sizeof(className), className, fID,
|
|
fBounds.fLeft, fBounds.fTop, fBounds.fRight, fBounds.fBottom);
|
|
}
|
|
#endif
|
|
|
|
private:
|
|
const SkPoint* fPts;
|
|
SkPath::Verb fVerb;
|
|
Bounds fBounds;
|
|
SkTDArray<Span> fTs; // two or more (always includes t=0 t=1)
|
|
// FIXME: coincident only needs two bits (-1, 0, 1)
|
|
int fCoincident; // non-zero if some coincident span inside
|
|
bool fDone;
|
|
#if DEBUG_DUMP
|
|
int fID;
|
|
#endif
|
|
};
|
|
|
|
class Contour {
|
|
public:
|
|
Contour() {
|
|
reset();
|
|
#if DEBUG_DUMP
|
|
fID = ++gContourID;
|
|
#endif
|
|
}
|
|
|
|
bool operator<(const Contour& rh) const {
|
|
return fBounds.fTop == rh.fBounds.fTop
|
|
? fBounds.fLeft < rh.fBounds.fLeft
|
|
: fBounds.fTop < rh.fBounds.fTop;
|
|
}
|
|
|
|
void addCubic(const SkPoint pts[4]) {
|
|
fSegments.push_back().addCubic(pts);
|
|
fContainsCurves = true;
|
|
}
|
|
|
|
void addLine(const SkPoint pts[2]) {
|
|
fSegments.push_back().addLine(pts);
|
|
}
|
|
|
|
void addQuad(const SkPoint pts[3]) {
|
|
fSegments.push_back().addQuad(pts);
|
|
fContainsCurves = true;
|
|
}
|
|
|
|
const Bounds& bounds() const {
|
|
return fBounds;
|
|
}
|
|
|
|
void complete() {
|
|
setBounds();
|
|
fContainsIntercepts = false;
|
|
}
|
|
|
|
void containsIntercepts() {
|
|
fContainsIntercepts = true;
|
|
}
|
|
|
|
void findTooCloseToCall(int winding) {
|
|
int segmentCount = fSegments.count();
|
|
for (int sIndex = 0; sIndex < segmentCount; ++sIndex) {
|
|
fSegments[sIndex].findTooCloseToCall(winding);
|
|
}
|
|
}
|
|
|
|
void reset() {
|
|
fSegments.reset();
|
|
fBounds.set(SK_ScalarMax, SK_ScalarMax, SK_ScalarMax, SK_ScalarMax);
|
|
fContainsCurves = fContainsIntercepts = false;
|
|
}
|
|
|
|
// OPTIMIZATION: feel pretty uneasy about this. It seems like once again
|
|
// we need to sort and walk edges in y, but that on the surface opens the
|
|
// same can of worms as before. But then, this is a rough sort based on
|
|
// segments' top, and not a true sort, so it could be ameniable to regular
|
|
// sorting instead of linear searching. Still feel like I'm missing something
|
|
Segment* topSegment() {
|
|
int segmentCount = fSegments.count();
|
|
SkASSERT(segmentCount > 0);
|
|
int best = -1;
|
|
Segment* bestSegment = NULL;
|
|
while (++best < segmentCount) {
|
|
Segment* testSegment = &fSegments[best];
|
|
if (testSegment->done()) {
|
|
continue;
|
|
}
|
|
bestSegment = testSegment;
|
|
break;
|
|
}
|
|
if (!bestSegment) {
|
|
return NULL;
|
|
}
|
|
SkScalar bestTop = bestSegment->bounds().fTop;
|
|
for (int test = best + 1; test < segmentCount; ++test) {
|
|
Segment* testSegment = &fSegments[test];
