i965/Gen4: Zero extra coordinates for ir_tex

We always emit U,V,R coordinates for this message, but the sampler gets
very angry if we pass garbage in the R coordinate for at least some
texture formats.

Fill the remaining coordinates with zero instead.

Fixes broken rendering on GM45 in Source games, and in VDrift.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=65236

NOTE: This is a candidate for stable branches.

Signed-off-by: Chris Forbes <chrisf@ijw.co.nz>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

diff --git a/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp b/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp
index fc7ae58..15d1c6a 100644 (file)
--- a/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp
@@ -891,6 +891,10 @@ fs_visitor::emit_texture_gen4(ir_texture *ir, fs_reg dst, fs_reg coordinate,
         emit(MOV(fs_reg(MRF, base_mrf + mlen + i), coordinate));
         coordinate.reg_offset++;
       }
+      /* zero the others. */
+      for (int i = ir->coordinate->type->vector_elements; i<3; i++) {
+         emit(MOV(fs_reg(MRF, base_mrf + mlen + i), fs_reg(0.0f)));
+      }
       /* gen4's SIMD8 sampler always has the slots for u,v,r present. */
       mlen += 3;
    } else if (ir->op == ir_txd) {