src/image/SkImage_Lazy.cpp - skia - Git at Google

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */

 #include "src/image/SkImage_Lazy.h"

 #include "include/core/SkBitmap.h"
 #include "include/core/SkData.h"
 #include "include/core/SkImageGenerator.h"
 #include "src/core/SkBitmapCache.h"
 #include "src/core/SkCachedData.h"
 #include "src/core/SkImagePriv.h"
 #include "src/core/SkNextID.h"

 #if SK_SUPPORT_GPU
 #include "include/private/GrRecordingContext.h"
 #include "include/private/GrResourceKey.h"
 #include "src/gpu/GrBitmapTextureMaker.h"
 #include "src/gpu/GrCaps.h"
 #include "src/gpu/GrGpuResourcePriv.h"
 #include "src/gpu/GrImageTextureMaker.h"
 #include "src/gpu/GrProxyProvider.h"
 #include "src/gpu/GrRecordingContextPriv.h"
 #include "src/gpu/GrSamplerState.h"
 #include "src/gpu/GrYUVProvider.h"
 #include "src/gpu/SkGr.h"
 #endif

 // Ref-counted tuple(SkImageGenerator, SkMutex) which allows sharing one generator among N images
 class SharedGenerator final : public SkNVRefCnt<SharedGenerator> {
 public:
     static sk_sp<SharedGenerator> Make(std::unique_ptr<SkImageGenerator> gen) {
         return gen ? sk_sp<SharedGenerator>(new SharedGenerator(std::move(gen))) : nullptr;
     }

     // This is thread safe.  It is a const field set in the constructor.
     const SkImageInfo& getInfo() { return fGenerator->getInfo(); }

 private:
     explicit SharedGenerator(std::unique_ptr<SkImageGenerator> gen)
             : fGenerator(std::move(gen)) {
         SkASSERT(fGenerator);
     }

     friend class ScopedGenerator;
     friend class SkImage_Lazy;

     std::unique_ptr<SkImageGenerator> fGenerator;
     SkMutex                           fMutex;
 };

 ///////////////////////////////////////////////////////////////////////////////

 SkImage_Lazy::Validator::Validator(sk_sp<SharedGenerator> gen, const SkIRect* subset,
                                    const SkColorType* colorType, sk_sp<SkColorSpace> colorSpace)
         : fSharedGenerator(std::move(gen)) {
     if (!fSharedGenerator) {
         return;
     }

     // The following generator accessors are safe without acquiring the mutex (const getters).
     // TODO: refactor to use a ScopedGenerator instead, for clarity.
     const SkImageInfo& info = fSharedGenerator->fGenerator->getInfo();
     if (info.isEmpty()) {
         fSharedGenerator.reset();
         return;
     }

     fUniqueID = fSharedGenerator->fGenerator->uniqueID();
     const SkIRect bounds = SkIRect::MakeWH(info.width(), info.height());
     if (subset) {
         if (!bounds.contains(*subset)) {
             fSharedGenerator.reset();
             return;
         }
         if (*subset != bounds) {
             // we need a different uniqueID since we really are a subset of the raw generator
             fUniqueID = SkNextID::ImageID();
         }
     } else {
         subset = &bounds;
     }

     fInfo   = info.makeDimensions(subset->size());
     fOrigin = SkIPoint::Make(subset->x(), subset->y());
     if (colorType || colorSpace) {
         if (colorType) {
             fInfo = fInfo.makeColorType(*colorType);
         }
         if (colorSpace) {
             fInfo = fInfo.makeColorSpace(colorSpace);
         }
         fUniqueID = SkNextID::ImageID();
     }
 }

 ///////////////////////////////////////////////////////////////////////////////

 // Helper for exclusive access to a shared generator.
 class SkImage_Lazy::ScopedGenerator {
 public:
     ScopedGenerator(const sk_sp<SharedGenerator>& gen)
       : fSharedGenerator(gen)
       , fAutoAquire(gen->fMutex) {}

     SkImageGenerator* operator->() const {
         fSharedGenerator->fMutex.assertHeld();
         return fSharedGenerator->fGenerator.get();
     }

     operator SkImageGenerator*() const {
         fSharedGenerator->fMutex.assertHeld();
         return fSharedGenerator->fGenerator.get();
     }

 private:
     const sk_sp<SharedGenerator>& fSharedGenerator;
     SkAutoMutexExclusive          fAutoAquire;
 };

 ///////////////////////////////////////////////////////////////////////////////

 SkImage_Lazy::SkImage_Lazy(Validator* validator)
         : INHERITED(validator->fInfo, validator->fUniqueID)
         , fSharedGenerator(std::move(validator->fSharedGenerator))
         , fOrigin(validator->fOrigin) {
     SkASSERT(fSharedGenerator);
 }


 //////////////////////////////////////////////////////////////////////////////////////////////////

 static bool generate_pixels(SkImageGenerator* gen, const SkPixmap& pmap, int originX, int originY) {
     const int genW = gen->getInfo().width();
     const int genH = gen->getInfo().height();
     const SkIRect srcR = SkIRect::MakeWH(genW, genH);
     const SkIRect dstR = SkIRect::MakeXYWH(originX, originY, pmap.width(), pmap.height());
     if (!srcR.contains(dstR)) {
         return false;
     }

