mesa: Fix array out-of-bounds access by _mesa_LightModeli.

[mesa.git] / src / mesa / main / light.c

/*
 * Mesa 3-D graphics library
 * Version:  7.5
 *
 * Copyright (C) 1999-2008  Brian Paul   All Rights Reserved.
 * Copyright (C) 2009  VMware, Inc.  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.
 */


#include "glheader.h"
#include "imports.h"
#include "context.h"
#include "enums.h"
#include "light.h"
#include "macros.h"
#include "simple_list.h"
#include "mtypes.h"
#include "math/m_matrix.h"


void GLAPIENTRY
_mesa_ShadeModel( GLenum mode )
{
   GET_CURRENT_CONTEXT(ctx);
   ASSERT_OUTSIDE_BEGIN_END(ctx);

   if (MESA_VERBOSE & VERBOSE_API)
      _mesa_debug(ctx, "glShadeModel %s\n", _mesa_lookup_enum_by_nr(mode));

   if (mode != GL_FLAT && mode != GL_SMOOTH) {
      _mesa_error(ctx, GL_INVALID_ENUM, "glShadeModel");
      return;
   }

   if (ctx->Light.ShadeModel == mode)
      return;

   FLUSH_VERTICES(ctx, _NEW_LIGHT);
   ctx->Light.ShadeModel = mode;
   if (mode == GL_FLAT)
      ctx->_TriangleCaps |= DD_FLATSHADE;
   else
      ctx->_TriangleCaps &= ~DD_FLATSHADE;

   if (ctx->Driver.ShadeModel)
      ctx->Driver.ShadeModel( ctx, mode );
}


/**
 * Set the provoking vertex (the vertex which specifies the prim's
 * color when flat shading) to either the first or last vertex of the
 * triangle or line.
 */
void GLAPIENTRY
_mesa_ProvokingVertexEXT(GLenum mode)
{
   GET_CURRENT_CONTEXT(ctx);
   ASSERT_OUTSIDE_BEGIN_END(ctx);

   if (MESA_VERBOSE&VERBOSE_API)
      _mesa_debug(ctx, "glProvokingVertexEXT 0x%x\n", mode);

   switch (mode) {
   case GL_FIRST_VERTEX_CONVENTION_EXT:
   case GL_LAST_VERTEX_CONVENTION_EXT:
      break;
   default:
      _mesa_error(ctx, GL_INVALID_ENUM, "glProvokingVertexEXT(0x%x)", mode);
      return;
   }

   if (ctx->Light.ProvokingVertex == mode)
      return;

   FLUSH_VERTICES(ctx, _NEW_LIGHT);
   ctx->Light.ProvokingVertex = mode;
}


/**
 * Helper function called by _mesa_Lightfv and _mesa_PopAttrib to set
 * per-light state.
 * For GL_POSITION and GL_SPOT_DIRECTION the params position/direction
 * will have already been transformed by the modelview matrix!
 * Also, all error checking should have already been done.
 */
void
_mesa_light(GLcontext *ctx, GLuint lnum, GLenum pname, const GLfloat *params)
{
   struct gl_light *light;

   ASSERT(lnum < MAX_LIGHTS);
   light = &ctx->Light.Light[lnum];

