Maintain a fragment program for current texturing state.

1 files changed, 772 insertions, 0 deletions

diff --git a/src/mesa/main/texenvprogram.c b/src/mesa/main/texenvprogram.c
new file mode 100644
index 00000000000..448c577b795
--- /dev/null
+++ b/src/mesa/main/texenvprogram.c
@@ -0,0 +1,772 @@
+/**************************************************************************
+ * 
+ * Copyright 2003 Tungsten Graphics, Inc., Cedar Park, Texas.
+ * All Rights Reserved.
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sub license, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ * 
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial portions
+ * of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
+ * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
+ * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ * 
+ **************************************************************************/
+
+#include <strings.h>
+
+#include "glheader.h"
+#include "macros.h"
+#include "enums.h"
+#include "texenvprogram.h"
+
+#include "shader/program.h"
+#include "shader/nvfragprog.h"
+#include "shader/arbfragparse.h"
+
+
+#define DISASSEM 1
+
+/* Use uregs to represent registers internally, translate to Mesa's
+ * expected formats on emit.  
+ *
+ * NOTE: These are passed by value extensively in this file rather
+ * than as usual by pointer reference.  If this disturbs you, try
+ * remembering they are just 32bits in size.
+ *
+ * GCC is smart enough to deal with these dword-sized structures in
+ * much the same way as if I had defined them as dwords and was using
+ * macros to access and set the fields.  This is much nicer and easier
+ * to evolve.
+ */
+struct ureg {
+   GLuint file:4;
+   GLuint idx:8;
+   GLuint negatebase:1;
+   GLuint abs:1;
+   GLuint negateabs:1;
+   GLuint swz:12;
+   GLuint pad:5;
+};
+
+const static struct ureg undef = { 
+   ~0,
+   ~0,
+   0,
+   0,
+   0,
+   0,
+   0
+};
+
+#define X    0
+#define Y    1
+#define Z    2
+#define W    3
+
+#define MAX_CONSTANT 32
+
+/* State used to build the fragment program:
+ */
+struct texenv_fragment_program {
+   struct fragment_program *prog;
+   GLcontext *ctx;
+
+   GLfloat constant[MAX_CONSTANT][4];
+   GLuint constant_flags[MAX_CONSTANT];
+   GLuint nr_constants;
+
+   GLuint temp_flag;		/* Tracks temporary regs which are in
+				 * use.
+				 */
+
+
+   struct { 
+      GLuint reg;		/* Hardware constant idx */
+      const GLfloat *values; 	/* Pointer to tracked values */
+   } param[MAX_CONSTANT];
+   GLuint nr_params;
+      
+
+   GLboolean error;
+
+   struct ureg src_texture;   /* Reg containing sampled texture color,
+			       * else undef.
+			       */
+
+   struct ureg src_previous;	/* Reg containing color from previous 
+				 * stage.  May need to be decl'd.
+				 */
+
+   GLuint last_tex_stage;	/* Number of last enabled texture unit */
+};
+
+
+
+static struct ureg make_ureg(GLuint file, GLuint idx)
+{
+   struct ureg reg;
+   reg.file = file;
+   reg.idx = idx;
+   reg.negatebase = 0;
+   reg.abs = 0;
+   reg.negateabs = 0;
+   reg.swz = SWIZZLE_NOOP;
+   reg.pad = 0;
+   return reg;
+}
+
+static struct ureg swizzle( struct ureg reg, int x, int y, int z, int w )
+{
+   reg.swz = MAKE_SWIZZLE4(GET_SWZ(reg.swz, x),
+			   GET_SWZ(reg.swz, y),
+			   GET_SWZ(reg.swz, z),
+			   GET_SWZ(reg.swz, w));
+
+   return reg;
+}
+
+static struct ureg swizzle1( struct ureg reg, int x )
+{
+   return swizzle(reg, x, x, x, x);
+}
+
+static GLboolean is_undef( struct ureg reg )
+{
+   return reg.file == 0xf;
+}
+
+static struct ureg get_temp( struct texenv_fragment_program *p )
+{
+   int bit = ffs( ~p->temp_flag );
+   if (!bit) {
+      fprintf(stderr, "%s: out of temporaries\n", __FILE__);
+      exit(1);
+   }
+
+   p->temp_flag |= 1<<(bit-1);
+   return make_ureg(PROGRAM_TEMPORARY, (bit-1));
+}
+
+
+static void release_temps( struct texenv_fragment_program *p )
+{
+   p->temp_flag = ~0x7;
+}
+
+
+static struct ureg emit_decl( struct texenv_fragment_program *p,
+			      GLuint type, GLuint nr )
+{
+   struct ureg reg = make_ureg(type, nr);
+
+   if (type == PROGRAM_INPUT) {
+      p->prog->InputsRead |= 1<<nr;
+   }
+   else {
+      /* Other ???