     // If they are requesting a subset, we have to have a temp allocation for full image, and
     // then copy the subset into their allocation
     SkBitmap full;
     SkPixmap fullPM;
     const SkPixmap* dstPM = &pmap;
     if (srcR != dstR) {
         if (!full.tryAllocPixels(pmap.info().makeWH(genW, genH))) {
             return false;
         }
         if (!full.peekPixels(&fullPM)) {
             return false;
         }
         dstPM = &fullPM;
     }

     if (!gen->getPixels(dstPM->info(), dstPM->writable_addr(), dstPM->rowBytes())) {
         return false;
     }

     if (srcR != dstR) {
         if (!full.readPixels(pmap, originX, originY)) {
             return false;
         }
     }
     return true;
 }

 bool SkImage_Lazy::getROPixels(SkBitmap* bitmap, SkImage::CachingHint chint) const {
     auto check_output_bitmap = [bitmap]() {
         SkASSERT(bitmap->isImmutable());
         SkASSERT(bitmap->getPixels());
         (void)bitmap;
     };

     auto desc = SkBitmapCacheDesc::Make(this);
     if (SkBitmapCache::Find(desc, bitmap)) {
         check_output_bitmap();
         return true;
     }

     if (SkImage::kAllow_CachingHint == chint) {
         SkPixmap pmap;
         SkBitmapCache::RecPtr cacheRec = SkBitmapCache::Alloc(desc, this->imageInfo(), &pmap);
         if (!cacheRec ||
             !generate_pixels(ScopedGenerator(fSharedGenerator), pmap,
                              fOrigin.x(), fOrigin.y())) {
             return false;
         }
         SkBitmapCache::Add(std::move(cacheRec), bitmap);
         this->notifyAddedToRasterCache();
     } else {
         if (!bitmap->tryAllocPixels(this->imageInfo()) ||
             !generate_pixels(ScopedGenerator(fSharedGenerator), bitmap->pixmap(), fOrigin.x(),
                              fOrigin.y())) {
             return false;
         }
         bitmap->setImmutable();
     }

     check_output_bitmap();
     return true;
 }

 //////////////////////////////////////////////////////////////////////////////////////////////////

 bool SkImage_Lazy::onReadPixels(const SkImageInfo& dstInfo, void* dstPixels, size_t dstRB,
                                 int srcX, int srcY, CachingHint chint) const {
     SkBitmap bm;
     if (this->getROPixels(&bm, chint)) {
         return bm.readPixels(dstInfo, dstPixels, dstRB, srcX, srcY);
     }
     return false;
 }

 sk_sp<SkData> SkImage_Lazy::onRefEncoded() const {
     ScopedGenerator generator(fSharedGenerator);
     return generator->refEncodedData();
 }

 bool SkImage_Lazy::onIsValid(GrContext* context) const {
     ScopedGenerator generator(fSharedGenerator);
     return generator->isValid(context);
 }

 ///////////////////////////////////////////////////////////////////////////////////////////////////

 #if SK_SUPPORT_GPU
 GrSurfaceProxyView SkImage_Lazy::refView(GrRecordingContext* context, GrMipMapped mipMapped) const {
     if (!context) {
         return {};
     }

     GrImageTextureMaker textureMaker(context, this, GrImageTexGenPolicy::kDraw);
     return textureMaker.view(mipMapped);
 }
 #endif

 sk_sp<SkImage> SkImage_Lazy::onMakeSubset(GrRecordingContext* context,
                                           const SkIRect& subset) const {
     SkASSERT(this->bounds().contains(subset));
     SkASSERT(this->bounds() != subset);

     const SkIRect generatorSubset = subset.makeOffset(fOrigin);
     const SkColorType colorType = this->colorType();
     Validator validator(fSharedGenerator, &generatorSubset, &colorType, this->refColorSpace());
     return validator ? sk_sp<SkImage>(new SkImage_Lazy(&validator)) : nullptr;
 }

 sk_sp<SkImage> SkImage_Lazy::onMakeColorTypeAndColorSpace(GrRecordingContext*,
                                                           SkColorType targetCT,
                                                           sk_sp<SkColorSpace> targetCS) const {
     SkAutoMutexExclusive autoAquire(fOnMakeColorTypeAndSpaceMutex);
     if (fOnMakeColorTypeAndSpaceResult &&
         targetCT == fOnMakeColorTypeAndSpaceResult->colorType() &&
         SkColorSpace::Equals(targetCS.get(), fOnMakeColorTypeAndSpaceResult->colorSpace())) {
         return fOnMakeColorTypeAndSpaceResult;
     }
     const SkIRect generatorSubset =
             SkIRect::MakeXYWH(fOrigin.x(), fOrigin.y(), this->width(), this->height());
     Validator validator(fSharedGenerator, &generatorSubset, &targetCT, targetCS);
     sk_sp<SkImage> result = validator ? sk_sp<SkImage>(new SkImage_Lazy(&validator)) : nullptr;
     if (result) {
         fOnMakeColorTypeAndSpaceResult = result;
     }
     return result;
 }

 sk_sp<SkImage> SkImage_Lazy::onReinterpretColorSpace(sk_sp<SkColorSpace> newCS) const {
     // TODO: The correct thing is to clone the generator, and modify its color space. That's hard,
     // because we don't have a clone method, and generator is public (and derived-from by clients).
     // So do the simple/inefficient thing here, and fallback to raster when this is called.