|
|
if (testSegment->done()) {
|
|
continue;
|
|
}
|
|
SkScalar testTop = testSegment->bounds().fTop;
|
|
if (bestTop > testTop) {
|
|
bestTop = testTop;
|
|
bestSegment = testSegment;
|
|
}
|
|
}
|
|
return bestSegment;
|
|
}
|
|
|
|
#if DEBUG_DUMP
|
|
void dump() {
|
|
int i;
|
|
const char className[] = "Contour";
|
|
const int tab = 4;
|
|
SkDebugf("%s %p (contour=%d)\n", className, this, fID);
|
|
for (i = 0; i < fSegments.count(); ++i) {
|
|
SkDebugf("%*s.fSegments[%d]:\n", tab + sizeof(className),
|
|
className, i);
|
|
fSegments[i].dump();
|
|
}
|
|
SkDebugf("%*s.fBounds=(l:%1.9g, t:%1.9g r:%1.9g, b:%1.9g)\n",
|
|
tab + sizeof(className), className,
|
|
fBounds.fLeft, fBounds.fTop,
|
|
fBounds.fRight, fBounds.fBottom);
|
|
SkDebugf("%*s.fContainsIntercepts=%d\n", tab + sizeof(className),
|
|
className, fContainsIntercepts);
|
|
SkDebugf("%*s.fContainsCurves=%d\n", tab + sizeof(className),
|
|
className, fContainsCurves);
|
|
}
|
|
#endif
|
|
|
|
protected:
|
|
void setBounds() {
|
|
int count = fSegments.count();
|
|
if (count == 0) {
|
|
SkDebugf("%s empty contour\n", __FUNCTION__);
|
|
SkASSERT(0);
|
|
// FIXME: delete empty contour?
|
|
return;
|
|
}
|
|
fBounds = fSegments.front().bounds();
|
|
for (int index = 1; index < count; ++index) {
|
|
fBounds.growToInclude(fSegments[index].bounds());
|
|
}
|
|
}
|
|
|
|
public:
|
|
SkTArray<Segment> fSegments; // not worth accessor functions?
|
|
|
|
private:
|
|
Bounds fBounds;
|
|
bool fContainsIntercepts;
|
|
bool fContainsCurves;
|
|
#if DEBUG_DUMP
|
|
int fID;
|
|
#endif
|
|
};
|
|
|
|
class EdgeBuilder {
|
|
public:
|
|
|
|
EdgeBuilder(const SkPath& path, SkTArray<Contour>& contours)
|
|
: fPath(path)
|
|
, fCurrentContour(NULL)
|
|
, fContours(contours)
|
|
{
|
|
#if DEBUG_DUMP
|
|
gContourID = 0;
|
|
gSegmentID = 0;
|
|
#endif
|
|
walk();
|
|
}
|
|
|
|
protected:
|
|
|
|
void complete() {
|
|
if (fCurrentContour && fCurrentContour->fSegments.count()) {
|
|
fCurrentContour->complete();
|
|
fCurrentContour = NULL;
|
|
}
|
|
}
|
|
|
|
void startContour() {
|
|
if (!fCurrentContour) {
|
|
fCurrentContour = fContours.push_back_n(1);
|
|
}
|
|
}
|
|
|
|
void walk() {
|
|
// FIXME:remove once we can access path pts directly
|
|
SkPath::RawIter iter(fPath); // FIXME: access path directly when allowed
|
|
SkPoint pts[4];
|
|
SkPath::Verb verb;
|
|
do {
|
|
verb = iter.next(pts);
|
|
*fPathVerbs.append() = verb;
|
|
if (verb == SkPath::kMove_Verb) {
|
|
*fPathPts.append() = pts[0];
|
|
} else if (verb >= SkPath::kLine_Verb && verb <= SkPath::kCubic_Verb) {
|
|
fPathPts.append(verb, &pts[1]);
|
|
}
|
|