+       */
+   }
+
+   return reg;
+}
+
+static void emit_arg( struct fp_src_register *reg,
+		      struct ureg ureg )
+{
+   reg->File = ureg.file;
+   reg->Index = ureg.idx;
+   reg->Swizzle = ureg.swz;
+   reg->NegateBase = ureg.negatebase;
+   reg->Abs = ureg.abs;
+   reg->NegateAbs = ureg.negateabs;
+}
+
+static void emit_dst( struct fp_dst_register *dst,
+		      struct ureg ureg, GLuint mask )
+{
+   dst->File = ureg.file;
+   dst->Index = ureg.idx;
+   dst->WriteMask = mask;
+   dst->CondMask = 0;
+   dst->CondSwizzle = 0;
+}
+
+static struct fp_instruction *
+emit_op(struct texenv_fragment_program *p,
+	GLuint op,
+	struct ureg dest,
+	GLuint mask,
+	GLuint saturate,
+	struct ureg src0,
+	struct ureg src1,
+	struct ureg src2 )
+{
+   GLuint nr = p->prog->Base.NumInstructions++;
+   struct fp_instruction *inst = &p->prog->Instructions[nr];
+      
+   memset(inst, 0, sizeof(*inst));
+   inst->Opcode = op;
+   
+   if (!is_undef(src0)) emit_arg( &inst->SrcReg[0], src0 );
+   if (!is_undef(src1)) emit_arg( &inst->SrcReg[1], src1 );
+   if (!is_undef(src2)) emit_arg( &inst->SrcReg[2], src2 );
+   
+   inst->Saturate = saturate;
+
+   emit_dst( &inst->DstReg, dest, mask );
+
+   return inst;
+}
+   
+
+static struct ureg emit_arith( struct texenv_fragment_program *p,
+			  GLuint op,
+			  struct ureg dest,
+			  GLuint mask,
+			  GLuint saturate,
+			  struct ureg src0,
+			  struct ureg src1,
+			  struct ureg src2 )
+{
+   emit_op(p, op, dest, mask, saturate, src0, src1, src2);
+   
+   p->prog->NumAluInstructions++;
+   return dest;
+}
+
+static struct ureg emit_texld( struct texenv_fragment_program *p,
+			  GLuint op,
+			  struct ureg dest,
+			  GLuint destmask,
+			  GLuint tex_unit,
+			  GLuint tex_idx,
+			  struct ureg coord )
+{
+   struct fp_instruction *inst = emit_op( p, op, 
+					  dest, destmask, 
+					  0,		/* don't saturate? */
+					  coord, 	/* arg 0? */
+					  undef,
+					  undef);
+   
+   inst->TexSrcIdx = tex_idx;
+   inst->TexSrcUnit = tex_unit;
+
+   p->prog->NumTexInstructions++;
+
+   if (coord.file != PROGRAM_INPUT &&
+       (coord.idx < VERT_ATTRIB_TEX0 ||
+	coord.idx > VERT_ATTRIB_TEX7)) {
+      p->prog->NumTexIndirections++;
+   }
+
+   return dest;
+}
+
+
+static struct ureg emit_const1f( struct texenv_fragment_program *p, GLfloat c0 )
+{
+   GLint reg, idx;
+
+   for (reg = 0; reg < MAX_CONSTANT; reg++) {
+      for (idx = 0; idx < 4; idx++) {
+	 if (!(p->constant_flags[reg] & (1<<idx)) ||
+	     p->constant[reg][idx] == c0) {
+	    p->constant[reg][idx] = c0;
+	    p->constant_flags[reg] |= 1<<idx;
+	    if (reg+1 > p->nr_constants) p->nr_constants = reg+1;
+	    return swizzle1(make_ureg(PROGRAM_LOCAL_PARAM, reg),idx);
+	 }
+      }
+   }
+
+   fprintf(stderr, "%s: out of constants\n", __FUNCTION__);
