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/*
* Copyright 2015 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 "SkPath.h"
DEF_SIMPLE_GM(PlusMergesAA, canvas, 256, 256) {
SkPaint p;
p.setColor(SK_ColorRED);
p.setAntiAlias(true); // <-- crucial to the test that we use AA
// Draw a two red squares.
canvas->drawRect(SkRect::MakeWH(100, 100), p);
canvas->drawRect(SkRect::MakeXYWH(150, 0, 100, 100), p);
p.setColor(0xf000ff00);
// We'll draw a green square on top of each using two triangles.
SkPath upperLeft;
upperLeft.lineTo(100, 0);
upperLeft.lineTo(0, 100);
upperLeft.lineTo(0, 0);
SkPath bottomRight;
bottomRight.moveTo(100, 0);
bottomRight.lineTo(100, 100);
bottomRight.lineTo(0, 100);
bottomRight.lineTo(100, 0);
// The left square is drawn simply with SrcOver. It will show a red seam.
canvas->drawPath(upperLeft, p);
canvas->drawPath(bottomRight, p);
// Using Plus on the right should merge the AA of seam together completely covering the red.
canvas->saveLayer(nullptr, nullptr);
p.setBlendMode(SkBlendMode::kPlus);
canvas->translate(150, 0);
canvas->drawPath(upperLeft, p);
canvas->drawPath(bottomRight, p);
canvas->restore();
}
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