gm/encode-alpha-jpeg.cpp

   1 /*
   2  * Copyright 2017 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 "SkImage.h"
  10 #include "SkJpegEncoder.h"
  11
  12 #include "Resources.h"
  13
  14 namespace skiagm {
  15
  16 static inline void read_into_pixmap(SkPixmap* dst, SkImageInfo dstInfo, void* dstPixels,
  17         sk_sp<SkImage> src) {
  18     dst->reset(dstInfo, dstPixels, dstInfo.minRowBytes());
  19     src->readPixels(*dst, 0, 0, SkImage::CachingHint::kDisallow_CachingHint);
  20 }
  21
  22 static inline sk_sp<SkImage> encode_pixmap_and_make_image(const SkPixmap& src,
  23         SkJpegEncoder::AlphaOption alphaOption, SkTransferFunctionBehavior blendBehavior) {
  24     SkDynamicMemoryWStream dst;
  25     SkJpegEncoder::Options options;
  26     options.fAlphaOption = alphaOption;
  27     options.fBlendBehavior = blendBehavior;
  28     SkJpegEncoder::Encode(&dst, src, options);
  29     return SkImage::MakeFromEncoded(dst.detachAsData());
  30 }
  31
  32 class EncodeJpegAlphaOptsGM : public GM {
  33 public:
  34     EncodeJpegAlphaOptsGM() {}
  35
  36 protected:
  37     SkString onShortName() override {
  38         return SkString("encode-alpha-jpeg");
  39     }
  40
  41     SkISize onISize() override {
  42         return SkISize::Make(400, 200);
  43     }
  44
  45     void onDraw(SkCanvas* canvas) override {
  46         sk_sp<SkImage> srcImg = GetResourceAsImage("rainbow-gradient.png");
  47         fStorage.reset(srcImg->width() * srcImg->height() *
  48                 SkColorTypeBytesPerPixel(kRGBA_F16_SkColorType));
  49
  50         SkPixmap src;
  51         SkImageInfo info = SkImageInfo::MakeN32Premul(srcImg->width(), srcImg->height(),
  52                 canvas->imageInfo().colorSpace() ? SkColorSpace::MakeSRGB() : nullptr);
  53         read_into_pixmap(&src, info, fStorage.get(), srcImg);
  54
  55         SkTransferFunctionBehavior behavior = canvas->imageInfo().colorSpace() ?
  56                 SkTransferFunctionBehavior::kRespect : SkTransferFunctionBehavior::kIgnore;
  57
  58         // Encode 8888 premul.
  59         sk_sp<SkImage> img0 = encode_pixmap_and_make_image(src, SkJpegEncoder::AlphaOption::kIgnore,
  60                 behavior);
  61         sk_sp<SkImage> img1 = encode_pixmap_and_make_image(src,
  62                 SkJpegEncoder::AlphaOption::kBlendOnBlack, behavior);
  63         canvas->drawImage(img0, 0.0f, 0.0f);
  64         canvas->drawImage(img1, 0.0f, 100.0f);
  65
  66         // Encode 8888 unpremul
  67         info = info.makeAlphaType(kUnpremul_SkAlphaType);
  68         read_into_pixmap(&src, info, fStorage.get(), srcImg);
  69         img0 = encode_pixmap_and_make_image(src, SkJpegEncoder::AlphaOption::kIgnore, behavior);
  70         img1 = encode_pixmap_and_make_image(src, SkJpegEncoder::AlphaOption::kBlendOnBlack,
  71                 behavior);
  72         canvas->drawImage(img0, 100.0f, 0.0f);
  73         canvas->drawImage(img1, 100.0f, 100.0f);
  74
  75         if (canvas->imageInfo().colorSpace()) {
  76             // Encode F16 premul
  77             info = SkImageInfo::Make(srcImg->width(), srcImg->height(), kRGBA_F16_SkColorType,
  78                     kPremul_SkAlphaType, SkColorSpace::MakeSRGBLinear());
  79             read_into_pixmap(&src, info, fStorage.get(), srcImg);
  80             img0 = encode_pixmap_and_make_image(src, SkJpegEncoder::AlphaOption::kIgnore, behavior);
  81             img1 = encode_pixmap_and_make_image(src, SkJpegEncoder::AlphaOption::kBlendOnBlack,
  82                     behavior);
  83             canvas->drawImage(img0, 200.0f, 0.0f);
  84             canvas->drawImage(img1, 200.0f, 100.0f);
  85
  86             // Encode F16 unpremul
  87             info = info.makeAlphaType(kUnpremul_SkAlphaType);
  88             read_into_pixmap(&src, info, fStorage.get(), srcImg);
  89             img0 = encode_pixmap_and_make_image(src, SkJpegEncoder::AlphaOption::kIgnore, behavior);
  90             img1 = encode_pixmap_and_make_image(src, SkJpegEncoder::AlphaOption::kBlendOnBlack,
  91                     behavior);
  92             canvas->drawImage(img0, 300.0f, 0.0f);
  93             canvas->drawImage(img1, 300.0f, 100.0f);
  94         }
  95     }
  96
  97 private:
  98     SkAutoTMalloc<uint8_t> fStorage;
  99
 100     typedef GM INHERITED;
 101 };
 102
 103 DEF_GM( return new EncodeJpegAlphaOptsGM; )
 104
 105 };