[Mesa-dev] [PATCH] mesa/st: Use more precision for GL_UNSIGNED_BYTE_3_3_2(_REV)

[jfonseca at vmware.com]

From: José Fonseca <jfonseca at vmware.com>

4bits and 3bits quantitization values differ significantly for
values other than 0 and 1.

Fixes piglit draw-pixels for softpipe/llvmpipe.
---
 src/mesa/state_tracker/st_cb_drawpixels.c |    3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/mesa/state_tracker/st_cb_drawpixels.c b/src/mesa/state_tracker/st_cb_drawpixels.c
index 4e2edd2..4532ded 100644
--- a/src/mesa/state_tracker/st_cb_drawpixels.c
+++ b/src/mesa/state_tracker/st_cb_drawpixels.c
@@ -396,6 +396,9 @@ internal_format(struct gl_context *ctx, GLenum format, GLenum type)
 
          case GL_UNSIGNED_BYTE_3_3_2:
          case GL_UNSIGNED_BYTE_2_3_3_REV:
+	    /* GL_RGBA4 introduces too much error for normalized values */
+            return GL_RGBA8;
+
          case GL_UNSIGNED_SHORT_4_4_4_4:
          case GL_UNSIGNED_SHORT_4_4_4_4_REV:
             return GL_RGBA4;
-- 
1.7.9.5