blob: 39779a70083592219bbeb6d5b2a6429f78b6482c [file] [log] [blame]
/*
* Copyright 2014 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef GrPathRange_DEFINED
#define GrPathRange_DEFINED
#include "GrGpuResource.h"
#include "SkPath.h"
#include "SkRefCnt.h"
#include "SkTArray.h"
class SkDescriptor;
/**
* Represents a contiguous range of GPU path objects.
* This object is immutable with the exception that individual paths may be
* initialized lazily.
*/
class GrPathRange : public GrGpuResource {
public:
enum PathIndexType {
kU8_PathIndexType, //!< uint8_t
kU16_PathIndexType, //!< uint16_t
kU32_PathIndexType, //!< uint32_t
kLast_PathIndexType = kU32_PathIndexType
};
static inline int PathIndexSizeInBytes(PathIndexType type) {
GR_STATIC_ASSERT(0 == kU8_PathIndexType);
GR_STATIC_ASSERT(1 == kU16_PathIndexType);
GR_STATIC_ASSERT(2 == kU32_PathIndexType);
GR_STATIC_ASSERT(kU32_PathIndexType == kLast_PathIndexType);
return 1 << type;
}
/**
* Class that generates the paths for a specific range.
*/
class PathGenerator : public SkRefCnt {
public:
virtual int getNumPaths() = 0;
virtual void generatePath(int index, SkPath* out) = 0;
#ifdef SK_DEBUG
virtual bool isEqualTo(const SkDescriptor&) const { return false; }
#endif
virtual ~PathGenerator() {}
};
/**
* Initialize a lazy-loaded path range. This class will generate an SkPath and call
* onInitPath() for each path within the range before it is drawn for the first time.
*/
GrPathRange(GrGpu*, PathGenerator*);
/**
* Initialize an eager-loaded path range. The subclass is responsible for ensuring all
* the paths are initialized up front.
*/
GrPathRange(GrGpu*, int numPaths);
int getNumPaths() const { return fNumPaths; }
const PathGenerator* getPathGenerator() const { return fPathGenerator.get(); }
void loadPathsIfNeeded(const void* indices, PathIndexType, int count) const;
template<typename IndexType> void loadPathsIfNeeded(const IndexType* indices, int count) const {
if (!fPathGenerator) {
return;
}
bool didLoadPaths = false;
for (int i = 0; i < count; ++i) {
SkASSERT(indices[i] < static_cast<uint32_t>(fNumPaths));
const int groupIndex = indices[i] / kPathsPerGroup;
const int groupByte = groupIndex / 8;
const uint8_t groupBit = 1 << (groupIndex % 8);
const bool hasPath = SkToBool(fGeneratedPaths[groupByte] & groupBit);
if (!hasPath) {
// We track which paths are loaded in groups of kPathsPerGroup. To
// mark a path as loaded we need to load the entire group.
const int groupFirstPath = groupIndex * kPathsPerGroup;
const int groupLastPath = SkTMin(groupFirstPath + kPathsPerGroup, fNumPaths) - 1;
SkPath path;
for (int pathIdx = groupFirstPath; pathIdx <= groupLastPath; ++pathIdx) {
fPathGenerator->generatePath(pathIdx, &path);
this->onInitPath(pathIdx, path);
}
fGeneratedPaths[groupByte] |= groupBit;
didLoadPaths = true;
}
}
if (didLoadPaths) {
this->didChangeGpuMemorySize();
}
}
#ifdef SK_DEBUG
void assertPathsLoaded(const void* indices, PathIndexType, int count) const;
template<typename IndexType> void assertPathsLoaded(const IndexType* indices, int count) const {
if (!fPathGenerator) {
return;
}
for (int i = 0; i < count; ++i) {
SkASSERT(indices[i] < static_cast<uint32_t>(fNumPaths));
const int groupIndex = indices[i] / kPathsPerGroup;
const int groupByte = groupIndex / 8;
const uint8_t groupBit = 1 << (groupIndex % 8);
SkASSERT(fGeneratedPaths[groupByte] & groupBit);
}
}
virtual bool isEqualTo(const SkDescriptor& desc) const {
return nullptr != fPathGenerator.get() && fPathGenerator->isEqualTo(desc);
}
#endif
protected:
// Initialize a path in the range before drawing. This is only called when
// fPathGenerator is non-null. The child class need not call didChangeGpuMemorySize(),
// GrPathRange will take care of that after the call is complete.
virtual void onInitPath(int index, const SkPath&) const = 0;
private:
enum {
kPathsPerGroup = 16 // Paths get tracked in groups of 16 for lazy loading.
};
mutable sk_sp<PathGenerator> fPathGenerator;
mutable SkTArray<uint8_t, true /*MEM_COPY*/> fGeneratedPaths;
const int fNumPaths;
typedef GrGpuResource INHERITED;
};
#endif