summaryrefslogtreecommitdiff
path: root/src
diff options
context:
space:
mode:
authorEric Anholt <eric@anholt.net>2010-04-20 13:40:28 -0700
committerEric Anholt <eric@anholt.net>2010-04-22 15:37:33 -0700
commit64516430be1cbe4904613903887a8178f4b4fc60 (patch)
tree6f65543d76cba12a8af7f8c1f4977babd6f585b2 /src
parent021e0dc78b15fab29e761012860276c2597c8d8f (diff)
i965: Fix scissoring when width or height is 0.
We would run into trouble due to the hardware using inclusive numbers and the subtraction to handle that producing negative (meaning large positive) coordinates. Bug #27643.
Diffstat (limited to 'src')
-rw-r--r--src/mesa/drivers/dri/i965/brw_sf_state.c15
1 files changed, 14 insertions, 1 deletions
diff --git a/src/mesa/drivers/dri/i965/brw_sf_state.c b/src/mesa/drivers/dri/i965/brw_sf_state.c
index 9712c31afe..1a6c8218fd 100644
--- a/src/mesa/drivers/dri/i965/brw_sf_state.c
+++ b/src/mesa/drivers/dri/i965/brw_sf_state.c
@@ -76,7 +76,20 @@ static void upload_sf_vp(struct brw_context *brw)
* Note that the hardware's coordinates are inclusive, while Mesa's min is
* inclusive but max is exclusive.
*/
- if (render_to_fbo) {
+
+ if (ctx->DrawBuffer->_Xmin == ctx->DrawBuffer->_Xmax ||
+ ctx->DrawBuffer->_Ymin == ctx->DrawBuffer->_Ymax) {
+ /* If the scissor was out of bounds and got clamped to 0
+ * width/height at the bounds, the subtraction of 1 from
+ * maximums could produce a negative number and thus not clip
+ * anything. Instead, just provide a min > max scissor inside
+ * the bounds, which produces the expected no rendering.
+ */
+ sfv.scissor.xmin = 1;
+ sfv.scissor.xmax = 0;
+ sfv.scissor.ymin = 1;
+ sfv.scissor.ymax = 0;
+ } else if (render_to_fbo) {
/* texmemory: Y=0=bottom */
sfv.scissor.xmin = ctx->DrawBuffer->_Xmin;
sfv.scissor.xmax = ctx->DrawBuffer->_Xmax - 1;