09a7bb2221
This is a reland of 2f2757fa6b
Original change's description:
> ccpr: Implement stroking with fine triangle strips
>
> Implements strokes by linearizing the curve into fine triangle strips
> and interpolating a coverage ramp for edge AA. Each triangle in the
> strip emits either positive or negative coverage, depending on its
> winding direction. Joins and caps are drawn with the existing CCPR
> shaders for triangles and conics.
>
> Conic strokes and non-rigid-body transforms are not yet supported.
>
> Bug: skia:
> Change-Id: I45a819abd64e91c2b62e992587eb85c703e09e77
> Reviewed-on: https://skia-review.googlesource.com/148243
> Commit-Queue: Chris Dalton <csmartdalton@google.com>
> Reviewed-by: Brian Salomon <bsalomon@google.com>
> Reviewed-by: Allan MacKinnon <allanmac@google.com>
TBR=robertphillips@google.com
Bug: skia:
Change-Id: I3f0065e80975ee8334300bc5e934231b66b49178
Reviewed-on: https://skia-review.googlesource.com/151188
Commit-Queue: Chris Dalton <csmartdalton@google.com>
Reviewed-by: Chris Dalton <csmartdalton@google.com>
100 lines
3.1 KiB
C++
100 lines
3.1 KiB
C++
/*
|
|
* Copyright 2018 Google Inc.
|
|
*
|
|
* Use of this source code is governed by a BSD-style license that can be
|
|
* found in the LICENSE file.
|
|
*/
|
|
|
|
#include "gm.h"
|
|
#include "SkCanvas.h"
|
|
#include "SkGeometry.h"
|
|
#include "SkPath.h"
|
|
#include "SkPaint.h"
|
|
#include "SkStrokeRec.h"
|
|
|
|
static constexpr float kStrokeWidth = 40;
|
|
static constexpr int kCellSize = 200;
|
|
|
|
static const SkPoint kCubics[][4] = {
|
|
{{122, 737}, {348, 553}, {403, 761}, {400, 760}},
|
|
{{244, 520}, {244, 518}, {1141, 634}, {394, 688}},
|
|
{{550, 194}, {138, 130}, {1035, 246}, {288, 300}},
|
|
{{226, 733}, {556, 779}, {-43, 471}, {348, 683}},
|
|
{{268, 204}, {492, 304}, {352, 23}, {433, 412}},
|
|
{{172, 480}, {396, 580}, {256, 299}, {338, 677}},
|
|
{{731, 340}, {318, 252}, {1026, -64}, {367, 265}},
|
|
{{475, 708}, {62, 620}, {770, 304}, {220, 659}},
|
|
};
|
|
|
|
static SkRect calc_tight_cubic_bounds(const SkPoint P[4], int depth=5) {
|
|
if (0 == depth) {
|
|
SkRect bounds;
|
|
bounds.fLeft = SkTMin(SkTMin(P[0].x(), P[1].x()), SkTMin(P[2].x(), P[3].x()));
|
|
bounds.fTop = SkTMin(SkTMin(P[0].y(), P[1].y()), SkTMin(P[2].y(), P[3].y()));
|
|
bounds.fRight = SkTMax(SkTMax(P[0].x(), P[1].x()), SkTMax(P[2].x(), P[3].x()));
|
|
bounds.fBottom = SkTMax(SkTMax(P[0].y(), P[1].y()), SkTMax(P[2].y(), P[3].y()));
|
|
return bounds;
|
|
}
|
|
|
|
SkPoint chopped[7];
|
|
SkChopCubicAt(P, chopped, .5f);
|
|
SkRect bounds = calc_tight_cubic_bounds(chopped, depth - 1);
|
|
bounds.join(calc_tight_cubic_bounds(chopped+3, depth - 1));
|
|
return bounds;
|
|
}
|
|
|
|
// This is a compilation of cubics that have given strokers grief. Feel free to add more.
|
|
class TrickyCubicStrokesGM : public skiagm::GM {
|
|
public:
|
|
TrickyCubicStrokesGM() {}
|
|
|
|
protected:
|
|
|
|
SkString onShortName() override {
|
|
return SkString("trickycubicstrokes");
|
|
}
|
|
|
|
SkISize onISize() override {
|
|
return SkISize::Make(3*kCellSize, 3*kCellSize);
|
|
}
|
|
|
|
void onOnceBeforeDraw() override {
|
|
fStrokePaint.setAntiAlias(true);
|
|
fStrokePaint.setStrokeWidth(kStrokeWidth);
|
|
fStrokePaint.setColor(SK_ColorGREEN);
|
|
fStrokePaint.setStyle(SkPaint::kStroke_Style);
|
|
}
|
|
|
|
void onDraw(SkCanvas* canvas) override {
|
|
canvas->clear(SK_ColorBLACK);
|
|
|
|
for (size_t i = 0; i < SK_ARRAY_COUNT(kCubics); ++i) {
|
|
this->drawStroke(canvas, kCubics[i],
|
|
SkRect::MakeXYWH((i%3) * kCellSize, (i/3) * kCellSize, kCellSize,
|
|
kCellSize));
|
|
}
|
|
}
|
|
|
|
void drawStroke(SkCanvas* canvas, const SkPoint P[4], const SkRect& location) {
|
|
SkRect strokeBounds = calc_tight_cubic_bounds(P);
|
|
strokeBounds.outset(kStrokeWidth, kStrokeWidth);
|
|
|
|
SkMatrix matrix;
|
|
matrix.setRectToRect(strokeBounds, location, SkMatrix::kCenter_ScaleToFit);
|
|
|
|
SkPath path;
|
|
path.moveTo(P[0]);
|
|
path.cubicTo(P[1], P[2], P[3]);
|
|
|
|
SkAutoCanvasRestore acr(canvas, true);
|
|
canvas->concat(matrix);
|
|
canvas->drawPath(path, fStrokePaint);
|
|
}
|
|
|
|
private:
|
|
SkPaint fStrokePaint;
|
|
typedef GM INHERITED;
|
|
};
|
|
|
|
DEF_GM( return new TrickyCubicStrokesGM; )
|