+   p->error = 1;
+   return undef;
+}
+
+static struct ureg emit_const2f( struct texenv_fragment_program *p, 
+			    GLfloat c0, GLfloat c1 )
+{
+   GLint reg, idx;
+
+   for (reg = 0; reg < MAX_CONSTANT; reg++) {
+      if (p->constant_flags[reg] == 0xf)
+	 continue;
+      for (idx = 0; idx < 3; idx++) {
+	 if (!(p->constant_flags[reg] & (3<<idx))) {
+	    p->constant[reg][idx] = c0;
+	    p->constant[reg][idx+1] = c1;
+	    p->constant_flags[reg] |= 3<<idx;
+	    if (reg+1 > p->nr_constants) p->nr_constants = reg+1;
+	    return swizzle(make_ureg(PROGRAM_LOCAL_PARAM, reg),idx,idx+1,idx,idx+1);
+	 }
+      }
+   }
+
+   fprintf(stderr, "%s: out of constants\n", __FUNCTION__);
+   p->error = 1;
+   return undef;
+}
+
+
+
+static struct ureg emit_const4f( struct texenv_fragment_program *p, 
+			    GLfloat c0, GLfloat c1, GLfloat c2, GLfloat c3 )
+{
+   GLint reg;
+
+   for (reg = 0; reg < MAX_CONSTANT; reg++) {
+      if (p->constant_flags[reg] == 0xf &&
+	  p->constant[reg][0] == c0 &&
+	  p->constant[reg][1] == c1 &&
+	  p->constant[reg][2] == c2 &&
+	  p->constant[reg][3] == c3) {
+	 return make_ureg(PROGRAM_LOCAL_PARAM, reg);
+      }
+      else if (p->constant_flags[reg] == 0) {
+	 p->constant[reg][0] = c0;
+	 p->constant[reg][1] = c1;
+	 p->constant[reg][2] = c2;
+	 p->constant[reg][3] = c3;
+	 p->constant_flags[reg] = 0xf;
+	 if (reg+1 > p->nr_constants) p->nr_constants = reg+1;
+	 return make_ureg(PROGRAM_LOCAL_PARAM, reg);
+      }
+   }
+
+   fprintf(stderr, "%s: out of constants\n", __FUNCTION__);
+   p->error = 1;
+   return undef;
+}
+
+
+static struct ureg emit_const4fv( struct texenv_fragment_program *p, const GLfloat *c )
+{
+   return emit_const4f( p, c[0], c[1], c[2], c[3] );
+}
+
+
+
+
+
+
+static void program_error( struct texenv_fragment_program *p, const char *msg )
+{
+   fprintf(stderr, "%s\n", msg);
+   p->error = 1;
+}
+
+
+static GLuint translate_tex_src_bit( struct texenv_fragment_program *p,
+				     GLuint bit )
+{
+   switch (bit) {
+   case TEXTURE_1D_BIT:   return TEXTURE_1D_INDEX;
+   case TEXTURE_2D_BIT:   return TEXTURE_2D_INDEX;
+   case TEXTURE_RECT_BIT: return TEXTURE_RECT_INDEX;
+   case TEXTURE_3D_BIT:   return TEXTURE_3D_INDEX;
+   case TEXTURE_CUBE_BIT: return TEXTURE_CUBE_INDEX;
+   default: program_error(p, "TexSrcBit"); return 0;
+   }
+}
+
+
+static struct ureg get_source( struct texenv_fragment_program *p, 
+			  GLenum src, GLuint unit )
+{
+   switch (src) {
+   case GL_TEXTURE: 
+      if (is_undef(p->src_texture)) {
+
+	 GLuint dim = translate_tex_src_bit( p, p->ctx->Texture.Unit[unit]._ReallyEnabled);
+	 struct ureg texcoord = emit_decl(p, 
+					  PROGRAM_INPUT, 
+					  VERT_ATTRIB_TEX0+unit);
+	 struct ureg tmp = get_temp( p );
+
+	 /* TODO: Use D0_MASK_XY where possible.