     // We allocate the bitmap with the new color space, then generate the image using the original.
     SkBitmap bitmap;
     if (bitmap.tryAllocPixels(this->imageInfo().makeColorSpace(std::move(newCS)))) {
         SkPixmap pixmap = bitmap.pixmap();
         pixmap.setColorSpace(this->refColorSpace());
         if (generate_pixels(ScopedGenerator(fSharedGenerator), pixmap, fOrigin.x(), fOrigin.y())) {
             bitmap.setImmutable();
             return SkImage::MakeFromBitmap(bitmap);
         }
     }
     return nullptr;
 }

 sk_sp<SkImage> SkImage::MakeFromGenerator(std::unique_ptr<SkImageGenerator> generator,
                                           const SkIRect* subset) {
     SkImage_Lazy::Validator
             validator(SharedGenerator::Make(std::move(generator)), subset, nullptr, nullptr);

     return validator ? sk_make_sp<SkImage_Lazy>(&validator) : nullptr;
 }

 sk_sp<SkImage> SkImage::DecodeToRaster(const void* encoded, size_t length, const SkIRect* subset) {
     // The generator will not outlive this function, so we can wrap the encoded data without copy
     auto gen = SkImageGenerator::MakeFromEncoded(SkData::MakeWithoutCopy(encoded, length));
     if (!gen) {
         return nullptr;
     }
     SkImageInfo info = gen->getInfo();
     if (info.isEmpty()) {
         return nullptr;
     }

     SkIPoint origin = {0, 0};
     if (subset) {
         if (!SkIRect::MakeWH(info.width(), info.height()).contains(*subset)) {
             return nullptr;
         }
         info = info.makeDimensions(subset->size());
         origin = {subset->x(), subset->y()};
     }

     size_t rb = info.minRowBytes();
     if (rb == 0) {
         return nullptr; // rb was too big
     }
     size_t size = info.computeByteSize(rb);
     if (size == SIZE_MAX) {
         return nullptr;
     }
     auto data = SkData::MakeUninitialized(size);

     SkPixmap pmap(info, data->writable_data(), rb);
     if (!generate_pixels(gen.get(), pmap, origin.x(), origin.y())) {
         return nullptr;
     }

     return SkImage::MakeRasterData(info, data, rb);
 }

 //////////////////////////////////////////////////////////////////////////////////////////////////

 #if SK_SUPPORT_GPU

 class Generator_GrYUVProvider : public GrYUVProvider {
 public:
     Generator_GrYUVProvider(SkImageGenerator* gen) : fGen(gen) {}

 private:
     uint32_t onGetID() const override { return fGen->uniqueID(); }
     bool onQueryYUVA8(SkYUVASizeInfo* sizeInfo,
                       SkYUVAIndex yuvaIndices[SkYUVAIndex::kIndexCount],
                       SkYUVColorSpace* colorSpace) const override {
         return fGen->queryYUVA8(sizeInfo, yuvaIndices, colorSpace);
     }
     bool onGetYUVA8Planes(const SkYUVASizeInfo& sizeInfo,
                           const SkYUVAIndex yuvaIndices[SkYUVAIndex::kIndexCount],
                           void* planes[]) override {
         return fGen->getYUVA8Planes(sizeInfo, yuvaIndices, planes);
     }

     SkImageGenerator* fGen;

     typedef GrYUVProvider INHERITED;
 };


 sk_sp<SkCachedData> SkImage_Lazy::getPlanes(SkYUVASizeInfo* yuvaSizeInfo,
                                             SkYUVAIndex yuvaIndices[SkYUVAIndex::kIndexCount],
                                             SkYUVColorSpace* yuvColorSpace,
                                             const void* planes[SkYUVASizeInfo::kMaxCount]) {
     ScopedGenerator generator(fSharedGenerator);
     Generator_GrYUVProvider provider(generator);

     sk_sp<SkCachedData> data = provider.getPlanes(yuvaSizeInfo, yuvaIndices, yuvColorSpace, planes);
     if (!data) {
         return nullptr;
     }

     return data;
 }


 /*
  *  We have 4 ways to try to return a texture (in sorted order)
  *
  *  1. Check the cache for a pre-existing one
  *  2. Ask the generator to natively create one
  *  3. Ask the generator to return YUV planes, which the GPU can convert
  *  4. Ask the generator to return RGB(A) data, which the GPU can convert
  */
 GrSurfaceProxyView SkImage_Lazy::lockTextureProxyView(GrRecordingContext* ctx,
                                                       GrImageTexGenPolicy texGenPolicy,
                                                       GrMipMapped mipMapped) const {
     // Values representing the various texture lock paths we can take. Used for logging the path
     // taken to a histogram.
     enum LockTexturePath {
         kFailure_LockTexturePath,
         kPreExisting_LockTexturePath,
         kNative_LockTexturePath,
         kCompressed_LockTexturePath, // Deprecated
         kYUV_LockTexturePath,
         kRGBA_LockTexturePath,
     };

     enum { kLockTexturePathCount = kRGBA_LockTexturePath + 1 };

     GrUniqueKey key;
     if (texGenPolicy == GrImageTexGenPolicy::kDraw) {
         GrMakeKeyFromImageID(&key, this->uniqueID(), SkIRect::MakeSize(this->dimensions()));
     }

     const GrCaps* caps = ctx->priv().caps();
     GrProxyProvider* proxyProvider = ctx->priv().proxyProvider();

     auto installKey = [&](const GrSurfaceProxyView& view) {
         SkASSERT(view && view.asTextureProxy());
         if (key.isValid()) {
             auto listener = GrMakeUniqueKeyInvalidationListener(&key, ctx->priv().contextID());
             this->addUniqueIDListener(std::move(listener));
             proxyProvider->assignUniqueKeyToProxy(key, view.asTextureProxy());
         }
     };

     auto ct = this->colorTypeOfLockTextureProxy(caps);

