1 files changed, 50 insertions, 4 deletions

diff --git a/src/mesa/state_tracker/st_mesa_to_tgsi.c b/src/mesa/state_tracker/st_mesa_to_tgsi.c
index bd94c9d79e..1611d53e2f 100644
--- a/src/mesa/state_tracker/st_mesa_to_tgsi.c
+++ b/src/mesa/state_tracker/st_mesa_to_tgsi.c
@@ -396,6 +396,23 @@ static void emit_swz( struct st_translate *t,
 }
 
 
+/**
+ * Negate the value of DDY to match GL semantics where (0,0) is the
+ * lower-left corner of the window.
+ * Note that the GL_ARB_fragment_coord_conventions extension will
+ * effect this someday.
+ */
+static void emit_ddy( struct st_translate *t,
+                      struct ureg_dst dst,
+                      const struct prog_src_register *SrcReg )
+{
+   struct ureg_program *ureg = t->ureg;
+   struct ureg_src src = translate_src( t, SrcReg );
+   src = ureg_negate( src );
+   ureg_DDY( ureg, dst, src );
+}
+
+
 
 static unsigned
 translate_opcode( unsigned op )
@@ -619,7 +636,9 @@ compile_instruction(
       ureg_MOV( ureg, dst[0], ureg_imm1f(ureg, 0.5) );
       break;
 		 
-
+   case OPCODE_DDY:
+      emit_ddy( t, dst[0], &inst->SrcReg[0] );
+      break;
 
    default:
       ureg_insn( ureg, 
@@ -676,6 +695,31 @@ emit_inverted_wpos( struct st_translate *t,
 
 
 /**
+ * OpenGL's fragment gl_FrontFace input is 1 for front-facing, 0 for back.
+ * TGSI uses +1 for front, -1 for back.
+ * This function converts the TGSI value to the GL value.  Simply clamping/
+ * saturating the value to [0,1] does the job.
+ */
+static void
+emit_face_var( struct st_translate *t,
+               const struct gl_program *program )
+{
+   struct ureg_program *ureg = t->ureg;
+   struct ureg_dst face_temp = ureg_DECL_temporary( ureg );
+   struct ureg_src face_input = t->inputs[t->inputMapping[FRAG_ATTRIB_FACE]];
+
+   /* MOV_SAT face_temp, input[face]
+    */
+   face_temp = ureg_saturate( face_temp );
+   ureg_MOV( ureg, face_temp, face_input );
+
+   /* Use face_temp as face input from here on:
+    */
+   t->inputs[t->inputMapping[FRAG_ATTRIB_FACE]] = ureg_src(face_temp);
+}
+
+
+/**
  * Translate Mesa program to TGSI format.
  * \param program  the program to translate
  * \param numInputs  number of input registers used
@@ -704,12 +748,10 @@ st_translate_mesa_program(
    const ubyte inputSemanticName[],
    const ubyte inputSemanticIndex[],
    const GLuint interpMode[],
-   const GLbitfield inputFlags[],
    GLuint numOutputs,
    const GLuint outputMapping[],
    const ubyte outputSemanticName[],
-   const ubyte outputSemanticIndex[],
-   const GLbitfield outputFlags[] )
+   const ubyte outputSemanticIndex[] )
 {
    struct st_translate translate, *t;
    struct ureg_program *ureg;
@@ -748,6 +790,10 @@ st_translate_mesa_program(
          emit_inverted_wpos( t, program );
       }
 
+      if (program->InputsRead & FRAG_BIT_FACE) {
+         emit_face_var( t, program );
+      }
+
       /*
        * Declare output attributes.
        */