/*
 * Mesa 3-D graphics library
 *
 * Copyright (C) 1999-2007  Brian Paul   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, sublicense,
 * 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 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 NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS 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.
 */

/**
 * \file prog_statevars.c
 * Program state variable management.
 * \author Brian Paul
 */


#include "main/glheader.h"
#include "main/context.h"
#include "main/blend.h"
#include "main/imports.h"
#include "main/macros.h"
#include "main/mtypes.h"
#include "main/fbobject.h"
#include "prog_statevars.h"
#include "prog_parameter.h"
#include "main/samplerobj.h"


/**
 * Use the list of tokens in the state[] array to find global GL state
 * and return it in <value>.  Usually, four values are returned in <value>
 * but matrix queries may return as many as 16 values.
 * This function is used for ARB vertex/fragment programs.
 * The program parser will produce the state[] values.
 */
static void
_mesa_fetch_state(struct gl_context *ctx, const gl_state_index state[],
                  GLfloat *value)
{
   switch (state[0]) {
   case STATE_MATERIAL:
      {
         /* state[1] is either 0=front or 1=back side */
         const GLuint face = (GLuint) state[1];
         const struct gl_material *mat = &ctx->Light.Material;
         ASSERT(face == 0 || face == 1);
         /* we rely on tokens numbered so that _BACK_ == _FRONT_+ 1 */
         ASSERT(MAT_ATTRIB_FRONT_AMBIENT + 1 == MAT_ATTRIB_BACK_AMBIENT);
         /* XXX we could get rid of this switch entirely with a little
          * work in arbprogparse.c's parse_state_single_item().
          */
         /* state[2] is the material attribute */
         switch (state[2]) {
         case STATE_AMBIENT:
            COPY_4V(value, mat->Attrib[MAT_ATTRIB_FRONT_AMBIENT + face]);
            return;
         case STATE_DIFFUSE:
            COPY_4V(value, mat->Attrib[MAT_ATTRIB_FRONT_DIFFUSE + face]);
            return;
         case STATE_SPECULAR:
            COPY_4V(value, mat->Attrib[MAT_ATTRIB_FRONT_SPECULAR + face]);
            return;
         case STATE_EMISSION:
            COPY_4V(value, mat->Attrib[MAT_ATTRIB_FRONT_EMISSION + face]);
            return;
         case STATE_SHININESS:
            value[0] = mat->Attrib[MAT_ATTRIB_FRONT_SHININESS + face][0];
            value[1] = 0.0F;
            value[2] = 0.0F;
            value[3] = 1.0F;
            return;
         default:
            _mesa_problem(ctx, "Invalid material state in fetch_state");
            return;
         }
      }
   case STATE_LIGHT:
      {
         /* state[1] is the light number */
         const GLuint ln = (GLuint) state[1];
         /* state[2] is the light attribute */
         switch (state[2]) {
         case STATE_AMBIENT:
            COPY_4V(value, ctx->Light.Light[ln].Ambient);
            return;
         case STATE_DIFFUSE:
            COPY_4V(value, ctx->Light.Light[ln].Diffuse);
            return;
         case STATE_SPECULAR:
            COPY_4V(value, ctx->Light.Light[ln].Specular);
            return;
         case STATE_POSITION:
            COPY_4V(value, ctx->Light.Light[ln].EyePosition);
            return;
         case STATE_ATTENUATION:
            value[0] = ctx->Light.Light[ln].ConstantAttenuation;
            value[1] = ctx->Light.Light[ln].LinearAttenuation;
            value[2] = ctx->Light.Light[ln].QuadraticAttenuation;
            value[3] = ctx->Light.Light[ln].SpotExponent;
            return;
         case STATE_SPOT_DIRECTION:
            COPY_3V(value, ctx->Light.Light[ln].SpotDirection);
            value[3] = ctx->Light.Light[ln]._CosCutoff;
            return;
         case STATE_SPOT_CUTOFF:
            value[0] = ctx->Light.Light[ln].SpotCutoff;
            return;
         case STATE_HALF_VECTOR:
            {
               static const GLfloat eye_z[] = {0, 0, 1};
               GLfloat p[3];
               /* Compute infinite half angle vector:
                *   halfVector = normalize(normalize(lightPos) + (0, 0, 1))
		* light.EyePosition.w should be 0 for infinite lights.
                */
               COPY_3V(p, ctx->Light.Light[ln].EyePosition);
               NORMALIZE_3FV(p);
	       ADD_3V(value, p, eye_z);
	       NORMALIZE_3FV(value);
	       value[3] = 1.0;
            }
            return;
         default:
