src/gpu/effects/GrTextureStripAtlas.cpp - platform/external/skqp - Gitiles

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */

 #include "GrTextureStripAtlas.h"
 #include "GrContext.h"
 #include "GrContextPriv.h"
 #include "GrResourceProvider.h"
 #include "GrSurfaceContext.h"
 #include "GrTextureProvider.h"
 #include "SkGr.h"
 #include "SkPixelRef.h"
 #include "SkTSearch.h"

 #ifdef SK_DEBUG
     #define VALIDATE this->validate()
 #else
     #define VALIDATE
 #endif

 class GrTextureStripAtlas::Hash : public SkTDynamicHash<GrTextureStripAtlas::AtlasEntry,
                                                         GrTextureStripAtlas::Desc> {};

 int32_t GrTextureStripAtlas::gCacheCount = 0;

 GrTextureStripAtlas::Hash* GrTextureStripAtlas::gAtlasCache = nullptr;

 GrTextureStripAtlas::Hash* GrTextureStripAtlas::GetCache() {

     if (nullptr == gAtlasCache) {
         gAtlasCache = new Hash;
     }

     return gAtlasCache;
 }

 // Remove the specified atlas from the cache
 void GrTextureStripAtlas::CleanUp(const GrContext*, void* info) {
     SkASSERT(info);

     AtlasEntry* entry = static_cast<AtlasEntry*>(info);

     // remove the cache entry
     GetCache()->remove(entry->fDesc);

     // remove the actual entry
     delete entry;

     if (0 == GetCache()->count()) {
         delete gAtlasCache;
         gAtlasCache = nullptr;
     }
 }

 GrTextureStripAtlas* GrTextureStripAtlas::GetAtlas(const GrTextureStripAtlas::Desc& desc) {
     AtlasEntry* entry = GetCache()->find(desc);
     if (nullptr == entry) {
         entry = new AtlasEntry;

         entry->fAtlas = new GrTextureStripAtlas(desc);
         entry->fDesc = desc;

         desc.fContext->addCleanUp(CleanUp, entry);

         GetCache()->add(entry);
     }

     return entry->fAtlas;
 }

 GrTextureStripAtlas::GrTextureStripAtlas(GrTextureStripAtlas::Desc desc)
     : fCacheKey(sk_atomic_inc(&gCacheCount))
     , fLockedRows(0)
     , fDesc(desc)
     , fNumRows(desc.fHeight / desc.fRowHeight)
     , fRows(new AtlasRow[fNumRows])
     , fLRUFront(nullptr)
     , fLRUBack(nullptr) {
     SkASSERT(fNumRows * fDesc.fRowHeight == fDesc.fHeight);
     this->initLRU();
     fNormalizedYHeight = SK_Scalar1 / fDesc.fHeight;
     VALIDATE;
 }

 GrTextureStripAtlas::~GrTextureStripAtlas() { delete[] fRows; }

 int GrTextureStripAtlas::lockRow(const SkBitmap& bitmap) {
     VALIDATE;
     if (0 == fLockedRows) {
         this->lockTexture();
         if (!fTexContext) {
             return -1;
         }
     }

     int key = bitmap.getGenerationID();
     int rowNumber = -1;
     int index = this->searchByKey(key);

     if (index >= 0) {
         // We already have the data in a row, so we can just return that row
         AtlasRow* row = fKeyTable[index];
         if (0 == row->fLocks) {
             this->removeFromLRU(row);
         }
         ++row->fLocks;
         ++fLockedRows;

         // Since all the rows are always stored in a contiguous array, we can save the memory
         // required for storing row numbers and just compute it with some pointer arithmetic
         rowNumber = static_cast<int>(row - fRows);
     } else {
         // ~index is the index where we will insert the new key to keep things sorted
         index = ~index;

         // We don't have this data cached, so pick the least recently used row to copy into
         AtlasRow* row = this->getLRU();

         ++fLockedRows;

         if (nullptr == row) {
             // force a flush, which should unlock all the rows; then try again
             fDesc.fContext->flush();
             row = this->getLRU();
             if (nullptr == row) {
                 --fLockedRows;
                 return -1;
             }
         }

         this->removeFromLRU(row);

         uint32_t oldKey = row->fKey;

