On Thu, Mar 8, 2012 at 7:19 PM, Brian Paul <bri...@vmware.com> wrote:
> There are several cases in which we need to explicity "rebase" colors
> (ex: set G=B=0) when getting GL_LUMINANCE textures:
> 1. If the luminance texture is actually stored as rgba
> 2. If getting a luminance texture, but returning rgba
> 3. If getting an rgba texture, but returning luminance
>
> Fixes https://bugs.freedesktop.org/show_bug.cgi?id=46679
>
> Also fixes the new piglit getteximage-luminance test.
> ---
> src/mesa/main/texgetimage.c | 30 ++++++++++++++++++++++++++++--
> 1 files changed, 28 insertions(+), 2 deletions(-)
>
> diff --git a/src/mesa/main/texgetimage.c b/src/mesa/main/texgetimage.c
> index 44a828a..05b052a 100644
> --- a/src/mesa/main/texgetimage.c
> +++ b/src/mesa/main/texgetimage.c
> @@ -298,6 +298,8 @@ get_tex_rgba_uncompressed(struct gl_context *ctx, GLuint
> dimensions,
> const gl_format texFormat =
> _mesa_get_srgb_format_linear(texImage->TexFormat);
> const GLuint width = texImage->Width;
> + const GLenum destBaseFormat = _mesa_base_tex_format(ctx, format);
> + GLenum rebaseFormat = GL_NONE;
> GLuint height = texImage->Height;
> GLuint depth = texImage->Depth;
> GLuint img, row;
> @@ -318,6 +320,28 @@ get_tex_rgba_uncompressed(struct gl_context *ctx, GLuint
> dimensions,
> height = 1;
> }
>
> + if (texImage->_BaseFormat == GL_LUMINANCE ||
> + texImage->_BaseFormat == GL_INTENSITY ||
> + texImage->_BaseFormat == GL_LUMINANCE_ALPHA) {
> + /* If a luminance (or intensity) texture is read back as RGB(A), the
> + * returned value should be (L,0,0,1), not (L,L,L,1). Set rebaseFormat
> + * here to get G=B=0.
> + */
> + rebaseFormat = texImage->_BaseFormat;
> + }
> + else if ((texImage->_BaseFormat == GL_RGBA ||
> + texImage->_BaseFormat == GL_RGB) &&
> + (destBaseFormat == GL_LUMINANCE ||
> + destBaseFormat == GL_LUMINANCE_ALPHA ||
> + destBaseFormat == GL_LUMINANCE_INTEGER_EXT ||
> + destBaseFormat == GL_LUMINANCE_ALPHA_INTEGER_EXT)) {
> + /* If we're reading back an RGB(A) texture as luminance then we need
> + * to return L=tex(R). Note, that's different from glReadPixels which
> + * returns L=R+G+B.
> + */
Brian, don't we need do handle the similar case for compressed textures?
i.e. _mesa_meta_GetTexImage()->decompress_texture_image() currently
uses _mesa_ReadPixels() to get the compressed texture data, which
returns L=R+G+B. I haven't yet tested how NVIDIA/AMD handle compressed
textures in glGetTexImage().
> + rebaseFormat = GL_LUMINANCE_ALPHA; /* this covers GL_LUMINANCE too */
> + }
> +
> for (img = 0; img < depth; img++) {
> GLubyte *srcMap;
> GLint rowstride;
> @@ -335,12 +359,14 @@ get_tex_rgba_uncompressed(struct gl_context *ctx,
> GLuint dimensions,
>
> if (is_integer) {
> _mesa_unpack_uint_rgba_row(texFormat, width, src, rgba_uint);
> - _mesa_rebase_rgba_uint(width, rgba_uint,
> texImage->_BaseFormat);
> + if (rebaseFormat)
> + _mesa_rebase_rgba_uint(width, rgba_uint, rebaseFormat);
> _mesa_pack_rgba_span_int(ctx, width, rgba_uint,
> format, type, dest);
> } else {
> _mesa_unpack_rgba_row(texFormat, width, src, rgba);
> - _mesa_rebase_rgba_float(width, rgba, texImage->_BaseFormat);
> + if (rebaseFormat)
> + _mesa_rebase_rgba_float(width, rgba, rebaseFormat);
> _mesa_pack_rgba_span_float(ctx, width, (GLfloat (*)[4]) rgba,
> format, type, dest,
> &ctx->Pack, transferOps);
> --
> 1.7.3.4
>
> _______________________________________________
> mesa-dev mailing list
> mesa-dev@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/mesa-dev
_______________________________________________
mesa-dev mailing list
mesa-dev@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/mesa-dev
