llvmpipe: initialize default fb correctly in setup

If lp_setup_bind_framebuffer() is never called, then setup fb x1/y1 was not
correctly initialized. This can happen if there's never a fb set - both
cso and llvmpipe would consider setting this with no cbufs and no zsbuf a
redundant change and therefore it would never get set.
We rely on this setup fb rect being initialized correctly for the tri intersect
tests, throwing away tris which don't intersect. Not initializing it meant
we'd then say it intersected, and we'd try to bin that despite that we have
no actual tiles to bin it to, leading to assertion failures (pretty harmless
since tile 0/0 always exists nevertheless as tiles are statically allocated,
albeit that should change at some point).
(Note probably not an issue with gl state tracker)

Reviewed-by: Jose Fonseca <jfonseca@vmware.com>

diff --git a/src/gallium/drivers/llvmpipe/lp_setup.c b/src/gallium/drivers/llvmpipe/lp_setup.c
index 38d91385cf396989245aee527748fb31e3b384ae..32387ab553204795a3c3b1f82156636b776d2cb1 100644 (file)
--- a/src/gallium/drivers/llvmpipe/lp_setup.c
+++ b/src/gallium/drivers/llvmpipe/lp_setup.c
@@ -1347,6 +1347,10 @@ lp_setup_create( struct pipe_context *pipe,
    
    setup->dirty = ~0;
 
+   /* Initialize empty default fb correctly, so the rect is empty */
+   setup->framebuffer.x1 = -1;
+   setup->framebuffer.y1 = -1;
+
    return setup;
 
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