1 /* 2 * Copyright 2015 Google Inc. 3 * 4 * Use of this source code is governed by a BSD-style license that can be 5 * found in the LICENSE file. 6 */ 7 8 #include "gm.h" 9 #include "SkPath.h" 10 11 DEF_SIMPLE_GM(PlusMergesAA, canvas, 256, 256) { 12 SkPaint p; 13 p.setColor(SK_ColorRED); 14 p.setAntiAlias(true); // <-- crucial to the test that we use AA 15 16 // Draw a two red squares. 17 canvas->drawRect(SkRect::MakeWH(100, 100), p); 18 canvas->drawRect(SkRect::MakeXYWH(150, 0, 100, 100), p); 19 20 p.setColor(0xf000ff00); 21 22 // We'll draw a green square on top of each using two triangles. 23 SkPath upperLeft; 24 upperLeft.lineTo(100, 0); 25 upperLeft.lineTo(0, 100); 26 upperLeft.lineTo(0, 0); 27 28 SkPath bottomRight; 29 bottomRight.moveTo(100, 0); 30 bottomRight.lineTo(100, 100); 31 bottomRight.lineTo(0, 100); 32 bottomRight.lineTo(100, 0); 33 34 // The left square is drawn simply with SrcOver. It will show a red seam. 35 canvas->drawPath(upperLeft, p); 36 canvas->drawPath(bottomRight, p); 37 38 // Using Plus on the right should merge the AA of seam together completely covering the red. 39 canvas->saveLayer(nullptr, nullptr); 40 p.setBlendMode(SkBlendMode::kPlus); 41 canvas->translate(150, 0); 42 canvas->drawPath(upperLeft, p); 43 canvas->drawPath(bottomRight, p); 44 canvas->restore(); 45 } 46