alphagradients.cpp 2.7 KB

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  1. /*
  2. * Copyright 2013 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/SkCanvas.h"
  9. #include "include/core/SkColor.h"
  10. #include "include/core/SkPaint.h"
  11. #include "include/core/SkPoint.h"
  12. #include "include/core/SkRect.h"
  13. #include "include/core/SkShader.h"
  14. #include "include/core/SkSize.h"
  15. #include "include/core/SkString.h"
  16. #include "include/core/SkTileMode.h"
  17. #include "include/core/SkTypes.h"
  18. #include "include/effects/SkGradientShader.h"
  19. class AlphaGradientsGM : public skiagm::GM {
  20. public:
  21. AlphaGradientsGM() {}
  22. protected:
  23. SkString onShortName() override {
  24. return SkString("alphagradients");
  25. }
  26. SkISize onISize() override {
  27. return SkISize::Make(640, 480);
  28. }
  29. static void draw_grad(SkCanvas* canvas, const SkRect& r,
  30. SkColor c0, SkColor c1, bool doPreMul) {
  31. SkColor colors[] = { c0, c1 };
  32. SkPoint pts[] = { { r.fLeft, r.fTop }, { r.fRight, r.fBottom } };
  33. SkPaint paint;
  34. uint32_t flags = doPreMul ? SkGradientShader::kInterpolateColorsInPremul_Flag : 0;
  35. paint.setShader(SkGradientShader::MakeLinear(pts, colors, nullptr, 2,
  36. SkTileMode::kClamp, flags, nullptr));
  37. canvas->drawRect(r, paint);
  38. paint.setShader(nullptr);
  39. paint.setStyle(SkPaint::kStroke_Style);
  40. canvas->drawRect(r, paint);
  41. }
  42. void onDraw(SkCanvas* canvas) override {
  43. constexpr struct {
  44. SkColor fColor0;
  45. SkColor fColor1;
  46. } gRec[] = {
  47. { 0xFFFFFFFF, 0x00000000 },
  48. { 0xFFFFFFFF, 0x00FF0000 },
  49. { 0xFFFFFFFF, 0x00FFFF00 },
  50. { 0xFFFFFFFF, 0x00FFFFFF },
  51. { 0xFFFF0000, 0x00000000 },
  52. { 0xFFFF0000, 0x00FF0000 },
  53. { 0xFFFF0000, 0x00FFFF00 },
  54. { 0xFFFF0000, 0x00FFFFFF },
  55. { 0xFF0000FF, 0x00000000 },
  56. { 0xFF0000FF, 0x00FF0000 },
  57. { 0xFF0000FF, 0x00FFFF00 },
  58. { 0xFF0000FF, 0x00FFFFFF },
  59. };
  60. SkRect r = SkRect::MakeWH(300, 30);
  61. canvas->translate(10, 10);
  62. for (int doPreMul = 0; doPreMul <= 1; ++doPreMul) {
  63. canvas->save();
  64. for (size_t i = 0; i < SK_ARRAY_COUNT(gRec); ++i) {
  65. draw_grad(canvas, r, gRec[i].fColor0, gRec[i].fColor1, SkToBool(doPreMul));
  66. canvas->translate(0, r.height() + 8);
  67. }
  68. canvas->restore();
  69. canvas->translate(r.width() + 10, 0);
  70. }
  71. }
  72. private:
  73. typedef skiagm::GM INHERITED;
  74. };
  75. DEF_GM(return new AlphaGradientsGM;)