swrast: fix span color type selection

Fixes a regression from commit 660ed923ded3552e023ef8c3dd9f92e6792f1bd2.
The basic idea is to look at the format of the dest renderbuffer and
choose either GLubyte or GLfloat for colors.  The previous code used
_mesa_format_to_type_and_comps() which could return a bunch types other
than ubyte/float.

Determine the datatype at renderbuffer mapping time to avoid frequent
calls to the format query functions.

NOTE: This is a candidate for the 8.0 branch.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=45578
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=45577

1 files changed, 7 insertions, 7 deletions

diff --git a/src/mesa/swrast/s_span.c b/src/mesa/swrast/s_span.c
index 422d86c00a7..025e7b2076d 100644
--- a/src/mesa/swrast/s_span.c
+++ b/src/mesa/swrast/s_span.c
@@ -1320,15 +1320,15 @@ _swrast_write_rgba_span( struct gl_context *ctx, SWspan *span)
 
          if (rb) {
             GLchan rgbaSave[MAX_WIDTH][4];
+            struct swrast_renderbuffer *srb = swrast_renderbuffer(rb);
+            GLenum colorType = srb->ColorType;
 
-	    GLenum datatype;
-	    GLuint comps;
+            assert(colorType == GL_UNSIGNED_BYTE ||
+                   colorType == GL_FLOAT);
 
-	    _mesa_format_to_type_and_comps(rb->Format, &datatype, &comps);
-
-            /* set span->array->rgba to colors for render buffer's datatype */
-            if (datatype != span->array->ChanType) {
-               convert_color_type(span, datatype, 0);
+            /* set span->array->rgba to colors for renderbuffer's datatype */
+            if (span->array->ChanType != colorType) {
+               convert_color_type(span, colorType, 0);
             }
             else {
                if (span->array->ChanType == GL_UNSIGNED_BYTE) {