} while (verb != SkPath::kDone_Verb);
|
|
// FIXME: end of section to remove once path pts are accessed directly
|
|
|
|
SkPath::Verb reducedVerb;
|
|
uint8_t* verbPtr = fPathVerbs.begin();
|
|
const SkPoint* pointsPtr = fPathPts.begin();
|
|
while ((verb = (SkPath::Verb) *verbPtr++) != SkPath::kDone_Verb) {
|
|
switch (verb) {
|
|
case SkPath::kMove_Verb:
|
|
complete();
|
|
startContour();
|
|
pointsPtr += 1;
|
|
continue;
|
|
case SkPath::kLine_Verb:
|
|
// skip degenerate points
|
|
if (pointsPtr[-1].fX != pointsPtr[0].fX
|
|
|| pointsPtr[-1].fY != pointsPtr[0].fY) {
|
|
fCurrentContour->addLine(&pointsPtr[-1]);
|
|
}
|
|
break;
|
|
case SkPath::kQuad_Verb:
|
|
reducedVerb = QuadReduceOrder(&pointsPtr[-1], fReducePts);
|
|
if (reducedVerb == 0) {
|
|
break; // skip degenerate points
|
|
}
|
|
if (reducedVerb == 1) {
|
|
fCurrentContour->addLine(fReducePts.end() - 2);
|
|
break;
|
|
}
|
|
fCurrentContour->addQuad(&pointsPtr[-1]);
|
|
break;
|
|
case SkPath::kCubic_Verb:
|
|
reducedVerb = CubicReduceOrder(&pointsPtr[-1], fReducePts);
|
|
if (reducedVerb == 0) {
|
|
break; // skip degenerate points
|
|
}
|
|
if (reducedVerb == 1) {
|
|
fCurrentContour->addLine(fReducePts.end() - 2);
|
|
break;
|
|
}
|
|
if (reducedVerb == 2) {
|
|
fCurrentContour->addQuad(fReducePts.end() - 3);
|
|
break;
|
|
}
|
|
fCurrentContour->addCubic(&pointsPtr[-1]);
|
|
break;
|
|
case SkPath::kClose_Verb:
|
|
SkASSERT(fCurrentContour);
|
|
complete();
|
|
continue;
|
|
default:
|
|
SkDEBUGFAIL("bad verb");
|
|
return;
|
|
}
|
|
pointsPtr += verb;
|
|
SkASSERT(fCurrentContour);
|
|
}
|
|
complete();
|
|
if (fCurrentContour && !fCurrentContour->fSegments.count()) {
|
|
fContours.pop_back();
|
|
}
|
|
}
|
|
|
|
private:
|
|
const SkPath& fPath;
|
|
SkTDArray<SkPoint> fPathPts; // FIXME: point directly to path pts instead
|
|
SkTDArray<uint8_t> fPathVerbs; // FIXME: remove
|
|
Contour* fCurrentContour;
|
|
SkTArray<Contour>& fContours;
|
|
SkTDArray<SkPoint> fReducePts; // segments created on the fly
|
|
};
|
|
|
|
class Work {
|
|
public:
|
|
enum SegmentType {
|
|
kHorizontalLine_Segment = -1,
|
|
kVerticalLine_Segment = 0,
|
|
kLine_Segment = SkPath::kLine_Verb,
|
|
kQuad_Segment = SkPath::kQuad_Verb,
|
|
kCubic_Segment = SkPath::kCubic_Verb,
|
|
};
|
|
|
|
void addOtherT(int index, double other) {
|
|
fContour->fSegments[fIndex].addOtherT(index, other);
|
|
}
|
|
|
|
// Avoid collapsing t values that are close to the same since
|
|
// we walk ts to describe consecutive intersections. Since a pair of ts can
|
|
// be nearly equal, any problems caused by this should be taken care
|
|
// of later.
