src/gpu/GrBatchAtlas.cpp - platform/external/skqp - Gitiles

 /*
  * 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 "GrBatchAtlas.h"
 #include "GrBatchFlushState.h"
 #include "GrRectanizer.h"
 #include "GrTracing.h"
 #include "GrVertexBuffer.h"

 // The backing GrTexture for a GrBatchAtlas is broken into a spatial grid of BatchPlots.
 // The BatchPlots keep track of subimage placement via their GrRectanizer. A BatchPlot
 // manages the lifetime of its data using two tokens, a last use token and a last upload token.
 // Once a BatchPlot is "full" (i.e. there is no room for the new subimage according to the
 // GrRectanizer), it can no longer be used unless the last use of the GrPlot has already been
 // flushed through to the gpu.

 class BatchPlot : public SkRefCnt {
     SK_DECLARE_INTERNAL_LLIST_INTERFACE(BatchPlot);

 public:
     // index() is a unique id for the plot relative to the owning GrAtlas.  genID() is a
     // monotonically incremented number which is bumped every time this plot is
     // evicted from the cache (i.e., there is continuity in genID() across atlas spills).
     uint32_t index() const { return fIndex; }
     uint64_t genID() const { return fGenID; }
     GrBatchAtlas::AtlasID id() const {
         SkASSERT(GrBatchAtlas::kInvalidAtlasID != fID);
         return fID;
     }
     SkDEBUGCODE(size_t bpp() const { return fBytesPerPixel; })

     bool addSubImage(int width, int height, const void* image, SkIPoint16* loc)  {
         SkASSERT(width <= fWidth && height <= fHeight);

         if (!fRects) {
             fRects = GrRectanizer::Factory(fWidth, fHeight);
         }

         if (!fRects->addRect(width, height, loc)) {
             return false;
         }

         if (!fData) {
             fData = reinterpret_cast<unsigned char*>(sk_calloc_throw(fBytesPerPixel * fWidth *
                                                                      fHeight));
         }
         size_t rowBytes = width * fBytesPerPixel;
         const unsigned char* imagePtr = (const unsigned char*)image;
         // point ourselves at the right starting spot
         unsigned char* dataPtr = fData;
         dataPtr += fBytesPerPixel * fWidth * loc->fY;
         dataPtr += fBytesPerPixel * loc->fX;
         // copy into the data buffer
         for (int i = 0; i < height; ++i) {
             memcpy(dataPtr, imagePtr, rowBytes);
             dataPtr += fBytesPerPixel * fWidth;
             imagePtr += rowBytes;
         }

         fDirtyRect.join(loc->fX, loc->fY, loc->fX + width, loc->fY + height);

         loc->fX += fOffset.fX;
         loc->fY += fOffset.fY;
         SkDEBUGCODE(fDirty = true;)

         return true;
     }

     // To manage the lifetime of a plot, we use two tokens.  We use the last upload token to know
     // when we can 'piggy back' uploads, ie if the last upload hasn't been flushed to gpu, we don't
     // need to issue a new upload even if we update the cpu backing store.  We use lastUse to
     // determine when we can evict a plot from the cache, ie if the last use has already flushed
     // through the gpu then we can reuse the plot.
     GrBatchToken lastUploadToken() const { return fLastUpload; }
     GrBatchToken lastUseToken() const { return fLastUse; }
     void setLastUploadToken(GrBatchToken batchToken) {
         SkASSERT(batchToken >= fLastUpload);
         fLastUpload = batchToken;
     }
     void setLastUseToken(GrBatchToken batchToken) {
         SkASSERT(batchToken >= fLastUse);
         fLastUse = batchToken;
     }

     void uploadToTexture(GrBatchUploader::TextureUploader* uploader, GrTexture* texture)  {
         // We should only be issuing uploads if we are in fact dirty
         SkASSERT(fDirty && fData && texture);
         TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("skia.gpu"), "GrBatchPlot::uploadToTexture");
         size_t rowBytes = fBytesPerPixel * fWidth;
         const unsigned char* dataPtr = fData;
         dataPtr += rowBytes * fDirtyRect.fTop;
         dataPtr += fBytesPerPixel * fDirtyRect.fLeft;
         uploader->writeTexturePixels(texture,
                                      fOffset.fX + fDirtyRect.fLeft, fOffset.fY + fDirtyRect.fTop,
                                      fDirtyRect.width(), fDirtyRect.height(),
                                      fConfig, dataPtr, rowBytes);
         fDirtyRect.setEmpty();
         SkDEBUGCODE(fDirty = false;)
     }

     void resetRects() {
         if (fRects) {
             fRects->reset();
         }

         fGenID++;
         fID = CreateId(fIndex, fGenID);

