program.c

这是一个开放源代码的与WINNT/WIN2K/WIN2003兼容的操作系统

/**
 * Add a new state reference to the parameter list.
 * \param paramList - the parameter list
 * \param state     - an array of 6 state tokens
 *
 * \return index of the new parameter.
 */
GLint
_mesa_add_state_reference(struct program_parameter_list *paramList,
                          GLint *stateTokens)
{
   /* XXX Should we parse <stateString> here and produce the parameter's
    * list of STATE_* tokens here, or in the parser?
    */
   GLint a, idx;

   idx = add_parameter(paramList, NULL, NULL, STATE);
	
   for (a=0; a<6; a++)
      paramList->Parameters[idx].StateIndexes[a] = (enum state_index) stateTokens[a];

   return idx;
}


/**
 * Lookup a parameter value by name in the given parameter list.
 * \return pointer to the float[4] values.
 */
GLfloat *
_mesa_lookup_parameter_value(struct program_parameter_list *paramList,
                             GLsizei nameLen, const char *name)
{
   GLuint i;

   if (!paramList)
      return NULL;

   if (nameLen == -1) {
      /* name is null-terminated */
      for (i = 0; i < paramList->NumParameters; i++) {
         if (paramList->Parameters[i].Name &&
	     _mesa_strcmp(paramList->Parameters[i].Name, name) == 0)
            return paramList->ParameterValues[i];
      }
   }
   else {
      /* name is not null-terminated, use nameLen */
      for (i = 0; i < paramList->NumParameters; i++) {
         if (paramList->Parameters[i].Name &&
	     _mesa_strncmp(paramList->Parameters[i].Name, name, nameLen) == 0
             && _mesa_strlen(paramList->Parameters[i].Name) == (size_t)nameLen)
            return paramList->ParameterValues[i];
      }
   }
   return NULL;
}


/**
 * Lookup a parameter index by name in the given parameter list.
 * \return index of parameter in the list.
 */
GLint
_mesa_lookup_parameter_index(struct program_parameter_list *paramList,
                             GLsizei nameLen, const char *name)
{
   GLint i;

   if (!paramList)
      return -1;

   if (nameLen == -1) {
      /* name is null-terminated */
      for (i = 0; i < (GLint) paramList->NumParameters; i++) {
         if (paramList->Parameters[i].Name &&
	     _mesa_strcmp(paramList->Parameters[i].Name, name) == 0)
            return i;
      }
   }
   else {
      /* name is not null-terminated, use nameLen */
      for (i = 0; i < (GLint) paramList->NumParameters; i++) {
         if (paramList->Parameters[i].Name &&
	     _mesa_strncmp(paramList->Parameters[i].Name, name, nameLen) == 0
             && _mesa_strlen(paramList->Parameters[i].Name) == (size_t)nameLen)
            return i;
      }
   }
   return -1;
}


/**
 * 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(GLcontext *ctx, const enum 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];
         /* state[2] is the material attribute */
         switch (state[2]) {
         case STATE_AMBIENT:
            if (face == 0)
               COPY_4V(value, ctx->Light.Material.Attrib[MAT_ATTRIB_FRONT_AMBIENT]);
            else
               COPY_4V(value, ctx->Light.Material.Attrib[MAT_ATTRIB_BACK_AMBIENT]);
            return;
         case STATE_DIFFUSE:
            if (face == 0)
               COPY_4V(value, ctx->Light.Material.Attrib[MAT_ATTRIB_FRONT_DIFFUSE]);
            else
               COPY_4V(value, ctx->Light.Material.Attrib[MAT_ATTRIB_BACK_DIFFUSE]);
            return;
         case STATE_SPECULAR:
            if (face == 0)
               COPY_4V(value, ctx->Light.Material.Attrib[MAT_ATTRIB_FRONT_SPECULAR]);
            else
               COPY_4V(value, ctx->Light.Material.Attrib[MAT_ATTRIB_BACK_SPECULAR]);
            return;
         case STATE_EMISSION:
            if (face == 0)
               COPY_4V(value, ctx->Light.Material.Attrib[MAT_ATTRIB_FRONT_EMISSION]);
            else
               COPY_4V(value, ctx->Light.Material.Attrib[MAT_ATTRIB_BACK_EMISSION]);
            return;
         case STATE_SHININESS:
            if (face == 0)
               value[0] = ctx->Light.Material.Attrib[MAT_ATTRIB_FRONT_SHININESS][0];
            else
               value[0] = ctx->Light.Material.Attrib[MAT_ATTRIB_BACK_SHININESS][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].EyeDirection);
            value[3] = ctx->Light.Light[ln]._CosCutoff;
            return;
         case STATE_HALF:
            {
               GLfloat eye_z[] = {0, 0, 1};
					