   switch (pname) {
   case GL_AMBIENT:
      if (TEST_EQ_4V(light->Ambient, params))
         return;
      FLUSH_VERTICES(ctx, _NEW_LIGHT);
      COPY_4V( light->Ambient, params );
      break;
   case GL_DIFFUSE:
      if (TEST_EQ_4V(light->Diffuse, params))
         return;
      FLUSH_VERTICES(ctx, _NEW_LIGHT);
      COPY_4V( light->Diffuse, params );
      break;
   case GL_SPECULAR:
      if (TEST_EQ_4V(light->Specular, params))
         return;
      FLUSH_VERTICES(ctx, _NEW_LIGHT);
      COPY_4V( light->Specular, params );
      break;
   case GL_POSITION:
      /* NOTE: position has already been transformed by ModelView! */
      if (TEST_EQ_4V(light->EyePosition, params))
         return;
      FLUSH_VERTICES(ctx, _NEW_LIGHT);
      COPY_4V(light->EyePosition, params);
      if (light->EyePosition[3] != 0.0F)
         light->_Flags |= LIGHT_POSITIONAL;
      else
         light->_Flags &= ~LIGHT_POSITIONAL;
      break;
   case GL_SPOT_DIRECTION:
      /* NOTE: Direction already transformed by inverse ModelView! */
      if (TEST_EQ_3V(light->SpotDirection, params))
         return;
      FLUSH_VERTICES(ctx, _NEW_LIGHT);
      COPY_3V(light->SpotDirection, params);
      break;
   case GL_SPOT_EXPONENT:
      ASSERT(params[0] >= 0.0);
      ASSERT(params[0] <= ctx->Const.MaxSpotExponent);
      if (light->SpotExponent == params[0])
         return;
      FLUSH_VERTICES(ctx, _NEW_LIGHT);
      light->SpotExponent = params[0];
      _mesa_invalidate_spot_exp_table(light);
      break;
   case GL_SPOT_CUTOFF:
      ASSERT(params[0] == 180.0 || (params[0] >= 0.0 && params[0] <= 90.0));
      if (light->SpotCutoff == params[0])
         return;
      FLUSH_VERTICES(ctx, _NEW_LIGHT);
      light->SpotCutoff = params[0];
      light->_CosCutoffNeg = (GLfloat) (_mesa_cos(light->SpotCutoff * DEG2RAD));
      if (light->_CosCutoffNeg < 0)
         light->_CosCutoff = 0;
      else
         light->_CosCutoff = light->_CosCutoffNeg;
      if (light->SpotCutoff != 180.0F)
         light->_Flags |= LIGHT_SPOT;
      else
         light->_Flags &= ~LIGHT_SPOT;
      break;
   case GL_CONSTANT_ATTENUATION:
      ASSERT(params[0] >= 0.0);
      if (light->ConstantAttenuation == params[0])
         return;
      FLUSH_VERTICES(ctx, _NEW_LIGHT);
      light->ConstantAttenuation = params[0];
      break;
   case GL_LINEAR_ATTENUATION:
      ASSERT(params[0] >= 0.0);
      if (light->LinearAttenuation == params[0])
         return;
      FLUSH_VERTICES(ctx, _NEW_LIGHT);
      light->LinearAttenuation = params[0];
      break;
   case GL_QUADRATIC_ATTENUATION:
      ASSERT(params[0] >= 0.0);
      if (light->QuadraticAttenuation == params[0])
         return;
      FLUSH_VERTICES(ctx, _NEW_LIGHT);
      light->QuadraticAttenuation = params[0];
      break;
   default:
      _mesa_problem(ctx, "Unexpected pname in _mesa_light()");
      return;
   }

   if (ctx->Driver.Lightfv)
      ctx->Driver.Lightfv( ctx, GL_LIGHT0 + lnum, pname, params );
}


void GLAPIENTRY
_mesa_Lightf( GLenum light, GLenum pname, GLfloat param )
{
   _mesa_Lightfv( light, pname, &param );
}


void GLAPIENTRY
_mesa_Lightfv( GLenum light, GLenum pname, const GLfloat *params )
{
   GET_CURRENT_CONTEXT(ctx);
   GLint i = (GLint) (light - GL_LIGHT0);
   GLfloat temp[4];
   ASSERT_OUTSIDE_BEGIN_END(ctx);

   if (i < 0 || i >= (GLint) ctx->Const.MaxLights) {
      _mesa_error( ctx, GL_INVALID_ENUM, "glLight(light=0x%x)", light );
      return;
   }

   /* do particular error checks, transformations */
   switch (pname) {
   case GL_AMBIENT:
   case GL_DIFFUSE:
   case GL_SPECULAR:
      /* nothing */
      break;
   case GL_POSITION:
      /* transform position by ModelView matrix */
      TRANSFORM_POINT(temp, ctx->ModelviewMatrixStack.Top->m, params);
      params = temp;
      break;
   case GL_SPOT_DIRECTION:
      /* transform direction by inverse modelview */
      if (_math_matrix_is_dirty(ctx->ModelviewMatrixStack.Top)) {
         _math_matrix_analyse(ctx->ModelviewMatrixStack.Top);
      }
      TRANSFORM_DIRECTION(temp, params, ctx->ModelviewMatrixStack.Top->m);
      params = temp;
      break;
   case GL_SPOT_EXPONENT:
      if (params[0] < 0.0 || params[0] > ctx->Const.MaxSpotExponent) {
         _mesa_error(ctx, GL_INVALID_VALUE, "glLight");
         return;
      }
      break;
   case GL_SPOT_CUTOFF:
      if ((params[0] < 0.0 || params[0] > 90.0) && params[0] != 180.0) {
         _mesa_error(ctx, GL_INVALID_VALUE, "glLight");
         return;
      }
      break;
   case GL_CONSTANT_ATTENUATION:
      if (params[0] < 0.0) {
         _mesa_error(ctx, GL_INVALID_VALUE, "glLight");
         return;
      }
      break;
   case GL_LINEAR_ATTENUATION:
      if (params[0] < 0.0) {
         _mesa_error(ctx, GL_INVALID_VALUE, "glLight");
         return;
      }
      break;
   case GL_QUADRATIC_ATTENUATION:
      if (params[0] < 0.0) {
         _mesa_error(ctx, GL_INVALID_VALUE, "glLight");
         return;
      }
      break;
   default:
      _mesa_error(ctx, GL_INVALID_ENUM, "glLight(pname=0x%x)", pname);
      return;
   }