+	  */
+	 p->src_texture = emit_texld( p, FP_OPCODE_TXP,
+				      tmp, WRITEMASK_XYZW, 
+				      unit, dim, texcoord );
+      }
+
+      return p->src_texture;
+
+      /* Crossbar: */
+   case GL_TEXTURE0:
+   case GL_TEXTURE1:
+   case GL_TEXTURE2:
+   case GL_TEXTURE3:
+   case GL_TEXTURE4:
+   case GL_TEXTURE5:
+   case GL_TEXTURE6:
+   case GL_TEXTURE7: {
+      return undef;
+   }
+
+   case GL_CONSTANT:
+      return emit_const4fv( p, p->ctx->Texture.Unit[unit].EnvColor );
+   case GL_PRIMARY_COLOR:
+      return emit_decl(p, PROGRAM_INPUT, VERT_ATTRIB_COLOR0);
+   case GL_PREVIOUS:
+   default: 
+      return emit_decl(p, 
+		       p->src_previous.file,
+		       p->src_previous.idx); 
+   }
+}
+			
+
+static struct ureg emit_combine_source( struct texenv_fragment_program *p, 
+				   GLuint mask,
+				   GLuint unit,
+				   GLenum source, 
+				   GLenum operand )
+{
+   struct ureg arg, src, one;
+
+   src = get_source(p, source, unit);
+
+   switch (operand) {
+   case GL_ONE_MINUS_SRC_COLOR: 
+      /* Get unused tmp,
+       * Emit tmp = 1.0 - arg.xyzw
+       */
+      arg = get_temp( p );
+      one = emit_const1f(p, 1);
+      return emit_arith( p, FP_OPCODE_SUB, arg, mask, 0, one, src, undef);
+
+   case GL_SRC_ALPHA: 
+      if (mask == WRITEMASK_W)
+	 return src;
+      else
+	 return swizzle1( src, W );
+   case GL_ONE_MINUS_SRC_ALPHA: 
+      /* Get unused tmp,
+       * Emit tmp = 1.0 - arg.wwww
+       */
+      arg = get_temp( p );
+      one = emit_const1f(p, 1);
+      return emit_arith( p, FP_OPCODE_SUB, arg, mask, 0,
+			 one, swizzle1(src, W), undef);
+   case GL_SRC_COLOR: 
+   default:
+      return src;
+   }
+}
+
+
+
+static int nr_args( GLenum mode )
+{
+   switch (mode) {
+   case GL_REPLACE: return 1; 
+   case GL_MODULATE: return 2;
+   case GL_ADD: return 2;
+   case GL_ADD_SIGNED: return 2;
+   case GL_INTERPOLATE:	return 3;
+   case GL_SUBTRACT: return 2;
+   case GL_DOT3_RGB_EXT: return 2;
+   case GL_DOT3_RGBA_EXT: return 2;
+   case GL_DOT3_RGB: return 2;
+   case GL_DOT3_RGBA: return 2;
+   default: return 0;
+   }
+}
+
+
+static GLboolean args_match( struct gl_texture_unit *texUnit )
+{
+   int i, nr = nr_args(texUnit->_CurrentCombine->ModeRGB);
+
+   for (i = 0 ; i < nr ; i++) {
+      if (texUnit->_CurrentCombine->SourceA[i] != texUnit->_CurrentCombine->SourceRGB[i]) 
+	 return GL_FALSE;
+
+      switch(texUnit->_CurrentCombine->OperandA[i]) {
+      case GL_SRC_ALPHA: 
+	 switch(texUnit->_CurrentCombine->OperandRGB[i]) {
+	 case GL_SRC_COLOR: 
+	 case GL_SRC_ALPHA: 
+	    break;
+	 default:
+	    return GL_FALSE;
+	 }
+	 break;
