Improves performance in Citybench:
- 320x240: 19.8008% +/- 0.937818%
- 1280x480: 6.53856% +/- 0.859083%
No apparent difference in OpenArena nor Xonotic.
Signed-off-by: Kenneth Graunke <kenn...@whitecape.org>
---
src/mesa/drivers/dri/i965/gen6_clip_state.c | 1 +
src/mesa/drivers/dri/i965/gen6_viewport_state.c | 24 +++++++++++++----------
2 files changed, 15 insertions(+), 10 deletions(-)
diff --git a/src/mesa/drivers/dri/i965/gen6_clip_state.c
b/src/mesa/drivers/dri/i965/gen6_clip_state.c
index abf1d76..5d88978 100644
--- a/src/mesa/drivers/dri/i965/gen6_clip_state.c
+++ b/src/mesa/drivers/dri/i965/gen6_clip_state.c
@@ -74,6 +74,7 @@ upload_clip_state(struct brw_context *brw)
GEN6_CLIP_MODE_NORMAL |
nonperspective_barycentric_enable_flag |
GEN6_CLIP_XY_TEST |
+ GEN6_CLIP_GB_TEST |
userclip << GEN6_USER_CLIP_CLIP_DISTANCES_SHIFT |
depth_clamp |
provoking);
diff --git a/src/mesa/drivers/dri/i965/gen6_viewport_state.c
b/src/mesa/drivers/dri/i965/gen6_viewport_state.c
index f787ac7..95243f0 100644
--- a/src/mesa/drivers/dri/i965/gen6_viewport_state.c
+++ b/src/mesa/drivers/dri/i965/gen6_viewport_state.c
@@ -33,31 +33,35 @@
/* The clip VP defines the guardband region where expensive clipping is skipped
* and fragments are allowed to be generated and clipped out cheaply by the SF.
- *
- * By setting it to NDC bounds of [-1,1], we don't do GB clipping. It's
- * supposed to cause seams to become visible in apps due to shared edges taking
- * different clip/no clip paths depending on whether the rest of the prim ends
- * up in the guardband or not.
*/
static void
gen6_upload_clip_vp(struct brw_context *brw)
{
+ struct gl_context *ctx = &brw->intel.ctx;
struct brw_clipper_viewport *vp;
vp = brw_state_batch(brw, AUB_TRACE_CLIP_VP_STATE,
sizeof(*vp), 32, &brw->clip.vp_offset);
- vp->xmin = -1.0;
- vp->xmax = 1.0;
- vp->ymin = -1.0;
- vp->ymax = 1.0;
+ /* According to the Sandybridge PRM, Volume 2, Part 1, Section 6.3.8
+ * "Vertex X,Y Clamping and Quantization", the screen-aligned 2D
+ * bounding-box of an object must not exceed 16K pixels in either X or Y.
+ */
+ const float maximum_post_clamp_delta = 16384;
+ float gbx = maximum_post_clamp_delta / (float) ctx->Viewport.Width;
+ float gby = maximum_post_clamp_delta / (float) ctx->Viewport.Height;
+
+ vp->xmin = -gbx;
+ vp->xmax = gbx;
+ vp->ymin = -gby;
+ vp->ymax = gby;
brw->state.dirty.cache |= CACHE_NEW_CLIP_VP;
}
const struct brw_tracked_state gen6_clip_vp = {
.dirty = {
- .mesa = 0,
+ .mesa = _NEW_VIEWPORT,
.brw = BRW_NEW_BATCH,
.cache = 0,
},
--
1.7.10.1
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