From d7a7b0a10dd355fbeb7a404091a42d4ab558c820 Mon Sep 17 00:00:00 2001
From: Brian Paul <brian.paul@tungstengraphics.com>
Date: Wed, 17 Sep 2008 16:48:13 -0600
Subject: mesa: new gl_fragment_program fields indicating use of fog,
 front-facing, point coord

---
 src/mesa/shader/slang/slang_link.c | 50 ++++++++++++++++++++++++--------------
 1 file changed, 32 insertions(+), 18 deletions(-)

(limited to 'src/mesa/shader/slang/slang_link.c')

diff --git a/src/mesa/shader/slang/slang_link.c b/src/mesa/shader/slang/slang_link.c
index a44d0014770..dd7d5be6d8b 100644
--- a/src/mesa/shader/slang/slang_link.c
+++ b/src/mesa/shader/slang/slang_link.c
@@ -42,6 +42,24 @@
 #include "slang_link.h"
 
 
+/** cast wrapper */
+static struct gl_vertex_program *
+vertex_program(struct gl_program *prog)
+{
+   assert(prog->Target == GL_VERTEX_PROGRAM_ARB);
+   return (struct gl_vertex_program *) prog;
+}
+
+
+/** cast wrapper */
+static struct gl_fragment_program *
+fragment_program(struct gl_program *prog)
+{
+   assert(prog->Target == GL_FRAGMENT_PROGRAM_ARB);
+   return (struct gl_fragment_program *) prog;
+}
+
+
 /**
  * Record a linking error.
  */
@@ -374,6 +392,20 @@ _slang_update_inputs_outputs(struct gl_program *prog)
       for (j = 0; j < numSrc; j++) {
          if (inst->SrcReg[j].File == PROGRAM_INPUT) {
             prog->InputsRead |= 1 << inst->SrcReg[j].Index;
+            if (prog->Target == GL_FRAGMENT_PROGRAM_ARB &&
+                inst->SrcReg[j].Index == FRAG_ATTRIB_FOGC) {
+               /* The fragment shader FOGC input is used for fog,
+                * front-facing and sprite/point coord.
+                */
+               struct gl_fragment_program *fp = fragment_program(prog);
+               const GLint swz = GET_SWZ(inst->SrcReg[j].Swizzle, 0);
+               if (swz == SWIZZLE_X)
+                  fp->UsesFogFragCoord = GL_TRUE;
+               else if (swz == SWIZZLE_Y)
+                  fp->UsesFrontFacing = GL_TRUE;
+               else if (swz == SWIZZLE_Z || swz == SWIZZLE_W)
+                  fp->UsesPointCoord = GL_TRUE;
+            }
          }
          else if (inst->SrcReg[j].File == PROGRAM_ADDRESS) {
             maxAddrReg = MAX2(maxAddrReg, inst->SrcReg[j].Index + 1);
@@ -391,24 +423,6 @@ _slang_update_inputs_outputs(struct gl_program *prog)
 }
 
 
-/** cast wrapper */
-static struct gl_vertex_program *
-vertex_program(struct gl_program *prog)
-{
-   assert(prog->Target == GL_VERTEX_PROGRAM_ARB);
-   return (struct gl_vertex_program *) prog;
-}
-
-
-/** cast wrapper */
-static struct gl_fragment_program *
-fragment_program(struct gl_program *prog)
-{
-   assert(prog->Target == GL_FRAGMENT_PROGRAM_ARB);
-   return (struct gl_fragment_program *) prog;
-}
-
-
 /**
  * Shader linker.  Currently:
  *
-- 
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