Mesa (master): i965/fs: Implement texture projection support.

[Kenneth Graunke]

Module: Mesa
Branch: master
Commit: 649173b473ded2d7b1aded91cd4aab42eaeb5766
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=649173b473ded2d7b1aded91cd4aab42eaeb5766

Author: Kenneth Graunke <kenneth at whitecape.org>
Date:   Sat Jan 31 23:36:52 2015 -0800

i965/fs: Implement texture projection support.

Our fragment program backend implements support for TXP directly, and
there's no NIR lowering pass to remove the projection.  When we switch
fragment program support over to NIR, we need to support it somehow.

It's easy enough to support directly.

v2: Split out offset/tex_offset rename (requested by Jordan).

Signed-off-by: Kenneth Graunke <kenneth at whitecape.org>
Reviewed-by: Jordan Justen <jordan.l.justen at intel.com>

---

 src/mesa/drivers/dri/i965/brw_fs_nir.cpp |   11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/src/mesa/drivers/dri/i965/brw_fs_nir.cpp b/src/mesa/drivers/dri/i965/brw_fs_nir.cpp
index 98ea70c..0b8ed1a 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_nir.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_nir.cpp
@@ -1744,6 +1744,7 @@ fs_visitor::nir_emit_texture(nir_tex_instr *instr)
    int lod_components = 0, offset_components = 0;
 
    fs_reg coordinate, shadow_comparitor, lod, lod2, sample_index, mcs, tex_offset;
+   fs_reg projector;
 
    for (unsigned i = 0; i < instr->num_srcs; i++) {
       fs_reg src = get_nir_src(instr->src[i].src);
@@ -1796,7 +1797,8 @@ fs_visitor::nir_emit_texture(nir_tex_instr *instr)
             offset_components = instr->coord_components;
          break;
       case nir_tex_src_projector:
-         unreachable("should be lowered");
+         projector = retype(src, BRW_REGISTER_TYPE_F);
+         break;
 
       case nir_tex_src_sampler_offset: {
          /* Figure out the highest possible sampler index and mark it as used */
@@ -1820,6 +1822,13 @@ fs_visitor::nir_emit_texture(nir_tex_instr *instr)
       }
    }
 
+   if (projector.file != BAD_FILE) {
+      fs_reg invproj = vgrf(glsl_type::float_type);
+      emit_math(SHADER_OPCODE_RCP, invproj, projector);
+      for (int i = 0; i < 3; i++)
+         emit(MUL(offset(coordinate, i), offset(coordinate, i), invproj));
+   }
+
    if (instr->op == nir_texop_txf_ms) {
       if (brw->gen >= 7 &&
           key_tex->compressed_multisample_layout_mask & (1 << sampler)) {