gm/readpixels.cpp - platform/external/skia - Gitiles

 /*
  * Copyright 2016 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 "Resources.h"
 #include "SkCodec.h"
 #include "SkColorSpace.h"
 #include "SkColorSpace_Base.h"
 #include "SkColorSpaceXform.h"
 #include "SkColorSpaceXformPriv.h"
 #include "SkHalf.h"
 #include "SkImage.h"
 #include "SkPictureRecorder.h"

 static void clamp_if_necessary(const SkImageInfo& info, void* pixels) {
     if (kRGBA_F16_SkColorType != info.colorType()) {
         return;
     }

     for (int y = 0; y < info.height(); y++) {
         for (int x = 0; x < info.width(); x++) {
             uint64_t pixel = ((uint64_t*) pixels)[y * info.width() + x];

             Sk4f rgba = SkHalfToFloat_finite_ftz(pixel);
             if (kUnpremul_SkAlphaType == info.alphaType()) {
                 rgba = Sk4f::Max(0.0f, Sk4f::Min(rgba, 1.0f));
             } else {
                 SkASSERT(kPremul_SkAlphaType == info.alphaType());
                 rgba = Sk4f::Max(0.0f, Sk4f::Min(rgba, rgba[3]));
             }
             SkFloatToHalf_finite_ftz(rgba).store(&pixel);

             ((uint64_t*) pixels)[y * info.width() + x] = pixel;
         }
     }
 }

 sk_sp<SkColorSpace> fix_for_colortype(SkColorSpace* colorSpace, SkColorType colorType) {
     if (kRGBA_F16_SkColorType == colorType) {
         return colorSpace->makeLinearGamma();
     }

     return sk_ref_sp(colorSpace);
 }

 static const int kWidth = 64;
 static const int kHeight = 64;

 static sk_sp<SkImage> make_raster_image(SkColorType colorType) {
     std::unique_ptr<SkStream> stream(GetResourceAsStream("images/google_chrome.ico"));
     std::unique_ptr<SkCodec> codec = SkCodec::MakeFromStream(std::move(stream));

     SkBitmap bitmap;
     SkImageInfo info = codec->getInfo().makeWH(kWidth, kHeight)
                                        .makeColorType(colorType)
                                        .makeAlphaType(kPremul_SkAlphaType)
             .makeColorSpace(fix_for_colortype(codec->getInfo().colorSpace(), colorType));
     bitmap.allocPixels(info);
     codec->getPixels(info, bitmap.getPixels(), bitmap.rowBytes());
     bitmap.setImmutable();
     return SkImage::MakeFromBitmap(bitmap);
 }

 static sk_sp<SkImage> make_codec_image() {
     sk_sp<SkData> encoded = GetResourceAsData("images/randPixels.png");
     return SkImage::MakeFromEncoded(encoded);
 }

 static void draw_contents(SkCanvas* canvas) {
     SkPaint paint;
     paint.setStyle(SkPaint::kStroke_Style);
     paint.setStrokeWidth(20);
     paint.setColor(0xFF800000);
     canvas->drawCircle(40, 40, 35, paint);
     paint.setColor(0xFF008000);
     canvas->drawCircle(50, 50, 35, paint);
     paint.setColor(0xFF000080);
     canvas->drawCircle(60, 60, 35, paint);
 }

 static sk_sp<SkImage> make_picture_image() {
     SkPictureRecorder recorder;
     draw_contents(recorder.beginRecording(SkRect::MakeIWH(kWidth, kHeight)));
     return SkImage::MakeFromPicture(recorder.finishRecordingAsPicture(),
                                     SkISize::Make(kWidth, kHeight), nullptr, nullptr,
                                     SkImage::BitDepth::kU8,
                                     SkColorSpace::MakeSRGB());
 }

 static sk_sp<SkColorSpace> make_parametric_transfer_fn(const SkColorSpacePrimaries& primaries) {
     SkMatrix44 toXYZD50(SkMatrix44::kUninitialized_Constructor);
     SkAssertResult(primaries.toXYZD50(&toXYZD50));
     SkColorSpaceTransferFn fn;
     fn.fA = 1.f; fn.fB = 0.f; fn.fC = 0.f; fn.fD = 0.f; fn.fE = 0.f; fn.fF = 0.f; fn.fG = 1.8f;
     return SkColorSpace::MakeRGB(fn, toXYZD50);
 }