         // zero out the plot
         if (fData) {
             sk_bzero(fData, fBytesPerPixel * fWidth * fHeight);
         }

         fDirtyRect.setEmpty();
         SkDEBUGCODE(fDirty = false;)
     }

 private:
     BatchPlot(int index, uint64_t genID, int offX, int offY, int width, int height,
               GrPixelConfig config)
         : fLastUpload(0)
         , fLastUse(0)
         , fIndex(index)
         , fGenID(genID)
         , fID(CreateId(fIndex, fGenID))
         , fData(nullptr)
         , fWidth(width)
         , fHeight(height)
         , fX(offX)
         , fY(offY)
         , fRects(nullptr)
         , fOffset(SkIPoint16::Make(fX * fWidth, fY * fHeight))
         , fConfig(config)
         , fBytesPerPixel(GrBytesPerPixel(config))
     #ifdef SK_DEBUG
         , fDirty(false)
     #endif
     {
         fDirtyRect.setEmpty();
     }

     ~BatchPlot() override {
         sk_free(fData);
         delete fRects;
     }

     // Create a clone of this plot. The cloned plot will take the place of the
     // current plot in the atlas.
     BatchPlot* clone() const {
         return new BatchPlot(fIndex, fGenID+1, fX, fY, fWidth, fHeight, fConfig);
     }

     static GrBatchAtlas::AtlasID CreateId(uint32_t index, uint64_t generation) {
         SkASSERT(index < (1 << 16));
         SkASSERT(generation < ((uint64_t)1 << 48));
         return generation << 16 | index;
     }

     GrBatchToken          fLastUpload;
     GrBatchToken          fLastUse;

     const uint32_t        fIndex;
     uint64_t              fGenID;
     GrBatchAtlas::AtlasID fID;
     unsigned char*        fData;
     const int             fWidth;
     const int             fHeight;
     const int             fX;
     const int             fY;
     GrRectanizer*         fRects;
     const SkIPoint16      fOffset;        // the offset of the plot in the backing texture
     const GrPixelConfig   fConfig;
     const size_t          fBytesPerPixel;
     SkIRect               fDirtyRect;
     SkDEBUGCODE(bool      fDirty;)

     friend class GrBatchAtlas;

     typedef SkRefCnt INHERITED;
 };

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

 class GrPlotUploader : public GrBatchUploader {
 public:
     GrPlotUploader(BatchPlot* plot, GrTexture* texture)
         : INHERITED(plot->lastUploadToken())
         , fPlot(SkRef(plot))
         , fTexture(texture) {
         SkASSERT(plot);
     }

     void upload(TextureUploader* uploader) override {
         fPlot->uploadToTexture(uploader, fTexture);
     }

 private:
     SkAutoTUnref<BatchPlot> fPlot;
     GrTexture*              fTexture;

     typedef GrBatchUploader INHERITED;
 };

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

 GrBatchAtlas::GrBatchAtlas(GrTexture* texture, int numPlotsX, int numPlotsY)
     : fTexture(texture)
     , fAtlasGeneration(kInvalidAtlasGeneration + 1) {

     int plotWidth = texture->width() / numPlotsX;
     int plotHeight = texture->height() / numPlotsY;
     SkASSERT(numPlotsX * numPlotsY <= BulkUseTokenUpdater::kMaxPlots);
     SkASSERT(plotWidth * numPlotsX == texture->width());
     SkASSERT(plotHeight * numPlotsY == texture->height());

     SkDEBUGCODE(fNumPlots = numPlotsX * numPlotsY;)