   _mesa_light(ctx, i, pname, params);
}


void GLAPIENTRY
_mesa_Lighti( GLenum light, GLenum pname, GLint param )
{
   _mesa_Lightiv( light, pname, &param );
}


void GLAPIENTRY
_mesa_Lightiv( GLenum light, GLenum pname, const GLint *params )
{
   GLfloat fparam[4];

   switch (pname) {
      case GL_AMBIENT:
      case GL_DIFFUSE:
      case GL_SPECULAR:
         fparam[0] = INT_TO_FLOAT( params[0] );
         fparam[1] = INT_TO_FLOAT( params[1] );
         fparam[2] = INT_TO_FLOAT( params[2] );
         fparam[3] = INT_TO_FLOAT( params[3] );
         break;
      case GL_POSITION:
         fparam[0] = (GLfloat) params[0];
         fparam[1] = (GLfloat) params[1];
         fparam[2] = (GLfloat) params[2];
         fparam[3] = (GLfloat) params[3];
         break;
      case GL_SPOT_DIRECTION:
         fparam[0] = (GLfloat) params[0];
         fparam[1] = (GLfloat) params[1];
         fparam[2] = (GLfloat) params[2];
         break;
      case GL_SPOT_EXPONENT:
      case GL_SPOT_CUTOFF:
      case GL_CONSTANT_ATTENUATION:
      case GL_LINEAR_ATTENUATION:
      case GL_QUADRATIC_ATTENUATION:
         fparam[0] = (GLfloat) params[0];
         break;
      default:
         /* error will be caught later in gl_Lightfv */
         ;
   }

   _mesa_Lightfv( light, pname, fparam );
}



void GLAPIENTRY
_mesa_GetLightfv( GLenum light, GLenum pname, GLfloat *params )
{
   GET_CURRENT_CONTEXT(ctx);
   GLint l = (GLint) (light - GL_LIGHT0);
   ASSERT_OUTSIDE_BEGIN_END(ctx);

   if (l < 0 || l >= (GLint) ctx->Const.MaxLights) {
      _mesa_error( ctx, GL_INVALID_ENUM, "glGetLightfv" );
      return;
   }

   switch (pname) {
      case GL_AMBIENT:
         COPY_4V( params, ctx->Light.Light[l].Ambient );
         break;
      case GL_DIFFUSE:
         COPY_4V( params, ctx->Light.Light[l].Diffuse );
         break;
      case GL_SPECULAR:
         COPY_4V( params, ctx->Light.Light[l].Specular );
         break;
      case GL_POSITION:
         COPY_4V( params, ctx->Light.Light[l].EyePosition );
         break;
      case GL_SPOT_DIRECTION:
         COPY_3V( params, ctx->Light.Light[l].SpotDirection );
         break;
      case GL_SPOT_EXPONENT:
         params[0] = ctx->Light.Light[l].SpotExponent;
         break;
      case GL_SPOT_CUTOFF:
         params[0] = ctx->Light.Light[l].SpotCutoff;
         break;
      case GL_CONSTANT_ATTENUATION:
         params[0] = ctx->Light.Light[l].ConstantAttenuation;
         break;
      case GL_LINEAR_ATTENUATION:
         params[0] = ctx->Light.Light[l].LinearAttenuation;
         break;
      case GL_QUADRATIC_ATTENUATION:
         params[0] = ctx->Light.Light[l].QuadraticAttenuation;
         break;
      default:
         _mesa_error( ctx, GL_INVALID_ENUM, "glGetLightfv" );
         break;
   }
}


