st/mesa: don't translate blend state when color writes are disabled

Reviewed-by: Eric Anholt <eric@anholt.net>

diff --git a/src/mesa/state_tracker/st_atom_blend.c b/src/mesa/state_tracker/st_atom_blend.c
index a5f7edbcfe492d0c6a49876d9a33f187ebeb6c65..2a8da75f360be0d87f56bb9e109a8de8d37d8e41 100644 (file)
--- a/src/mesa/state_tracker/st_atom_blend.c
+++ b/src/mesa/state_tracker/st_atom_blend.c
@@ -153,6 +153,10 @@ st_update_blend( struct st_context *st )
       num_state = ctx->Const.MaxDrawBuffers;
       blend->independent_blend_enable = 1;
    }
+
+   for (i = 0; i < num_state; i++)
+      blend->rt[i].colormask = GET_COLORMASK(ctx->Color.ColorMask, i);
+
    if (ctx->Color.ColorLogicOpEnabled) {
       /* logicop enabled */
       blend->logicop_enable = 1;
@@ -161,7 +165,8 @@ st_update_blend( struct st_context *st )
    else if (ctx->Color.BlendEnabled && !ctx->Color._AdvancedBlendMode) {
       /* blending enabled */
       for (i = 0, j = 0; i < num_state; i++) {
-         if (!(ctx->Color.BlendEnabled & (1 << i)))
+         if (!(ctx->Color.BlendEnabled & (1 << i)) ||
+             !blend->rt[i].colormask)
             continue;
 
         if (ctx->Extensions.ARB_draw_buffers_blend)
@@ -205,9 +210,6 @@ st_update_blend( struct st_context *st )
       /* no blending / logicop */
    }
 
-   for (i = 0; i < num_state; i++)
-      blend->rt[i].colormask = GET_COLORMASK(ctx->Color.ColorMask, i);
-
    blend->dither = ctx->Color.DitherFlag;
 
    if (_mesa_is_multisample_enabled(ctx) &&