| /* |
| * Copyright 2014 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #include "gm.h" |
| #include "SkCanvas.h" |
| #include "SkColorShader.h" |
| #include "SkPaint.h" |
| #include "SkRandom.h" |
| #include "SkSurface.h" |
| |
| #if SK_SUPPORT_GPU |
| |
| namespace skiagm { |
| |
| /* |
| * This GM exercises SkCanvas::discard() by creating an offscreen SkSurface and repeatedly |
| * discarding it, drawing to it, and then drawing it to the main canvas. |
| */ |
| class DiscardGM : public GM { |
| |
| public: |
| DiscardGM() { |
| } |
| |
| protected: |
| SkString onShortName() override { |
| return SkString("discard"); |
| } |
| |
| SkISize onISize() override { |
| return SkISize::Make(100, 100); |
| } |
| |
| void onDraw(SkCanvas* canvas) override { |
| GrContext* context = canvas->getGrContext(); |
| if (NULL == context) { |
| return; |
| } |
| |
| SkISize size = this->getISize(); |
| size.fWidth /= 10; |
| size.fHeight /= 10; |
| SkImageInfo info = SkImageInfo::MakeN32Premul(size); |
| SkSurface* surface = SkSurface::NewRenderTarget(context, SkSurface::kNo_Budgeted, info); |
| |
| if (NULL == surface) { |
| return; |
| } |
| |
| canvas->clear(SK_ColorBLACK); |
| |
| SkRandom rand; |
| for (int x = 0; x < 10; ++x) { |
| for (int y = 0; y < 10; ++y) { |
| surface->getCanvas()->discard(); |
| // Make something that isn't too close to the background color, black. |
| SkColor color = rand.nextU() | 0xFF404040; |
| switch (rand.nextULessThan(3)) { |
| case 0: |
| surface->getCanvas()->drawColor(color); |
| break; |
| case 1: |
| surface->getCanvas()->clear(color); |
| break; |
| case 2: |
| SkColorShader shader(color); |
| SkPaint paint; |
| paint.setShader(&shader); |
| surface->getCanvas()->drawPaint(paint); |
| break; |
| } |
| surface->draw(canvas, 10.f*x, 10.f*y, NULL); |
| } |
| } |
| |
| surface->getCanvas()->discard(); |
| surface->unref(); |
| } |
| |
| private: |
| typedef GM INHERITED; |
| }; |
| |
| ////////////////////////////////////////////////////////////////////////////// |
| |
| DEF_GM( return SkNEW(DiscardGM); ) |
| |
| } // end namespace |
| |
| #endif |