util: clean the 24-bit unused field to avoid an issues

This is a field of FLOAT_32_UNSIGNED_INT_24_8_REV texture pixel.
OpenGL spec "8.4.4.2 Special Interpretations" is saying:
   "the second word contains a packed 24-bit unused field,
    followed by an 8-bit index"
The spec doesn't require us to clear this unused field
however it make sense to do it to avoid some
undefined behavior in some apps.

Suggested-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=110305
Signed-off-by: Andrii Simiklit <andrii.simiklit@globallogic.com>

diff --git a/src/gallium/auxiliary/util/u_format_zs.c b/src/gallium/auxiliary/util/u_format_zs.c
index ff584769d12c8fc03530e9fb5ef0f44c1d61865e..4c977172b1b978c6d52afc7154763bc6979a41c3 100644 (file)
--- a/src/gallium/auxiliary/util/u_format_zs.c
+++ b/src/gallium/auxiliary/util/u_format_zs.c
@@ -830,11 +830,11 @@ util_format_z32_float_s8x24_uint_pack_s_8uint(uint8_t *dst_row, unsigned dst_str
    unsigned x, y;
    for(y = 0; y < height; ++y) {
       const uint8_t *src = src_row;
-      uint8_t *dst = dst_row + 4;
+      uint32_t *dst = ((uint32_t *)dst_row) + 1;
       for(x = 0; x < width; ++x) {
-         *dst = *src;
+         *dst = util_cpu_to_le32(*src);
          src += 1;
-         dst += 8;
+         dst += 2;
       }
       dst_row += dst_stride/sizeof(*dst_row);
       src_row += src_stride/sizeof(*src_row);