int GrBufferAllocPool::currentBufferItems(size_t itemSize) const {
VALIDATE();
if (NULL != fBufferPtr) {
const BufferBlock& back = fBlocks.back();
size_t usedBytes = back.fBuffer->sizeInBytes() - back.fBytesFree;
size_t pad = GrSizeAlignUpPad(usedBytes, itemSize);
return static_cast<int>((back.fBytesFree - pad) / itemSize);
} else if (fPreallocBuffersInUse < fPreallocBuffers.count()) {
return static_cast<int>(fMinBlockSize / itemSize);
}
return 0;
}
void* GrBufferAllocPool::makeSpace(size_t size,
size_t alignment,
const GrGeometryBuffer** buffer,
size_t* offset) {
VALIDATE();
SkASSERT(buffer);
SkASSERT(offset);
if (fBufferPtr) {
BufferBlock& back = fBlocks.back();
size_t usedBytes = back.fBuffer->gpuMemorySize() - back.fBytesFree;
size_t pad = GrSizeAlignUpPad(usedBytes,
alignment);
if ((size + pad) <= back.fBytesFree) {
memset((void*)(reinterpret_cast<intptr_t>(fBufferPtr) + usedBytes), 0, pad);
usedBytes += pad;
*offset = usedBytes;
*buffer = back.fBuffer;
back.fBytesFree -= size + pad;
fBytesInUse += size + pad;
VALIDATE();
return (void*)(reinterpret_cast<intptr_t>(fBufferPtr) + usedBytes);
}
}
// We could honor the space request using by a partial update of the current
// VB (if there is room). But we don't currently use draw calls to GL that
// allow the driver to know that previously issued draws won't read from
// the part of the buffer we update. Also, the GL buffer implementation
// may be cheating on the actual buffer size by shrinking the buffer on
// updateData() if the amount of data passed is less than the full buffer
// size.
if (!this->createBlock(size)) {
return NULL;
}
SkASSERT(fBufferPtr);
*offset = 0;
BufferBlock& back = fBlocks.back();
*buffer = back.fBuffer;
back.fBytesFree -= size;
fBytesInUse += size;
VALIDATE();
return fBufferPtr;
}