 static sk_sp<SkColorSpace> make_wide_gamut() {
     // ProPhoto
     SkColorSpacePrimaries primaries;
     primaries.fRX = 0.7347f;
     primaries.fRY = 0.2653f;
     primaries.fGX = 0.1596f;
     primaries.fGY = 0.8404f;
     primaries.fBX = 0.0366f;
     primaries.fBY = 0.0001f;
     primaries.fWX = 0.34567f;
     primaries.fWY = 0.35850f;
     return make_parametric_transfer_fn(primaries);
 }

 static sk_sp<SkColorSpace> make_small_gamut() {
     SkColorSpacePrimaries primaries;
     primaries.fRX = 0.50f;
     primaries.fRY = 0.33f;
     primaries.fGX = 0.30f;
     primaries.fGY = 0.50f;
     primaries.fBX = 0.25f;
     primaries.fBY = 0.16f;
     primaries.fWX = 0.3127f;
     primaries.fWY = 0.3290f;
     return make_parametric_transfer_fn(primaries);
 }

 static void draw_image(SkCanvas* canvas, SkImage* image, SkColorType dstColorType,
                        SkAlphaType dstAlphaType, sk_sp<SkColorSpace> dstColorSpace,
                        SkImage::CachingHint hint) {
     size_t rowBytes = image->width() * SkColorTypeBytesPerPixel(dstColorType);
     sk_sp<SkData> data = SkData::MakeUninitialized(rowBytes * image->height());
     dstColorSpace = fix_for_colortype(dstColorSpace.get(), dstColorType);
     SkImageInfo dstInfo = SkImageInfo::Make(image->width(), image->height(), dstColorType,
                                             dstAlphaType, dstColorSpace);
     if (!image->readPixels(dstInfo, data->writable_data(), rowBytes, 0, 0, hint)) {
         memset(data->writable_data(), 0, rowBytes * image->height());
     }

     // SkImage must be premul, so manually premul the data if we unpremul'd during readPixels
     if (kUnpremul_SkAlphaType == dstAlphaType) {
         auto xform = SkColorSpaceXform::New(dstColorSpace.get(), dstColorSpace.get());
         if (!xform->apply(select_xform_format(dstColorType), data->writable_data(),
                           select_xform_format(dstColorType), data->data(),
                           image->width() * image->height(), kPremul_SkAlphaType)) {
             memset(data->writable_data(), 0, rowBytes * image->height());
         }
         dstInfo = dstInfo.makeAlphaType(kPremul_SkAlphaType);
     }

     // readPixels() does not always clamp F16.  The drawing code expects pixels in the 0-1 range.
     clamp_if_necessary(dstInfo, data->writable_data());

     // Now that we have called readPixels(), dump the raw pixels into an srgb image.
     sk_sp<SkColorSpace> srgb = fix_for_colortype(
             SkColorSpace::MakeSRGB().get(), dstColorType);
     sk_sp<SkImage> raw = SkImage::MakeRasterData(dstInfo.makeColorSpace(srgb), data, rowBytes);
     canvas->drawImage(raw.get(), 0.0f, 0.0f, nullptr);
 }

 class ReadPixelsGM : public skiagm::GM {
 public:
     ReadPixelsGM() {}

 protected:
     SkString onShortName() override {
         return SkString("readpixels");
     }

     SkISize onISize() override {
         return SkISize::Make(6 * kWidth, 9 * kHeight);
     }

     void onDraw(SkCanvas* canvas) override {
         if (!canvas->imageInfo().colorSpace()) {
             // This gm is only interesting in color correct modes.
             return;
         }

         const SkAlphaType alphaTypes[] = {
                 kUnpremul_SkAlphaType,
                 kPremul_SkAlphaType,
         };
         const SkColorType colorTypes[] = {
                 kRGBA_8888_SkColorType,
                 kBGRA_8888_SkColorType,
                 kRGBA_F16_SkColorType,
         };
         const sk_sp<SkColorSpace> colorSpaces[] = {
                 make_wide_gamut(),
                 SkColorSpace::MakeSRGB(),
                 make_small_gamut(),
         };

         for (sk_sp<SkColorSpace> dstColorSpace : colorSpaces) {
             for (SkColorType srcColorType : colorTypes) {
                 canvas->save();
                 sk_sp<SkImage> image = make_raster_image(srcColorType);
                 if (GrContext* context = canvas->getGrContext()) {
                     image = image->makeTextureImage(context, canvas->imageInfo().colorSpace());
                 }
                 if (image) {
                     for (SkColorType dstColorType : colorTypes) {
                         for (SkAlphaType dstAlphaType : alphaTypes) {
                             draw_image(canvas, image.get(), dstColorType, dstAlphaType,
                                        dstColorSpace, SkImage::kAllow_CachingHint);
                             canvas->translate((float)kWidth, 0.0f);
                         }
                     }
                 }
                 canvas->restore();
                 canvas->translate(0.0f, (float) kHeight);
             }
         }
     }

