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kwin: Use glBufferSubData() when preferred

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Use glBufferData() to reallocate the data store, and glBufferSubData()
to upload data to unused ranges of vertex buffers.
This commit is contained in:
Fredrik Höglund 2013-06-28 20:20:45 +02:00
parent 9de4c490ba
commit 4b120288b6
1 changed files with 40 additions and 20 deletions
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60
libkwineffects/kwinglutils.cpp
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@ -1591,6 +1591,7 @@ public:
void interleaveArrays(float *array, int dim, const float *vertices, const float *texcoords, int count);
void bindArrays();
void unbindArrays();
void reallocateBuffer(size_t size);
GLvoid *mapNextFreeRange(size_t size);
GLuint buffer;
@ -1725,6 +1726,17 @@ void GLVertexBufferPrivate::unbindArrays()
#endif
}
void GLVertexBufferPrivate::reallocateBuffer(size_t size)
{
// Round the size up to 4 Kb for streaming/dynamic buffers.
const size_t minSize = 32768; // Minimum size for streaming buffers
const size_t alloc = usage != GL_STATIC_DRAW ? align(qMax(size, minSize), 4096) : size;
glBufferData(GL_ARRAY_BUFFER, alloc, 0, usage);
bufferSize = alloc;
}
GLvoid *GLVertexBufferPrivate::mapNextFreeRange(size_t size)
{
GLbitfield access = GL_MAP_WRITE_BIT | GL_MAP_INVALIDATE_RANGE_BIT | GL_MAP_UNSYNCHRONIZED_BIT;
@ -1732,13 +1744,7 @@ GLvoid *GLVertexBufferPrivate::mapNextFreeRange(size_t size)
if ((nextOffset + size) > bufferSize) {
// Reallocate the data store if it's too small.
if (size > bufferSize) {
// Round the size up to 4 Kb for streaming/dynamic buffers.
const size_t minSize = 32768; // Minimum size for streaming buffers
const size_t alloc = usage != GL_STATIC_DRAW ? align(qMax(size, minSize), 4096) : size;
glBufferData(GL_ARRAY_BUFFER, alloc, 0, usage);
bufferSize = alloc;
reallocateBuffer(size);
} else {
access |= GL_MAP_INVALIDATE_BUFFER_BIT;
access ^= GL_MAP_UNSYNCHRONIZED_BIT;
@ -1796,7 +1802,9 @@ GLvoid *GLVertexBuffer::map(size_t size)
if (GLVertexBufferPrivate::supported)
glBindBuffer(GL_ARRAY_BUFFER, d->buffer);
if (GLVertexBufferPrivate::hasMapBufferRange)
bool preferBufferSubData = GLPlatform::instance()->preferBufferSubData();
if (GLVertexBufferPrivate::hasMapBufferRange && !preferBufferSubData)
return (GLvoid *) d->mapNextFreeRange(size);
// If we can't map the buffer we allocate local memory to hold the
@ -1810,26 +1818,38 @@ GLvoid *GLVertexBuffer::map(size_t size)
void GLVertexBuffer::unmap()
{
if (GLVertexBufferPrivate::hasMapBufferRange) {
bool preferBufferSubData = GLPlatform::instance()->preferBufferSubData();
if (GLVertexBufferPrivate::hasMapBufferRange && !preferBufferSubData) {
glUnmapBuffer(GL_ARRAY_BUFFER);
d->baseAddress = d->nextOffset;
d->nextOffset += align(d->mappedSize, 16); // Align to 16 bytes for SSE
} else {
if (GLVertexBufferPrivate::supported) {
// Upload the data from local memory to the buffer object
glBufferData(GL_ARRAY_BUFFER, d->mappedSize, d->dataStore.data(), d->usage);
} else if (GLVertexBufferPrivate::supported) {
// Upload the data from local memory to the buffer object
if (preferBufferSubData) {
if ((d->nextOffset + d->mappedSize) > d->bufferSize) {
d->reallocateBuffer(d->mappedSize);
d->nextOffset = 0;
}
// Free the local memory buffer if it's unlikely to be used again
if (d->usage == GL_STATIC_DRAW)
d->dataStore = QByteArray();
glBufferSubData(GL_ARRAY_BUFFER, d->nextOffset, d->mappedSize, d->dataStore.constData());
d->baseAddress = 0;
d->baseAddress = d->nextOffset;
d->nextOffset += align(d->mappedSize, 16); // Align to 16 bytes for SSE
} else {
// If buffer objects aren't supported we just need to update
// the client memory pointer and we're done.
d->baseAddress = intptr_t(d->dataStore.data());
glBufferData(GL_ARRAY_BUFFER, d->mappedSize, d->dataStore.data(), d->usage);
d->baseAddress = 0;
}
// Free the local memory buffer if it's unlikely to be used again
if (d->usage == GL_STATIC_DRAW)
d->dataStore = QByteArray();
} else {
// If buffer objects aren't supported we just need to update
// the client memory pointer and we're done.
d->baseAddress = intptr_t(d->dataStore.data());
}
d->mappedSize = 0;