     // We currently do not support compressed atlases...
     SkASSERT(!GrPixelConfigIsCompressed(texture->desc().fConfig));

     // set up allocated plots
     fPlotArray = new SkAutoTUnref<BatchPlot>[numPlotsX * numPlotsY];

     SkAutoTUnref<BatchPlot>* currPlot = fPlotArray;
     for (int y = numPlotsY - 1, r = 0; y >= 0; --y, ++r) {
         for (int x = numPlotsX - 1, c = 0; x >= 0; --x, ++c) {
             uint32_t index = r * numPlotsX + c;
             currPlot->reset(new BatchPlot(index, 1, x, y, plotWidth, plotHeight,
                                           texture->desc().fConfig));

             // build LRU list
             fPlotList.addToHead(currPlot->get());
             ++currPlot;
         }
     }
 }

 GrBatchAtlas::~GrBatchAtlas() {
     SkSafeUnref(fTexture);
     delete[] fPlotArray;
 }

 void GrBatchAtlas::processEviction(AtlasID id) {
     for (int i = 0; i < fEvictionCallbacks.count(); i++) {
         (*fEvictionCallbacks[i].fFunc)(id, fEvictionCallbacks[i].fData);
     }
 }

 void GrBatchAtlas::makeMRU(BatchPlot* plot) {
     if (fPlotList.head() == plot) {
         return;
     }

     fPlotList.remove(plot);
     fPlotList.addToHead(plot);
 }

 inline void GrBatchAtlas::updatePlot(GrDrawBatch::Target* target, AtlasID* id, BatchPlot* plot) {
     this->makeMRU(plot);

     // If our most recent upload has already occurred then we have to insert a new
     // upload. Otherwise, we already have a scheduled upload that hasn't yet ocurred.
     // This new update will piggy back on that previously scheduled update.
     if (target->hasTokenBeenFlushed(plot->lastUploadToken())) {
         plot->setLastUploadToken(target->asapToken());
         SkAutoTUnref<GrPlotUploader> uploader(new GrPlotUploader(plot, fTexture));
         target->upload(uploader);
     }
     *id = plot->id();
 }

 bool GrBatchAtlas::addToAtlas(AtlasID* id, GrDrawBatch::Target* batchTarget,
                               int width, int height, const void* image, SkIPoint16* loc) {
     // We should already have a texture, TODO clean this up
     SkASSERT(fTexture);

     // now look through all allocated plots for one we can share, in Most Recently Refed order
     GrBatchPlotList::Iter plotIter;
     plotIter.init(fPlotList, GrBatchPlotList::Iter::kHead_IterStart);
     BatchPlot* plot;
     while ((plot = plotIter.get())) {
         SkASSERT(GrBytesPerPixel(fTexture->desc().fConfig) == plot->bpp());
         if (plot->addSubImage(width, height, image, loc)) {
             this->updatePlot(batchTarget, id, plot);
             return true;
         }
         plotIter.next();
     }

     // If the above fails, then see if the least recently refed plot has already been flushed to the
     // gpu
     plot = fPlotList.tail();
     SkASSERT(plot);
     if (batchTarget->hasTokenBeenFlushed(plot->lastUseToken())) {
         this->processEviction(plot->id());
         plot->resetRects();
         SkASSERT(GrBytesPerPixel(fTexture->desc().fConfig) == plot->bpp());
         SkDEBUGCODE(bool verify = )plot->addSubImage(width, height, image, loc);
         SkASSERT(verify);
         this->updatePlot(batchTarget, id, plot);
         fAtlasGeneration++;
         return true;
     }

     // The least recently used plot hasn't been flushed to the gpu yet, however, if we have flushed
     // it to the batch target than we can reuse it.  Our last use token is guaranteed to be less
     // than or equal to the current token.  If its 'less than' the current token, than we can spin
     // off the plot (ie let the batch target manage it) and create a new plot in its place in our
     // array.  If it is equal to the currentToken, then the caller has to flush draws to the batch
     // target so we can spin off the plot
     if (plot->lastUseToken() == batchTarget->currentToken()) {
         return false;
     }

