st/mesa: use the first non-VOID channel in st_format_datatype

Otherwise PIPE_FORMAT_X8B8G8R8_UNORM and friends would fail.

NOTE: This is a candidate for the 7.10 and 7.11 branches.

Reviewed-by: Brian Paul <[email protected]>

1 files changed, 16 insertions, 3 deletions

diff --git a/src/mesa/state_tracker/st_format.c b/src/mesa/state_tracker/st_format.c
index fa5d8f5050a..3260297c6c1 100644
--- a/src/mesa/state_tracker/st_format.c
+++ b/src/mesa/state_tracker/st_format.c
@@ -68,10 +68,18 @@ GLenum
 st_format_datatype(enum pipe_format format)
 {
    const struct util_format_description *desc;
+   int i;
 
    desc = util_format_description(format);
    assert(desc);
 
+   /* Find the first non-VOID channel. */
+   for (i = 0; i < 4; i++) {
+       if (desc->channel[i].type != UTIL_FORMAT_TYPE_VOID) {
+           break;
+       }
+   }
+
    if (desc->layout == UTIL_FORMAT_LAYOUT_PLAIN) {
       if (format == PIPE_FORMAT_B5G5R5A1_UNORM ||
           format == PIPE_FORMAT_B5G6R5_UNORM) {
@@ -85,21 +93,26 @@ st_format_datatype(enum pipe_format format)
       }
       else {
          const GLuint size = format_max_bits(format);
+
+         assert(i < 4);
+         if (i == 4)
+            return GL_NONE;
+
          if (size == 8) {
-            if (desc->channel[0].type == UTIL_FORMAT_TYPE_UNSIGNED)
+            if (desc->channel[i].type == UTIL_FORMAT_TYPE_UNSIGNED)
                return GL_UNSIGNED_BYTE;
             else
                return GL_BYTE;
          }
          else if (size == 16) {
-            if (desc->channel[0].type == UTIL_FORMAT_TYPE_UNSIGNED)
+            if (desc->channel[i].type == UTIL_FORMAT_TYPE_UNSIGNED)
                return GL_UNSIGNED_SHORT;
             else
                return GL_SHORT;
          }
          else {
             assert( size <= 32 );
-            if (desc->channel[0].type == UTIL_FORMAT_TYPE_UNSIGNED)
+            if (desc->channel[i].type == UTIL_FORMAT_TYPE_UNSIGNED)
                return GL_UNSIGNED_INT;
             else
                return GL_INT;