void GLAPIENTRY
_mesa_GetLightiv( GLenum light, GLenum pname, GLint *params )
{
   GET_CURRENT_CONTEXT(ctx);
   GLint l = (GLint) (light - GL_LIGHT0);
   ASSERT_OUTSIDE_BEGIN_END(ctx);

   if (l < 0 || l >= (GLint) ctx->Const.MaxLights) {
      _mesa_error( ctx, GL_INVALID_ENUM, "glGetLightiv" );
      return;
   }

   switch (pname) {
      case GL_AMBIENT:
         params[0] = FLOAT_TO_INT(ctx->Light.Light[l].Ambient[0]);
         params[1] = FLOAT_TO_INT(ctx->Light.Light[l].Ambient[1]);
         params[2] = FLOAT_TO_INT(ctx->Light.Light[l].Ambient[2]);
         params[3] = FLOAT_TO_INT(ctx->Light.Light[l].Ambient[3]);
         break;
      case GL_DIFFUSE:
         params[0] = FLOAT_TO_INT(ctx->Light.Light[l].Diffuse[0]);
         params[1] = FLOAT_TO_INT(ctx->Light.Light[l].Diffuse[1]);
         params[2] = FLOAT_TO_INT(ctx->Light.Light[l].Diffuse[2]);
         params[3] = FLOAT_TO_INT(ctx->Light.Light[l].Diffuse[3]);
         break;
      case GL_SPECULAR:
         params[0] = FLOAT_TO_INT(ctx->Light.Light[l].Specular[0]);
         params[1] = FLOAT_TO_INT(ctx->Light.Light[l].Specular[1]);
         params[2] = FLOAT_TO_INT(ctx->Light.Light[l].Specular[2]);
         params[3] = FLOAT_TO_INT(ctx->Light.Light[l].Specular[3]);
         break;
      case GL_POSITION:
         params[0] = (GLint) ctx->Light.Light[l].EyePosition[0];
         params[1] = (GLint) ctx->Light.Light[l].EyePosition[1];
         params[2] = (GLint) ctx->Light.Light[l].EyePosition[2];
         params[3] = (GLint) ctx->Light.Light[l].EyePosition[3];
         break;
      case GL_SPOT_DIRECTION:
         params[0] = (GLint) ctx->Light.Light[l].SpotDirection[0];
         params[1] = (GLint) ctx->Light.Light[l].SpotDirection[1];
         params[2] = (GLint) ctx->Light.Light[l].SpotDirection[2];
         break;
      case GL_SPOT_EXPONENT:
         params[0] = (GLint) ctx->Light.Light[l].SpotExponent;
         break;
      case GL_SPOT_CUTOFF:
         params[0] = (GLint) ctx->Light.Light[l].SpotCutoff;
         break;
      case GL_CONSTANT_ATTENUATION:
         params[0] = (GLint) ctx->Light.Light[l].ConstantAttenuation;
         break;
      case GL_LINEAR_ATTENUATION:
         params[0] = (GLint) ctx->Light.Light[l].LinearAttenuation;
         break;
      case GL_QUADRATIC_ATTENUATION:
         params[0] = (GLint) ctx->Light.Light[l].QuadraticAttenuation;
         break;
      default:
         _mesa_error( ctx, GL_INVALID_ENUM, "glGetLightiv" );
         break;
   }
}



/**********************************************************************/
/***                        Light Model                             ***/
/**********************************************************************/


void GLAPIENTRY
_mesa_LightModelfv( GLenum pname, const GLfloat *params )
{
   GLenum newenum;
   GLboolean newbool;
   GET_CURRENT_CONTEXT(ctx);
   ASSERT_OUTSIDE_BEGIN_END(ctx);