            _mesa_problem(ctx, "Invalid light state in fetch_state");
            return;
         }
      }
   case STATE_LIGHTMODEL_AMBIENT:
      COPY_4V(value, ctx->Light.Model.Ambient);
      return;
   case STATE_LIGHTMODEL_SCENECOLOR:
      if (state[1] == 0) {
         /* front */
         GLint i;
         for (i = 0; i < 3; i++) {
            value[i] = ctx->Light.Model.Ambient[i]
               * ctx->Light.Material.Attrib[MAT_ATTRIB_FRONT_AMBIENT][i]
               + ctx->Light.Material.Attrib[MAT_ATTRIB_FRONT_EMISSION][i];
         }
	 value[3] = ctx->Light.Material.Attrib[MAT_ATTRIB_FRONT_DIFFUSE][3];
      }
      else {
         /* back */
         GLint i;
         for (i = 0; i < 3; i++) {
            value[i] = ctx->Light.Model.Ambient[i]
               * ctx->Light.Material.Attrib[MAT_ATTRIB_BACK_AMBIENT][i]
               + ctx->Light.Material.Attrib[MAT_ATTRIB_BACK_EMISSION][i];
         }
	 value[3] = ctx->Light.Material.Attrib[MAT_ATTRIB_BACK_DIFFUSE][3];
      }
      return;
   case STATE_LIGHTPROD:
      {
         const GLuint ln = (GLuint) state[1];
         const GLuint face = (GLuint) state[2];
         GLint i;
         ASSERT(face == 0 || face == 1);
         switch (state[3]) {
            case STATE_AMBIENT:
               for (i = 0; i < 3; i++) {
                  value[i] = ctx->Light.Light[ln].Ambient[i] *
                     ctx->Light.Material.Attrib[MAT_ATTRIB_FRONT_AMBIENT+face][i];
               }
               /* [3] = material alpha */
               value[3] = ctx->Light.Material.Attrib[MAT_ATTRIB_FRONT_AMBIENT+face][3];
               return;
            case STATE_DIFFUSE:
               for (i = 0; i < 3; i++) {
                  value[i] = ctx->Light.Light[ln].Diffuse[i] *
                     ctx->Light.Material.Attrib[MAT_ATTRIB_FRONT_DIFFUSE+face][i];
               }
               /* [3] = material alpha */
               value[3] = ctx->Light.Material.Attrib[MAT_ATTRIB_FRONT_DIFFUSE+face][3];
               return;
            case STATE_SPECULAR:
               for (i = 0; i < 3; i++) {
                  value[i] = ctx->Light.Light[ln].Specular[i] *
                     ctx->Light.Material.Attrib[MAT_ATTRIB_FRONT_SPECULAR+face][i];
               }
               /* [3] = material alpha */
               value[3] = ctx->Light.Material.Attrib[MAT_ATTRIB_FRONT_SPECULAR+face][3];
               return;
            default:
               _mesa_problem(ctx, "Invalid lightprod state in fetch_state");
               return;
         }
      }
   case STATE_TEXGEN:
      {
         /* state[1] is the texture unit */
         const GLuint unit = (GLuint) state[1];
         /* state[2] is the texgen attribute */
         switch (state[2]) {
         case STATE_TEXGEN_EYE_S:
            COPY_4V(value, ctx->Texture.Unit[unit].GenS.EyePlane);
            return;
         case STATE_TEXGEN_EYE_T:
            COPY_4V(value, ctx->Texture.Unit[unit].GenT.EyePlane);
            return;
         case STATE_TEXGEN_EYE_R:
            COPY_4V(value, ctx->Texture.Unit[unit].GenR.EyePlane);
            return;
         case STATE_TEXGEN_EYE_Q:
            COPY_4V(value, ctx->Texture.Unit[unit].GenQ.EyePlane);
            return;
         case STATE_TEXGEN_OBJECT_S:
            COPY_4V(value, ctx->Texture.Unit[unit].GenS.ObjectPlane);
            return;
         case STATE_TEXGEN_OBJECT_T:
            COPY_4V(value, ctx->Texture.Unit[unit].GenT.ObjectPlane);
            return;
         case STATE_TEXGEN_OBJECT_R:
            COPY_4V(value, ctx->Texture.Unit[unit].GenR.ObjectPlane);
            return;
         case STATE_TEXGEN_OBJECT_Q:
            COPY_4V(value, ctx->Texture.Unit[unit].GenQ.ObjectPlane);
            return;
         default:
            _mesa_problem(ctx, "Invalid texgen state in fetch_state");
            return;
         }
      }
   case STATE_TEXENV_COLOR:
      {
         /* state[1] is the texture unit */
         const GLuint unit = (GLuint) state[1];
         if (_mesa_get_clamp_fragment_color(ctx))
            COPY_4V(value, ctx->Texture.Unit[unit].EnvColor);
         else
            COPY_4V(value, ctx->Texture.Unit[unit].EnvColorUnclamped);
      }
      return;
   case STATE_FOG_COLOR:
      if (_mesa_get_clamp_fragment_color(ctx))
         COPY_4V(value, ctx->Fog.Color);
      else
         COPY_4V(value, ctx->Fog.ColorUnclamped);
      return;
   case STATE_FOG_PARAMS:
      value[0] = ctx->Fog.Density;