 private:
     typedef skiagm::GM INHERITED;
 };
 DEF_GM( return new ReadPixelsGM; )

 class ReadPixelsCodecGM : public skiagm::GM {
 public:
     ReadPixelsCodecGM() {}

 protected:
     SkString onShortName() override {
         return SkString("readpixelscodec");
     }

     SkISize onISize() override {
         return SkISize::Make(3 * (kEncodedWidth + 1), 12 * (kEncodedHeight + 1));
     }

     void onDraw(SkCanvas* canvas) override {
         if (!canvas->imageInfo().colorSpace()) {
             // This gm is only interesting in color correct modes.
             return;
         }

         const SkAlphaType alphaTypes[] = {
                 kUnpremul_SkAlphaType,
                 kPremul_SkAlphaType,
         };
         const SkColorType colorTypes[] = {
                 kRGBA_8888_SkColorType,
                 kBGRA_8888_SkColorType,
                 kRGBA_F16_SkColorType,
         };
         const sk_sp<SkColorSpace> colorSpaces[] = {
                 make_wide_gamut(),
                 SkColorSpace::MakeSRGB(),
                 make_small_gamut(),
         };
         const SkImage::CachingHint hints[] = {
                 SkImage::kAllow_CachingHint,
                 SkImage::kDisallow_CachingHint,
         };

         sk_sp<SkImage> image = make_codec_image();
         for (sk_sp<SkColorSpace> dstColorSpace : colorSpaces) {
             canvas->save();
             for (SkColorType dstColorType : colorTypes) {
                 for (SkAlphaType dstAlphaType : alphaTypes) {
                     for (SkImage::CachingHint hint : hints) {
                         draw_image(canvas, image.get(), dstColorType, dstAlphaType, dstColorSpace,
                                    hint);
                         canvas->translate(0.0f, (float) kEncodedHeight + 1);
                     }
                 }
             }
             canvas->restore();
             canvas->translate((float) kEncodedWidth + 1, 0.0f);
         }
     }

 private:
     static const int kEncodedWidth = 8;
     static const int kEncodedHeight = 8;

     typedef skiagm::GM INHERITED;
 };
 DEF_GM( return new ReadPixelsCodecGM; )

 class ReadPixelsPictureGM : public skiagm::GM {
 public:
     ReadPixelsPictureGM() {}

 protected:
     SkString onShortName() override {
         return SkString("readpixelspicture");
     }

     SkISize onISize() override {
         return SkISize::Make(3 * kWidth, 12 * kHeight);
     }

     void onDraw(SkCanvas* canvas) override {
         if (!canvas->imageInfo().colorSpace()) {
             // This gm is only interesting in color correct modes.
             return;
         }

         const sk_sp<SkImage> images[] = {
                 make_picture_image(),
         };
         const SkAlphaType alphaTypes[] = {
                 kUnpremul_SkAlphaType,
                 kPremul_SkAlphaType,
         };
         const SkColorType colorTypes[] = {
                 kRGBA_8888_SkColorType,
                 kBGRA_8888_SkColorType,
                 kRGBA_F16_SkColorType,
         };
         const sk_sp<SkColorSpace> colorSpaces[] = {
                 make_wide_gamut(),
                 SkColorSpace::MakeSRGB(),
                 make_small_gamut(),
         };
         const SkImage::CachingHint hints[] = {
                 SkImage::kAllow_CachingHint,
                 SkImage::kDisallow_CachingHint,
         };

         for (sk_sp<SkImage> image : images) {
             for (sk_sp<SkColorSpace> dstColorSpace : colorSpaces) {
                 canvas->save();
                 for (SkColorType dstColorType : colorTypes) {
                     for (SkAlphaType dstAlphaType : alphaTypes) {
                         for (SkImage::CachingHint hint : hints) {
                             draw_image(canvas, image.get(), dstColorType, dstAlphaType,
                                        dstColorSpace, hint);
                             canvas->translate(0.0f, (float) kHeight);
                         }
                     }
                 }
                 canvas->restore();
                 canvas->translate((float) kWidth, 0.0f);
             }
         }
     }

