[Mesa-dev] [PATCH] mesa: Don't allow blits to / from the same buffer in OpenGL ES 3.0

[Kenneth Graunke]

On 01/18/2013 10:54 AM, Ian Romanick wrote:
> From: Ian Romanick <ian.d.romanick at intel.com>
>
> Fixes gles3conform test CoverageES30.  It temporarily regresses some
> framebuffer_blit tests, but the failing subcases have been determined to
> be invalid for OpenGL ES 3.0.
>
> Signed-off-by: Ian Romanick <ian.d.romanick at intel.com>
> ---
>   src/mesa/main/fbobject.c | 31 +++++++++++++++++++++++++++++++
>   1 file changed, 31 insertions(+)
>
> diff --git a/src/mesa/main/fbobject.c b/src/mesa/main/fbobject.c
> index 9db5035..721ecea 100644
> --- a/src/mesa/main/fbobject.c
> +++ b/src/mesa/main/fbobject.c
> @@ -2856,6 +2856,23 @@ _mesa_BlitFramebuffer(GLint srcX0, GLint srcY0, GLint srcX1, GLint srcY1,
>               if (!colorDrawRb)
>                  continue;
>
> +            /* Page 193 (page 205 of the PDF) in section 4.3.2 of the OpenGL
> +             * ES 3.0.1 spec says:
> +             *
> +             *     "If the source and destination buffers are identical, an
> +             *     INVALID_OPERATION error is generated. Different mipmap
> +             *     levels of a texture, different layers of a three-
> +             *     dimensional texture or two-dimensional array texture, and
> +             *     different faces of a cube map texture do not constitute
> +             *     identical buffers."
> +             */
> +            if (_mesa_is_gles3(ctx) && (colorDrawRb == colorReadRb)) {
> +               _mesa_error(ctx, GL_INVALID_OPERATION,
> +                           "glBlitFramebuffer(source and destination color "
> +                           "buffer cannot be the same)");
> +               return;
> +            }
> +
>               if (!compatible_color_datatypes(colorReadRb->Format,
>                                               colorDrawRb->Format)) {
>                  _mesa_error(ctx, GL_INVALID_OPERATION,
> @@ -2905,6 +2922,13 @@ _mesa_BlitFramebuffer(GLint srcX0, GLint srcY0, GLint srcX1, GLint srcY1,
>         else {
>            int read_z_bits, draw_z_bits;
>
> +         if (_mesa_is_gles3(ctx) && (drawFb == readFb)) {

Don't you want drawRb == readRb here?

> +            _mesa_error(ctx, GL_INVALID_OPERATION,
> +                        "glBlitFramebuffer(source and destination stencil "
> +                        "buffer cannot be the same)");
> +            return;
> +         }
> +
>            if (_mesa_get_format_bits(readRb->Format, GL_STENCIL_BITS) !=
>                _mesa_get_format_bits(drawRb->Format, GL_STENCIL_BITS)) {
>               /* There is no need to check the stencil datatype here, because
> @@ -2952,6 +2976,13 @@ _mesa_BlitFramebuffer(GLint srcX0, GLint srcY0, GLint srcX1, GLint srcY1,
>         else {
>            int read_s_bit, draw_s_bit;
>
> +         if (_mesa_is_gles3(ctx) && (drawFb == readFb)) {

Ditto.

> +            _mesa_error(ctx, GL_INVALID_OPERATION,
> +                        "glBlitFramebuffer(source and destination depth "
> +                        "buffer cannot be the same)");
> +            return;
> +         }
> +
>            if ((_mesa_get_format_bits(readRb->Format, GL_DEPTH_BITS) !=
>                 _mesa_get_format_bits(drawRb->Format, GL_DEPTH_BITS)) ||
>                (_mesa_get_format_datatype(readRb->Format) !=