      value[1] = ctx->Fog.Start;
      value[2] = ctx->Fog.End;
      value[3] = 1.0f / (ctx->Fog.End - ctx->Fog.Start);
      return;
   case STATE_CLIPPLANE:
      {
         const GLuint plane = (GLuint) state[1];
         COPY_4V(value, ctx->Transform.EyeUserPlane[plane]);
      }
      return;
   case STATE_POINT_SIZE:
      value[0] = ctx->Point.Size;
      value[1] = ctx->Point.MinSize;
      value[2] = ctx->Point.MaxSize;
      value[3] = ctx->Point.Threshold;
      return;
   case STATE_POINT_ATTENUATION:
      value[0] = ctx->Point.Params[0];
      value[1] = ctx->Point.Params[1];
      value[2] = ctx->Point.Params[2];
      value[3] = 1.0F;
      return;
   case STATE_MODELVIEW_MATRIX:
   case STATE_PROJECTION_MATRIX:
   case STATE_MVP_MATRIX:
   case STATE_TEXTURE_MATRIX:
   case STATE_PROGRAM_MATRIX:
      {
         /* state[0] = modelview, projection, texture, etc. */
         /* state[1] = which texture matrix or program matrix */
         /* state[2] = first row to fetch */
         /* state[3] = last row to fetch */
         /* state[4] = transpose, inverse or invtrans */
         const GLmatrix *matrix;
         const gl_state_index mat = state[0];
         const GLuint index = (GLuint) state[1];
         const GLuint firstRow = (GLuint) state[2];
         const GLuint lastRow = (GLuint) state[3];
         const gl_state_index modifier = state[4];
         const GLfloat *m;
         GLuint row, i;
         ASSERT(firstRow >= 0);
         ASSERT(firstRow < 4);
         ASSERT(lastRow >= 0);
         ASSERT(lastRow < 4);
         if (mat == STATE_MODELVIEW_MATRIX) {
            matrix = ctx->ModelviewMatrixStack.Top;
         }
         else if (mat == STATE_PROJECTION_MATRIX) {
            matrix = ctx->ProjectionMatrixStack.Top;
         }
         else if (mat == STATE_MVP_MATRIX) {
            matrix = &ctx->_ModelProjectMatrix;
         }
         else if (mat == STATE_TEXTURE_MATRIX) {
            ASSERT(index < Elements(ctx->TextureMatrixStack));
            matrix = ctx->TextureMatrixStack[index].Top;
         }
         else if (mat == STATE_PROGRAM_MATRIX) {
            ASSERT(index < Elements(ctx->ProgramMatrixStack));
            matrix = ctx->ProgramMatrixStack[index].Top;
         }
         else {
            _mesa_problem(ctx, "Bad matrix name in _mesa_fetch_state()");
            return;
         }
         if (modifier == STATE_MATRIX_INVERSE ||
             modifier == STATE_MATRIX_INVTRANS) {
            /* Be sure inverse is up to date:
	     */
	    _math_matrix_analyse( (GLmatrix*) matrix );
            m = matrix->inv;
         }
         else {
            m = matrix->m;
         }
         if (modifier == STATE_MATRIX_TRANSPOSE ||
             modifier == STATE_MATRIX_INVTRANS) {
            for (i = 0, row = firstRow; row <= lastRow; row++) {
               value[i++] = m[row * 4 + 0];
               value[i++] = m[row * 4 + 1];
               value[i++] = m[row * 4 + 2];
               value[i++] = m[row * 4 + 3];
            }
         }
         else {
            for (i = 0, row = firstRow; row <= lastRow; row++) {
               value[i++] = m[row + 0];
               value[i++] = m[row + 4];
               value[i++] = m[row + 8];
               value[i++] = m[row + 12];
            }
         }
      }
      return;
   case STATE_NUM_SAMPLES:
      ((int *)value)[0] = ctx->DrawBuffer->Visual.samples;
      return;
   case STATE_DEPTH_RANGE:
      value[0] = ctx->ViewportArray[0].Near;                /* near       */
      value[1] = ctx->ViewportArray[0].Far;                 /* far        */
      value[2] = ctx->ViewportArray[0].Far - ctx->ViewportArray[0].Near; /* far - near */
      value[3] = 1.0;
      return;
   case STATE_FRAGMENT_PROGRAM:
      {
         /* state[1] = {STATE_ENV, STATE_LOCAL} */
         /* state[2] = parameter index          */
         const int idx = (int) state[2];
         switch (state[1]) {
            case STATE_ENV:
               COPY_4V(value, ctx->FragmentProgram.Parameters[idx]);
               return;
            case STATE_LOCAL:
               if (!ctx->FragmentProgram.Current->Base.LocalParams) {
                  ctx->FragmentProgram.Current->Base.LocalParams =
                     calloc(MAX_PROGRAM_LOCAL_PARAMS, sizeof(float[4]));
                  if (!ctx->FragmentProgram.Current->Base.LocalParams)
                     return;
               }