 private:

     typedef skiagm::GM INHERITED;
 };
 DEF_GM( return new ReadPixelsPictureGM; )
	/*
	* Copyright 2016 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 "Resources.h"
	#include "SkCodec.h"
	#include "SkColorSpace.h"
	#include "SkColorSpace_Base.h"
	#include "SkColorSpaceXform.h"
	#include "SkColorSpaceXformPriv.h"
	#include "SkHalf.h"
	#include "SkImage.h"
	#include "SkPictureRecorder.h"

	static void clamp_if_necessary(const SkImageInfo& info, void* pixels) {
	if (kRGBA_F16_SkColorType != info.colorType()) {
	return;
	}

	for (int y = 0; y < info.height(); y++) {
	for (int x = 0; x < info.width(); x++) {
	uint64_t pixel = ((uint64_t) pixels)[y info.width() + x];

	Sk4f rgba = SkHalfToFloat_finite_ftz(pixel);
	if (kUnpremul_SkAlphaType == info.alphaType()) {
	rgba = Sk4f::Max(0.0f, Sk4f::Min(rgba, 1.0f));
	} else {
	SkASSERT(kPremul_SkAlphaType == info.alphaType());
	rgba = Sk4f::Max(0.0f, Sk4f::Min(rgba, rgba[3]));
	}
	SkFloatToHalf_finite_ftz(rgba).store(&pixel);

	((uint64_t) pixels)[y info.width() + x] = pixel;
	}
	}
	}

	sk_sp<SkColorSpace> fix_for_colortype(SkColorSpace* colorSpace, SkColorType colorType) {
	if (kRGBA_F16_SkColorType == colorType) {
	return colorSpace->makeLinearGamma();
	}

	return sk_ref_sp(colorSpace);
	}

	static const int kWidth = 64;
	static const int kHeight = 64;

	static sk_sp<SkImage> make_raster_image(SkColorType colorType) {
	std::unique_ptr<SkStream> stream(GetResourceAsStream("images/google_chrome.ico"));
	std::unique_ptr<SkCodec> codec = SkCodec::MakeFromStream(std::move(stream));

	SkBitmap bitmap;
	SkImageInfo info = codec->getInfo().makeWH(kWidth, kHeight)
	.makeColorType(colorType)
	.makeAlphaType(kPremul_SkAlphaType)
	.makeColorSpace(fix_for_colortype(codec->getInfo().colorSpace(), colorType));
	bitmap.allocPixels(info);
	codec->getPixels(info, bitmap.getPixels(), bitmap.rowBytes());
	bitmap.setImmutable();
	return SkImage::MakeFromBitmap(bitmap);
	}

	static sk_sp<SkImage> make_codec_image() {
	sk_sp<SkData> encoded = GetResourceAsData("images/randPixels.png");
	return SkImage::MakeFromEncoded(encoded);
	}

	static void draw_contents(SkCanvas* canvas) {
	SkPaint paint;
	paint.setStyle(SkPaint::kStroke_Style);
	paint.setStrokeWidth(20);
	paint.setColor(0xFF800000);
	canvas->drawCircle(40, 40, 35, paint);
	paint.setColor(0xFF008000);
	canvas->drawCircle(50, 50, 35, paint);
	paint.setColor(0xFF000080);
	canvas->drawCircle(60, 60, 35, paint);
	}

	static sk_sp<SkImage> make_picture_image() {
	SkPictureRecorder recorder;
	draw_contents(recorder.beginRecording(SkRect::MakeIWH(kWidth, kHeight)));
	return SkImage::MakeFromPicture(recorder.finishRecordingAsPicture(),
	SkISize::Make(kWidth, kHeight), nullptr, nullptr,
	SkImage::BitDepth::kU8,
	SkColorSpace::MakeSRGB());
	}

	static sk_sp<SkColorSpace> make_parametric_transfer_fn(const SkColorSpacePrimaries& primaries) {
	SkMatrix44 toXYZD50(SkMatrix44::kUninitialized_Constructor);
	SkAssertResult(primaries.toXYZD50(&toXYZD50));
	SkColorSpaceTransferFn fn;
	fn.fA = 1.f; fn.fB = 0.f; fn.fC = 0.f; fn.fD = 0.f; fn.fE = 0.f; fn.fF = 0.f; fn.fG = 1.8f;
	return SkColorSpace::MakeRGB(fn, toXYZD50);
	}