|
|
// On the edge or out of range values are negative; add 2 to get end
|
|
int addT(double newT, const Work& other, int coincident) {
|
|
fContour->containsIntercepts();
|
|
return fContour->fSegments[fIndex].addT(newT,
|
|
other.fContour->fSegments[other.fIndex], coincident);
|
|
}
|
|
|
|
bool advance() {
|
|
return ++fIndex < fLast;
|
|
}
|
|
|
|
SkScalar bottom() const {
|
|
return bounds().fBottom;
|
|
}
|
|
|
|
const Bounds& bounds() const {
|
|
return fContour->fSegments[fIndex].bounds();
|
|
}
|
|
|
|
const SkPoint* cubic() const {
|
|
return fCubic;
|
|
}
|
|
|
|
void init(Contour* contour) {
|
|
fContour = contour;
|
|
fIndex = 0;
|
|
fLast = contour->fSegments.count();
|
|
}
|
|
|
|
SkScalar left() const {
|
|
return bounds().fLeft;
|
|
}
|
|
|
|
void promoteToCubic() {
|
|
fCubic[0] = pts()[0];
|
|
fCubic[2] = pts()[1];
|
|
fCubic[3] = pts()[2];
|
|
fCubic[1].fX = (fCubic[0].fX + fCubic[2].fX * 2) / 3;
|
|
fCubic[1].fY = (fCubic[0].fY + fCubic[2].fY * 2) / 3;
|
|
fCubic[2].fX = (fCubic[3].fX + fCubic[2].fX * 2) / 3;
|
|
fCubic[2].fY = (fCubic[3].fY + fCubic[2].fY * 2) / 3;
|
|
}
|
|
|
|
const SkPoint* pts() const {
|
|
return fContour->fSegments[fIndex].pts();
|
|
}
|
|
|
|
SkScalar right() const {
|
|
return bounds().fRight;
|
|
}
|
|
|
|
ptrdiff_t segmentIndex() const {
|
|
return fIndex;
|
|
}
|
|
|
|
SegmentType segmentType() const {
|
|
const Segment& segment = fContour->fSegments[fIndex];
|
|
SegmentType type = (SegmentType) segment.verb();
|
|
if (type != kLine_Segment) {
|
|
return type;
|
|
}
|
|
if (segment.isHorizontal()) {
|
|
return kHorizontalLine_Segment;
|
|
}
|
|
if (segment.isVertical()) {
|
|
return kVerticalLine_Segment;
|
|
}
|
|
return kLine_Segment;
|
|
}
|
|
|
|
bool startAfter(const Work& after) {
|
|
fIndex = after.fIndex;
|
|
return advance();
|
|
}
|
|
|
|
SkScalar top() const {
|
|
return bounds().fTop;
|
|
}
|
|
|
|
SkPath::Verb verb() const {
|
|
return fContour->fSegments[fIndex].verb();
|
|
}
|
|
|
|
SkScalar x() const {
|
|
return bounds().fLeft;
|
|
}
|
|
|
|
bool xFlipped() const {
|
|
return x() != pts()[0].fX;
|
|
}
|
|
|
|
SkScalar y() const {
|
|
return bounds().fTop;
|
|
}
|
|
|
|
bool yFlipped() const {
|
|
return y() != pts()[0].fX;
|
|
}
|
|
|
|
protected:
|
|
Contour* fContour;
|
|
SkPoint fCubic[4];
|
|
int fIndex;
|
|
int fLast;
|
|
};
|
|
|
|
static void debugShowLineIntersection(int pts, const Work& wt,
|
|
const Work& wn, const double wtTs[2], const double wnTs[2]) {
|
|
#if DEBUG_ADD_INTERSECTING_TS
|
|
if (!pts) {
|
|
return;
|
|
}
|
|
SkPoint wtOutPt, wnOutPt;
|
|
LineXYAtT(wt.pts(), wtTs[0], &wtOutPt);
|
|
LineXYAtT(wn.pts(), wnTs[0], &wnOutPt);
|
|
SkDebugf("%s wtTs[0]=%g (%g,%g, %g,%g) (%g,%g)\n",
|
|
__FUNCTION__,
|
|
wtTs[0], wt.pts()[0].fX, wt.pts()[0].fY,
|
|
wt.pts()[1].fX, wt.pts()[1].fY, wtOutPt.fX, wtOutPt.fY);
|
|
if (pts == 2) {
|
|
