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, SkPMColor*,
  32                      int*) override {
  33         if (info.colorType() == kIndex_8_SkColorType) {
  34             return false;
  35         }
  36
  37         SkImageInfo surfaceInfo = info;
  38         if (kAlpha_8_SkColorType == info.colorType()) {
  39             surfaceInfo = surfaceInfo.makeColorSpace(nullptr);
  40         }
  41
  42         make_mask(SkSurface::MakeRasterDirect(surfaceInfo, pixels, rowBytes));
  43         return true;
  44     }
  45
  46 private:
  47     typedef SkImageGenerator INHERITED;
  48 };
  49
  50 using MakerT = sk_sp<SkImage>(*)(SkCanvas*, const SkImageInfo&);
  51 const MakerT makers[] = {
  52     // SkImage_Raster
  53     [](SkCanvas*, const SkImageInfo& info) -> sk_sp<SkImage> {
  54         return make_mask(SkSurface::MakeRaster(info));
  55     },
  56
  57     // SkImage_Gpu
  58     [](SkCanvas* c, const SkImageInfo& info) -> sk_sp<SkImage> {
  59         sk_sp<SkSurface> surface;
  60 #if SK_SUPPORT_GPU
  61         surface = SkSurface::MakeRenderTarget(c->getGrContext(), SkBudgeted::kNo, info);
  62 #endif
  63         return make_mask(surface ? surface : SkSurface::MakeRaster(info));
  64     },
  65
  66     // SkImage_Generator
  67     [](SkCanvas*, const SkImageInfo& info) -> sk_sp<SkImage> {
  68         return SkImage::MakeFromGenerator(skstd::make_unique<MaskGenerator>(info));
  69     },
  70 };
  71
  72 } // anonymous ns
  73
  74 // Checks whether subset SkImages preserve the original color type (A8 in this case).
  75 DEF_SIMPLE_GM(imagemasksubset, canvas, 480, 480) {
  76     SkPaint paint;
  77     paint.setColor(0xff00ff00);
  78
  79     const SkImageInfo info = SkImageInfo::MakeA8(kSize.width(), kSize.height());
  80
  81     for (size_t i = 0; i < SK_ARRAY_COUNT(makers); ++i) {
  82         sk_sp<SkImage> image = makers[i](canvas, info);
  83         if (image) {
  84             canvas->drawImageRect(image, SkRect::Make(kSubset), kDest, &paint);
  85             sk_sp<SkImage> subset = image->makeSubset(kSubset);
  86             canvas->drawImageRect(subset, kDest.makeOffset(kSize.width() * 1.5f, 0), &paint);
  87         }
  88         canvas->translate(0, kSize.height() * 1.5f);
  89     }
  90 }