gm/imagemasksubset.cpp

   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
   8 #include "gm.h"
   9 #include "sk_tool_utils.h"
  10 #include "SkCanvas.h"
  11 #include "SkImage.h"
  12 #include "SkImageGenerator.h"
  13 #include "SkMakeUnique.h"
  14 #include "SkSurface.h"
  15
  16 namespace {
  17
  18 const SkISize   kSize = SkISize::Make(100, 100);
  19 const SkIRect kSubset = SkIRect::MakeLTRB(25, 25, 75, 75);
  20 const SkRect    kDest = SkRect::MakeXYWH(10, 10, 100, 100);
  21
  22 sk_sp<SkImage> make_mask(const sk_sp<SkSurface>& surface) {
  23     sk_tool_utils::draw_checkerboard(surface->getCanvas(), 0x80808080, 0x00000000, 5);
  24     return surface->makeImageSnapshot();
  25 }
  26
  27 class MaskGenerator final : public SkImageGenerator {
  28 public:
  29     MaskGenerator(const SkImageInfo& info) : INHERITED(info) {}
  30
  31     bool onGetPixels(const SkImageInfo& info, void* pixels, size_t rowBytes, const Options&)
  32     override {
  33         SkImageInfo surfaceInfo = info;
  34         if (kAlpha_8_SkColorType == info.colorType()) {
  35             surfaceInfo = surfaceInfo.makeColorSpace(nullptr);
  36         }
  37
  38         make_mask(SkSurface::MakeRasterDirect(surfaceInfo, pixels, rowBytes));
  39         return true;
  40     }
  41
  42 private:
  43     typedef SkImageGenerator INHERITED;
  44 };
  45
  46 using MakerT = sk_sp<SkImage>(*)(SkCanvas*, const SkImageInfo&);
  47 const MakerT makers[] = {
  48     // SkImage_Raster
  49     [](SkCanvas*, const SkImageInfo& info) -> sk_sp<SkImage> {
  50         return make_mask(SkSurface::MakeRaster(info));
  51     },
  52
  53     // SkImage_Gpu
  54     [](SkCanvas* c, const SkImageInfo& info) -> sk_sp<SkImage> {
  55         sk_sp<SkSurface> surface;
  56 #if SK_SUPPORT_GPU
  57         surface = SkSurface::MakeRenderTarget(c->getGrContext(), SkBudgeted::kNo, info);
  58 #endif
  59         return make_mask(surface ? surface : SkSurface::MakeRaster(info));
  60     },
  61
  62     // SkImage_Lazy
  63     [](SkCanvas*, const SkImageInfo& info) -> sk_sp<SkImage> {
  64         return SkImage::MakeFromGenerator(skstd::make_unique<MaskGenerator>(info));
  65     },
  66 };
  67
  68 } // anonymous ns
  69
  70 // Checks whether subset SkImages preserve the original color type (A8 in this case).
  71 DEF_SIMPLE_GM(imagemasksubset, canvas, 480, 480) {
  72     SkPaint paint;
  73     paint.setColor(0xff00ff00);
  74
  75     const SkImageInfo info = SkImageInfo::MakeA8(kSize.width(), kSize.height());
  76
  77     for (size_t i = 0; i < SK_ARRAY_COUNT(makers); ++i) {
  78         sk_sp<SkImage> image = makers[i](canvas, info);
  79         if (image) {
  80             canvas->drawImageRect(image, SkRect::Make(kSubset), kDest, &paint);
  81             sk_sp<SkImage> subset = image->makeSubset(kSubset);
  82             canvas->drawImageRect(subset, kDest.makeOffset(kSize.width() * 1.5f, 0), &paint);
  83         }
  84         canvas->translate(0, kSize.height() * 1.5f);
  85     }
  86 }