	static sk_sp<SkColorSpace> make_wide_gamut() {
	// ProPhoto
	SkColorSpacePrimaries primaries;
	primaries.fRX = 0.7347f;
	primaries.fRY = 0.2653f;
	primaries.fGX = 0.1596f;
	primaries.fGY = 0.8404f;
	primaries.fBX = 0.0366f;
	primaries.fBY = 0.0001f;
	primaries.fWX = 0.34567f;
	primaries.fWY = 0.35850f;
	return make_parametric_transfer_fn(primaries);
	}

	static sk_sp<SkColorSpace> make_small_gamut() {
	SkColorSpacePrimaries primaries;
	primaries.fRX = 0.50f;
	primaries.fRY = 0.33f;
	primaries.fGX = 0.30f;
	primaries.fGY = 0.50f;
	primaries.fBX = 0.25f;
	primaries.fBY = 0.16f;
	primaries.fWX = 0.3127f;
	primaries.fWY = 0.3290f;
	return make_parametric_transfer_fn(primaries);
	}

	static void draw_image(SkCanvas* canvas, SkImage* image, SkColorType dstColorType,
	SkAlphaType dstAlphaType, sk_sp<SkColorSpace> dstColorSpace,
	SkImage::CachingHint hint) {
	size_t rowBytes = image->width() * SkColorTypeBytesPerPixel(dstColorType);
	sk_sp<SkData> data = SkData::MakeUninitialized(rowBytes * image->height());
	dstColorSpace = fix_for_colortype(dstColorSpace.get(), dstColorType);
	SkImageInfo dstInfo = SkImageInfo::Make(image->width(), image->height(), dstColorType,
	dstAlphaType, dstColorSpace);
	if (!image->readPixels(dstInfo, data->writable_data(), rowBytes, 0, 0, hint)) {
	memset(data->writable_data(), 0, rowBytes * image->height());
	}

	// SkImage must be premul, so manually premul the data if we unpremul'd during readPixels
	if (kUnpremul_SkAlphaType == dstAlphaType) {
	auto xform = SkColorSpaceXform::New(dstColorSpace.get(), dstColorSpace.get());
	if (!xform->apply(select_xform_format(dstColorType), data->writable_data(),
	select_xform_format(dstColorType), data->data(),
	image->width() * image->height(), kPremul_SkAlphaType)) {
	memset(data->writable_data(), 0, rowBytes * image->height());
	}
	dstInfo = dstInfo.makeAlphaType(kPremul_SkAlphaType);
	}

	// readPixels() does not always clamp F16. The drawing code expects pixels in the 0-1 range.
	clamp_if_necessary(dstInfo, data->writable_data());

	// Now that we have called readPixels(), dump the raw pixels into an srgb image.
	sk_sp<SkColorSpace> srgb = fix_for_colortype(
	SkColorSpace::MakeSRGB().get(), dstColorType);
	sk_sp<SkImage> raw = SkImage::MakeRasterData(dstInfo.makeColorSpace(srgb), data, rowBytes);
	canvas->drawImage(raw.get(), 0.0f, 0.0f, nullptr);
	}

	class ReadPixelsGM : public skiagm::GM {
	public:
	ReadPixelsGM() {}

	protected:
	SkString onShortName() override {
	return SkString("readpixels");
	}

	SkISize onISize() override {
	return SkISize::Make(6 * kWidth, 9 * kHeight);
	}

	void onDraw(SkCanvas* canvas) override {
	if (!canvas->imageInfo().colorSpace()) {
	// This gm is only interesting in color correct modes.
	return;
	}

	const SkAlphaType alphaTypes[] = {
	kUnpremul_SkAlphaType,
	kPremul_SkAlphaType,
	};
	const SkColorType colorTypes[] = {
	kRGBA_8888_SkColorType,
	kBGRA_8888_SkColorType,
	kRGBA_F16_SkColorType,
	};
	const sk_sp<SkColorSpace> colorSpaces[] = {
	make_wide_gamut(),
	SkColorSpace::MakeSRGB(),
	make_small_gamut(),
	};

	for (sk_sp<SkColorSpace> dstColorSpace : colorSpaces) {
	for (SkColorType srcColorType : colorTypes) {
	canvas->save();
	sk_sp<SkImage> image = make_raster_image(srcColorType);
	if (GrContext* context = canvas->getGrContext()) {
	image = image->makeTextureImage(context, canvas->imageInfo().colorSpace());
	}
	if (image) {
	for (SkColorType dstColorType : colorTypes) {
	for (SkAlphaType dstAlphaType : alphaTypes) {
	draw_image(canvas, image.get(), dstColorType, dstAlphaType,
	dstColorSpace, SkImage::kAllow_CachingHint);
	canvas->translate((float)kWidth, 0.0f);
	}
	}
	}
	canvas->restore();
	canvas->translate(0.0f, (float) kHeight);
	}
	}
	}