               COPY_4V(value, ctx->FragmentProgram.Current->Base.LocalParams[idx]);
               return;
            default:
               _mesa_problem(ctx, "Bad state switch in _mesa_fetch_state()");
               return;
         }
      }
      return;

   case STATE_VERTEX_PROGRAM:
      {
         /* state[1] = {STATE_ENV, STATE_LOCAL} */
         /* state[2] = parameter index          */
         const int idx = (int) state[2];
         switch (state[1]) {
            case STATE_ENV:
               COPY_4V(value, ctx->VertexProgram.Parameters[idx]);
               return;
            case STATE_LOCAL:
               if (!ctx->VertexProgram.Current->Base.LocalParams) {
                  ctx->VertexProgram.Current->Base.LocalParams =
                     calloc(MAX_PROGRAM_LOCAL_PARAMS, sizeof(float[4]));
                  if (!ctx->VertexProgram.Current->Base.LocalParams)
                     return;
               }

               COPY_4V(value, ctx->VertexProgram.Current->Base.LocalParams[idx]);
               return;
            default:
               _mesa_problem(ctx, "Bad state switch in _mesa_fetch_state()");
               return;
         }
      }
      return;

   case STATE_NORMAL_SCALE:
      ASSIGN_4V(value, ctx->_ModelViewInvScale, 0, 0, 1);
      return;

   case STATE_INTERNAL:
      switch (state[1]) {
      case STATE_CURRENT_ATTRIB:
         {
            const GLuint idx = (GLuint) state[2];
            COPY_4V(value, ctx->Current.Attrib[idx]);
         }
         return;

      case STATE_CURRENT_ATTRIB_MAYBE_VP_CLAMPED:
         {
            const GLuint idx = (GLuint) state[2];
            if(ctx->Light._ClampVertexColor &&
               (idx == VERT_ATTRIB_COLOR0 ||
                idx == VERT_ATTRIB_COLOR1)) {
               value[0] = CLAMP(ctx->Current.Attrib[idx][0], 0.0f, 1.0f);
               value[1] = CLAMP(ctx->Current.Attrib[idx][1], 0.0f, 1.0f);
               value[2] = CLAMP(ctx->Current.Attrib[idx][2], 0.0f, 1.0f);
               value[3] = CLAMP(ctx->Current.Attrib[idx][3], 0.0f, 1.0f);
            }
            else
               COPY_4V(value, ctx->Current.Attrib[idx]);
         }
         return;

      case STATE_NORMAL_SCALE:
         ASSIGN_4V(value, 
                   ctx->_ModelViewInvScale, 
                   ctx->_ModelViewInvScale, 
                   ctx->_ModelViewInvScale, 
                   1);
         return;

      case STATE_TEXRECT_SCALE:
         /* Value = { 1/texWidth, 1/texHeight, 0, 1 }.
          * Used to convert unnormalized texcoords to normalized texcoords.
          */
         {
            const int unit = (int) state[2];
            const struct gl_texture_object *texObj
               = ctx->Texture.Unit[unit]._Current;
            if (texObj) {
               struct gl_texture_image *texImage = texObj->Image[0][0];
               ASSIGN_4V(value,
                         (GLfloat) (1.0 / texImage->Width),
                         (GLfloat) (1.0 / texImage->Height),
                         0.0f, 1.0f);
            }
         }
         return;

      case STATE_FOG_PARAMS_OPTIMIZED:
         /* for simpler per-vertex/pixel fog calcs. POW (for EXP/EXP2 fog)
          * might be more expensive than EX2 on some hw, plus it needs
          * another constant (e) anyway. Linear fog can now be done with a
          * single MAD.
          * linear: fogcoord * -1/(end-start) + end/(end-start)
          * exp: 2^-(density/ln(2) * fogcoord)
          * exp2: 2^-((density/(ln(2)^2) * fogcoord)^2)
          */
         value[0] = (ctx->Fog.End == ctx->Fog.Start)
            ? 1.0f : (GLfloat)(-1.0F / (ctx->Fog.End - ctx->Fog.Start));
         value[1] = ctx->Fog.End * -value[0];
         value[2] = (GLfloat)(ctx->Fog.Density * M_LOG2E); /* M_LOG2E == 1/ln(2) */
         value[3] = (GLfloat)(ctx->Fog.Density * ONE_DIV_SQRT_LN2);
         return;

