On Thu, Jan 26, 2012 at 2:56 PM, Brian Paul <<a href="mailto:brian.e.paul@gmail.com">brian.e.paul@gmail.com</a>> wrote: <div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> <div class="HOEnZb"><div class="h5">On Thu, Jan 26, 2012 at 4:55 PM, Ian Romanick <<a href="mailto:idr@freedesktop.org">idr@freedesktop.org</a>> wrote: > On 01/26/2012 06:40 AM, Brian Paul wrote: >> >> On Tue, Jan 24, 2012 at 10:58 PM, Anuj Phogat<<a href="mailto:anuj.phogat@gmail.com">anuj.phogat@gmail.com</a>> >> wrote: >>> >>> Color clamping should be enabled in glGetTexImage if texture dataType is >>> GL_UNSIGNED_NORMALIZED and format is GL_LUMINANCE or GL_LUMINANCE_ALPHA >>> >>> Fixes 2 Intel oglconform test cases: pxconv-gettex and pxtrans-gettex >>> <a href="https://bugs.freedesktop.org/show_bug.cgi?id=40864" target="_blank">https://bugs.freedesktop.org/show_bug.cgi?id=40864</a> >>> >>> NOTE: This is a candidate for the 8.0 branch >>> >>> Signed-off-by: Anuj Phogat<<a href="mailto:anuj.phogat@gmail.com">anuj.phogat@gmail.com</a>> >>> --- >>> src/mesa/main/texgetimage.c | 7 ++++++- >>> 1 files changed, 6 insertions(+), 1 deletions(-) >>> >>> diff --git a/src/mesa/main/texgetimage.c b/src/mesa/main/texgetimage.c >>> index 8c85c1e..f89b868 100644 >>> --- a/src/mesa/main/texgetimage.c >>> +++ b/src/mesa/main/texgetimage.c >>> @@ -415,7 +415,12 @@ get_tex_rgba(struct gl_context *ctx, GLuint >>> dimensions, >>> transferOps |= IMAGE_CLAMP_BIT; >>> } >>> } >>> - >>> + else if ((format == GL_LUMINANCE || >>> + format == GL_LUMINANCE_ALPHA)&& >>> + dataType == GL_UNSIGNED_NORMALIZED) { >>> + transferOps |= IMAGE_CLAMP_BIT; >>> + } >>> + >>> if (_mesa_is_format_compressed(texImage->TexFormat)) { >>> get_tex_rgba_compressed(ctx, dimensions, format, type, >>> pixels, texImage, transferOps); >>> -- >> >> >> This looks OK. However, we need to add more comments here. I had to >> do some digging to recall why luminance and lum/alpha are special. >> The reason is if the source image is RGB, the returned luminance is >> R+G+B and we need to clamp the sum to [0,1]. > > > When Anuj and I discussed this patch, I had another concern, but I'm not > sure it matters. If dataType is GL_SIGNED_NORMALIZED, it seems like the > value should clamp to [-1,1]. We don't currently have a way to do that. > Does that seem right to you? </div></div>I would expect so too. I'll put it on my to-do list, but it might be a while.</blockquote><div>I can add clamp [-1, 1] . I'll send out a separate patch for that.</div></div>