SkOverdrawColorFilter.cpp 2.9 KB

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  1. /*
  2. * Copyright 2016 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 "include/effects/SkOverdrawColorFilter.h"
  8. #include "src/core/SkArenaAlloc.h"
  9. #include "src/core/SkEffectPriv.h"
  10. #include "src/core/SkRasterPipeline.h"
  11. #include "src/core/SkReadBuffer.h"
  12. #if SK_SUPPORT_GPU
  13. #include "src/gpu/effects/GrSkSLFP.h"
  14. GR_FP_SRC_STRING SKSL_OVERDRAW_SRC = R"(
  15. layout(ctype=SkPMColor) in uniform half4 color0;
  16. layout(ctype=SkPMColor) in uniform half4 color1;
  17. layout(ctype=SkPMColor) in uniform half4 color2;
  18. layout(ctype=SkPMColor) in uniform half4 color3;
  19. layout(ctype=SkPMColor) in uniform half4 color4;
  20. layout(ctype=SkPMColor) in uniform half4 color5;
  21. void main(inout half4 color) {
  22. half alpha = 255.0 * color.a;
  23. if (alpha < 0.5) {
  24. color = color0;
  25. } else if (alpha < 1.5) {
  26. color = color1;
  27. } else if (alpha < 2.5) {
  28. color = color2;
  29. } else if (alpha < 3.5) {
  30. color = color3;
  31. } else if (alpha < 4.5) {
  32. color = color4;
  33. } else {
  34. color = color5;
  35. }
  36. }
  37. )";
  38. #endif
  39. bool SkOverdrawColorFilter::onAppendStages(const SkStageRec& rec, bool shader_is_opaque) const {
  40. struct Ctx : public SkRasterPipeline_CallbackCtx {
  41. const SkPMColor* colors;
  42. };
  43. // TODO: do we care about transforming to dstCS?
  44. auto ctx = rec.fAlloc->make<Ctx>();
  45. ctx->colors = fColors;
  46. ctx->fn = [](SkRasterPipeline_CallbackCtx* arg, int active_pixels) {
  47. auto ctx = (Ctx*)arg;
  48. auto pixels = (SkPMColor4f*)ctx->rgba;
  49. for (int i = 0; i < active_pixels; i++) {
  50. uint8_t alpha = (int)(pixels[i].fA * 255);
  51. if (alpha >= kNumColors) {
  52. alpha = kNumColors - 1;
  53. }
  54. pixels[i] = SkPMColor4f::FromPMColor(ctx->colors[alpha]);
  55. }
  56. };
  57. rec.fPipeline->append(SkRasterPipeline::callback, ctx);
  58. return true;
  59. }
  60. void SkOverdrawColorFilter::flatten(SkWriteBuffer& buffer) const {
  61. buffer.writeByteArray(fColors, kNumColors * sizeof(SkPMColor));
  62. }
  63. sk_sp<SkFlattenable> SkOverdrawColorFilter::CreateProc(SkReadBuffer& buffer) {
  64. SkPMColor colors[kNumColors];
  65. size_t size = buffer.getArrayCount();
  66. if (!buffer.validate(size == sizeof(colors))) {
  67. return nullptr;
  68. }
  69. if (!buffer.readByteArray(colors, sizeof(colors))) {
  70. return nullptr;
  71. }
  72. return SkOverdrawColorFilter::Make(colors);
  73. }
  74. void SkOverdrawColorFilter::RegisterFlattenables() {
  75. SK_REGISTER_FLATTENABLE(SkOverdrawColorFilter);
  76. }
  77. #if SK_SUPPORT_GPU
  78. #include "include/private/GrRecordingContext.h"
  79. std::unique_ptr<GrFragmentProcessor> SkOverdrawColorFilter::asFragmentProcessor(
  80. GrRecordingContext* context, const GrColorSpaceInfo&) const {
  81. static int overdrawIndex = GrSkSLFP::NewIndex();
  82. return GrSkSLFP::Make(context, overdrawIndex, "Overdraw", SKSL_OVERDRAW_SRC, fColors,
  83. sizeof(fColors));
  84. }
  85. #endif