+      case GL_ONE_MINUS_SRC_ALPHA: 
+	 switch(texUnit->_CurrentCombine->OperandRGB[i]) {
+	 case GL_ONE_MINUS_SRC_COLOR: 
+	 case GL_ONE_MINUS_SRC_ALPHA: 
+	    break;
+	 default:
+	    return GL_FALSE;
+	 }
+	 break;
+      default: 
+	 return GL_FALSE;	/* impossible */
+      }
+   }
+
+   return GL_TRUE;
+}
+
+
+static struct ureg emit_combine( struct texenv_fragment_program *p,
+			    struct ureg dest,
+			    GLuint mask,
+			    GLuint saturate,
+			    GLuint unit,
+			    GLenum mode,
+			    const GLenum *source,
+			    const GLenum *operand)
+{
+   int nr = nr_args(mode);
+   struct ureg src[3];
+   struct ureg tmp;
+   int i;
+
+   for (i = 0; i < nr; i++)
+      src[i] = emit_combine_source( p, mask, unit, source[i], operand[i] );
+
+   switch (mode) {
+   case GL_REPLACE: 
+      if (mask == WRITEMASK_XYZW && !saturate)
+	 return src[0];
+      else
+	 return emit_arith( p, FP_OPCODE_MOV, dest, mask, saturate, src[0], undef, undef );
+   case GL_MODULATE: 
+      return emit_arith( p, FP_OPCODE_MUL, dest, mask, saturate,
+			     src[0], src[1], undef );
+   case GL_ADD: 
+      return emit_arith( p, FP_OPCODE_ADD, dest, mask, saturate, 
+			     src[0], src[1], undef );
+   case GL_ADD_SIGNED:
+      /* tmp = arg0 + arg1
+       * result = tmp + -.5
+       */
+      tmp = emit_const1f(p, .5);
+      tmp = swizzle1(tmp,X);
+      emit_arith( p, FP_OPCODE_ADD, dest, mask, 0, src[0], src[1], undef );
+      emit_arith( p, FP_OPCODE_SUB, dest, mask, saturate, dest, tmp, undef );
+      return dest;
+   case GL_INTERPOLATE: 
+      /* Arg0 * (Arg2) + Arg1 * (1-Arg2) -- note arguments are reordered:
+       */
+      return emit_arith( p, FP_OPCODE_LRP, dest, mask, saturate, src[2], src[0], src[1] );
+
+   case GL_SUBTRACT: 
+      return emit_arith( p, FP_OPCODE_SUB, dest, mask, saturate, src[0], src[1], undef );
+
+   case GL_DOT3_RGBA:
+   case GL_DOT3_RGBA_EXT: 
+   case GL_DOT3_RGB_EXT:
+   case GL_DOT3_RGB: {
+      struct ureg tmp0 = get_temp( p );
+      struct ureg tmp1 = get_temp( p );
+      struct ureg neg1 = emit_const1f(p, -1);
+      struct ureg two  = emit_const1f(p, 2);
+
+      /* tmp0 = 2*src0 - 1
+       * tmp1 = 2*src1 - 1
+       *
+       * dst = tmp0 dot3 tmp1 
+       */
+      emit_arith( p, FP_OPCODE_MAD, tmp0, WRITEMASK_XYZW, 0, 
+		      two, src[0], neg1);
+
+      if (memcmp(&src[0], &src[1], sizeof(struct ureg)) == 0)
+	 tmp1 = tmp0;
+      else
+	 emit_arith( p, FP_OPCODE_MAD, tmp1, WRITEMASK_XYZW, 0, 
+			 two, src[1], neg1);
+      emit_arith( p, FP_OPCODE_DP3, dest, mask, saturate, tmp0, tmp1, undef);
+      return dest;
+   }
