st: also check for a8 texture support in bitmap code

diff --git a/src/mesa/state_tracker/st_cb_bitmap.c b/src/mesa/state_tracker/st_cb_bitmap.c
index eecedc20f0265e3251299f7a616cedaa00b2a788..3f503f1253290060f32e59d550e3ea05d722d499 100644 (file)
--- a/src/mesa/state_tracker/st_cb_bitmap.c
+++ b/src/mesa/state_tracker/st_cb_bitmap.c
@@ -795,6 +795,10 @@ st_init_bitmap(struct st_context *st)
                                    PIPE_TEXTURE_USAGE_SAMPLER, 0)) {
       st->bitmap.tex_format = PIPE_FORMAT_I8_UNORM;
    }
+   else if (screen->is_format_supported(screen, PIPE_FORMAT_A8_UNORM, PIPE_TEXTURE_2D, 
+                                        PIPE_TEXTURE_USAGE_SAMPLER, 0)) {
+      st->bitmap.tex_format = PIPE_FORMAT_A8_UNORM;
+   }
    else if (screen->is_format_supported(screen, PIPE_FORMAT_L8_UNORM, PIPE_TEXTURE_2D, 
                                         PIPE_TEXTURE_USAGE_SAMPLER, 0)) {
       st->bitmap.tex_format = PIPE_FORMAT_L8_UNORM;