   switch (pname) {
      case GL_LIGHT_MODEL_AMBIENT:
         if (TEST_EQ_4V( ctx->Light.Model.Ambient, params ))
            return;
         FLUSH_VERTICES(ctx, _NEW_LIGHT);
         COPY_4V( ctx->Light.Model.Ambient, params );
         break;
      case GL_LIGHT_MODEL_LOCAL_VIEWER:
         newbool = (params[0]!=0.0);
         if (ctx->Light.Model.LocalViewer == newbool)
            return;
         FLUSH_VERTICES(ctx, _NEW_LIGHT);
         ctx->Light.Model.LocalViewer = newbool;
         break;
      case GL_LIGHT_MODEL_TWO_SIDE:
         newbool = (params[0]!=0.0);
         if (ctx->Light.Model.TwoSide == newbool)
            return;
         FLUSH_VERTICES(ctx, _NEW_LIGHT);
         ctx->Light.Model.TwoSide = newbool;
         if (ctx->Light.Enabled && ctx->Light.Model.TwoSide)
            ctx->_TriangleCaps |= DD_TRI_LIGHT_TWOSIDE;
         else
            ctx->_TriangleCaps &= ~DD_TRI_LIGHT_TWOSIDE;
         break;
      case GL_LIGHT_MODEL_COLOR_CONTROL:
         if (params[0] == (GLfloat) GL_SINGLE_COLOR)
            newenum = GL_SINGLE_COLOR;
         else if (params[0] == (GLfloat) GL_SEPARATE_SPECULAR_COLOR)
            newenum = GL_SEPARATE_SPECULAR_COLOR;
         else {
            _mesa_error( ctx, GL_INVALID_ENUM, "glLightModel(param=0x0%x)",
                         (GLint) params[0] );
            return;
         }
         if (ctx->Light.Model.ColorControl == newenum)
            return;
         FLUSH_VERTICES(ctx, _NEW_LIGHT);
         ctx->Light.Model.ColorControl = newenum;
         break;
      default:
         _mesa_error( ctx, GL_INVALID_ENUM, "glLightModel(pname=0x%x)", pname );
         break;
   }

   if (ctx->Driver.LightModelfv)
      ctx->Driver.LightModelfv( ctx, pname, params );
}


void GLAPIENTRY
_mesa_LightModeliv( GLenum pname, const GLint *params )
{
   GLfloat fparam[4];

   switch (pname) {
      case GL_LIGHT_MODEL_AMBIENT:
         fparam[0] = INT_TO_FLOAT( params[0] );
         fparam[1] = INT_TO_FLOAT( params[1] );
         fparam[2] = INT_TO_FLOAT( params[2] );
         fparam[3] = INT_TO_FLOAT( params[3] );
         break;
      case GL_LIGHT_MODEL_LOCAL_VIEWER:
      case GL_LIGHT_MODEL_TWO_SIDE:
      case GL_LIGHT_MODEL_COLOR_CONTROL:
         fparam[0] = (GLfloat) params[0];
         break;
      default:
         /* Error will be caught later in gl_LightModelfv */
         ASSIGN_4V(fparam, 0.0F, 0.0F, 0.0F, 0.0F);
   }
   _mesa_LightModelfv( pname, fparam );
}


void GLAPIENTRY
_mesa_LightModeli( GLenum pname, GLint param )
{
   GLint iparam[4];
   iparam[0] = param;
   iparam[1] = iparam[2] = iparam[3] = 0;
   _mesa_LightModeliv( pname, iparam );
}


void GLAPIENTRY
_mesa_LightModelf( GLenum pname, GLfloat param )
{
   _mesa_LightModelfv( pname, &param );
}



/********** MATERIAL **********/


/*
 * Given a face and pname value (ala glColorMaterial), compute a bitmask
 * of the targeted material values.
 */
GLuint
_mesa_material_bitmask( GLcontext *ctx, GLenum face, GLenum pname,
                        GLuint legal, const char *where )
{
   GLuint bitmask = 0;

   /* Make a bitmask indicating what material attribute(s) we're updating */
   switch (pname) {
      case GL_EMISSION:
         bitmask |= MAT_BIT_FRONT_EMISSION | MAT_BIT_BACK_EMISSION;
         break;
      case GL_AMBIENT:
         bitmask |= MAT_BIT_FRONT_AMBIENT | MAT_BIT_BACK_AMBIENT;
         break;
      case GL_DIFFUSE:
         bitmask |= MAT_BIT_FRONT_DIFFUSE | MAT_BIT_BACK_DIFFUSE;
         break;
      case GL_SPECULAR:
         bitmask |= MAT_BIT_FRONT_SPECULAR | MAT_BIT_BACK_SPECULAR;
         break;
      case GL_SHININESS:
         bitmask |= MAT_BIT_FRONT_SHININESS | MAT_BIT_BACK_SHININESS;
         break;
      case GL_AMBIENT_AND_DIFFUSE:
         bitmask |= MAT_BIT_FRONT_AMBIENT | MAT_BIT_BACK_AMBIENT;
         bitmask |= MAT_BIT_FRONT_DIFFUSE | MAT_BIT_BACK_DIFFUSE;
         break;
      case GL_COLOR_INDEXES:
         bitmask |= MAT_BIT_FRONT_INDEXES  | MAT_BIT_BACK_INDEXES;
         break;
      default:
         _mesa_error( ctx, GL_INVALID_ENUM, where );
         return 0;
   }