         // If we are writing into a row that already held bitmap data, we need to remove the
         // reference to that genID which is stored in our sorted table of key values.
         if (oldKey != kEmptyAtlasRowKey) {

             // Find the entry in the list; if it's before the index where we plan on adding the new
             // entry, we decrement since it will shift elements ahead of it back by one.
             int oldIndex = this->searchByKey(oldKey);
             if (oldIndex < index) {
                 --index;
             }

             fKeyTable.remove(oldIndex);
         }

         row->fKey = key;
         row->fLocks = 1;
         fKeyTable.insert(index, 1, &row);
         rowNumber = static_cast<int>(row - fRows);

         SkAutoLockPixels lock(bitmap);

         SkASSERT(bitmap.width() == fDesc.fWidth);
         SkASSERT(bitmap.height() == fDesc.fRowHeight);

         // Pass in the kDontFlush flag, since we know we're writing to a part of this texture
         // that is not currently in use
         fTexContext->writePixels(bitmap.info(), bitmap.getPixels(), bitmap.rowBytes(),
                                  0, rowNumber * fDesc.fRowHeight,
                                  GrContext::kDontFlush_PixelOpsFlag);
     }

     SkASSERT(rowNumber >= 0);
     VALIDATE;
     return rowNumber;
 }

 sk_sp<GrTextureProxy> GrTextureStripAtlas::asTextureProxyRef() const {
     return fTexContext->asTextureProxyRef();
 }

 void GrTextureStripAtlas::unlockRow(int row) {
     VALIDATE;
     --fRows[row].fLocks;
     --fLockedRows;
     SkASSERT(fRows[row].fLocks >= 0 && fLockedRows >= 0);
     if (0 == fRows[row].fLocks) {
         this->appendLRU(fRows + row);
     }
     if (0 == fLockedRows) {
         this->unlockTexture();
     }
     VALIDATE;
 }

 GrTextureStripAtlas::AtlasRow* GrTextureStripAtlas::getLRU() {
     // Front is least-recently-used
     AtlasRow* row = fLRUFront;
     return row;
 }

 void GrTextureStripAtlas::lockTexture() {
     GrSurfaceDesc texDesc;
     texDesc.fWidth = fDesc.fWidth;
     texDesc.fHeight = fDesc.fHeight;
     texDesc.fConfig = fDesc.fConfig;
     texDesc.fIsMipMapped = false;

     static const GrUniqueKey::Domain kDomain = GrUniqueKey::GenerateDomain();
     GrUniqueKey key;
     GrUniqueKey::Builder builder(&key, kDomain, 1);
     builder[0] = static_cast<uint32_t>(fCacheKey);
     builder.finish();

     // MDB TODO (caching): this side-steps the issue of proxies with unique IDs
     sk_sp<GrTexture> texture(fDesc.fContext->textureProvider()->findAndRefTextureByUniqueKey(key));
     if (!texture) {
         texture.reset(fDesc.fContext->textureProvider()->createTexture(
                                                         texDesc, SkBudgeted::kYes,
                                                         nullptr, 0,
                                                         GrResourceProvider::kNoPendingIO_Flag));
         if (!texture) {
             return;
         }

         fDesc.fContext->textureProvider()->assignUniqueKeyToTexture(key, texture.get());
         // This is a new texture, so all of our cache info is now invalid
         this->initLRU();
         fKeyTable.rewind();
     }
     SkASSERT(texture);
     fTexContext = fDesc.fContext->contextPriv().makeWrappedSurfaceContext(std::move(texture));
 }

 void GrTextureStripAtlas::unlockTexture() {
     SkASSERT(fTexContext && 0 == fLockedRows);
     fTexContext.reset();
 }

 void GrTextureStripAtlas::initLRU() {
     fLRUFront = nullptr;
     fLRUBack = nullptr;
     // Initially all the rows are in the LRU list
     for (int i = 0; i < fNumRows; ++i) {
         fRows[i].fKey = kEmptyAtlasRowKey;
         fRows[i].fNext = nullptr;
         fRows[i].fPrev = nullptr;
         this->appendLRU(fRows + i);
     }
     SkASSERT(nullptr == fLRUFront || nullptr == fLRUFront->fPrev);
     SkASSERT(nullptr == fLRUBack || nullptr == fLRUBack->fNext);
 }