SkDebugf("%s wtTs[1]=%g\n", __FUNCTION__, wtTs[1]);
|
|
}
|
|
SkDebugf("%s wnTs[0]=%g (%g,%g, %g,%g) (%g,%g)\n",
|
|
__FUNCTION__,
|
|
wnTs[0], wn.pts()[0].fX, wn.pts()[0].fY,
|
|
wn.pts()[1].fX, wn.pts()[1].fY, wnOutPt.fX, wnOutPt.fY);
|
|
if (pts == 2) {
|
|
SkDebugf("%s wnTs[1]=%g\n", __FUNCTION__, wnTs[1]);
|
|
}
|
|
#endif
|
|
}
|
|
|
|
static bool addIntersectTs(Contour* test, Contour* next, int winding) {
|
|
if (test != next) {
|
|
if (test->bounds().fBottom < next->bounds().fTop) {
|
|
return false;
|
|
}
|
|
if (!Bounds::Intersects(test->bounds(), next->bounds())) {
|
|
return true;
|
|
}
|
|
}
|
|
Work wt, wn;
|
|
wt.init(test);
|
|
wn.init(next);
|
|
do {
|
|
if (test == next && !wn.startAfter(wt)) {
|
|
continue;
|
|
}
|
|
do {
|
|
if (!Bounds::Intersects(wt.bounds(), wn.bounds())) {
|
|
continue;
|
|
}
|
|
int pts;
|
|
Intersections ts;
|
|
bool swap = false;
|
|
switch (wt.segmentType()) {
|
|
case Work::kHorizontalLine_Segment:
|
|
swap = true;
|
|
switch (wn.segmentType()) {
|
|
case Work::kHorizontalLine_Segment:
|
|
case Work::kVerticalLine_Segment:
|
|
case Work::kLine_Segment: {
|
|
pts = HLineIntersect(wn.pts(), wt.left(),
|
|
wt.right(), wt.y(), wt.xFlipped(), ts);
|
|
break;
|
|
}
|
|
case Work::kQuad_Segment: {
|
|
pts = HQuadIntersect(wn.pts(), wt.left(),
|
|
wt.right(), wt.y(), wt.xFlipped(), ts);
|
|
break;
|
|
}
|
|
case Work::kCubic_Segment: {
|
|
pts = HCubicIntersect(wn.pts(), wt.left(),
|
|
wt.right(), wt.y(), wt.xFlipped(), ts);
|
|
break;
|
|
}
|
|
default:
|
|
SkASSERT(0);
|
|
}
|
|
break;
|
|
case Work::kVerticalLine_Segment:
|
|
swap = true;
|
|
switch (wn.segmentType()) {
|
|
case Work::kHorizontalLine_Segment:
|
|
case Work::kVerticalLine_Segment:
|
|
case Work::kLine_Segment: {
|
|
pts = VLineIntersect(wn.pts(), wt.top(),
|
|
wt.bottom(), wt.x(), wt.yFlipped(), ts);
|
|
break;
|
|
}
|
|
case Work::kQuad_Segment: {
|
|
pts = VQuadIntersect(wn.pts(), wt.top(),
|
|
wt.bottom(), wt.x(), wt.yFlipped(), ts);
|
|
break;
|
|
}
|
|
case Work::kCubic_Segment: {
|
|
pts = VCubicIntersect(wn.pts(), wt.top(),
|
|
wt.bottom(), wt.x(), wt.yFlipped(), ts);
|
|
break;
|
|
}
|
|
default:
|
|
SkASSERT(0);
|
|
}
|
|
break;
|
|
case Work::kLine_Segment:
|
|
switch (wn.segmentType()) {
|
|
case Work::kHorizontalLine_Segment:
|
|
pts = HLineIntersect(wt.pts(), wn.left(),
|
|
wn.right(), wn.y(), wn.xFlipped(), ts);
|
|
break;
|
|
case Work::kVerticalLine_Segment:
|
|
pts = VLineIntersect(wt.pts(), wn.top(),
|
|
wn.bottom(), wn.x(), wn.yFlipped(), ts);
|
|
break;
|
|
case Work::kLine_Segment: {
|
|
pts = LineIntersect(wt.pts(), wn.pts(), ts);
|
|
debugShowLineIntersection(pts, wt, wn,
|
|
ts.fT[1], ts.fT[0]);
|
|
break;
|
|
}
|
|
case Work::kQuad_Segment: {
|
|
swap = true;
|
|
pts = QuadLineIntersect(wn.pts(), wt.pts(), ts);
|
|
break;
|
|
}
|
|
case Work::kCubic_Segment: {
|
|
swap = true;
|
|
pts = CubicLineIntersect(wn.pts(), wt.pts(), ts);
