/**
* Resizes the buffer to the passed in number of indices.
* Preserves internal data
*/
void FSlateOpenGLVertexBuffer::ResizeBuffer( uint32 NewSize )
{
ConditionalCreateBuffer();
// Only resize if the buffer cant provide the number of bytes requestd
if( NewSize > BufferSize )
{
uint8 *SavedVertices = NULL;
// If there are any indices at all save them off now
if( BufferSize > 0 )
{
void *Vertices = Lock( 0 );
SavedVertices = new uint8[BufferSize];
FMemory::Memcpy( SavedVertices, Vertices, BufferSize );
Unlock();
DestroyBuffer();
}
// Create the vertex buffer
ConditionalCreateBuffer();
// Bind the buffer so we can give it data
Bind();
// Set the vertex buffer's size
glBufferData( GL_ARRAY_BUFFER, NewSize, NULL, GL_DYNAMIC_DRAW );
// If there are any saved vertices, copy them back now.
if( SavedVertices )
{
void *Vertices = Lock( 0 );
FMemory::Memcpy( Vertices, SavedVertices, BufferSize );
Unlock();
delete[] SavedVertices;
}
BufferSize = NewSize;
}
}
/**
* Resizes the buffer to the passed in number of indices.
* Preserves internal data
*/
void FSlateOpenGLIndexBuffer::ResizeBuffer( uint32 NumIndices )
{
// Only resize if the index buffer cant provide the number of indices requested
if( NumIndices > MaxNumIndices )
{
// Determine the current buffer size so we can save off the current indices
uint32 CurrentBufferSize = MaxNumIndices*sizeof(SlateIndex);
uint8 *SavedIndices = NULL;
// If there are any indices at all save them off now
if( MaxNumIndices > 0 )
{
void *Indices = Lock( 0 );
SavedIndices = new uint8[CurrentBufferSize];
FMemory::Memcpy( SavedIndices, Indices, CurrentBufferSize );
Unlock();
// Destroy the current buffer. It needs to be recreated with a larger size
DestroyBuffer();
}
// Calculate the new buffer size
BufferSize = NumIndices*sizeof(SlateIndex);
// Create the index buffer
ConditionalCreateBuffer();
// Bind the buffer so we can give it data
Bind();
MaxNumIndices = NumIndices;
// Set the index buffer's size
glBufferData( GL_ELEMENT_ARRAY_BUFFER, BufferSize, NULL, GL_DYNAMIC_DRAW );
// If there are any saved indices, copy them back now.
if( SavedIndices )
{
void *Indices = Lock( 0 );
FMemory::Memcpy( Indices, SavedIndices, CurrentBufferSize );
Unlock();
delete[] SavedIndices;
}
}
}