 void GrTextureStripAtlas::appendLRU(AtlasRow* row) {
     SkASSERT(nullptr == row->fPrev && nullptr == row->fNext);
     if (nullptr == fLRUFront && nullptr == fLRUBack) {
         fLRUFront = row;
         fLRUBack = row;
     } else {
         row->fPrev = fLRUBack;
         fLRUBack->fNext = row;
         fLRUBack = row;
     }
 }

 void GrTextureStripAtlas::removeFromLRU(AtlasRow* row) {
     SkASSERT(row);
     if (row->fNext && row->fPrev) {
         row->fPrev->fNext = row->fNext;
         row->fNext->fPrev = row->fPrev;
     } else {
         if (nullptr == row->fNext) {
             SkASSERT(row == fLRUBack);
             fLRUBack = row->fPrev;
             if (fLRUBack) {
                 fLRUBack->fNext = nullptr;
             }
         }
         if (nullptr == row->fPrev) {
             SkASSERT(row == fLRUFront);
             fLRUFront = row->fNext;
             if (fLRUFront) {
                 fLRUFront->fPrev = nullptr;
             }
         }
     }
     row->fNext = nullptr;
     row->fPrev = nullptr;
 }

 int GrTextureStripAtlas::searchByKey(uint32_t key) {
     AtlasRow target;
     target.fKey = key;
     return SkTSearch<const AtlasRow,
                      GrTextureStripAtlas::KeyLess>((const AtlasRow**)fKeyTable.begin(),
                                                    fKeyTable.count(),
                                                    &target,
                                                    sizeof(AtlasRow*));
 }

 #ifdef SK_DEBUG
 void GrTextureStripAtlas::validate() {

     // Our key table should be sorted
     uint32_t prev = 1 > fKeyTable.count() ? 0 : fKeyTable[0]->fKey;
     for (int i = 1; i < fKeyTable.count(); ++i) {
         SkASSERT(prev < fKeyTable[i]->fKey);
         SkASSERT(fKeyTable[i]->fKey != kEmptyAtlasRowKey);
         prev = fKeyTable[i]->fKey;
     }

     int lruCount = 0;
     // Validate LRU pointers, and count LRU entries
     SkASSERT(nullptr == fLRUFront || nullptr == fLRUFront->fPrev);
     SkASSERT(nullptr == fLRUBack  || nullptr == fLRUBack->fNext);
     for (AtlasRow* r = fLRUFront; r != nullptr; r = r->fNext) {
         if (nullptr == r->fNext) {
             SkASSERT(r == fLRUBack);
         } else {
             SkASSERT(r->fNext->fPrev == r);
         }
         ++lruCount;
     }

     int rowLocks = 0;
     int freeRows = 0;

     for (int i = 0; i < fNumRows; ++i) {
         rowLocks += fRows[i].fLocks;
         if (0 == fRows[i].fLocks) {
             ++freeRows;
             bool inLRU = false;
             // Step through the LRU and make sure it's present
             for (AtlasRow* r = fLRUFront; r != nullptr; r = r->fNext) {
                 if (r == &fRows[i]) {
                     inLRU = true;
                     break;
                 }
             }
             SkASSERT(inLRU);
         } else {
             // If we are locked, we should have a key
             SkASSERT(kEmptyAtlasRowKey != fRows[i].fKey);
         }

         // If we have a key != kEmptyAtlasRowKey, it should be in the key table
         SkASSERT(fRows[i].fKey == kEmptyAtlasRowKey || this->searchByKey(fRows[i].fKey) >= 0);
     }

     // Our count of locks should equal the sum of row locks, unless we ran out of rows and flushed,
     // in which case we'll have one more lock than recorded in the rows (to represent the pending
     // lock of a row; which ensures we don't unlock the texture prematurely).
     SkASSERT(rowLocks == fLockedRows || rowLocks + 1 == fLockedRows);

     // We should have one lru entry for each free row
     SkASSERT(freeRows == lruCount);

     // If we have locked rows, we should have a locked texture, otherwise
     // it should be unlocked
     if (fLockedRows == 0) {
         SkASSERT(!fTexContext);
     } else {
         SkASSERT(fTexContext);
     }
 }
 #endif
	/*
	* Copyright 2012 Google Inc.
	*
	* Use of this source code is governed by a BSD-style license that can be
	* found in the LICENSE file.
	*/