	private:
	typedef skiagm::GM INHERITED;
	};
	DEF_GM( return new ReadPixelsGM; )

	class ReadPixelsCodecGM : public skiagm::GM {
	public:
	ReadPixelsCodecGM() {}

	protected:
	SkString onShortName() override {
	return SkString("readpixelscodec");
	}

	SkISize onISize() override {
	return SkISize::Make(3 * (kEncodedWidth + 1), 12 * (kEncodedHeight + 1));
	}

	void onDraw(SkCanvas* canvas) override {
	if (!canvas->imageInfo().colorSpace()) {
	// This gm is only interesting in color correct modes.
	return;
	}

	const SkAlphaType alphaTypes[] = {
	kUnpremul_SkAlphaType,
	kPremul_SkAlphaType,
	};
	const SkColorType colorTypes[] = {
	kRGBA_8888_SkColorType,
	kBGRA_8888_SkColorType,
	kRGBA_F16_SkColorType,
	};
	const sk_sp<SkColorSpace> colorSpaces[] = {
	make_wide_gamut(),
	SkColorSpace::MakeSRGB(),
	make_small_gamut(),
	};
	const SkImage::CachingHint hints[] = {
	SkImage::kAllow_CachingHint,
	SkImage::kDisallow_CachingHint,
	};

	sk_sp<SkImage> image = make_codec_image();
	for (sk_sp<SkColorSpace> dstColorSpace : colorSpaces) {
	canvas->save();
	for (SkColorType dstColorType : colorTypes) {
	for (SkAlphaType dstAlphaType : alphaTypes) {
	for (SkImage::CachingHint hint : hints) {
	draw_image(canvas, image.get(), dstColorType, dstAlphaType, dstColorSpace,
	hint);
	canvas->translate(0.0f, (float) kEncodedHeight + 1);
	}
	}
	}
	canvas->restore();
	canvas->translate((float) kEncodedWidth + 1, 0.0f);
	}
	}

	private:
	static const int kEncodedWidth = 8;
	static const int kEncodedHeight = 8;

	typedef skiagm::GM INHERITED;
	};
	DEF_GM( return new ReadPixelsCodecGM; )

	class ReadPixelsPictureGM : public skiagm::GM {
	public:
	ReadPixelsPictureGM() {}

	protected:
	SkString onShortName() override {
	return SkString("readpixelspicture");
	}

	SkISize onISize() override {
	return SkISize::Make(3 * kWidth, 12 * kHeight);
	}

	void onDraw(SkCanvas* canvas) override {
	if (!canvas->imageInfo().colorSpace()) {
	// This gm is only interesting in color correct modes.
	return;
	}

	const sk_sp<SkImage> images[] = {
	make_picture_image(),
	};
	const SkAlphaType alphaTypes[] = {
	kUnpremul_SkAlphaType,
	kPremul_SkAlphaType,
	};
	const SkColorType colorTypes[] = {
	kRGBA_8888_SkColorType,
	kBGRA_8888_SkColorType,
	kRGBA_F16_SkColorType,
	};
	const sk_sp<SkColorSpace> colorSpaces[] = {
	make_wide_gamut(),
	SkColorSpace::MakeSRGB(),
	make_small_gamut(),
	};
	const SkImage::CachingHint hints[] = {
	SkImage::kAllow_CachingHint,
	SkImage::kDisallow_CachingHint,
	};

	for (sk_sp<SkImage> image : images) {
	for (sk_sp<SkColorSpace> dstColorSpace : colorSpaces) {
	canvas->save();
	for (SkColorType dstColorType : colorTypes) {
	for (SkAlphaType dstAlphaType : alphaTypes) {
	for (SkImage::CachingHint hint : hints) {
	draw_image(canvas, image.get(), dstColorType, dstAlphaType,
	dstColorSpace, hint);
	canvas->translate(0.0f, (float) kHeight);
	}
	}
	}
	canvas->restore();
	canvas->translate((float) kWidth, 0.0f);
	}
	}
	}

	private:

	typedef skiagm::GM INHERITED;
	};
	DEF_GM( return new ReadPixelsPictureGM; )