unpremul.cpp 2.0 KB

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  1. /*
  2. * Copyright 2018 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. #include "gm/gm.h"
  8. #include "include/core/SkBitmap.h"
  9. #include "include/core/SkBlendMode.h"
  10. #include "include/core/SkCanvas.h"
  11. #include "include/core/SkColor.h"
  12. #include "include/core/SkColorSpace.h"
  13. #include "include/core/SkImageInfo.h"
  14. #include "include/core/SkPaint.h"
  15. #include <string.h>
  16. DEF_SIMPLE_GM(unpremul, canvas, 200, 200) {
  17. const SkColor color = 0xbf400000;
  18. auto grade = [&](int x, int y){
  19. SkBitmap bm;
  20. bm.allocPixels(SkImageInfo::Make(1,1,
  21. kBGRA_8888_SkColorType,
  22. kUnpremul_SkAlphaType,
  23. SkColorSpace::MakeSRGB()));
  24. if (!canvas->readPixels(bm, x,y)) {
  25. // Picture-backed canvases, that sort of thing. Just assume they're good.
  26. MarkGMGood(canvas, 140,40);
  27. return;
  28. }
  29. SkColor pixel;
  30. memcpy(&pixel, bm.getAddr(0,0), sizeof(pixel));
  31. auto close = [](int x, int y) {
  32. return x-y < 2
  33. && y-x < 2;
  34. };
  35. if (close(SkColorGetR(pixel), SkColorGetR(color)) &&
  36. close(SkColorGetG(pixel), SkColorGetG(color)) &&
  37. close(SkColorGetB(pixel), SkColorGetB(color)) &&
  38. close(SkColorGetA(pixel), SkColorGetA(color))) {
  39. MarkGMGood(canvas, 140,40);
  40. } else {
  41. MarkGMBad(canvas, 140,40);
  42. }
  43. };
  44. {
  45. SkPaint paint;
  46. paint.setBlendMode(SkBlendMode::kSrc);
  47. paint.setColor(color);
  48. canvas->drawRect({0,0,100,100}, paint);
  49. grade(50,50);
  50. }
  51. canvas->translate(0,100);
  52. {
  53. SkPaint paint;
  54. paint.setBlendMode(SkBlendMode::kSrc);
  55. SkBitmap bm;
  56. bm.allocPixels(SkImageInfo::Make(100,100, kRGBA_8888_SkColorType, kUnpremul_SkAlphaType));
  57. bm.eraseColor(color);
  58. canvas->drawBitmap(bm, 0,0, &paint);
  59. grade(50,150);
  60. }
  61. }