               /* Compute infinite half angle vector:
                *   half-vector = light_position + (0, 0, 1) 
                * and then normalize.  w = 0
		*
		* light.EyePosition.w should be 0 for infinite lights.
                */
	       ADD_3V(value, eye_z, ctx->Light.Light[ln].EyePosition);
	       NORMALIZE_3FV(value);
	       value[3] = 0;
            }						  
            return;
	 case STATE_POSITION_NORMALIZED:
            COPY_4V(value, ctx->Light.Light[ln].EyePosition);
	    NORMALIZE_3FV( value );
            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_DIFFUSE+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_DIFFUSE+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].EyePlaneS);
            return;
         case STATE_TEXGEN_EYE_T:
            COPY_4V(value, ctx->Texture.Unit[unit].EyePlaneT);
            return;
         case STATE_TEXGEN_EYE_R:
            COPY_4V(value, ctx->Texture.Unit[unit].EyePlaneR);
            return;
         case STATE_TEXGEN_EYE_Q:
            COPY_4V(value, ctx->Texture.Unit[unit].EyePlaneQ);
            return;
         case STATE_TEXGEN_OBJECT_S:
            COPY_4V(value, ctx->Texture.Unit[unit].ObjectPlaneS);
            return;
         case STATE_TEXGEN_OBJECT_T:
            COPY_4V(value, ctx->Texture.Unit[unit].ObjectPlaneT);
            return;
         case STATE_TEXGEN_OBJECT_R:
            COPY_4V(value, ctx->Texture.Unit[unit].ObjectPlaneR);
            return;
         case STATE_TEXGEN_OBJECT_Q:
            COPY_4V(value, ctx->Texture.Unit[unit].ObjectPlaneQ);
            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];
         COPY_4V(value, ctx->Texture.Unit[unit].EnvColor);
      }			
      return;
   case STATE_FOG_COLOR:
      COPY_4V(value, ctx->Fog.Color);
      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_MATRIX:
      {
         /* state[1] = modelview, projection, texture, etc. */
         /* state[2] = which texture matrix or program matrix */
         /* state[3] = first column to fetch */
         /* state[4] = last column to fetch */
         /* state[5] = transpose, inverse or invtrans */

         const GLmatrix *matrix;
         const enum state_index mat = state[1];
         const GLuint index = (GLuint) state[2];
         const GLuint first = (GLuint) state[3];
         const GLuint last = (GLuint) state[4];
         const enum state_index modifier = state[5];
         const GLfloat *m;
         GLuint row, i;
         if (mat == STATE_MODELVIEW) {
            matrix = ctx->ModelviewMatrixStack.Top;
         }
         else if (mat == STATE_PROJECTION) {
            matrix = ctx->ProjectionMatrixStack.Top;
         }
         else if (mat == STATE_MVP) {
            matrix = &ctx->_ModelProjectMatrix;
         }
         else if (mat == STATE_TEXTURE) {
            matrix = ctx->TextureMatrixStack[index].Top;
         }
         else if (mat == STATE_PROGRAM) {
            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 = first; row <= last; 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 = first; row <= last; row++) {
               value[i++] = m[row + 0];
               value[i++] = m[row + 4];
               value[i++] = m[row + 8];
               value[i++] = m[row + 12];
            }
         }
      }
      return;
   case STATE_DEPTH_RANGE:
      value[0] = ctx->Viewport.Near;                     /* near       */
      value[1] = ctx->Viewport.Far;                      /* far        */
      value[2] = ctx->Viewport.Far - ctx->Viewport.Near; /* far - near */
      value[3] = 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]);
               break;
            case STATE_LOCAL:
               COPY_4V(value, ctx->FragmentProgram.Current->Base.LocalParams[idx]);
               break;
            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]);
               break;
            case STATE_LOCAL:
               COPY_4V(value, ctx->VertexProgram.Current->Base.LocalParams[idx]);
               break;
            default:
               _mesa_problem(ctx, "Bad state switch in _mesa_fetch_state()");
               return;
         }
      }
      return;

   case STATE_INTERNAL:
      {
         switch (state[1]) {
	    case STATE_NORMAL_SCALE:
               ASSIGN_4V(value, ctx->_ModelViewInvScale, 0, 0, 1);
               break;
	    default:
               _mesa_problem(ctx, "Bad state switch in _mesa_fetch_state()");
               return;
         }
      }
      return;

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


/**
 * 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.
 * This would be called at glBegin time when using a fragment program.
 */
void
_mesa_load_state_parameters(GLcontext *ctx,
                            struct program_parameter_list *paramList)