+
+   default: 
+      return src[0];
+   }
+}
+
+static struct ureg get_dest( struct texenv_fragment_program *p, int unit )
+{
+   if (p->ctx->_TriangleCaps & DD_SEPARATE_SPECULAR)
+      return get_temp( p );
+   else if (unit != p->last_tex_stage)
+      return get_temp( p );
+   else
+      return make_ureg(PROGRAM_OUTPUT, VERT_ATTRIB_COLOR0);
+}
+      
+
+
+static struct ureg emit_texenv( struct texenv_fragment_program *p, int unit )
+{
+   struct gl_texture_unit *texUnit = &p->ctx->Texture.Unit[unit];
+   GLuint saturate = (unit < p->last_tex_stage);
+   GLuint rgb_shift, alpha_shift;
+   struct ureg out, shift;
+   struct ureg dest = get_dest(p, unit);
+
+   if (!texUnit->_ReallyEnabled) {
+      return get_source(p, GL_PREVIOUS, 0);
+   }
+
+   switch (texUnit->_CurrentCombine->ModeRGB) {
+   case GL_DOT3_RGB_EXT:
+      alpha_shift = texUnit->_CurrentCombine->ScaleShiftA;
+      rgb_shift = 0;
+      break;
+
+   case GL_DOT3_RGBA_EXT:
+      alpha_shift = 0;
+      rgb_shift = 0;
+      break;
+
+   default:
+      rgb_shift = texUnit->_CurrentCombine->ScaleShiftRGB;
+      alpha_shift = texUnit->_CurrentCombine->ScaleShiftA;
+      break;
+   }
+
+
+   /* Emit the RGB and A combine ops
+    */
+   if (texUnit->_CurrentCombine->ModeRGB == texUnit->_CurrentCombine->ModeA && 
+       args_match( texUnit )) {
+      out = emit_combine( p, dest, WRITEMASK_XYZW, saturate,
+			  unit,
+			  texUnit->_CurrentCombine->ModeRGB,
+			  texUnit->_CurrentCombine->SourceRGB,
+			  texUnit->_CurrentCombine->OperandRGB );
+   }
+   else if (texUnit->_CurrentCombine->ModeRGB == GL_DOT3_RGBA_EXT ||
+	    texUnit->_CurrentCombine->ModeRGB == GL_DOT3_RGBA) {
+
+      out = emit_combine( p, dest, WRITEMASK_XYZW, saturate,
+			  unit,
+			  texUnit->_CurrentCombine->ModeRGB,
+			  texUnit->_CurrentCombine->SourceRGB,
+			  texUnit->_CurrentCombine->OperandRGB );
+   }
+   else {
+      /* Need to do something to stop from re-emitting identical
+       * argument calculations here:
+       */
+      out = emit_combine( p, dest, WRITEMASK_XYZ, saturate,
+			  unit,
+			  texUnit->_CurrentCombine->ModeRGB,
+			  texUnit->_CurrentCombine->SourceRGB,
+			  texUnit->_CurrentCombine->OperandRGB );
+      out = emit_combine( p, dest, WRITEMASK_W, saturate,
+			  unit,
+			  texUnit->_CurrentCombine->ModeA,
+			  texUnit->_CurrentCombine->SourceA,
+			  texUnit->_CurrentCombine->OperandA );
+   }
+
+   /* Deal with the final shift:
+    */
+   if (alpha_shift || rgb_shift) {
+      if (rgb_shift == alpha_shift) {
+	 shift = emit_const1f(p, 1<<rgb_shift);
+	 shift = swizzle1(shift,X);
+      }
