prog_statevars.c

Mesa is an open-source implementation of the OpenGL specification - a system for rendering interacti

/*
 * Mesa 3-D graphics library
 * Version:  7.1
 *
 * 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
 * BRIAN PAUL 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 "glheader.h"
#include "context.h"
#include "hash.h"
#include "imports.h"
#include "macros.h"
#include "mtypes.h"
#include "prog_statevars.h"
#include "prog_parameter.h"
#include "nvvertparse.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(GLcontext *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].EyeDirection);
            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;
	 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_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].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] = (ctx->Fog.End == ctx->Fog.Start)
         ? 1.0f : (GLfloat)(1.0 / (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:
   case STATE_COLOR_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) {
            matrix = ctx->TextureMatrixStack[index].Top;
         }
         else if (mat == STATE_PROGRAM_MATRIX) {
            matrix = ctx->ProgramMatrixStack[index].Top;
         }
         else if (mat == STATE_COLOR_MATRIX) {
            matrix = ctx->ColorMatrixStack.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_alloc_inv( (GLmatrix *) matrix );