     SkASSERT(plot->lastUseToken() < batchTarget->currentToken());
     SkASSERT(!batchTarget->hasTokenBeenFlushed(batchTarget->currentToken()));

     SkASSERT(!plot->unique());  // The GrPlotUpdater should have a ref too

     this->processEviction(plot->id());
     fPlotList.remove(plot);
     SkAutoTUnref<BatchPlot>& newPlot = fPlotArray[plot->index()];
     newPlot.reset(plot->clone());

     fPlotList.addToHead(newPlot.get());
     SkASSERT(GrBytesPerPixel(fTexture->desc().fConfig) == newPlot->bpp());
     SkDEBUGCODE(bool verify = )newPlot->addSubImage(width, height, image, loc);
     SkASSERT(verify);

     // Note that this plot will be uploaded inline with the draws whereas the
     // one it displaced most likely was uploaded asap.
     newPlot->setLastUploadToken(batchTarget->currentToken());
     SkAutoTUnref<GrPlotUploader> uploader(new GrPlotUploader(newPlot, fTexture));
     batchTarget->upload(uploader);
     *id = newPlot->id();

     fAtlasGeneration++;
     return true;
 }

 bool GrBatchAtlas::hasID(AtlasID id) {
     uint32_t index = GetIndexFromID(id);
     SkASSERT(index < fNumPlots);
     return fPlotArray[index]->genID() == GetGenerationFromID(id);
 }

 void GrBatchAtlas::setLastUseToken(AtlasID id, GrBatchToken batchToken) {
     SkASSERT(this->hasID(id));
     uint32_t index = GetIndexFromID(id);
     SkASSERT(index < fNumPlots);
     this->makeMRU(fPlotArray[index]);
     fPlotArray[index]->setLastUseToken(batchToken);
 }

 void GrBatchAtlas::setLastUseTokenBulk(const BulkUseTokenUpdater& updater,
                                        GrBatchToken batchToken) {
     int count = updater.fPlotsToUpdate.count();
     for (int i = 0; i < count; i++) {
         BatchPlot* plot = fPlotArray[updater.fPlotsToUpdate[i]];
         this->makeMRU(plot);
         plot->setLastUseToken(batchToken);
     }
 }
	/*
	* 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 "GrBatchAtlas.h"
	#include "GrBatchFlushState.h"
	#include "GrRectanizer.h"
	#include "GrTracing.h"
	#include "GrVertexBuffer.h"

	// The backing GrTexture for a GrBatchAtlas is broken into a spatial grid of BatchPlots.
	// The BatchPlots keep track of subimage placement via their GrRectanizer. A BatchPlot
	// manages the lifetime of its data using two tokens, a last use token and a last upload token.
	// Once a BatchPlot is "full" (i.e. there is no room for the new subimage according to the
	// GrRectanizer), it can no longer be used unless the last use of the GrPlot has already been
	// flushed through to the gpu.

	class BatchPlot : public SkRefCnt {
	SK_DECLARE_INTERNAL_LLIST_INTERFACE(BatchPlot);

	public:
	// index() is a unique id for the plot relative to the owning GrAtlas. genID() is a
	// monotonically incremented number which is bumped every time this plot is
	// evicted from the cache (i.e., there is continuity in genID() across atlas spills).
	uint32_t index() const { return fIndex; }
	uint64_t genID() const { return fGenID; }
	GrBatchAtlas::AtlasID id() const {
	SkASSERT(GrBatchAtlas::kInvalidAtlasID != fID);
	return fID;
	}
	SkDEBUGCODE(size_t bpp() const { return fBytesPerPixel; })

	bool addSubImage(int width, int height, const void* image, SkIPoint16* loc) {
	SkASSERT(width <= fWidth && height <= fHeight);