     // 1. Check the cache for a pre-existing one.
     if (key.isValid()) {
         auto proxy = proxyProvider->findOrCreateProxyByUniqueKey(key);
         if (proxy) {
             SK_HISTOGRAM_ENUMERATION("LockTexturePath", kPreExisting_LockTexturePath,
                                      kLockTexturePathCount);
             GrSwizzle swizzle = caps->getReadSwizzle(proxy->backendFormat(), ct);
             GrSurfaceProxyView view(std::move(proxy), kTopLeft_GrSurfaceOrigin, swizzle);
             if (mipMapped == GrMipMapped::kNo ||
                 view.asTextureProxy()->mipMapped() == GrMipMapped::kYes) {
                 return view;
             } else {
                 // We need a mipped proxy, but we found a cached proxy that wasn't mipped. Thus we
                 // generate a new mipped surface and copy the original proxy into the base layer. We
                 // will then let the gpu generate the rest of the mips.
                 auto mippedView = GrCopyBaseMipMapToView(ctx, view);
                 if (!mippedView) {
                     // We failed to make a mipped proxy with the base copied into it. This could
                     // have been from failure to make the proxy or failure to do the copy. Thus we
                     // will fall back to just using the non mipped proxy; See skbug.com/7094.
                     return view;
                 }
                 proxyProvider->removeUniqueKeyFromProxy(view.asTextureProxy());
                 installKey(mippedView);
                 return mippedView;
             }
         }
     }

     // 2. Ask the generator to natively create one.
     {
         ScopedGenerator generator(fSharedGenerator);
         if (auto view = generator->generateTexture(ctx, this->imageInfo(), fOrigin, mipMapped,
                                                    texGenPolicy)) {
             SK_HISTOGRAM_ENUMERATION("LockTexturePath", kNative_LockTexturePath,
                                      kLockTexturePathCount);
             installKey(view);
             return view;
         }
     }

     // 3. Ask the generator to return YUV planes, which the GPU can convert. If we will be mipping
     //    the texture we skip this step so the CPU generate non-planar MIP maps for us.
     if (mipMapped == GrMipMapped::kNo && !ctx->priv().options().fDisableGpuYUVConversion) {
         SkColorType colorType = this->colorType();

         ScopedGenerator generator(fSharedGenerator);
         Generator_GrYUVProvider provider(generator);

         // The pixels in the texture will be in the generator's color space.
         // If onMakeColorTypeAndColorSpace has been called then this will not match this image's
         // color space. To correct this, apply a color space conversion from the generator's color
         // space to this image's color space.
         SkColorSpace* generatorColorSpace = fSharedGenerator->fGenerator->getInfo().colorSpace();
         SkColorSpace* thisColorSpace = this->colorSpace();

         // TODO: Update to create the mipped surface in the YUV generator and draw the base
         // layer directly into the mipped surface.
         SkBudgeted budgeted = texGenPolicy == GrImageTexGenPolicy::kNew_Uncached_Unbudgeted
                                       ? SkBudgeted::kNo
                                       : SkBudgeted::kYes;
         auto view = provider.refAsTextureProxyView(ctx, this->imageInfo().dimensions(),
                                                    SkColorTypeToGrColorType(colorType),
                                                    generatorColorSpace, thisColorSpace, budgeted);
         if (view) {
             SK_HISTOGRAM_ENUMERATION("LockTexturePath", kYUV_LockTexturePath,
                                      kLockTexturePathCount);
             installKey(view);
             return view;
         }
     }

     // 4. Ask the generator to return a bitmap, which the GPU can convert.
     auto hint = texGenPolicy == GrImageTexGenPolicy::kDraw ? CachingHint::kAllow_CachingHint
                                                            : CachingHint::kDisallow_CachingHint;
     if (SkBitmap bitmap; this->getROPixels(&bitmap, hint)) {
         // We always pass uncached here because we will cache it external to the maker based on
         // *our* cache policy. We're just using the maker to generate the texture.
         auto makerPolicy = texGenPolicy == GrImageTexGenPolicy::kNew_Uncached_Unbudgeted
                                    ? GrImageTexGenPolicy::kNew_Uncached_Unbudgeted
                                    : GrImageTexGenPolicy::kNew_Uncached_Budgeted;
         GrBitmapTextureMaker bitmapMaker(ctx, bitmap, makerPolicy);
         auto view = bitmapMaker.view(mipMapped);
         if (view) {
             installKey(view);
             SK_HISTOGRAM_ENUMERATION("LockTexturePath", kRGBA_LockTexturePath,
                                      kLockTexturePathCount);
             return view;
         }
     }

     SK_HISTOGRAM_ENUMERATION("LockTexturePath", kFailure_LockTexturePath, kLockTexturePathCount);
     return {};
 }

 GrColorType SkImage_Lazy::colorTypeOfLockTextureProxy(const GrCaps* caps) const {
     GrColorType ct = SkColorTypeToGrColorType(this->colorType());
     GrBackendFormat format = caps->getDefaultBackendFormat(ct, GrRenderable::kNo);
     if (!format.isValid()) {
         ct = GrColorType::kRGBA_8888;
     }
     return ct;
 }

 #if SK_SUPPORT_GPU
 void SkImage_Lazy::addUniqueIDListener(sk_sp<SkIDChangeListener> listener) const {
     bool singleThreaded = this->unique();
     fUniqueIDListeners.add(std::move(listener), singleThreaded);
 }
 #endif

 ///////////////////////////////////////////////////////////////////////////////////////////////////

 sk_sp<SkImage> SkImage::DecodeToTexture(GrContext* ctx, const void* encoded, size_t length,
                                         const SkIRect* subset) {
     // img will not survive this function, so we don't need to copy/own the encoded data,
     auto img = MakeFromEncoded(SkData::MakeWithoutCopy(encoded, length), subset);
     if (!img) {
         return nullptr;
     }
     return img->makeTextureImage(ctx);
 }