      case STATE_POINT_SIZE_CLAMPED:
         {
           /* this includes implementation dependent limits, to avoid
            * another potentially necessary clamp.
            * Note: for sprites, point smooth (point AA) is ignored
            * and we'll clamp to MinPointSizeAA and MaxPointSize, because we
            * expect drivers will want to say their minimum for AA size is 0.0
            * but for non-AA it's 1.0 (because normal points with size below 1.0
            * need to get rounded up to 1.0, hence never disappear). GL does
            * not specify max clamp size for sprites, other than it needs to be
            * at least as large as max AA size, hence use non-AA size there.
            */
            GLfloat minImplSize;
            GLfloat maxImplSize;
            if (ctx->Point.PointSprite) {
               minImplSize = ctx->Const.MinPointSizeAA;
               maxImplSize = ctx->Const.MaxPointSize;
            }
            else if (ctx->Point.SmoothFlag || ctx->Multisample._Enabled) {
               minImplSize = ctx->Const.MinPointSizeAA;
               maxImplSize = ctx->Const.MaxPointSizeAA;
            }
            else {
               minImplSize = ctx->Const.MinPointSize;
               maxImplSize = ctx->Const.MaxPointSize;
            }
            value[0] = ctx->Point.Size;
            value[1] = ctx->Point.MinSize >= minImplSize ? ctx->Point.MinSize : minImplSize;
            value[2] = ctx->Point.MaxSize <= maxImplSize ? ctx->Point.MaxSize : maxImplSize;
            value[3] = ctx->Point.Threshold;
         }
         return;
      case STATE_LIGHT_SPOT_DIR_NORMALIZED:
         {
            /* here, state[2] is the light number */
            /* pre-normalize spot dir */
            const GLuint ln = (GLuint) state[2];
            COPY_3V(value, ctx->Light.Light[ln]._NormSpotDirection);
            value[3] = ctx->Light.Light[ln]._CosCutoff;
         }
         return;

      case STATE_LIGHT_POSITION:
         {
            const GLuint ln = (GLuint) state[2];
            COPY_4V(value, ctx->Light.Light[ln]._Position);
         }
         return;

      case STATE_LIGHT_POSITION_NORMALIZED:
         {
            const GLuint ln = (GLuint) state[2];
            COPY_4V(value, ctx->Light.Light[ln]._Position);
            NORMALIZE_3FV( value );
         }
         return;

      case STATE_LIGHT_HALF_VECTOR:
         {
            const GLuint ln = (GLuint) state[2];
            GLfloat p[3];
            /* Compute infinite half angle vector:
             *   halfVector = normalize(normalize(lightPos) + (0, 0, 1))
             * light.EyePosition.w should be 0 for infinite lights.
             */
            COPY_3V(p, ctx->Light.Light[ln]._Position);
            NORMALIZE_3FV(p);
            ADD_3V(value, p, ctx->_EyeZDir);
            NORMALIZE_3FV(value);
            value[3] = 1.0;
         }
         return;

      case STATE_PT_SCALE:
         value[0] = ctx->Pixel.RedScale;
         value[1] = ctx->Pixel.GreenScale;
         value[2] = ctx->Pixel.BlueScale;
         value[3] = ctx->Pixel.AlphaScale;
         return;

      case STATE_PT_BIAS:
         value[0] = ctx->Pixel.RedBias;
         value[1] = ctx->Pixel.GreenBias;
         value[2] = ctx->Pixel.BlueBias;
         value[3] = ctx->Pixel.AlphaBias;
         return;

      case STATE_FB_SIZE:
         value[0] = (GLfloat) (ctx->DrawBuffer->Width - 1);
         value[1] = (GLfloat) (ctx->DrawBuffer->Height - 1);
         value[2] = 0.0F;
         value[3] = 0.0F;
         return;

      case STATE_FB_WPOS_Y_TRANSFORM:
         /* A driver may negate this conditional by using ZW swizzle
          * instead of XY (based on e.g. some other state). */
         if (_mesa_is_user_fbo(ctx->DrawBuffer)) {
            /* Identity (XY) followed by flipping Y upside down (ZW). */
            value[0] = 1.0F;
            value[1] = 0.0F;
            value[2] = -1.0F;
            value[3] = (GLfloat) ctx->DrawBuffer->Height;
         } else {
            /* Flipping Y upside down (XY) followed by identity (ZW). */
            value[0] = -1.0F;
            value[1] = (GLfloat) ctx->DrawBuffer->Height;
            value[2] = 1.0F;
            value[3] = 0.0F;
         }
         return;

      case STATE_ROT_MATRIX_0:
         {
            const int unit = (int) state[2];
            GLfloat *rotMat22 = ctx->Texture.Unit[unit].RotMatrix;
            value[0] = rotMat22[0]; 
            value[1] = rotMat22[2];
            value[2] = 0.0;
            value[3] = 0.0;
         }
         return;

      case STATE_ROT_MATRIX_1:
         {
            const int unit = (int) state[2];
            GLfloat *rotMat22 = ctx->Texture.Unit[unit].RotMatrix;
            value[0] = rotMat22[1];
            value[1] = rotMat22[3];
            value[2] = 0.0;
            value[3] = 0.0;
         }
         return;

      /* XXX: make sure new tokens added here are also handled in the 
       * _mesa_program_state_flags() switch, below.
       */
      default:
         /* Unknown state indexes are silently ignored here.
          * Drivers may do something special.
          */
         return;
      }
      return;

   default:
      _mesa_problem(ctx, "Invalid state in _mesa_fetch_state");
      return;
   }
}