+      else {
+	 shift = emit_const2f(p, 1<<rgb_shift, 1<<alpha_shift);
+	 shift = swizzle(shift,X,X,X,Y);
+      }
+      return emit_arith( p, FP_OPCODE_MUL, dest, WRITEMASK_XYZW, 
+			 saturate, out, shift, undef );
+   }
+   else
+      return out;
+}
+
+void _mesa_UpdateTexEnvProgram( GLcontext *ctx )
+{
+   struct texenv_fragment_program p;
+   GLuint unit;
+   struct ureg cf, out;
+
+   p.ctx = ctx;
+   p.prog = &ctx->_TexEnvProgram;
+
+   if (p.prog->Instructions == NULL) {
+      p.prog->Instructions = MALLOC(sizeof(struct fp_instruction) * 100);
+   }
+
+   p.prog->Base.NumInstructions = 0;
+   p.prog->NumTexIndirections = 1;	/* correct? */
+   p.prog->NumTexInstructions = 0;
+   p.prog->NumAluInstructions = 0;
+
+   memset( p.constant_flags, 0, sizeof(p.constant_flags) );
+
+   p.src_texture = undef;
+   p.src_previous = make_ureg(PROGRAM_INPUT, VERT_ATTRIB_COLOR0);
+   p.last_tex_stage = 0;
+
+   if (ctx->Texture._EnabledUnits) {
+      for (unit = 0 ; unit < ctx->Const.MaxTextureUnits ; unit++)
+	 if (ctx->Texture.Unit[unit]._ReallyEnabled) {
+	    p.last_tex_stage = unit;
+	 }
+
+      for (unit = 0 ; unit < ctx->Const.MaxTextureUnits; unit++)
+	 if (ctx->Texture.Unit[unit]._ReallyEnabled) {
+	    p.src_previous = emit_texenv( &p, unit );
+	    p.src_texture = undef;
+	    p.temp_flag = 0xffff000;
+	    p.temp_flag |= 1 << p.src_previous.idx;
+	 }
+   }
+
+   cf = get_source( &p, GL_PREVIOUS, 0 );
+   out = make_ureg( PROGRAM_OUTPUT, VERT_ATTRIB_COLOR0 );
+
+   if (ctx->_TriangleCaps & DD_SEPARATE_SPECULAR) {
+      /* Emit specular add.
+       */
+      struct ureg s = emit_decl(&p, PROGRAM_INPUT, VERT_ATTRIB_COLOR1);
+      emit_arith( &p, FP_OPCODE_ADD, out, WRITEMASK_XYZ, 0, cf, s, undef );
+   }
+   else if (memcmp(&cf, &out, sizeof(cf)) != 0) {
+      /* Will wind up in here if no texture enabled or a couple of
+       * other scenarios (GL_REPLACE for instance).
+       */
+      emit_arith( &p, FP_OPCODE_MOV, out, WRITEMASK_XYZW, 0, cf, undef, undef );
+   }
+
+   if (p.prog->NumTexIndirections > ctx->Const.MaxFragmentProgramTexIndirections) 
+      program_error(&p, "Exceeded max nr indirect texture lookups");
+
+   if (p.prog->NumTexInstructions > ctx->Const.MaxFragmentProgramTexInstructions)
+      program_error(&p, "Exceeded max TEX instructions");
+
+   if (p.prog->NumAluInstructions > ctx->Const.MaxFragmentProgramAluInstructions)
+      program_error(&p, "Exceeded max ALU instructions");
+
+#if DISASSEM
+   _mesa_debug_fp_inst(p.prog->NumTexInstructions + p.prog->NumAluInstructions,
+		       p.prog->Instructions);
+   _mesa_printf("\n");
+#endif
+}
+
+