 #endif
	/*
	* Copyright 2015 Google Inc.
	*
	* Use of this source code is governed by a BSD-style license that can be
	* found in the LICENSE file.
	*/

	#include "src/image/SkImage_Lazy.h"

	#include "include/core/SkBitmap.h"
	#include "include/core/SkData.h"
	#include "include/core/SkImageGenerator.h"
	#include "src/core/SkBitmapCache.h"
	#include "src/core/SkCachedData.h"
	#include "src/core/SkImagePriv.h"
	#include "src/core/SkNextID.h"

	#if SK_SUPPORT_GPU
	#include "include/private/GrRecordingContext.h"
	#include "include/private/GrResourceKey.h"
	#include "src/gpu/GrBitmapTextureMaker.h"
	#include "src/gpu/GrCaps.h"
	#include "src/gpu/GrGpuResourcePriv.h"
	#include "src/gpu/GrImageTextureMaker.h"
	#include "src/gpu/GrProxyProvider.h"
	#include "src/gpu/GrRecordingContextPriv.h"
	#include "src/gpu/GrSamplerState.h"
	#include "src/gpu/GrYUVProvider.h"
	#include "src/gpu/SkGr.h"
	#endif

	// Ref-counted tuple(SkImageGenerator, SkMutex) which allows sharing one generator among N images
	class SharedGenerator final : public SkNVRefCnt<SharedGenerator> {
	public:
	static sk_sp<SharedGenerator> Make(std::unique_ptr<SkImageGenerator> gen) {
	return gen ? sk_sp<SharedGenerator>(new SharedGenerator(std::move(gen))) : nullptr;
	}

	// This is thread safe. It is a const field set in the constructor.
	const SkImageInfo& getInfo() { return fGenerator->getInfo(); }

	private:
	explicit SharedGenerator(std::unique_ptr<SkImageGenerator> gen)
	: fGenerator(std::move(gen)) {
	SkASSERT(fGenerator);
	}

	friend class ScopedGenerator;
	friend class SkImage_Lazy;

	std::unique_ptr<SkImageGenerator> fGenerator;
	SkMutex fMutex;
	};

	///////////////////////////////////////////////////////////////////////////////

	SkImage_Lazy::Validator::Validator(sk_sp<SharedGenerator> gen, const SkIRect* subset,
	const SkColorType* colorType, sk_sp<SkColorSpace> colorSpace)
	: fSharedGenerator(std::move(gen)) {
	if (!fSharedGenerator) {
	return;
	}

	// The following generator accessors are safe without acquiring the mutex (const getters).
	// TODO: refactor to use a ScopedGenerator instead, for clarity.
	const SkImageInfo& info = fSharedGenerator->fGenerator->getInfo();
	if (info.isEmpty()) {
	fSharedGenerator.reset();
	return;
	}

	fUniqueID = fSharedGenerator->fGenerator->uniqueID();
	const SkIRect bounds = SkIRect::MakeWH(info.width(), info.height());
	if (subset) {
	if (!bounds.contains(*subset)) {
	fSharedGenerator.reset();
	return;
	}
	if (*subset != bounds) {
	// we need a different uniqueID since we really are a subset of the raw generator
	fUniqueID = SkNextID::ImageID();
	}
	} else {
	subset = &bounds;
	}

	fInfo = info.makeDimensions(subset->size());
	fOrigin = SkIPoint::Make(subset->x(), subset->y());
	if (colorType \|\| colorSpace) {
	if (colorType) {
	fInfo = fInfo.makeColorType(*colorType);
	}
	if (colorSpace) {
	fInfo = fInfo.makeColorSpace(colorSpace);
	}
	fUniqueID = SkNextID::ImageID();
	}
	}

	///////////////////////////////////////////////////////////////////////////////

	// Helper for exclusive access to a shared generator.
	class SkImage_Lazy::ScopedGenerator {
	public:
	ScopedGenerator(const sk_sp<SharedGenerator>& gen)
	: fSharedGenerator(gen)
	, fAutoAquire(gen->fMutex) {}

	SkImageGenerator* operator->() const {
	fSharedGenerator->fMutex.assertHeld();
	return fSharedGenerator->fGenerator.get();
	}

	operator SkImageGenerator*() const {
	fSharedGenerator->fMutex.assertHeld();
	return fSharedGenerator->fGenerator.get();
	}

	private:
	const sk_sp<SharedGenerator>& fSharedGenerator;
	SkAutoMutexExclusive fAutoAquire;
	};

	///////////////////////////////////////////////////////////////////////////////

	SkImage_Lazy::SkImage_Lazy(Validator* validator)
	: INHERITED(validator->fInfo, validator->fUniqueID)
	, fSharedGenerator(std::move(validator->fSharedGenerator))
	, fOrigin(validator->fOrigin) {
	SkASSERT(fSharedGenerator);
	}


	//////////////////////////////////////////////////////////////////////////////////////////////////

	static bool generate_pixels(SkImageGenerator* gen, const SkPixmap& pmap, int originX, int originY) {
	const int genW = gen->getInfo().width();
	const int genH = gen->getInfo().height();
	const SkIRect srcR = SkIRect::MakeWH(genW, genH);
	const SkIRect dstR = SkIRect::MakeXYWH(originX, originY, pmap.width(), pmap.height());
	if (!srcR.contains(dstR)) {
	return false;
	}

