| /* |
| * Copyright 2021 Google LLC |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| /* |
| * This GM creates the same gradients as the Chromium test fillrect_gradient: |
| * http://osscs/chromium/chromium/src/+/main:third_party/blink/web_tests/fast/canvas/fillrect_gradient.html |
| */ |
| |
| #include "gm/gm.h" |
| #include "include/core/SkCanvas.h" |
| #include "include/core/SkColor.h" |
| #include "include/core/SkPaint.h" |
| #include "include/core/SkPoint.h" |
| #include "include/core/SkRect.h" |
| #include "include/core/SkRefCnt.h" |
| #include "include/core/SkScalar.h" |
| #include "include/core/SkShader.h" |
| #include "include/core/SkSize.h" |
| #include "include/core/SkString.h" |
| #include "include/core/SkTileMode.h" |
| #include "include/effects/SkGradientShader.h" |
| |
| #include <vector> |
| |
| const int kCellSize = 50; |
| const int kNumColumns = 2; |
| const int kNumRows = 9; |
| const int kPadSize = 10; |
| |
| class FillrectGradientGM : public skiagm::GM { |
| public: |
| FillrectGradientGM() {} |
| |
| protected: |
| struct GradientStop { |
| float pos; |
| SkColor color; |
| }; |
| |
| SkString getName() const override { return SkString("fillrect_gradient"); } |
| |
| SkISize getISize() override { |
| return SkISize::Make(kNumColumns * (kCellSize + kPadSize), |
| kNumRows * (kCellSize + kPadSize)); |
| } |
| |
| void drawGradient(SkCanvas* canvas, std::initializer_list<GradientStop> stops) { |
| std::vector<SkColor> colors; |
| std::vector<SkScalar> positions; |
| colors.reserve(stops.size()); |
| positions.reserve(stops.size()); |
| |
| for (const GradientStop& stop : stops) { |
| colors.push_back(stop.color); |
| positions.push_back(stop.pos); |
| } |
| |
| static constexpr SkPoint points[] = { |
| SkPoint::Make(kCellSize, 0), |
| SkPoint::Make(kCellSize, kCellSize), |
| }; |
| |
| // Draw the gradient linearly. |
| sk_sp<SkShader> shader = SkGradientShader::MakeLinear(points, |
| colors.data(), |
| positions.data(), |
| colors.size(), |
| SkTileMode::kClamp); |
| SkPaint paint; |
| paint.setShader(shader); |
| canvas->drawRect(SkRect::MakeXYWH(0, 0, kCellSize, kCellSize), paint); |
| |
| canvas->save(); |
| canvas->translate(kCellSize + kPadSize, 0); |
| |
| // Draw the gradient radially. |
| shader = SkGradientShader::MakeRadial(SkPoint::Make(kCellSize / 2, kCellSize / 2), |
| kCellSize / 2, |
| colors.data(), |
| positions.data(), |
| colors.size(), |
| SkTileMode::kClamp); |
| paint.setShader(shader); |
| canvas->drawRect(SkRect::MakeXYWH(0, 0, kCellSize, kCellSize), paint); |
| |
| canvas->restore(); |
| canvas->translate(0, kCellSize + kPadSize); |
| } |
| |
| void onDraw(SkCanvas* canvas) override { |
| // Simple gradient: Green to white |
| this->drawGradient(canvas, {{0.0f, SK_ColorGREEN}, {1.0f, SK_ColorWHITE}}); |
| |
| // Multiple sections: Green to white to red |
| this->drawGradient(canvas, |
| {{0.0f, SK_ColorGREEN}, {0.5f, SK_ColorWHITE}, {1.0f, SK_ColorRED}}); |
| |
| // No stops at 0.0 or 1.0: Larger green to white to larger red |
| this->drawGradient(canvas, |
| {{0.4f, SK_ColorGREEN}, {0.5f, SK_ColorWHITE}, {0.6f, SK_ColorRED}}); |
| |
| // Only one stop, at zero: Solid red |
| this->drawGradient(canvas, {{0.0f, SK_ColorRED}}); |
| |
| // Only one stop, at 1.0: Solid red |
| this->drawGradient(canvas, {{1.0f, SK_ColorRED}}); |
| |
| // Only one stop, in the middle: Solid red |
| this->drawGradient(canvas, {{0.5f, SK_ColorRED}}); |
| |
| // Disjoint gradients (multiple stops at the same offset) |
| // Blue to white in the top (inner) half, red to yellow in the bottom (outer) half |
| this->drawGradient(canvas, |
| {{0.0f, SK_ColorBLUE}, |
| {0.5f, SK_ColorWHITE}, |
| {0.5f, SK_ColorRED}, |
| {1.0f, SK_ColorYELLOW}}); |
| |
| // Ignored stops: Blue to white, red to yellow (same as previous) |
| this->drawGradient(canvas, |
| {{0.0f, SK_ColorBLUE}, |
| {0.5f, SK_ColorWHITE}, |
| {0.5f, SK_ColorGRAY}, |
| {0.5f, SK_ColorCYAN}, |
| {0.5f, SK_ColorRED}, |
| {1.0f, SK_ColorYELLOW}}); |
| |
| // Unsorted stops: Blue to white, red to yellow |
| // Unlike Chrome, we don't sort the stops, so this renders differently than the prior cell. |
| this->drawGradient(canvas, |
| {{0.5f, SK_ColorWHITE}, |
| {0.5f, SK_ColorGRAY}, |
| {1.0f, SK_ColorYELLOW}, |
| {0.5f, SK_ColorCYAN}, |
| {0.5f, SK_ColorRED}, |
| {0.0f, SK_ColorBLUE}}); |
| } |
| |
| private: |
| using INHERITED = skiagm::GM; |
| }; |
| |
| DEF_GM(return new FillrectGradientGM;) |