[Mesa-stable] [PATCH] mesa: allow GL_UNSIGNED_BYTE type for SNORM reads

[Tapani Pälli]

OpenGL ES spec states:
   "For normalized fixed-point rendering surfaces, the combination format
    RGBA and type UNSIGNED_BYTE is accepted."

This fixes following failing VK-GL-CTS tests:

   KHR-GLES3.packed_pixels.pbo_rectangle.rgba8_snorm
   KHR-GLES3.packed_pixels.rectangle.rgba8_snorm
   KHR-GLES3.packed_pixels.varied_rectangle.rgba8_snorm

Signed-off-by: Tapani Pälli <tapani.palli at intel.com>
https://bugs.freedesktop.org/show_bug.cgi?id=107658
Cc: mesa-stable at lists.freedesktop.org
---

This is a partial fix to the bug. I believe there are 2 separate
issues within reported bug and this fixes the first one.

 src/mesa/main/readpix.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/src/mesa/main/readpix.c b/src/mesa/main/readpix.c
index 2cbb578a37f..556c860d393 100644
--- a/src/mesa/main/readpix.c
+++ b/src/mesa/main/readpix.c
@@ -958,6 +958,15 @@ read_pixels_es3_error_check(struct gl_context *ctx, GLenum format, GLenum type,
                return GL_NO_ERROR;
          }
       }
+      if (type == GL_UNSIGNED_BYTE) {
+         switch (internalFormat) {
+         case GL_R8_SNORM:
+         case GL_RG8_SNORM:
+         case GL_RGBA8_SNORM:
+            if (_mesa_has_EXT_render_snorm(ctx))
+               return GL_NO_ERROR;
+         }
+      }
       break;
    case GL_BGRA:
       /* GL_EXT_read_format_bgra */
-- 
2.14.4