[Mesa-dev] [PATCH 04/17] mesa: Add support for glGetTexImage() from integer textures.

[Brian Paul]

On 01/20/2012 04:39 PM, Eric Anholt wrote:
> This is a step toward fixing Intel oglconform's
> int-textures advanced.fbo.rtt.
>
> NOTE: This is a candidate for the 8.0 branch.
> ---
>   src/mesa/main/texgetimage.c |  118 +++++++++++++++++++++++++++++--------------
>   1 files changed, 80 insertions(+), 38 deletions(-)
>
> diff --git a/src/mesa/main/texgetimage.c b/src/mesa/main/texgetimage.c
> index 8c85c1e..95de24a 100644
> --- a/src/mesa/main/texgetimage.c
> +++ b/src/mesa/main/texgetimage.c
> @@ -316,9 +316,12 @@ get_tex_rgba_uncompressed(struct gl_context *ctx, GLuint dimensions,
>      const GLuint depth = texImage->Depth;
>      GLuint img, row;
>      GLfloat (*rgba)[4];
> +   GLuint (*rgba_uint)[4];
> +   GLboolean is_integer = _mesa_is_format_integer_color(texImage->TexFormat);
>
>      /* Allocate buffer for one row of texels */
>      rgba = (GLfloat (*)[4]) malloc(4 * width * sizeof(GLfloat));
> +   rgba_uint = (GLuint (*)[4]) rgba;
>      if (!rgba) {
>         _mesa_error(ctx, GL_OUT_OF_MEMORY, "glGetTexImage()");
>         return;
> @@ -339,44 +342,83 @@ get_tex_rgba_uncompressed(struct gl_context *ctx, GLuint dimensions,
>                                                width, height, format, type,
>                                                img, row, 0);
>
> -            _mesa_unpack_rgba_row(texFormat, width, src, rgba);
> -
> -            if (texImage->_BaseFormat == GL_ALPHA) {
> -               GLint col;
> -               for (col = 0; col<  width; col++) {
> -                  rgba[col][RCOMP] = 0.0F;
> -                  rgba[col][GCOMP] = 0.0F;
> -                  rgba[col][BCOMP] = 0.0F;
> -               }
> -            }
> -            else if (texImage->_BaseFormat == GL_LUMINANCE) {
> -               GLint col;
> -               for (col = 0; col<  width; col++) {
> -                  rgba[col][GCOMP] = 0.0F;
> -                  rgba[col][BCOMP] = 0.0F;
> -                  rgba[col][ACOMP] = 1.0F;
> -               }
> -            }
> -            else if (texImage->_BaseFormat == GL_LUMINANCE_ALPHA) {
> -               GLint col;
> -               for (col = 0; col<  width; col++) {
> -                  rgba[col][GCOMP] = 0.0F;
> -                  rgba[col][BCOMP] = 0.0F;
> -               }
> -            }
> -            else if (texImage->_BaseFormat == GL_INTENSITY) {
> -               GLint col;
> -               for (col = 0; col<  width; col++) {
> -                  rgba[col][GCOMP] = 0.0F;
> -                  rgba[col][BCOMP] = 0.0F;
> -                  rgba[col][ACOMP] = 1.0F;
> -               }
> -            }
> -
> -            _mesa_pack_rgba_span_float(ctx, width, (GLfloat (*)[4]) rgba,
> -                                       format, type, dest,
> -&ctx->Pack, transferOps);
> -         }
> +	    if (is_integer) {
> +	       _mesa_unpack_uint_rgba_row(texFormat, width, src, rgba_uint);
> +
> +	       if (texImage->_BaseFormat == GL_ALPHA) {
> +		  GLint col;

I realize the original code used "GLint col" but it would be nicer to 
use "GLuint col" to avoid a bunch of signed/unsigned comparison 
warnings with MSVC.

Reviewed-by: Brian Paul <brianp at vmware.com>