   if (face==GL_FRONT) {
      bitmask &= FRONT_MATERIAL_BITS;
   }
   else if (face==GL_BACK) {
      bitmask &= BACK_MATERIAL_BITS;
   }
   else if (face != GL_FRONT_AND_BACK) {
      _mesa_error( ctx, GL_INVALID_ENUM, where );
      return 0;
   }

   if (bitmask & ~legal) {
      _mesa_error( ctx, GL_INVALID_ENUM, where );
      return 0;
   }

   return bitmask;
}



/* Perform a straight copy between materials.
 */
void
_mesa_copy_materials( struct gl_material *dst,
                      const struct gl_material *src,
                      GLuint bitmask )
{
   int i;

   for (i = 0 ; i < MAT_ATTRIB_MAX ; i++) 
      if (bitmask & (1<<i))
         COPY_4FV( dst->Attrib[i], src->Attrib[i] );
}



/* Update derived values following a change in ctx->Light.Material
 */
void
_mesa_update_material( GLcontext *ctx, GLuint bitmask )
{
   struct gl_light *light, *list = &ctx->Light.EnabledList;
   GLfloat (*mat)[4] = ctx->Light.Material.Attrib;

   if (MESA_VERBOSE&VERBOSE_IMMEDIATE) 
      _mesa_debug(ctx, "_mesa_update_material, mask 0x%x\n", bitmask);

   if (!bitmask)
      return;

   /* update material ambience */
   if (bitmask & MAT_BIT_FRONT_AMBIENT) {
      foreach (light, list) {
         SCALE_3V( light->_MatAmbient[0], light->Ambient, 
                   mat[MAT_ATTRIB_FRONT_AMBIENT]);
      }
   }

   if (bitmask & MAT_BIT_BACK_AMBIENT) {
      foreach (light, list) {
         SCALE_3V( light->_MatAmbient[1], light->Ambient, 
                   mat[MAT_ATTRIB_BACK_AMBIENT]);
      }
   }

   /* update BaseColor = emission + scene's ambience * material's ambience */
   if (bitmask & (MAT_BIT_FRONT_EMISSION | MAT_BIT_FRONT_AMBIENT)) {
      COPY_3V( ctx->Light._BaseColor[0], mat[MAT_ATTRIB_FRONT_EMISSION] );
      ACC_SCALE_3V( ctx->Light._BaseColor[0], mat[MAT_ATTRIB_FRONT_AMBIENT],
                    ctx->Light.Model.Ambient );
   }

   if (bitmask & (MAT_BIT_BACK_EMISSION | MAT_BIT_BACK_AMBIENT)) {
      COPY_3V( ctx->Light._BaseColor[1], mat[MAT_ATTRIB_BACK_EMISSION] );
      ACC_SCALE_3V( ctx->Light._BaseColor[1], mat[MAT_ATTRIB_BACK_AMBIENT],
                    ctx->Light.Model.Ambient );
   }

   /* update material diffuse values */
   if (bitmask & MAT_BIT_FRONT_DIFFUSE) {
      foreach (light, list) {
         SCALE_3V( light->_MatDiffuse[0], light->Diffuse, 
                   mat[MAT_ATTRIB_FRONT_DIFFUSE] );
      }
   }

   if (bitmask & MAT_BIT_BACK_DIFFUSE) {
      foreach (light, list) {
         SCALE_3V( light->_MatDiffuse[1], light->Diffuse, 
                   mat[MAT_ATTRIB_BACK_DIFFUSE] );
      }
   }

   /* update material specular values */
   if (bitmask & MAT_BIT_FRONT_SPECULAR) {
      foreach (light, list) {
         SCALE_3V( light->_MatSpecular[0], light->Specular, 
                   mat[MAT_ATTRIB_FRONT_SPECULAR]);
      }
   }

   if (bitmask & MAT_BIT_BACK_SPECULAR) {
      foreach (light, list) {
         SCALE_3V( light->_MatSpecular[1], light->Specular,
                   mat[MAT_ATTRIB_BACK_SPECULAR]);
      }
   }

   if (bitmask & MAT_BIT_FRONT_SHININESS) {
      _mesa_invalidate_shine_table( ctx, 0 );
   }

   if (bitmask & MAT_BIT_BACK_SHININESS) {
      _mesa_invalidate_shine_table( ctx, 1 );
   }
}