/**
 * Return a bitmask of the Mesa state flags (_NEW_* values) which would
 * indicate that the given context state may have changed.
 * The bitmask is used during validation to determine if we need to update
 * vertex/fragment program parameters (like "state.material.color") when
 * some GL state has changed.
 */
GLbitfield
_mesa_program_state_flags(const gl_state_index state[STATE_LENGTH])
{
   switch (state[0]) {
   case STATE_MATERIAL:
   case STATE_LIGHTPROD:
   case STATE_LIGHTMODEL_SCENECOLOR:
      /* these can be effected by glColor when colormaterial mode is used */
      return _NEW_LIGHT | _NEW_CURRENT_ATTRIB;

   case STATE_LIGHT:
   case STATE_LIGHTMODEL_AMBIENT:
      return _NEW_LIGHT;

   case STATE_TEXGEN:
      return _NEW_TEXTURE;
   case STATE_TEXENV_COLOR:
      return _NEW_TEXTURE | _NEW_BUFFERS | _NEW_FRAG_CLAMP;

   case STATE_FOG_COLOR:
      return _NEW_FOG | _NEW_BUFFERS | _NEW_FRAG_CLAMP;
   case STATE_FOG_PARAMS:
      return _NEW_FOG;

   case STATE_CLIPPLANE:
      return _NEW_TRANSFORM;

   case STATE_POINT_SIZE:
   case STATE_POINT_ATTENUATION:
      return _NEW_POINT;

   case STATE_MODELVIEW_MATRIX:
      return _NEW_MODELVIEW;
   case STATE_PROJECTION_MATRIX:
      return _NEW_PROJECTION;
   case STATE_MVP_MATRIX:
      return _NEW_MODELVIEW | _NEW_PROJECTION;
   case STATE_TEXTURE_MATRIX:
      return _NEW_TEXTURE_MATRIX;
   case STATE_PROGRAM_MATRIX:
      return _NEW_TRACK_MATRIX;

   case STATE_NUM_SAMPLES:
      return _NEW_BUFFERS;

   case STATE_DEPTH_RANGE:
      return _NEW_VIEWPORT;

   case STATE_FRAGMENT_PROGRAM:
   case STATE_VERTEX_PROGRAM:
      return _NEW_PROGRAM;

   case STATE_NORMAL_SCALE:
      return _NEW_MODELVIEW;

   case STATE_INTERNAL:
      switch (state[1]) {
      case STATE_CURRENT_ATTRIB:
         return _NEW_CURRENT_ATTRIB;
      case STATE_CURRENT_ATTRIB_MAYBE_VP_CLAMPED:
         return _NEW_CURRENT_ATTRIB | _NEW_LIGHT | _NEW_BUFFERS;

      case STATE_NORMAL_SCALE:
         return _NEW_MODELVIEW;

      case STATE_TEXRECT_SCALE:
      case STATE_ROT_MATRIX_0:
      case STATE_ROT_MATRIX_1:
	 return _NEW_TEXTURE;
      case STATE_FOG_PARAMS_OPTIMIZED:
	 return _NEW_FOG;
      case STATE_POINT_SIZE_CLAMPED:
         return _NEW_POINT | _NEW_MULTISAMPLE;
      case STATE_LIGHT_SPOT_DIR_NORMALIZED:
      case STATE_LIGHT_POSITION:
      case STATE_LIGHT_POSITION_NORMALIZED:
      case STATE_LIGHT_HALF_VECTOR:
         return _NEW_LIGHT;

      case STATE_PT_SCALE:
      case STATE_PT_BIAS:
         return _NEW_PIXEL;

      case STATE_FB_SIZE:
      case STATE_FB_WPOS_Y_TRANSFORM:
         return _NEW_BUFFERS;

      default:
         /* unknown state indexes are silently ignored and
         *  no flag set, since it is handled by the driver.
         */
	 return 0;
      }

   default:
      _mesa_problem(NULL, "unexpected state[0] in make_state_flags()");
      return 0;
   }
}


static void
append(char *dst, const char *src)
{
   while (*dst)
      dst++;
   while (*src)
     *dst++ = *src++;
   *dst = 0;
}


