llvmpipe: implement scissor testing

The scissor test is implemented as another per-quad operation in
the JIT code.  The four scissor box params are passed via the
lp_jit_context.  In the JIT code we compare the quad's x/y coords
against the clip bounds and create a new in/out mask that's AND'd
with the main quad mask.

Note: we should also do scissor testing in the triangle setup code
to improve efficiency.  That's not done yet.

1 files changed, 1 insertions, 0 deletions

diff --git a/src/gallium/drivers/llvmpipe/lp_state.h b/src/gallium/drivers/llvmpipe/lp_state.h
index 4c6747bb2b..ddb152c074 100644
--- a/src/gallium/drivers/llvmpipe/lp_state.h
+++ b/src/gallium/drivers/llvmpipe/lp_state.h
@@ -72,6 +72,7 @@ struct lp_fragment_shader_variant_key
    enum pipe_format zsbuf_format;
    unsigned nr_cbufs:8;
    unsigned flatshade:1;
+   unsigned scissor:1;
 
    struct {
       ubyte colormask;