	// If they are requesting a subset, we have to have a temp allocation for full image, and
	// then copy the subset into their allocation
	SkBitmap full;
	SkPixmap fullPM;
	const SkPixmap* dstPM = &pmap;
	if (srcR != dstR) {
	if (!full.tryAllocPixels(pmap.info().makeWH(genW, genH))) {
	return false;
	}
	if (!full.peekPixels(&fullPM)) {
	return false;
	}
	dstPM = &fullPM;
	}

	if (!gen->getPixels(dstPM->info(), dstPM->writable_addr(), dstPM->rowBytes())) {
	return false;
	}

	if (srcR != dstR) {
	if (!full.readPixels(pmap, originX, originY)) {
	return false;
	}
	}
	return true;
	}

	bool SkImage_Lazy::getROPixels(SkBitmap* bitmap, SkImage::CachingHint chint) const {
	auto check_output_bitmap = [bitmap]() {
	SkASSERT(bitmap->isImmutable());
	SkASSERT(bitmap->getPixels());
	(void)bitmap;
	};

	auto desc = SkBitmapCacheDesc::Make(this);
	if (SkBitmapCache::Find(desc, bitmap)) {
	check_output_bitmap();
	return true;
	}

	if (SkImage::kAllow_CachingHint == chint) {
	SkPixmap pmap;
	SkBitmapCache::RecPtr cacheRec = SkBitmapCache::Alloc(desc, this->imageInfo(), &pmap);
	if (!cacheRec \|\|
	!generate_pixels(ScopedGenerator(fSharedGenerator), pmap,
	fOrigin.x(), fOrigin.y())) {
	return false;
	}
	SkBitmapCache::Add(std::move(cacheRec), bitmap);
	this->notifyAddedToRasterCache();
	} else {
	if (!bitmap->tryAllocPixels(this->imageInfo()) \|\|
	!generate_pixels(ScopedGenerator(fSharedGenerator), bitmap->pixmap(), fOrigin.x(),
	fOrigin.y())) {
	return false;
	}
	bitmap->setImmutable();
	}

	check_output_bitmap();
	return true;
	}

	//////////////////////////////////////////////////////////////////////////////////////////////////

	bool SkImage_Lazy::onReadPixels(const SkImageInfo& dstInfo, void* dstPixels, size_t dstRB,
	int srcX, int srcY, CachingHint chint) const {
	SkBitmap bm;
	if (this->getROPixels(&bm, chint)) {
	return bm.readPixels(dstInfo, dstPixels, dstRB, srcX, srcY);
	}
	return false;
	}

	sk_sp<SkData> SkImage_Lazy::onRefEncoded() const {
	ScopedGenerator generator(fSharedGenerator);
	return generator->refEncodedData();
	}

	bool SkImage_Lazy::onIsValid(GrContext* context) const {
	ScopedGenerator generator(fSharedGenerator);
	return generator->isValid(context);
	}

	///////////////////////////////////////////////////////////////////////////////////////////////////

	#if SK_SUPPORT_GPU
	GrSurfaceProxyView SkImage_Lazy::refView(GrRecordingContext* context, GrMipMapped mipMapped) const {
	if (!context) {
	return {};
	}

	GrImageTextureMaker textureMaker(context, this, GrImageTexGenPolicy::kDraw);
	return textureMaker.view(mipMapped);
	}
	#endif

	sk_sp<SkImage> SkImage_Lazy::onMakeSubset(GrRecordingContext* context,
	const SkIRect& subset) const {
	SkASSERT(this->bounds().contains(subset));
	SkASSERT(this->bounds() != subset);

	const SkIRect generatorSubset = subset.makeOffset(fOrigin);
	const SkColorType colorType = this->colorType();
	Validator validator(fSharedGenerator, &generatorSubset, &colorType, this->refColorSpace());
	return validator ? sk_sp<SkImage>(new SkImage_Lazy(&validator)) : nullptr;
	}

	sk_sp<SkImage> SkImage_Lazy::onMakeColorTypeAndColorSpace(GrRecordingContext*,
	SkColorType targetCT,
	sk_sp<SkColorSpace> targetCS) const {
	SkAutoMutexExclusive autoAquire(fOnMakeColorTypeAndSpaceMutex);
	if (fOnMakeColorTypeAndSpaceResult &&
	targetCT == fOnMakeColorTypeAndSpaceResult->colorType() &&
	SkColorSpace::Equals(targetCS.get(), fOnMakeColorTypeAndSpaceResult->colorSpace())) {
	return fOnMakeColorTypeAndSpaceResult;
	}
	const SkIRect generatorSubset =
	SkIRect::MakeXYWH(fOrigin.x(), fOrigin.y(), this->width(), this->height());
	Validator validator(fSharedGenerator, &generatorSubset, &targetCT, targetCS);
	sk_sp<SkImage> result = validator ? sk_sp<SkImage>(new SkImage_Lazy(&validator)) : nullptr;
	if (result) {
	fOnMakeColorTypeAndSpaceResult = result;
	}
	return result;
	}

	sk_sp<SkImage> SkImage_Lazy::onReinterpretColorSpace(sk_sp<SkColorSpace> newCS) const {
	// TODO: The correct thing is to clone the generator, and modify its color space. That's hard,
	// because we don't have a clone method, and generator is public (and derived-from by clients).
	// So do the simple/inefficient thing here, and fallback to raster when this is called.