	#include "GrTextureStripAtlas.h"
	#include "GrContext.h"
	#include "GrContextPriv.h"
	#include "GrResourceProvider.h"
	#include "GrSurfaceContext.h"
	#include "GrTextureProvider.h"
	#include "SkGr.h"
	#include "SkPixelRef.h"
	#include "SkTSearch.h"

	#ifdef SK_DEBUG
	#define VALIDATE this->validate()
	#else
	#define VALIDATE
	#endif

	class GrTextureStripAtlas::Hash : public SkTDynamicHash<GrTextureStripAtlas::AtlasEntry,
	GrTextureStripAtlas::Desc> {};

	int32_t GrTextureStripAtlas::gCacheCount = 0;

	GrTextureStripAtlas::Hash* GrTextureStripAtlas::gAtlasCache = nullptr;

	GrTextureStripAtlas::Hash* GrTextureStripAtlas::GetCache() {

	if (nullptr == gAtlasCache) {
	gAtlasCache = new Hash;
	}

	return gAtlasCache;
	}

	// Remove the specified atlas from the cache
	void GrTextureStripAtlas::CleanUp(const GrContext, void info) {
	SkASSERT(info);

	AtlasEntry* entry = static_cast<AtlasEntry*>(info);

	// remove the cache entry
	GetCache()->remove(entry->fDesc);

	// remove the actual entry
	delete entry;

	if (0 == GetCache()->count()) {
	delete gAtlasCache;
	gAtlasCache = nullptr;
	}
	}

	GrTextureStripAtlas* GrTextureStripAtlas::GetAtlas(const GrTextureStripAtlas::Desc& desc) {
	AtlasEntry* entry = GetCache()->find(desc);
	if (nullptr == entry) {
	entry = new AtlasEntry;

	entry->fAtlas = new GrTextureStripAtlas(desc);
	entry->fDesc = desc;

	desc.fContext->addCleanUp(CleanUp, entry);

	GetCache()->add(entry);
	}

	return entry->fAtlas;
	}

	GrTextureStripAtlas::GrTextureStripAtlas(GrTextureStripAtlas::Desc desc)
	: fCacheKey(sk_atomic_inc(&gCacheCount))
	, fLockedRows(0)
	, fDesc(desc)
	, fNumRows(desc.fHeight / desc.fRowHeight)
	, fRows(new AtlasRow[fNumRows])
	, fLRUFront(nullptr)
	, fLRUBack(nullptr) {
	SkASSERT(fNumRows * fDesc.fRowHeight == fDesc.fHeight);
	this->initLRU();
	fNormalizedYHeight = SK_Scalar1 / fDesc.fHeight;
	VALIDATE;
	}

	GrTextureStripAtlas::~GrTextureStripAtlas() { delete[] fRows; }

	int GrTextureStripAtlas::lockRow(const SkBitmap& bitmap) {
	VALIDATE;
	if (0 == fLockedRows) {
	this->lockTexture();
	if (!fTexContext) {
	return -1;
	}
	}

	int key = bitmap.getGenerationID();
	int rowNumber = -1;
	int index = this->searchByKey(key);

	if (index >= 0) {
	// We already have the data in a row, so we can just return that row
	AtlasRow* row = fKeyTable[index];
	if (0 == row->fLocks) {
	this->removeFromLRU(row);
	}
	++row->fLocks;
	++fLockedRows;

	// Since all the rows are always stored in a contiguous array, we can save the memory
	// required for storing row numbers and just compute it with some pointer arithmetic
	rowNumber = static_cast<int>(row - fRows);
	} else {
	// ~index is the index where we will insert the new key to keep things sorted
	index = ~index;

	// We don't have this data cached, so pick the least recently used row to copy into
	AtlasRow* row = this->getLRU();

	++fLockedRows;

	if (nullptr == row) {
	// force a flush, which should unlock all the rows; then try again
	fDesc.fContext->flush();
	row = this->getLRU();
	if (nullptr == row) {
	--fLockedRows;
	return -1;
	}
	}

	this->removeFromLRU(row);

	uint32_t oldKey = row->fKey;