/*
 * Update the current materials from the given rgba color
 * according to the bitmask in ColorMaterialBitmask, which is
 * set by glColorMaterial().
 */
void
_mesa_update_color_material( GLcontext *ctx, const GLfloat color[4] )
{
   GLuint bitmask = ctx->Light.ColorMaterialBitmask;
   struct gl_material *mat = &ctx->Light.Material;
   int i;

   for (i = 0 ; i < MAT_ATTRIB_MAX ; i++) 
      if (bitmask & (1<<i))
         COPY_4FV( mat->Attrib[i], color );

   _mesa_update_material( ctx, bitmask );
}


void GLAPIENTRY
_mesa_ColorMaterial( GLenum face, GLenum mode )
{
   GET_CURRENT_CONTEXT(ctx);
   GLuint bitmask;
   GLuint legal = (MAT_BIT_FRONT_EMISSION | MAT_BIT_BACK_EMISSION |
                   MAT_BIT_FRONT_SPECULAR | MAT_BIT_BACK_SPECULAR |
                   MAT_BIT_FRONT_DIFFUSE  | MAT_BIT_BACK_DIFFUSE  |
                   MAT_BIT_FRONT_AMBIENT  | MAT_BIT_BACK_AMBIENT);
   ASSERT_OUTSIDE_BEGIN_END(ctx);

   if (MESA_VERBOSE&VERBOSE_API)
      _mesa_debug(ctx, "glColorMaterial %s %s\n",
                  _mesa_lookup_enum_by_nr(face),
                  _mesa_lookup_enum_by_nr(mode));

   bitmask = _mesa_material_bitmask(ctx, face, mode, legal, "glColorMaterial");

   if (ctx->Light.ColorMaterialBitmask == bitmask &&
       ctx->Light.ColorMaterialFace == face &&
       ctx->Light.ColorMaterialMode == mode)
      return;

   FLUSH_VERTICES(ctx, _NEW_LIGHT);
   ctx->Light.ColorMaterialBitmask = bitmask;
   ctx->Light.ColorMaterialFace = face;
   ctx->Light.ColorMaterialMode = mode;

   if (ctx->Light.ColorMaterialEnabled) {
      FLUSH_CURRENT( ctx, 0 );
      _mesa_update_color_material(ctx,ctx->Current.Attrib[VERT_ATTRIB_COLOR0]);
   }

   if (ctx->Driver.ColorMaterial)
      ctx->Driver.ColorMaterial( ctx, face, mode );
}


void GLAPIENTRY
_mesa_GetMaterialfv( GLenum face, GLenum pname, GLfloat *params )
{
   GET_CURRENT_CONTEXT(ctx);
   GLuint f;
   GLfloat (*mat)[4] = ctx->Light.Material.Attrib;
   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx); /* update materials */

   FLUSH_CURRENT(ctx, 0); /* update ctx->Light.Material from vertex buffer */

   if (face==GL_FRONT) {
      f = 0;
   }
   else if (face==GL_BACK) {
      f = 1;
   }
   else {
      _mesa_error( ctx, GL_INVALID_ENUM, "glGetMaterialfv(face)" );
      return;
   }

   switch (pname) {
      case GL_AMBIENT:
         COPY_4FV( params, mat[MAT_ATTRIB_AMBIENT(f)] );
         break;
      case GL_DIFFUSE:
         COPY_4FV( params, mat[MAT_ATTRIB_DIFFUSE(f)] );
         break;
      case GL_SPECULAR:
         COPY_4FV( params, mat[MAT_ATTRIB_SPECULAR(f)] );
         break;
      case GL_EMISSION:
         COPY_4FV( params, mat[MAT_ATTRIB_EMISSION(f)] );
         break;
      case GL_SHININESS:
         *params = mat[MAT_ATTRIB_SHININESS(f)][0];
         break;
      case GL_COLOR_INDEXES:
         params[0] = mat[MAT_ATTRIB_INDEXES(f)][0];
         params[1] = mat[MAT_ATTRIB_INDEXES(f)][1];
         params[2] = mat[MAT_ATTRIB_INDEXES(f)][2];
         break;
      default:
         _mesa_error( ctx, GL_INVALID_ENUM, "glGetMaterialfv(pname)" );
   }
}


void GLAPIENTRY
_mesa_GetMaterialiv( GLenum face, GLenum pname, GLint *params )
{
   GET_CURRENT_CONTEXT(ctx);
   GLuint f;
   GLfloat (*mat)[4] = ctx->Light.Material.Attrib;
   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx); /* update materials */