	if (!fRects) {
	fRects = GrRectanizer::Factory(fWidth, fHeight);
	}

	if (!fRects->addRect(width, height, loc)) {
	return false;
	}

	if (!fData) {
	fData = reinterpret_cast<unsigned char>(sk_calloc_throw(fBytesPerPixel fWidth *
	fHeight));
	}
	size_t rowBytes = width * fBytesPerPixel;
	const unsigned char* imagePtr = (const unsigned char*)image;
	// point ourselves at the right starting spot
	unsigned char* dataPtr = fData;
	dataPtr += fBytesPerPixel * fWidth * loc->fY;
	dataPtr += fBytesPerPixel * loc->fX;
	// copy into the data buffer
	for (int i = 0; i < height; ++i) {
	memcpy(dataPtr, imagePtr, rowBytes);
	dataPtr += fBytesPerPixel * fWidth;
	imagePtr += rowBytes;
	}

	fDirtyRect.join(loc->fX, loc->fY, loc->fX + width, loc->fY + height);

	loc->fX += fOffset.fX;
	loc->fY += fOffset.fY;
	SkDEBUGCODE(fDirty = true;)

	return true;
	}

	// To manage the lifetime of a plot, we use two tokens. We use the last upload token to know
	// when we can 'piggy back' uploads, ie if the last upload hasn't been flushed to gpu, we don't
	// need to issue a new upload even if we update the cpu backing store. We use lastUse to
	// determine when we can evict a plot from the cache, ie if the last use has already flushed
	// through the gpu then we can reuse the plot.
	GrBatchToken lastUploadToken() const { return fLastUpload; }
	GrBatchToken lastUseToken() const { return fLastUse; }
	void setLastUploadToken(GrBatchToken batchToken) {
	SkASSERT(batchToken >= fLastUpload);
	fLastUpload = batchToken;
	}
	void setLastUseToken(GrBatchToken batchToken) {
	SkASSERT(batchToken >= fLastUse);
	fLastUse = batchToken;
	}

	void uploadToTexture(GrBatchUploader::TextureUploader* uploader, GrTexture* texture) {
	// We should only be issuing uploads if we are in fact dirty
	SkASSERT(fDirty && fData && texture);
	TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("skia.gpu"), "GrBatchPlot::uploadToTexture");
	size_t rowBytes = fBytesPerPixel * fWidth;
	const unsigned char* dataPtr = fData;
	dataPtr += rowBytes * fDirtyRect.fTop;
	dataPtr += fBytesPerPixel * fDirtyRect.fLeft;
	uploader->writeTexturePixels(texture,
	fOffset.fX + fDirtyRect.fLeft, fOffset.fY + fDirtyRect.fTop,
	fDirtyRect.width(), fDirtyRect.height(),
	fConfig, dataPtr, rowBytes);
	fDirtyRect.setEmpty();
	SkDEBUGCODE(fDirty = false;)
	}

	void resetRects() {
	if (fRects) {
	fRects->reset();
	}

	fGenID++;
	fID = CreateId(fIndex, fGenID);

	// zero out the plot
	if (fData) {
	sk_bzero(fData, fBytesPerPixel * fWidth * fHeight);
	}

	fDirtyRect.setEmpty();
	SkDEBUGCODE(fDirty = false;)
	}

	private:
	BatchPlot(int index, uint64_t genID, int offX, int offY, int width, int height,
	GrPixelConfig config)
	: fLastUpload(0)
	, fLastUse(0)
	, fIndex(index)
	, fGenID(genID)
	, fID(CreateId(fIndex, fGenID))
	, fData(nullptr)
	, fWidth(width)
	, fHeight(height)
	, fX(offX)
	, fY(offY)
	, fRects(nullptr)
	, fOffset(SkIPoint16::Make(fX * fWidth, fY * fHeight))
	, fConfig(config)
	, fBytesPerPixel(GrBytesPerPixel(config))
	#ifdef SK_DEBUG
	, fDirty(false)
	#endif
	{
	fDirtyRect.setEmpty();
	}

	~BatchPlot() override {
	sk_free(fData);
	delete fRects;
	}

	// Create a clone of this plot. The cloned plot will take the place of the
	// current plot in the atlas.
	BatchPlot* clone() const {
	return new BatchPlot(fIndex, fGenID+1, fX, fY, fWidth, fHeight, fConfig);
	}

	static GrBatchAtlas::AtlasID CreateId(uint32_t index, uint64_t generation) {
	SkASSERT(index < (1 << 16));
	SkASSERT(generation < ((uint64_t)1 << 48));
	return generation << 16 \| index;
	}