	// We allocate the bitmap with the new color space, then generate the image using the original.
	SkBitmap bitmap;
	if (bitmap.tryAllocPixels(this->imageInfo().makeColorSpace(std::move(newCS)))) {
	SkPixmap pixmap = bitmap.pixmap();
	pixmap.setColorSpace(this->refColorSpace());
	if (generate_pixels(ScopedGenerator(fSharedGenerator), pixmap, fOrigin.x(), fOrigin.y())) {
	bitmap.setImmutable();
	return SkImage::MakeFromBitmap(bitmap);
	}
	}
	return nullptr;
	}

	sk_sp<SkImage> SkImage::MakeFromGenerator(std::unique_ptr<SkImageGenerator> generator,
	const SkIRect* subset) {
	SkImage_Lazy::Validator
	validator(SharedGenerator::Make(std::move(generator)), subset, nullptr, nullptr);

	return validator ? sk_make_sp<SkImage_Lazy>(&validator) : nullptr;
	}

	sk_sp<SkImage> SkImage::DecodeToRaster(const void* encoded, size_t length, const SkIRect* subset) {
	// The generator will not outlive this function, so we can wrap the encoded data without copy
	auto gen = SkImageGenerator::MakeFromEncoded(SkData::MakeWithoutCopy(encoded, length));
	if (!gen) {
	return nullptr;
	}
	SkImageInfo info = gen->getInfo();
	if (info.isEmpty()) {
	return nullptr;
	}

	SkIPoint origin = {0, 0};
	if (subset) {
	if (!SkIRect::MakeWH(info.width(), info.height()).contains(*subset)) {
	return nullptr;
	}
	info = info.makeDimensions(subset->size());
	origin = {subset->x(), subset->y()};
	}

	size_t rb = info.minRowBytes();
	if (rb == 0) {
	return nullptr; // rb was too big
	}
	size_t size = info.computeByteSize(rb);
	if (size == SIZE_MAX) {
	return nullptr;
	}
	auto data = SkData::MakeUninitialized(size);

	SkPixmap pmap(info, data->writable_data(), rb);
	if (!generate_pixels(gen.get(), pmap, origin.x(), origin.y())) {
	return nullptr;
	}

	return SkImage::MakeRasterData(info, data, rb);
	}

	//////////////////////////////////////////////////////////////////////////////////////////////////

	#if SK_SUPPORT_GPU

	class Generator_GrYUVProvider : public GrYUVProvider {
	public:
	Generator_GrYUVProvider(SkImageGenerator* gen) : fGen(gen) {}

	private:
	uint32_t onGetID() const override { return fGen->uniqueID(); }
	bool onQueryYUVA8(SkYUVASizeInfo* sizeInfo,
	SkYUVAIndex yuvaIndices[SkYUVAIndex::kIndexCount],
	SkYUVColorSpace* colorSpace) const override {
	return fGen->queryYUVA8(sizeInfo, yuvaIndices, colorSpace);
	}
	bool onGetYUVA8Planes(const SkYUVASizeInfo& sizeInfo,
	const SkYUVAIndex yuvaIndices[SkYUVAIndex::kIndexCount],
	void* planes[]) override {
	return fGen->getYUVA8Planes(sizeInfo, yuvaIndices, planes);
	}

	SkImageGenerator* fGen;

	typedef GrYUVProvider INHERITED;
	};


	sk_sp<SkCachedData> SkImage_Lazy::getPlanes(SkYUVASizeInfo* yuvaSizeInfo,
	SkYUVAIndex yuvaIndices[SkYUVAIndex::kIndexCount],
	SkYUVColorSpace* yuvColorSpace,
	const void* planes[SkYUVASizeInfo::kMaxCount]) {
	ScopedGenerator generator(fSharedGenerator);
	Generator_GrYUVProvider provider(generator);

	sk_sp<SkCachedData> data = provider.getPlanes(yuvaSizeInfo, yuvaIndices, yuvColorSpace, planes);
	if (!data) {
	return nullptr;
	}

	return data;
	}


	/*
	* We have 4 ways to try to return a texture (in sorted order)
	*
	* 1. Check the cache for a pre-existing one
	* 2. Ask the generator to natively create one
	* 3. Ask the generator to return YUV planes, which the GPU can convert
	* 4. Ask the generator to return RGB(A) data, which the GPU can convert
	*/
	GrSurfaceProxyView SkImage_Lazy::lockTextureProxyView(GrRecordingContext* ctx,
	GrImageTexGenPolicy texGenPolicy,
	GrMipMapped mipMapped) const {
	// Values representing the various texture lock paths we can take. Used for logging the path
	// taken to a histogram.
	enum LockTexturePath {
	kFailure_LockTexturePath,
	kPreExisting_LockTexturePath,
	kNative_LockTexturePath,
	kCompressed_LockTexturePath, // Deprecated
	kYUV_LockTexturePath,
	kRGBA_LockTexturePath,
	};

	enum { kLockTexturePathCount = kRGBA_LockTexturePath + 1 };

	GrUniqueKey key;
	if (texGenPolicy == GrImageTexGenPolicy::kDraw) {
	GrMakeKeyFromImageID(&key, this->uniqueID(), SkIRect::MakeSize(this->dimensions()));
	}

	const GrCaps* caps = ctx->priv().caps();
	GrProxyProvider* proxyProvider = ctx->priv().proxyProvider();

	auto installKey = [&](const GrSurfaceProxyView& view) {
	SkASSERT(view && view.asTextureProxy());
	if (key.isValid()) {
	auto listener = GrMakeUniqueKeyInvalidationListener(&key, ctx->priv().contextID());
	this->addUniqueIDListener(std::move(listener));
	proxyProvider->assignUniqueKeyToProxy(key, view.asTextureProxy());
	}
	};

	auto ct = this->colorTypeOfLockTextureProxy(caps);

