/*
* Copyright 2015 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef GrBatchAtlas_DEFINED
#define GrBatchAtlas_DEFINED
#include "GrTexture.h"
#include "SkPoint.h"
#include "SkTDArray.h"
#include "SkTInternalLList.h"
#include "batches/GrDrawBatch.h"
class GrRectanizer;
struct GrBatchAtlasConfig {
int numPlotsX() const { return fWidth / fPlotWidth; }
int numPlotsY() const { return fHeight / fPlotWidth; }
int fWidth;
int fHeight;
int fLog2Width;
int fLog2Height;
int fPlotWidth;
int fPlotHeight;
};
class GrBatchAtlas {
public:
// An AtlasID is an opaque handle which callers can use to determine if the atlas contains
// a specific piece of data
typedef uint64_t AtlasID;
static const uint32_t kInvalidAtlasID = 0;
static const uint64_t kInvalidAtlasGeneration = 0;
// A function pointer for use as a callback during eviction. Whenever GrBatchAtlas evicts a
// specific AtlasID, it will call all of the registered listeners so they can optionally process
// the eviction
typedef void (*EvictionFunc)(GrBatchAtlas::AtlasID, void*);
GrBatchAtlas(GrTexture*, int numPlotsX, int numPlotsY);
~GrBatchAtlas();
// Adds a width x height subimage to the atlas. Upon success it returns
// the containing GrPlot and absolute location in the backing texture.
// nullptr is returned if the subimage cannot fit in the atlas.
// If provided, the image data will be written to the CPU-side backing bitmap.
// NOTE: If the client intends to refer to the atlas, they should immediately call 'setUseToken'
// with the currentToken from the batch target, otherwise the next call to addToAtlas might
// cause an eviction
bool addToAtlas(AtlasID*, GrDrawBatch::Target*, int width, int height, const void* image,
SkIPoint16* loc);
GrTexture* getTexture() const { return fTexture; }
uint64_t atlasGeneration() const { return fAtlasGeneration; }
inline bool hasID(AtlasID id) {
uint32_t index = GetIndexFromID(id);
SkASSERT(index < fNumPlots);
return fPlotArray[index]->genID() == GetGenerationFromID(id);
}
// To ensure the atlas does not evict a given entry, the client must set the last use token
inline void 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);
}
inline void registerEvictionCallback(EvictionFunc func, void* userData) {
EvictionData* data = fEvictionCallbacks.append();
data->fFunc = func;
data->fData = userData;
}
/*
* A class which can be handed back to GrBatchAtlas for updating in bulk last use tokens. The
* current max number of plots the GrBatchAtlas can handle is 32, if in the future this is
* insufficient then we can move to a 64 bit int
*/
class BulkUseTokenUpdater {
public:
BulkUseTokenUpdater() : fPlotAlreadyUpdated(0) {}
BulkUseTokenUpdater(const BulkUseTokenUpdater& that)
: fPlotsToUpdate(that.fPlotsToUpdate)
, fPlotAlreadyUpdated(that.fPlotAlreadyUpdated) {
}
void add(AtlasID id) {
int index = GrBatchAtlas::GetIndexFromID(id);
if (!this->find(index)) {
this->set(index);
}
}
void reset() {
fPlotsToUpdate.reset();
fPlotAlreadyUpdated = 0;
}
private:
bool find(int index) const {
SkASSERT(index < kMaxPlots);
return (fPlotAlreadyUpdated >> index) & 1;
}
void set(int index) {
SkASSERT(!this->find(index));
fPlotAlreadyUpdated = fPlotAlreadyUpdated | (1 << index);
fPlotsToUpdate.push_back(index);
}
static const int kMinItems = 4;
static const int kMaxPlots = 32;
SkSTArray<kMinItems, int, true> fPlotsToUpdate;
uint32_t fPlotAlreadyUpdated;
friend class GrBatchAtlas;
};
void 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);
}
}
static const int kGlyphMaxDim = 256;
static bool GlyphTooLargeForAtlas(int width, int height) {
return width > kGlyphMaxDim || height > kGlyphMaxDim;
}
private:
// 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);
// 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);
void resetRects();
private:
BatchPlot(int index, uint64_t genID, int offX, int offY, int width, int height,
GrPixelConfig config);
~BatchPlot() override;
// 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;
};
typedef SkTInternalLList<BatchPlot> GrBatchPlotList;
static uint32_t GetIndexFromID(AtlasID id) {
return id & 0xffff;
}
// top 48 bits are reserved for the generation ID
static uint64_t GetGenerationFromID(AtlasID id) {
return (id >> 16) & 0xffffffffffff;
}
inline void updatePlot(GrDrawBatch::Target*, AtlasID*, BatchPlot*);
inline void makeMRU(BatchPlot* plot) {
if (fPlotList.head() == plot) {
return;
}
fPlotList.remove(plot);
fPlotList.addToHead(plot);
}
inline void processEviction(AtlasID);
friend class GrPlotUploader; // to access GrBatchPlot
GrTexture* fTexture;
SkDEBUGCODE(uint32_t fNumPlots;)
uint64_t fAtlasGeneration;
struct EvictionData {
EvictionFunc fFunc;
void* fData;
};
SkTDArray<EvictionData> fEvictionCallbacks;
// allocated array of GrBatchPlots
SkAutoTUnref<BatchPlot>* fPlotArray;
// LRU list of GrPlots (MRU at head - LRU at tail)
GrBatchPlotList fPlotList;
};
#endif