	GrBatchToken fLastUpload;
	GrBatchToken fLastUse;

	const uint32_t fIndex;
	uint64_t fGenID;
	GrBatchAtlas::AtlasID fID;
	unsigned char* fData;
	const int fWidth;
	const int fHeight;
	const int fX;
	const int fY;
	GrRectanizer* fRects;
	const SkIPoint16 fOffset; // the offset of the plot in the backing texture
	const GrPixelConfig fConfig;
	const size_t fBytesPerPixel;
	SkIRect fDirtyRect;
	SkDEBUGCODE(bool fDirty;)

	friend class GrBatchAtlas;

	typedef SkRefCnt INHERITED;
	};

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

	class GrPlotUploader : public GrBatchUploader {
	public:
	GrPlotUploader(BatchPlot* plot, GrTexture* texture)
	: INHERITED(plot->lastUploadToken())
	, fPlot(SkRef(plot))
	, fTexture(texture) {
	SkASSERT(plot);
	}

	void upload(TextureUploader* uploader) override {
	fPlot->uploadToTexture(uploader, fTexture);
	}

	private:
	SkAutoTUnref<BatchPlot> fPlot;
	GrTexture* fTexture;

	typedef GrBatchUploader INHERITED;
	};

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

	GrBatchAtlas::GrBatchAtlas(GrTexture* texture, int numPlotsX, int numPlotsY)
	: fTexture(texture)
	, fAtlasGeneration(kInvalidAtlasGeneration + 1) {

	int plotWidth = texture->width() / numPlotsX;
	int plotHeight = texture->height() / numPlotsY;
	SkASSERT(numPlotsX * numPlotsY <= BulkUseTokenUpdater::kMaxPlots);
	SkASSERT(plotWidth * numPlotsX == texture->width());
	SkASSERT(plotHeight * numPlotsY == texture->height());

	SkDEBUGCODE(fNumPlots = numPlotsX * numPlotsY;)

	// We currently do not support compressed atlases...
	SkASSERT(!GrPixelConfigIsCompressed(texture->desc().fConfig));

	// set up allocated plots
	fPlotArray = new SkAutoTUnref<BatchPlot>[numPlotsX * numPlotsY];

	SkAutoTUnref<BatchPlot>* currPlot = fPlotArray;
	for (int y = numPlotsY - 1, r = 0; y >= 0; --y, ++r) {
	for (int x = numPlotsX - 1, c = 0; x >= 0; --x, ++c) {
	uint32_t index = r * numPlotsX + c;
	currPlot->reset(new BatchPlot(index, 1, x, y, plotWidth, plotHeight,
	texture->desc().fConfig));

	// build LRU list
	fPlotList.addToHead(currPlot->get());
	++currPlot;
	}
	}
	}

	GrBatchAtlas::~GrBatchAtlas() {
	SkSafeUnref(fTexture);
	delete[] fPlotArray;
	}

	void GrBatchAtlas::processEviction(AtlasID id) {
	for (int i = 0; i < fEvictionCallbacks.count(); i++) {
	(*fEvictionCallbacks[i].fFunc)(id, fEvictionCallbacks[i].fData);
	}
	}

	void GrBatchAtlas::makeMRU(BatchPlot* plot) {
	if (fPlotList.head() == plot) {
	return;
	}

	fPlotList.remove(plot);
	fPlotList.addToHead(plot);
	}

	inline void GrBatchAtlas::updatePlot(GrDrawBatch::Target* target, AtlasID* id, BatchPlot* plot) {
	this->makeMRU(plot);

	// If our most recent upload has already occurred then we have to insert a new
	// upload. Otherwise, we already have a scheduled upload that hasn't yet ocurred.
	// This new update will piggy back on that previously scheduled update.
	if (target->hasTokenBeenFlushed(plot->lastUploadToken())) {
	plot->setLastUploadToken(target->asapToken());
	SkAutoTUnref<GrPlotUploader> uploader(new GrPlotUploader(plot, fTexture));
	target->upload(uploader);
	}
	*id = plot->id();
	}

	bool GrBatchAtlas::addToAtlas(AtlasID* id, GrDrawBatch::Target* batchTarget,
	int width, int height, const void* image, SkIPoint16* loc) {
	// We should already have a texture, TODO clean this up
	SkASSERT(fTexture);