	// 1. Check the cache for a pre-existing one.
	if (key.isValid()) {
	auto proxy = proxyProvider->findOrCreateProxyByUniqueKey(key);
	if (proxy) {
	SK_HISTOGRAM_ENUMERATION("LockTexturePath", kPreExisting_LockTexturePath,
	kLockTexturePathCount);
	GrSwizzle swizzle = caps->getReadSwizzle(proxy->backendFormat(), ct);
	GrSurfaceProxyView view(std::move(proxy), kTopLeft_GrSurfaceOrigin, swizzle);
	if (mipMapped == GrMipMapped::kNo \|\|
	view.asTextureProxy()->mipMapped() == GrMipMapped::kYes) {
	return view;
	} else {
	// We need a mipped proxy, but we found a cached proxy that wasn't mipped. Thus we
	// generate a new mipped surface and copy the original proxy into the base layer. We
	// will then let the gpu generate the rest of the mips.
	auto mippedView = GrCopyBaseMipMapToView(ctx, view);
	if (!mippedView) {
	// We failed to make a mipped proxy with the base copied into it. This could
	// have been from failure to make the proxy or failure to do the copy. Thus we
	// will fall back to just using the non mipped proxy; See skbug.com/7094.
	return view;
	}
	proxyProvider->removeUniqueKeyFromProxy(view.asTextureProxy());
	installKey(mippedView);
	return mippedView;
	}
	}
	}

	// 2. Ask the generator to natively create one.
	{
	ScopedGenerator generator(fSharedGenerator);
	if (auto view = generator->generateTexture(ctx, this->imageInfo(), fOrigin, mipMapped,
	texGenPolicy)) {
	SK_HISTOGRAM_ENUMERATION("LockTexturePath", kNative_LockTexturePath,
	kLockTexturePathCount);
	installKey(view);
	return view;
	}
	}

	// 3. Ask the generator to return YUV planes, which the GPU can convert. If we will be mipping
	// the texture we skip this step so the CPU generate non-planar MIP maps for us.
	if (mipMapped == GrMipMapped::kNo && !ctx->priv().options().fDisableGpuYUVConversion) {
	SkColorType colorType = this->colorType();

	ScopedGenerator generator(fSharedGenerator);
	Generator_GrYUVProvider provider(generator);

	// The pixels in the texture will be in the generator's color space.
	// If onMakeColorTypeAndColorSpace has been called then this will not match this image's
	// color space. To correct this, apply a color space conversion from the generator's color
	// space to this image's color space.
	SkColorSpace* generatorColorSpace = fSharedGenerator->fGenerator->getInfo().colorSpace();
	SkColorSpace* thisColorSpace = this->colorSpace();

	// TODO: Update to create the mipped surface in the YUV generator and draw the base
	// layer directly into the mipped surface.
	SkBudgeted budgeted = texGenPolicy == GrImageTexGenPolicy::kNew_Uncached_Unbudgeted
	? SkBudgeted::kNo
	: SkBudgeted::kYes;
	auto view = provider.refAsTextureProxyView(ctx, this->imageInfo().dimensions(),
	SkColorTypeToGrColorType(colorType),
	generatorColorSpace, thisColorSpace, budgeted);
	if (view) {
	SK_HISTOGRAM_ENUMERATION("LockTexturePath", kYUV_LockTexturePath,
	kLockTexturePathCount);
	installKey(view);
	return view;
	}
	}

	// 4. Ask the generator to return a bitmap, which the GPU can convert.
	auto hint = texGenPolicy == GrImageTexGenPolicy::kDraw ? CachingHint::kAllow_CachingHint
	: CachingHint::kDisallow_CachingHint;
	if (SkBitmap bitmap; this->getROPixels(&bitmap, hint)) {
	// We always pass uncached here because we will cache it external to the maker based on
	// our cache policy. We're just using the maker to generate the texture.
	auto makerPolicy = texGenPolicy == GrImageTexGenPolicy::kNew_Uncached_Unbudgeted
	? GrImageTexGenPolicy::kNew_Uncached_Unbudgeted
	: GrImageTexGenPolicy::kNew_Uncached_Budgeted;
	GrBitmapTextureMaker bitmapMaker(ctx, bitmap, makerPolicy);
	auto view = bitmapMaker.view(mipMapped);
	if (view) {
	installKey(view);
	SK_HISTOGRAM_ENUMERATION("LockTexturePath", kRGBA_LockTexturePath,
	kLockTexturePathCount);
	return view;
	}
	}

	SK_HISTOGRAM_ENUMERATION("LockTexturePath", kFailure_LockTexturePath, kLockTexturePathCount);
	return {};
	}

	GrColorType SkImage_Lazy::colorTypeOfLockTextureProxy(const GrCaps* caps) const {
	GrColorType ct = SkColorTypeToGrColorType(this->colorType());
	GrBackendFormat format = caps->getDefaultBackendFormat(ct, GrRenderable::kNo);
	if (!format.isValid()) {
	ct = GrColorType::kRGBA_8888;
	}
	return ct;
	}

	#if SK_SUPPORT_GPU
	void SkImage_Lazy::addUniqueIDListener(sk_sp<SkIDChangeListener> listener) const {
	bool singleThreaded = this->unique();
	fUniqueIDListeners.add(std::move(listener), singleThreaded);
	}
	#endif

	///////////////////////////////////////////////////////////////////////////////////////////////////

	sk_sp<SkImage> SkImage::DecodeToTexture(GrContext* ctx, const void* encoded, size_t length,
	const SkIRect* subset) {
	// img will not survive this function, so we don't need to copy/own the encoded data,
	auto img = MakeFromEncoded(SkData::MakeWithoutCopy(encoded, length), subset);
	if (!img) {
	return nullptr;
	}
	return img->makeTextureImage(ctx);
	}

	#endif