|
|
break;
|
|
}
|
|
default:
|
|
SkASSERT(0);
|
|
}
|
|
break;
|
|
case Work::kQuad_Segment:
|
|
switch (wn.segmentType()) {
|
|
case Work::kHorizontalLine_Segment:
|
|
pts = HQuadIntersect(wt.pts(), wn.left(),
|
|
wn.right(), wn.y(), wn.xFlipped(), ts);
|
|
break;
|
|
case Work::kVerticalLine_Segment:
|
|
pts = VQuadIntersect(wt.pts(), wn.top(),
|
|
wn.bottom(), wn.x(), wn.yFlipped(), ts);
|
|
break;
|
|
case Work::kLine_Segment: {
|
|
pts = QuadLineIntersect(wt.pts(), wn.pts(), ts);
|
|
break;
|
|
}
|
|
case Work::kQuad_Segment: {
|
|
pts = QuadIntersect(wt.pts(), wn.pts(), ts);
|
|
break;
|
|
}
|
|
case Work::kCubic_Segment: {
|
|
wt.promoteToCubic();
|
|
pts = CubicIntersect(wt.cubic(), wn.pts(), ts);
|
|
break;
|
|
}
|
|
default:
|
|
SkASSERT(0);
|
|
}
|
|
break;
|
|
case Work::kCubic_Segment:
|
|
switch (wn.segmentType()) {
|
|
case Work::kHorizontalLine_Segment:
|
|
pts = HCubicIntersect(wt.pts(), wn.left(),
|
|
wn.right(), wn.y(), wn.xFlipped(), ts);
|
|
break;
|
|
case Work::kVerticalLine_Segment:
|
|
pts = VCubicIntersect(wt.pts(), wn.top(),
|
|
wn.bottom(), wn.x(), wn.yFlipped(), ts);
|
|
break;
|
|
case Work::kLine_Segment: {
|
|
pts = CubicLineIntersect(wt.pts(), wn.pts(), ts);
|
|
break;
|
|
}
|
|
case Work::kQuad_Segment: {
|
|
wn.promoteToCubic();
|
|
pts = CubicIntersect(wt.pts(), wn.cubic(), ts);
|
|
break;
|
|
}
|
|
case Work::kCubic_Segment: {
|
|
pts = CubicIntersect(wt.pts(), wn.pts(), ts);
|
|
break;
|
|
}
|
|
default:
|
|
SkASSERT(0);
|
|
}
|
|
break;
|
|
default:
|
|
SkASSERT(0);
|
|
}
|
|
// in addition to recording T values, record matching segment
|
|
int coincident = pts == 2 && wn.segmentType() <= Work::kLine_Segment
|
|
&& wt.segmentType() <= Work::kLine_Segment ? -1 :0;
|
|
for (int pt = 0; pt < pts; ++pt) {
|
|
SkASSERT(ts.fT[0][pt] >= 0 && ts.fT[0][pt] <= 1);
|
|
SkASSERT(ts.fT[1][pt] >= 0 && ts.fT[1][pt] <= 1);
|
|
int testTAt = wt.addT(ts.fT[swap][pt], wn, coincident);
|
|
int nextTAt = wn.addT(ts.fT[!swap][pt], wt, coincident);
|
|
wt.addOtherT(testTAt, ts.fT[!swap][pt]);
|
|
wn.addOtherT(nextTAt, ts.fT[swap][pt]);
|
|
coincident = -coincident;
|
|
}
|
|
} while (wn.advance());
|
|
} while (wt.advance());
|
|
return true;
|
|
}
|
|
|
|
// see if coincidence is formed by clipping non-concident segments
|
|
static void coincidenceCheck(SkTDArray<Contour*>& contourList, int winding) {
|
|
int contourCount = contourList.count();
|
|
for (size_t cIndex = 0; cIndex < contourCount; ++cIndex) {
|
|
Contour* contour = contourList[cIndex];
|
|
contour->findTooCloseToCall(winding);
|
|
}
|
|
}
|
|
|
|
// Each segment may have an inside or an outside. Segments contained within
|
|
// winding may have insides on either side, and form a contour that should be
|
|
// ignored. Segments that are coincident with opposing direction segments may
|
|
// have outsides on either side, and should also disappear.
