softpipe: implement some support for multiple viewports

Mostly related to making sure the rasterizer can correctly
pick out the correct scissor box for the current viewport.

Signed-off-by: Edward O'Callaghan <[email protected]>
Reviewed-by: Roland Scheidegger <[email protected]>

1 files changed, 5 insertions, 0 deletions

diff --git a/src/gallium/drivers/softpipe/sp_setup.h b/src/gallium/drivers/softpipe/sp_setup.h
index 885be739033..191494acbb8 100644
--- a/src/gallium/drivers/softpipe/sp_setup.h
+++ b/src/gallium/drivers/softpipe/sp_setup.h
@@ -45,6 +45,11 @@ void
 sp_setup_point( struct setup_context *setup,
              const float (*v0)[4] );
 
+static inline unsigned
+sp_clamp_viewport_idx(int idx)
+{
+   return (PIPE_MAX_VIEWPORTS > idx && idx >= 0) ? idx : 0;
+}
 
 struct setup_context *sp_setup_create_context( struct softpipe_context *softpipe );
 void sp_setup_prepare( struct setup_context *setup );