[Mesa-dev] [PATCH] mesa: only map src/dest regions in _mesa_copy_buffer_subdata()

[Kenneth Graunke]

On 01/04/2012 01:55 PM, Brian Paul wrote:
> We were wastefully mapping the whole source/dest buffers before.
> ---
>  src/mesa/main/bufferobj.c |   12 ++++++------
>  1 files changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/src/mesa/main/bufferobj.c b/src/mesa/main/bufferobj.c
> index 66957e4..c4a7b8d 100644
> --- a/src/mesa/main/bufferobj.c
> +++ b/src/mesa/main/bufferobj.c
> @@ -502,19 +502,19 @@ _mesa_copy_buffer_subdata(struct gl_context *ctx,
>                            GLintptr readOffset, GLintptr writeOffset,
>                            GLsizeiptr size)
>  {
> -   GLubyte *srcPtr, *dstPtr;
> +   void *srcPtr, *dstPtr;
>  
>     /* buffer should not already be mapped */
>     assert(!_mesa_bufferobj_mapped(src));
>     assert(!_mesa_bufferobj_mapped(dst));
>  
> -   srcPtr = (GLubyte *) ctx->Driver.MapBufferRange(ctx, 0, src->Size,
> -						   GL_MAP_READ_BIT, src);
> -   dstPtr = (GLubyte *) ctx->Driver.MapBufferRange(ctx, 0, dst->Size,
> -						   GL_MAP_WRITE_BIT, dst);
> +   srcPtr = ctx->Driver.MapBufferRange(ctx, readOffset, size,
> +                                       GL_MAP_READ_BIT, src);
> +   dstPtr = ctx->Driver.MapBufferRange(ctx, writeOffset, size,
> +                                       GL_MAP_WRITE_BIT, dst);
>  
>     if (srcPtr && dstPtr)
> -      memcpy(dstPtr + writeOffset, srcPtr + readOffset, size);
> +      memcpy(dstPtr, srcPtr, size);
>  
>     ctx->Driver.UnmapBuffer(ctx, src);
>     ctx->Driver.UnmapBuffer(ctx, dst);

LGTM.

Reviewed-by: Kenneth Graunke <kenneth at whitecape.org>