	// If we are writing into a row that already held bitmap data, we need to remove the
	// reference to that genID which is stored in our sorted table of key values.
	if (oldKey != kEmptyAtlasRowKey) {

	// Find the entry in the list; if it's before the index where we plan on adding the new
	// entry, we decrement since it will shift elements ahead of it back by one.
	int oldIndex = this->searchByKey(oldKey);
	if (oldIndex < index) {
	--index;
	}

	fKeyTable.remove(oldIndex);
	}

	row->fKey = key;
	row->fLocks = 1;
	fKeyTable.insert(index, 1, &row);
	rowNumber = static_cast<int>(row - fRows);

	SkAutoLockPixels lock(bitmap);

	SkASSERT(bitmap.width() == fDesc.fWidth);
	SkASSERT(bitmap.height() == fDesc.fRowHeight);

	// Pass in the kDontFlush flag, since we know we're writing to a part of this texture
	// that is not currently in use
	fTexContext->writePixels(bitmap.info(), bitmap.getPixels(), bitmap.rowBytes(),
	0, rowNumber * fDesc.fRowHeight,
	GrContext::kDontFlush_PixelOpsFlag);
	}

	SkASSERT(rowNumber >= 0);
	VALIDATE;
	return rowNumber;
	}

	sk_sp<GrTextureProxy> GrTextureStripAtlas::asTextureProxyRef() const {
	return fTexContext->asTextureProxyRef();
	}

	void GrTextureStripAtlas::unlockRow(int row) {
	VALIDATE;
	--fRows[row].fLocks;
	--fLockedRows;
	SkASSERT(fRows[row].fLocks >= 0 && fLockedRows >= 0);
	if (0 == fRows[row].fLocks) {
	this->appendLRU(fRows + row);
	}
	if (0 == fLockedRows) {
	this->unlockTexture();
	}
	VALIDATE;
	}

	GrTextureStripAtlas::AtlasRow* GrTextureStripAtlas::getLRU() {
	// Front is least-recently-used
	AtlasRow* row = fLRUFront;
	return row;
	}

	void GrTextureStripAtlas::lockTexture() {
	GrSurfaceDesc texDesc;
	texDesc.fWidth = fDesc.fWidth;
	texDesc.fHeight = fDesc.fHeight;
	texDesc.fConfig = fDesc.fConfig;
	texDesc.fIsMipMapped = false;

	static const GrUniqueKey::Domain kDomain = GrUniqueKey::GenerateDomain();
	GrUniqueKey key;
	GrUniqueKey::Builder builder(&key, kDomain, 1);
	builder[0] = static_cast<uint32_t>(fCacheKey);
	builder.finish();

	// MDB TODO (caching): this side-steps the issue of proxies with unique IDs
	sk_sp<GrTexture> texture(fDesc.fContext->textureProvider()->findAndRefTextureByUniqueKey(key));
	if (!texture) {
	texture.reset(fDesc.fContext->textureProvider()->createTexture(
	texDesc, SkBudgeted::kYes,
	nullptr, 0,
	GrResourceProvider::kNoPendingIO_Flag));
	if (!texture) {
	return;
	}

	fDesc.fContext->textureProvider()->assignUniqueKeyToTexture(key, texture.get());
	// This is a new texture, so all of our cache info is now invalid
	this->initLRU();
	fKeyTable.rewind();
	}
	SkASSERT(texture);
	fTexContext = fDesc.fContext->contextPriv().makeWrappedSurfaceContext(std::move(texture));
	}

	void GrTextureStripAtlas::unlockTexture() {
	SkASSERT(fTexContext && 0 == fLockedRows);
	fTexContext.reset();
	}

	void GrTextureStripAtlas::initLRU() {
	fLRUFront = nullptr;
	fLRUBack = nullptr;
	// Initially all the rows are in the LRU list
	for (int i = 0; i < fNumRows; ++i) {
	fRows[i].fKey = kEmptyAtlasRowKey;
	fRows[i].fNext = nullptr;
	fRows[i].fPrev = nullptr;
	this->appendLRU(fRows + i);
	}
	SkASSERT(nullptr == fLRUFront \|\| nullptr == fLRUFront->fPrev);
	SkASSERT(nullptr == fLRUBack \|\| nullptr == fLRUBack->fNext);
	}