|
|
// 'Normal' segments will have one inside and one outside. Subsequent connections
|
|
// when winding should follow the intersection direction. If more than one edge
|
|
// is an option, choose first edge that continues the inside.
|
|
|
|
static void bridge(SkTDArray<Contour*>& contourList) {
|
|
int contourCount = contourList.count();
|
|
do {
|
|
// OPTIMIZATION: not crazy about linear search here to find top active y.
|
|
// seems like we should break down and do the sort, or maybe sort each
|
|
// contours' segments?
|
|
// Once the segment array is built, there's no reason I can think of not to
|
|
// sort it in Y. hmmm
|
|
int cIndex = 0;
|
|
Segment* topStart;
|
|
do {
|
|
Contour* topContour = contourList[cIndex];
|
|
topStart = topContour->topSegment();
|
|
} while (!topStart && ++cIndex < contourCount);
|
|
if (!topStart) {
|
|
break;
|
|
}
|
|
SkScalar top = topStart->bounds().fTop;
|
|
for (int cTest = cIndex + 1; cTest < contourCount; ++cTest) {
|
|
Contour* contour = contourList[cTest];
|
|
if (top < contour->bounds().fTop) {
|
|
continue;
|
|
}
|
|
Segment* test = contour->topSegment();
|
|
if (top > test->bounds().fTop) {
|
|
cIndex = cTest;
|
|
topStart = test;
|
|
top = test->bounds().fTop;
|
|
}
|
|
}
|
|
int index;
|
|
const Segment* topSegment = topStart->findTop(index);
|
|
// Start at the top. Above the top is outside, below is inside.
|
|
// follow edges to intersection
|
|
// at intersection, stay on outside, but mark remaining edges as inside
|
|
// or, only mark first pair as inside?
|
|
// how is this going to work for contained (but not intersecting)
|
|
// segments?
|
|
// start here ;
|
|
// find span
|
|
// mark neighbors winding coverage
|
|
// output span
|
|
// mark span as processed
|
|
|
|
} while (true);
|
|
|
|
|
|
}
|
|
|
|
static void makeContourList(SkTArray<Contour>& contours, Contour& sentinel,
|
|
SkTDArray<Contour*>& list) {
|
|
int count = contours.count();
|
|
if (count == 0) {
|
|
return;
|
|
}
|
|
for (int index = 0; index < count; ++index) {
|
|
*list.append() = &contours[index];
|
|
}
|
|
*list.append() = &sentinel;
|
|
QSort<Contour>(list.begin(), list.end() - 1);
|
|
}
|
|
|
|
void simplifyx(const SkPath& path, bool asFill, SkPath& simple) {
|
|
// returns 1 for evenodd, -1 for winding, regardless of inverse-ness
|
|
int winding = (path.getFillType() & 1) ? 1 : -1;
|
|
simple.reset();
|
|
simple.setFillType(SkPath::kEvenOdd_FillType);
|
|
|
|
// turn path into list of segments
|
|
SkTArray<Contour> contours;
|
|
// FIXME: add self-intersecting cubics' T values to segment
|
|
EdgeBuilder builder(path, contours);
|
|
SkTDArray<Contour*> contourList;
|
|
Contour sentinel;
|
|
sentinel.reset();
|
|
makeContourList(contours, sentinel, contourList);
|
|
Contour** currentPtr = contourList.begin();
|
|
if (!currentPtr) {
|
|
return;
|
|
}
|
|
// find all intersections between segments
|
|
do {
|
|
Contour** nextPtr = currentPtr;
|
|
Contour* current = *currentPtr++;
|
|
Contour* next;
|
|
do {
|
|
next = *nextPtr++;
|
|
} while (next != &sentinel && addIntersectTs(current, next, winding));
|
|
} while (*currentPtr != &sentinel);
|
|
// eat through coincident edges
|
|
coincidenceCheck(contourList, winding);
|
|
// construct closed contours
|
|
bridge(contourList);
|
|
}
|
|
|