mesa: set clamp bit in glGetTexImage for GL_UNSIGNED_NORMALIZED

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
https://bugs.freedesktop.org/show_bug.cgi?id=40864

NOTE: This is a candidate for the 8.0 branch

Signed-off-by: Anuj Phogat <anuj.phogat@gmail.com>
Reviewed-by: Brian Paul <brianp@vmware.com>
(cherry picked from commit 5665b5cc31da70e833f80e7a17bfa034d2f7ba44)

diff --git a/src/mesa/main/texgetimage.c b/src/mesa/main/texgetimage.c
index 4eaa035..8362199 100644 (file)
--- a/src/mesa/main/texgetimage.c
+++ b/src/mesa/main/texgetimage.c
@@ -462,6 +462,15 @@ get_tex_rgba(struct gl_context *ctx, GLuint dimensions,
          transferOps |= IMAGE_CLAMP_BIT;
       }
    }
+   /* This applies to RGB, RGBA textures. if the format is either LUMINANCE
+    * or LUMINANCE ALPHA, luminance (L) is computed as L=R+G+B .we need to
+    * clamp the sum to [0,1].
+    */
+   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,