Add a quad 'bufloop' stage to handle glDrawBuffer(GL_FRONT_AND_BACK).

This removes the notion of multiple color buffers from all other stages.
Will need a bit more work when shaders with multiple render targets arrive.

1 files changed, 10 insertions, 0 deletions

diff --git a/src/mesa/pipe/softpipe/sp_quad.c b/src/mesa/pipe/softpipe/sp_quad.c
index 419a720de9a..5f34f5f1b34 100644
--- a/src/mesa/pipe/softpipe/sp_quad.c
+++ b/src/mesa/pipe/softpipe/sp_quad.c
@@ -21,6 +21,16 @@ sp_build_quad_pipeline(struct softpipe_context *sp)
       sp->quad.first = sp->quad.blend;
    }
 
+   if (sp->framebuffer.num_cbufs == 1) {
+      /* the usual case: write to exactly one colorbuf */
+      sp->cbuf = sp->framebuffer.cbufs[0];
+   }
+   else {
+      /* insert bufloop stage */
+      sp->quad.bufloop->next = sp->quad.first;
+      sp->quad.first = sp->quad.bufloop;
+   }
+
    if (   sp->stencil.front_enabled
        || sp->stencil.front_enabled) {
       sp->quad.stencil_test->next = sp->quad.first;