	void GrTextureStripAtlas::appendLRU(AtlasRow* row) {
	SkASSERT(nullptr == row->fPrev && nullptr == row->fNext);
	if (nullptr == fLRUFront && nullptr == fLRUBack) {
	fLRUFront = row;
	fLRUBack = row;
	} else {
	row->fPrev = fLRUBack;
	fLRUBack->fNext = row;
	fLRUBack = row;
	}
	}

	void GrTextureStripAtlas::removeFromLRU(AtlasRow* row) {
	SkASSERT(row);
	if (row->fNext && row->fPrev) {
	row->fPrev->fNext = row->fNext;
	row->fNext->fPrev = row->fPrev;
	} else {
	if (nullptr == row->fNext) {
	SkASSERT(row == fLRUBack);
	fLRUBack = row->fPrev;
	if (fLRUBack) {
	fLRUBack->fNext = nullptr;
	}
	}
	if (nullptr == row->fPrev) {
	SkASSERT(row == fLRUFront);
	fLRUFront = row->fNext;
	if (fLRUFront) {
	fLRUFront->fPrev = nullptr;
	}
	}
	}
	row->fNext = nullptr;
	row->fPrev = nullptr;
	}

	int GrTextureStripAtlas::searchByKey(uint32_t key) {
	AtlasRow target;
	target.fKey = key;
	return SkTSearch<const AtlasRow,
	GrTextureStripAtlas::KeyLess>((const AtlasRow**)fKeyTable.begin(),
	fKeyTable.count(),
	&target,
	sizeof(AtlasRow*));
	}

	#ifdef SK_DEBUG
	void GrTextureStripAtlas::validate() {

	// Our key table should be sorted
	uint32_t prev = 1 > fKeyTable.count() ? 0 : fKeyTable[0]->fKey;
	for (int i = 1; i < fKeyTable.count(); ++i) {
	SkASSERT(prev < fKeyTable[i]->fKey);
	SkASSERT(fKeyTable[i]->fKey != kEmptyAtlasRowKey);
	prev = fKeyTable[i]->fKey;
	}

	int lruCount = 0;
	// Validate LRU pointers, and count LRU entries
	SkASSERT(nullptr == fLRUFront \|\| nullptr == fLRUFront->fPrev);
	SkASSERT(nullptr == fLRUBack \|\| nullptr == fLRUBack->fNext);
	for (AtlasRow* r = fLRUFront; r != nullptr; r = r->fNext) {
	if (nullptr == r->fNext) {
	SkASSERT(r == fLRUBack);
	} else {
	SkASSERT(r->fNext->fPrev == r);
	}
	++lruCount;
	}

	int rowLocks = 0;
	int freeRows = 0;

	for (int i = 0; i < fNumRows; ++i) {
	rowLocks += fRows[i].fLocks;
	if (0 == fRows[i].fLocks) {
	++freeRows;
	bool inLRU = false;
	// Step through the LRU and make sure it's present
	for (AtlasRow* r = fLRUFront; r != nullptr; r = r->fNext) {
	if (r == &fRows[i]) {
	inLRU = true;
	break;
	}
	}
	SkASSERT(inLRU);
	} else {
	// If we are locked, we should have a key
	SkASSERT(kEmptyAtlasRowKey != fRows[i].fKey);
	}

	// If we have a key != kEmptyAtlasRowKey, it should be in the key table
	SkASSERT(fRows[i].fKey == kEmptyAtlasRowKey \|\| this->searchByKey(fRows[i].fKey) >= 0);
	}

	// Our count of locks should equal the sum of row locks, unless we ran out of rows and flushed,
	// in which case we'll have one more lock than recorded in the rows (to represent the pending
	// lock of a row; which ensures we don't unlock the texture prematurely).
	SkASSERT(rowLocks == fLockedRows \|\| rowLocks + 1 == fLockedRows);

	// We should have one lru entry for each free row
	SkASSERT(freeRows == lruCount);

	// If we have locked rows, we should have a locked texture, otherwise
	// it should be unlocked
	if (fLockedRows == 0) {
	SkASSERT(!fTexContext);
	} else {
	SkASSERT(fTexContext);
	}
	}
	#endif