On 02/11/2014 05:11 PM, Eric Anholt wrote:
> From the GL_ARB_fbo spec:
>
> If the source and destination buffers are identical, and the
> source and destination rectangles overlap, the result of the blit
> operation is undefined.
>
> As far as I know, that's the only thing that would have been of concern
> for this.
That's the only thing I can think of. It was Brian's code, so maybe he
remembers something?
OpenGL ES 3.0 says, "If the source and destination buffers are
identical, an INVALID_OPERATION error is generated." That should be
handled elsewhere, though.
> ---
> src/mesa/drivers/common/meta.c | 20 --------------------
> 1 file changed, 20 deletions(-)
>
> diff --git a/src/mesa/drivers/common/meta.c b/src/mesa/drivers/common/meta.c
> index 3c4f706..03811bd 100644
> --- a/src/mesa/drivers/common/meta.c
> +++ b/src/mesa/drivers/common/meta.c
> @@ -1684,7 +1684,6 @@ setup_glsl_blit_framebuffer(struct gl_context *ctx,
> /**
> * Try to do a glBlitFramebuffer using no-copy texturing.
> * We can do this when the src renderbuffer is actually a texture.
> - * But if the src buffer == dst buffer we cannot do this.
> *
> * \return new buffer mask indicating the buffers left to blit using the
> * normal path.
> @@ -1697,9 +1696,7 @@ blitframebuffer_texture(struct gl_context *ctx,
> GLint flipY, GLboolean glsl_version)
> {
> if (mask & GL_COLOR_BUFFER_BIT) {
> - const struct gl_framebuffer *drawFb = ctx->DrawBuffer;
> const struct gl_framebuffer *readFb = ctx->ReadBuffer;
> - const struct gl_renderbuffer_attachment *drawAtt;
> const struct gl_renderbuffer_attachment *readAtt =
> &readFb->Attachment[readFb->_ColorReadBufferIndex];
>
> @@ -1717,23 +1714,6 @@ blitframebuffer_texture(struct gl_context *ctx,
> GLuint sampler, samplerSave =
> ctx->Texture.Unit[ctx->Texture.CurrentUnit].Sampler ?
> ctx->Texture.Unit[ctx->Texture.CurrentUnit].Sampler->Name : 0;
> - int i;
> -
> - /* Iterate through all draw buffers */
> - for (i = 0; i < ctx->DrawBuffer->_NumColorDrawBuffers; i++) {
> - int idx = ctx->DrawBuffer->_ColorDrawBufferIndexes[i];
> - if (idx == -1)
> - continue;
> - drawAtt = &drawFb->Attachment[idx];
> -
> - if (drawAtt->Texture == readAtt->Texture) {
> - /* Can't use same texture as both the source and dest. We
> need
> - * to handle overlapping blits and besides, some hw may not
> - * support this.
> - */
> - return mask;
> - }
> - }
>
> if (target != GL_TEXTURE_2D && target != GL_TEXTURE_RECTANGLE_ARB) {
> /* Can't handle other texture types at this time */
>
_______________________________________________
mesa-dev mailing list
mesa-dev@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/mesa-dev