/**
 * Convert token 'k' to a string, append it onto 'dst' string.
 */
static void
append_token(char *dst, gl_state_index k)
{
   switch (k) {
   case STATE_MATERIAL:
      append(dst, "material");
      break;
   case STATE_LIGHT:
      append(dst, "light");
      break;
   case STATE_LIGHTMODEL_AMBIENT:
      append(dst, "lightmodel.ambient");
      break;
   case STATE_LIGHTMODEL_SCENECOLOR:
      break;
   case STATE_LIGHTPROD:
      append(dst, "lightprod");
      break;
   case STATE_TEXGEN:
      append(dst, "texgen");
      break;
   case STATE_FOG_COLOR:
      append(dst, "fog.color");
      break;
   case STATE_FOG_PARAMS:
      append(dst, "fog.params");
      break;
   case STATE_CLIPPLANE:
      append(dst, "clip");
      break;
   case STATE_POINT_SIZE:
      append(dst, "point.size");
      break;
   case STATE_POINT_ATTENUATION:
      append(dst, "point.attenuation");
      break;
   case STATE_MODELVIEW_MATRIX:
      append(dst, "matrix.modelview");
      break;
   case STATE_PROJECTION_MATRIX:
      append(dst, "matrix.projection");
      break;
   case STATE_MVP_MATRIX:
      append(dst, "matrix.mvp");
      break;
   case STATE_TEXTURE_MATRIX:
      append(dst, "matrix.texture");
      break;
   case STATE_PROGRAM_MATRIX:
      append(dst, "matrix.program");
      break;
   case STATE_MATRIX_INVERSE:
      append(dst, ".inverse");
      break;
   case STATE_MATRIX_TRANSPOSE:
      append(dst, ".transpose");
      break;
   case STATE_MATRIX_INVTRANS:
      append(dst, ".invtrans");
      break;
   case STATE_AMBIENT:
      append(dst, ".ambient");
      break;
   case STATE_DIFFUSE:
      append(dst, ".diffuse");
      break;
   case STATE_SPECULAR:
      append(dst, ".specular");
      break;
   case STATE_EMISSION:
      append(dst, ".emission");
      break;
   case STATE_SHININESS:
      append(dst, "lshininess");
      break;
   case STATE_HALF_VECTOR:
      append(dst, ".half");
      break;
   case STATE_POSITION:
      append(dst, ".position");
      break;
   case STATE_ATTENUATION:
      append(dst, ".attenuation");
      break;
   case STATE_SPOT_DIRECTION:
      append(dst, ".spot.direction");
      break;
   case STATE_SPOT_CUTOFF:
      append(dst, ".spot.cutoff");
      break;
   case STATE_TEXGEN_EYE_S:
      append(dst, ".eye.s");
      break;
   case STATE_TEXGEN_EYE_T:
      append(dst, ".eye.t");
      break;
   case STATE_TEXGEN_EYE_R:
      append(dst, ".eye.r");
      break;
   case STATE_TEXGEN_EYE_Q:
      append(dst, ".eye.q");
      break;
   case STATE_TEXGEN_OBJECT_S:
      append(dst, ".object.s");
      break;
   case STATE_TEXGEN_OBJECT_T:
      append(dst, ".object.t");
      break;
   case STATE_TEXGEN_OBJECT_R:
      append(dst, ".object.r");
      break;
   case STATE_TEXGEN_OBJECT_Q:
      append(dst, ".object.q");
      break;
   case STATE_TEXENV_COLOR:
      append(dst, "texenv");
      break;
   case STATE_NUM_SAMPLES:
      append(dst, "numsamples");
      break;
   case STATE_DEPTH_RANGE:
      append(dst, "depth.range");
      break;
   case STATE_VERTEX_PROGRAM:
   case STATE_FRAGMENT_PROGRAM:
      break;
   case STATE_ENV:
      append(dst, "env");
      break;
   case STATE_LOCAL:
      append(dst, "local");
      break;
   /* BEGIN internal state vars */
   case STATE_INTERNAL:
      append(dst, ".internal.");
      break;
   case STATE_CURRENT_ATTRIB:
      append(dst, "current");
      break;
   case STATE_CURRENT_ATTRIB_MAYBE_VP_CLAMPED:
      append(dst, "currentAttribMaybeVPClamped");
      break;
   case STATE_NORMAL_SCALE:
      append(dst, "normalScale");
      break;
   case STATE_TEXRECT_SCALE:
      append(dst, "texrectScale");
      break;
   case STATE_FOG_PARAMS_OPTIMIZED:
      append(dst, "fogParamsOptimized");
      break;
   case STATE_POINT_SIZE_CLAMPED:
      append(dst, "pointSizeClamped");
      break;
   case STATE_LIGHT_SPOT_DIR_NORMALIZED:
      append(dst, "lightSpotDirNormalized");
      break;
   case STATE_LIGHT_POSITION:
      append(dst, "lightPosition");
      break;
   case STATE_LIGHT_POSITION_NORMALIZED:
      append(dst, "light.position.normalized");
      break;
   case STATE_LIGHT_HALF_VECTOR:
      append(dst, "lightHalfVector");
      break;
   case STATE_PT_SCALE:
      append(dst, "PTscale");
      break;
   case STATE_PT_BIAS:
      append(dst, "PTbias");
      break;
   case STATE_FB_SIZE:
      append(dst, "FbSize");
      break;
   case STATE_FB_WPOS_Y_TRANSFORM:
      append(dst, "FbWposYTransform");
      break;
   case STATE_ROT_MATRIX_0:
      append(dst, "rotMatrixRow0");
      break;
   case STATE_ROT_MATRIX_1:
      append(dst, "rotMatrixRow1");
      break;
   default:
      /* probably STATE_INTERNAL_DRIVER+i (driver private state) */
      append(dst, "driverState");
   }
}

static void
append_face(char *dst, GLint face)
{
   if (face == 0)
      append(dst, "front.");
   else
      append(dst, "back.");
}

static void
append_index(char *dst, GLint index)
{
   char s[20];
   sprintf(s, "[%d]", index);
   append(dst, s);
}