	// now look through all allocated plots for one we can share, in Most Recently Refed order
	GrBatchPlotList::Iter plotIter;
	plotIter.init(fPlotList, GrBatchPlotList::Iter::kHead_IterStart);
	BatchPlot* plot;
	while ((plot = plotIter.get())) {
	SkASSERT(GrBytesPerPixel(fTexture->desc().fConfig) == plot->bpp());
	if (plot->addSubImage(width, height, image, loc)) {
	this->updatePlot(batchTarget, id, plot);
	return true;
	}
	plotIter.next();
	}

	// If the above fails, then see if the least recently refed plot has already been flushed to the
	// gpu
	plot = fPlotList.tail();
	SkASSERT(plot);
	if (batchTarget->hasTokenBeenFlushed(plot->lastUseToken())) {
	this->processEviction(plot->id());
	plot->resetRects();
	SkASSERT(GrBytesPerPixel(fTexture->desc().fConfig) == plot->bpp());
	SkDEBUGCODE(bool verify = )plot->addSubImage(width, height, image, loc);
	SkASSERT(verify);
	this->updatePlot(batchTarget, id, plot);
	fAtlasGeneration++;
	return true;
	}

	// The least recently used plot hasn't been flushed to the gpu yet, however, if we have flushed
	// it to the batch target than we can reuse it. Our last use token is guaranteed to be less
	// than or equal to the current token. If its 'less than' the current token, than we can spin
	// off the plot (ie let the batch target manage it) and create a new plot in its place in our
	// array. If it is equal to the currentToken, then the caller has to flush draws to the batch
	// target so we can spin off the plot
	if (plot->lastUseToken() == batchTarget->currentToken()) {
	return false;
	}

	SkASSERT(plot->lastUseToken() < batchTarget->currentToken());
	SkASSERT(!batchTarget->hasTokenBeenFlushed(batchTarget->currentToken()));

	SkASSERT(!plot->unique()); // The GrPlotUpdater should have a ref too

	this->processEviction(plot->id());
	fPlotList.remove(plot);
	SkAutoTUnref<BatchPlot>& newPlot = fPlotArray[plot->index()];
	newPlot.reset(plot->clone());

	fPlotList.addToHead(newPlot.get());
	SkASSERT(GrBytesPerPixel(fTexture->desc().fConfig) == newPlot->bpp());
	SkDEBUGCODE(bool verify = )newPlot->addSubImage(width, height, image, loc);
	SkASSERT(verify);

	// Note that this plot will be uploaded inline with the draws whereas the
	// one it displaced most likely was uploaded asap.
	newPlot->setLastUploadToken(batchTarget->currentToken());
	SkAutoTUnref<GrPlotUploader> uploader(new GrPlotUploader(newPlot, fTexture));
	batchTarget->upload(uploader);
	*id = newPlot->id();

	fAtlasGeneration++;
	return true;
	}

	bool GrBatchAtlas::hasID(AtlasID id) {
	uint32_t index = GetIndexFromID(id);
	SkASSERT(index < fNumPlots);
	return fPlotArray[index]->genID() == GetGenerationFromID(id);
	}

	void GrBatchAtlas::setLastUseToken(AtlasID id, GrBatchToken batchToken) {
	SkASSERT(this->hasID(id));
	uint32_t index = GetIndexFromID(id);
	SkASSERT(index < fNumPlots);
	this->makeMRU(fPlotArray[index]);
	fPlotArray[index]->setLastUseToken(batchToken);
	}

	void GrBatchAtlas::setLastUseTokenBulk(const BulkUseTokenUpdater& updater,
	GrBatchToken batchToken) {
	int count = updater.fPlotsToUpdate.count();
	for (int i = 0; i < count; i++) {
	BatchPlot* plot = fPlotArray[updater.fPlotsToUpdate[i]];
	this->makeMRU(plot);
	plot->setLastUseToken(batchToken);
	}
	}