From 1c04731b8721850b6abb12a43a3eec616b850e86 Mon Sep 17 00:00:00 2001
From: Zack Rusin <zack@kde.org>
Date: Wed, 1 Jul 2009 10:42:58 -0400
Subject: gallium: fix the front face semantics

mesa allocates both frontface and pointcoord registers within the fog
coordinate register, by using swizzling. to make it cleaner and easier
for drivers we want each of them in its own register. so when doing
compilation from the mesa IR to tgsi allocate new registers for both
and add new semantics to the respective declarations.
---
 src/mesa/state_tracker/st_atom_shader.c  | 19 +++++++++++++++++--
 src/mesa/state_tracker/st_mesa_to_tgsi.c | 23 ++++++++++++++++++++++-
 src/mesa/state_tracker/st_program.c      |  7 ++++++-
 3 files changed, 45 insertions(+), 4 deletions(-)

(limited to 'src/mesa/state_tracker')

diff --git a/src/mesa/state_tracker/st_atom_shader.c b/src/mesa/state_tracker/st_atom_shader.c
index ee649be885..c02ccc3528 100644
--- a/src/mesa/state_tracker/st_atom_shader.c
+++ b/src/mesa/state_tracker/st_atom_shader.c
@@ -137,8 +137,23 @@ find_translated_vp(struct st_context *st,
 
       for (inAttr = 0; inAttr < FRAG_ATTRIB_MAX; inAttr++) {
          if (fragInputsRead & (1 << inAttr)) {
-            stfp->input_to_slot[inAttr] = numIn;
-            numIn++;
+            if ((fragInputsRead & FRAG_BIT_FOGC)) {
+               if (stfp->Base.UsesPointCoord) {
+                  stfp->input_to_slot[inAttr] = numIn;
+                  numIn++;
+               }
+               if (stfp->Base.UsesFrontFacing) {
+                  stfp->input_to_slot[inAttr] = numIn;
+                  numIn++;
+               }
+               if (stfp->Base.UsesFogFragCoord) {
+                  stfp->input_to_slot[inAttr] = numIn;
+                  numIn++;
+               }
+            } else {
+               stfp->input_to_slot[inAttr] = numIn;
+               numIn++;
+            }
          }
          else {
             stfp->input_to_slot[inAttr] = UNUSED;
diff --git a/src/mesa/state_tracker/st_mesa_to_tgsi.c b/src/mesa/state_tracker/st_mesa_to_tgsi.c
index 43c9afccc3..3140ebe04a 100644
--- a/src/mesa/state_tracker/st_mesa_to_tgsi.c
+++ b/src/mesa/state_tracker/st_mesa_to_tgsi.c
@@ -101,8 +101,10 @@ map_register_file(
  */
 static GLuint
 map_register_file_index(
+   GLuint procType,
    GLuint file,
    GLuint index,
+   GLuint *swizzle,
    const GLuint inputMapping[],
    const GLuint outputMapping[],
    const GLuint immediateMapping[],
@@ -110,6 +112,20 @@ map_register_file_index(
 {
    switch( file ) {
    case TGSI_FILE_INPUT:
+      if (procType == TGSI_PROCESSOR_FRAGMENT &&
+          index == FRAG_ATTRIB_FOGC) {
+         if (GET_SWZ(*swizzle, 0) == SWIZZLE_X) {
+            /* do nothing we're, ok */
+         } else if (GET_SWZ(*swizzle, 0) == SWIZZLE_Y) {
+            /* replace the swizzle with xxxx */
+            *swizzle = MAKE_SWIZZLE4(SWIZZLE_X,
+                                     SWIZZLE_X,
+                                     SWIZZLE_X,
+                                     SWIZZLE_X);
+         } else {
+            /* fixme: point coord */
+         }
+      }
       /* inputs are mapped according to the user-defined map */
       return inputMapping[index];
 
@@ -236,8 +252,10 @@ compile_instruction(
    fulldst = &fullinst->FullDstRegisters[0];
    fulldst->DstRegister.File = map_register_file( inst->DstReg.File, 0, NULL, GL_FALSE );
    fulldst->DstRegister.Index = map_register_file_index(
+      procType,
       fulldst->DstRegister.File,
       inst->DstReg.Index,
+      NULL,
       inputMapping,
       outputMapping,
       NULL,
@@ -246,6 +264,7 @@ compile_instruction(
 
    for (i = 0; i < fullinst->Instruction.NumSrcRegs; i++) {
       GLuint j;
+      GLuint swizzle = inst->SrcReg[i].Swizzle;
 
       fullsrc = &fullinst->FullSrcRegisters[i];
 
@@ -264,8 +283,10 @@ compile_instruction(
             immediateMapping,
             indirectAccess );
          fullsrc->SrcRegister.Index = map_register_file_index(
+            procType,
             fullsrc->SrcRegister.File,
             inst->SrcReg[i].Index,
+            &swizzle,
             inputMapping,
             outputMapping,
             immediateMapping,
@@ -278,7 +299,7 @@ compile_instruction(
          GLboolean extended = (inst->SrcReg[i].Negate != NEGATE_NONE &&
                                inst->SrcReg[i].Negate != NEGATE_XYZW);
          for( j = 0; j < 4; j++ ) {
-            swz[j] = GET_SWZ( inst->SrcReg[i].Swizzle, j );
+            swz[j] = GET_SWZ( swizzle, j );
             if (swz[j] > SWIZZLE_W)
                extended = GL_TRUE;
          }
diff --git a/src/mesa/state_tracker/st_program.c b/src/mesa/state_tracker/st_program.c
index 72ca852458..9a346fbde0 100644
--- a/src/mesa/state_tracker/st_program.c
+++ b/src/mesa/state_tracker/st_program.c
@@ -437,11 +437,16 @@ st_translate_fragment_program(struct st_context *st,
             if (stfp->Base.UsesPointCoord) {
                stfp->input_semantic_name[slot] = TGSI_SEMANTIC_GENERIC;
                stfp->input_semantic_index[slot] = num_generic++;
+               interpMode[slot] = TGSI_INTERPOLATE_PERSPECTIVE;
+            } else if (stfp->Base.UsesFrontFacing) {
+               stfp->input_semantic_name[slot] = TGSI_SEMANTIC_FACE;
+               stfp->input_semantic_index[slot] = 0;
+               interpMode[slot] = TGSI_INTERPOLATE_CONSTANT;
             } else {
                stfp->input_semantic_name[slot] = TGSI_SEMANTIC_FOG;
                stfp->input_semantic_index[slot] = 0;
+               interpMode[slot] = TGSI_INTERPOLATE_PERSPECTIVE;
 	    }
-            interpMode[slot] = TGSI_INTERPOLATE_PERSPECTIVE;
             break;
          case FRAG_ATTRIB_TEX0:
          case FRAG_ATTRIB_TEX1:
-- 
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