/**
 * Make a string from the given state vector.
 * For example, return "state.matrix.texture[2].inverse".
 * Use free() to deallocate the string.
 */
char *
_mesa_program_state_string(const gl_state_index state[STATE_LENGTH])
{
   char str[1000] = "";
   char tmp[30];

   append(str, "state.");
   append_token(str, state[0]);

   switch (state[0]) {
   case STATE_MATERIAL:
      append_face(str, state[1]);
      append_token(str, state[2]);
      break;
   case STATE_LIGHT:
      append_index(str, state[1]); /* light number [i]. */
      append_token(str, state[2]); /* coefficients */
      break;
   case STATE_LIGHTMODEL_AMBIENT:
      append(str, "lightmodel.ambient");
      break;
   case STATE_LIGHTMODEL_SCENECOLOR:
      if (state[1] == 0) {
         append(str, "lightmodel.front.scenecolor");
      }
      else {
         append(str, "lightmodel.back.scenecolor");
      }
      break;
   case STATE_LIGHTPROD:
      append_index(str, state[1]); /* light number [i]. */
      append_face(str, state[2]);
      append_token(str, state[3]);
      break;
   case STATE_TEXGEN:
      append_index(str, state[1]); /* tex unit [i] */
      append_token(str, state[2]); /* plane coef */
      break;
   case STATE_TEXENV_COLOR:
      append_index(str, state[1]); /* tex unit [i] */
      append(str, "color");
      break;
   case STATE_CLIPPLANE:
      append_index(str, state[1]); /* plane [i] */
      append(str, ".plane");
      break;
   case STATE_MODELVIEW_MATRIX:
   case STATE_PROJECTION_MATRIX:
   case STATE_MVP_MATRIX:
   case STATE_TEXTURE_MATRIX:
   case STATE_PROGRAM_MATRIX:
      {
         /* state[0] = modelview, projection, texture, etc. */
         /* state[1] = which texture matrix or program matrix */
         /* state[2] = first row to fetch */
         /* state[3] = last row to fetch */
         /* state[4] = transpose, inverse or invtrans */
         const gl_state_index mat = state[0];
         const GLuint index = (GLuint) state[1];
         const GLuint firstRow = (GLuint) state[2];
         const GLuint lastRow = (GLuint) state[3];
         const gl_state_index modifier = state[4];
         if (index ||
             mat == STATE_TEXTURE_MATRIX ||
             mat == STATE_PROGRAM_MATRIX)
            append_index(str, index);
         if (modifier)
            append_token(str, modifier);
         if (firstRow == lastRow)
            sprintf(tmp, ".row[%d]", firstRow);
         else
            sprintf(tmp, ".row[%d..%d]", firstRow, lastRow);
         append(str, tmp);
      }
      break;
   case STATE_POINT_SIZE:
      break;
   case STATE_POINT_ATTENUATION:
      break;
   case STATE_FOG_PARAMS:
      break;
   case STATE_FOG_COLOR:
      break;
   case STATE_NUM_SAMPLES:
      break;
   case STATE_DEPTH_RANGE:
      break;
   case STATE_FRAGMENT_PROGRAM:
   case STATE_VERTEX_PROGRAM:
      /* state[1] = {STATE_ENV, STATE_LOCAL} */
      /* state[2] = parameter index          */
      append_token(str, state[1]);
      append_index(str, state[2]);
      break;
   case STATE_NORMAL_SCALE:
      break;
   case STATE_INTERNAL:
      append_token(str, state[1]);
      if (state[1] == STATE_CURRENT_ATTRIB)
         append_index(str, state[2]);
       break;
   default:
      _mesa_problem(NULL, "Invalid state in _mesa_program_state_string");
      break;
   }

   return _mesa_strdup(str);
}


/**
 * Loop over all the parameters in a parameter list.  If the parameter
 * is a GL state reference, look up the current value of that state
 * variable and put it into the parameter's Value[4] array.
 * Other parameter types never change or are explicitly set by the user
 * with glUniform() or glProgramParameter(), etc.
 * This would be called at glBegin time.
 */
void
_mesa_load_state_parameters(struct gl_context *ctx,
                            struct gl_program_parameter_list *paramList)
{
   GLuint i;

   if (!paramList)
      return;

   for (i = 0; i < paramList->NumParameters; i++) {
      if (paramList->Parameters[i].Type == PROGRAM_STATE_VAR) {
         _mesa_fetch_state(ctx,
			   paramList->Parameters[i].StateIndexes,
                           &paramList->ParameterValues[i][0].f);
      }
   }
}
