skia_paint_util.cc 4.5 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112
  1. // Copyright (c) 2017 The Chromium Authors. All rights reserved.
  2. // Use of this source code is governed by a BSD-style license that can be
  3. // found in the LICENSE file.
  4. #include "ui/gfx/skia_paint_util.h"
  5. #include "cc/paint/paint_image_builder.h"
  6. #include "third_party/skia/include/core/SkColorFilter.h"
  7. #include "third_party/skia/include/core/SkMaskFilter.h"
  8. #include "third_party/skia/include/effects/SkGradientShader.h"
  9. #include "third_party/skia/include/effects/SkLayerDrawLooper.h"
  10. #include "ui/gfx/geometry/skia_conversions.h"
  11. #include "ui/gfx/image/image_skia_rep.h"
  12. #include "ui/gfx/switches.h"
  13. namespace gfx {
  14. sk_sp<cc::PaintShader> CreateImageRepShader(const gfx::ImageSkiaRep& image_rep,
  15. SkTileMode tile_mode_x,
  16. SkTileMode tile_mode_y,
  17. const SkMatrix& local_matrix) {
  18. return CreateImageRepShaderForScale(image_rep, tile_mode_x, tile_mode_y,
  19. local_matrix, image_rep.scale());
  20. }
  21. sk_sp<cc::PaintShader> CreateImageRepShaderForScale(
  22. const gfx::ImageSkiaRep& image_rep,
  23. SkTileMode tile_mode_x,
  24. SkTileMode tile_mode_y,
  25. const SkMatrix& local_matrix,
  26. SkScalar scale) {
  27. // Unscale matrix by |scale| such that the bitmap is drawn at the
  28. // correct density.
  29. // Convert skew and translation to pixel coordinates.
  30. // Thus, for |bitmap_scale| = 2:
  31. // x scale = 2, x translation = 1 DIP,
  32. // should be converted to
  33. // x scale = 1, x translation = 2 pixels.
  34. SkMatrix shader_scale = local_matrix;
  35. shader_scale.preScale(scale, scale);
  36. shader_scale.setScaleX(local_matrix.getScaleX() / scale);
  37. shader_scale.setScaleY(local_matrix.getScaleY() / scale);
  38. // TODO(malaykeshav): The check for has_paint_image was only added here to
  39. // prevent generating a paint record in tests. Tests need an instance of
  40. // base::DiscardableMemoryAllocator to generate the PaintRecord. However most
  41. // test suites don't have this set.
  42. // https://crbug.com/891469
  43. if (!image_rep.has_paint_image()) {
  44. return cc::PaintShader::MakePaintRecord(
  45. image_rep.GetPaintRecord(),
  46. SkRect::MakeIWH(image_rep.pixel_width(), image_rep.pixel_height()),
  47. tile_mode_x, tile_mode_y, &shader_scale);
  48. } else {
  49. return cc::PaintShader::MakeImage(image_rep.paint_image(), tile_mode_x,
  50. tile_mode_y, &shader_scale);
  51. }
  52. }
  53. sk_sp<cc::PaintShader> CreateGradientShader(const gfx::Point& start_point,
  54. const gfx::Point& end_point,
  55. SkColor start_color,
  56. SkColor end_color) {
  57. // TODO(crbug/1308932): Remove FromColor and make all SkColor4f.
  58. SkColor4f grad_colors[2] = {SkColor4f::FromColor(start_color),
  59. SkColor4f::FromColor(end_color)};
  60. SkPoint grad_points[2] = {gfx::PointToSkPoint(start_point),
  61. gfx::PointToSkPoint(end_point)};
  62. return cc::PaintShader::MakeLinearGradient(grad_points, grad_colors, nullptr,
  63. 2, SkTileMode::kClamp);
  64. }
  65. // This is copied from
  66. // third_party/WebKit/Source/platform/graphics/skia/SkiaUtils.h
  67. static SkScalar RadiusToSigma(double radius) {
  68. return radius > 0 ? SkDoubleToScalar(0.288675f * radius + 0.5f) : 0;
  69. }
  70. sk_sp<SkDrawLooper> CreateShadowDrawLooper(
  71. const std::vector<ShadowValue>& shadows) {
  72. if (shadows.empty())
  73. return nullptr;
  74. SkLayerDrawLooper::Builder looper_builder;
  75. looper_builder.addLayer(); // top layer of the original.
  76. SkLayerDrawLooper::LayerInfo layer_info;
  77. layer_info.fPaintBits |= SkLayerDrawLooper::kMaskFilter_Bit;
  78. layer_info.fPaintBits |= SkLayerDrawLooper::kColorFilter_Bit;
  79. layer_info.fColorMode = SkBlendMode::kSrc;
  80. for (size_t i = 0; i < shadows.size(); ++i) {
  81. const ShadowValue& shadow = shadows[i];
  82. layer_info.fOffset.set(SkIntToScalar(shadow.x()),
  83. SkIntToScalar(shadow.y()));
  84. SkPaint* paint = looper_builder.addLayer(layer_info);
  85. // Skia's blur radius defines the range to extend the blur from
  86. // original mask, which is half of blur amount as defined in ShadowValue.
  87. paint->setMaskFilter(SkMaskFilter::MakeBlur(
  88. kNormal_SkBlurStyle, RadiusToSigma(shadow.blur() / 2)));
  89. paint->setColorFilter(
  90. SkColorFilters::Blend(shadow.color(), SkBlendMode::kSrcIn));
  91. }
  92. return looper_builder.detach();
  93. }
  94. } // namespace gfx