   FLUSH_CURRENT(ctx, 0); /* update ctx->Light.Material from vertex buffer */

   if (face==GL_FRONT) {
      f = 0;
   }
   else if (face==GL_BACK) {
      f = 1;
   }
   else {
      _mesa_error( ctx, GL_INVALID_ENUM, "glGetMaterialiv(face)" );
      return;
   }
   switch (pname) {
      case GL_AMBIENT:
         params[0] = FLOAT_TO_INT( mat[MAT_ATTRIB_AMBIENT(f)][0] );
         params[1] = FLOAT_TO_INT( mat[MAT_ATTRIB_AMBIENT(f)][1] );
         params[2] = FLOAT_TO_INT( mat[MAT_ATTRIB_AMBIENT(f)][2] );
         params[3] = FLOAT_TO_INT( mat[MAT_ATTRIB_AMBIENT(f)][3] );
         break;
      case GL_DIFFUSE:
         params[0] = FLOAT_TO_INT( mat[MAT_ATTRIB_DIFFUSE(f)][0] );
         params[1] = FLOAT_TO_INT( mat[MAT_ATTRIB_DIFFUSE(f)][1] );
         params[2] = FLOAT_TO_INT( mat[MAT_ATTRIB_DIFFUSE(f)][2] );
         params[3] = FLOAT_TO_INT( mat[MAT_ATTRIB_DIFFUSE(f)][3] );
         break;
      case GL_SPECULAR:
         params[0] = FLOAT_TO_INT( mat[MAT_ATTRIB_SPECULAR(f)][0] );
         params[1] = FLOAT_TO_INT( mat[MAT_ATTRIB_SPECULAR(f)][1] );
         params[2] = FLOAT_TO_INT( mat[MAT_ATTRIB_SPECULAR(f)][2] );
         params[3] = FLOAT_TO_INT( mat[MAT_ATTRIB_SPECULAR(f)][3] );
         break;
      case GL_EMISSION:
         params[0] = FLOAT_TO_INT( mat[MAT_ATTRIB_EMISSION(f)][0] );
         params[1] = FLOAT_TO_INT( mat[MAT_ATTRIB_EMISSION(f)][1] );
         params[2] = FLOAT_TO_INT( mat[MAT_ATTRIB_EMISSION(f)][2] );
         params[3] = FLOAT_TO_INT( mat[MAT_ATTRIB_EMISSION(f)][3] );
         break;
      case GL_SHININESS:
         *params = IROUND( mat[MAT_ATTRIB_SHININESS(f)][0] );
         break;
      case GL_COLOR_INDEXES:
         params[0] = IROUND( mat[MAT_ATTRIB_INDEXES(f)][0] );
         params[1] = IROUND( mat[MAT_ATTRIB_INDEXES(f)][1] );
         params[2] = IROUND( mat[MAT_ATTRIB_INDEXES(f)][2] );
         break;
      default:
         _mesa_error( ctx, GL_INVALID_ENUM, "glGetMaterialfv(pname)" );
   }
}



/**********************************************************************/
/*****                  Lighting computation                      *****/
/**********************************************************************/


/*
 * Notes:
 *   When two-sided lighting is enabled we compute the color (or index)
 *   for both the front and back side of the primitive.  Then, when the
 *   orientation of the facet is later learned, we can determine which
 *   color (or index) to use for rendering.
 *
 *   KW: We now know orientation in advance and only shade for
 *       the side or sides which are actually required.
 *
 * Variables:
 *   n = normal vector
 *   V = vertex position
 *   P = light source position
 *   Pe = (0,0,0,1)
 *
 * Precomputed:
 *   IF P[3]==0 THEN
 *       // light at infinity
 *       IF local_viewer THEN
 *           _VP_inf_norm = unit vector from V to P      // Precompute
 *       ELSE
 *           // eye at infinity
 *           _h_inf_norm = Normalize( VP + <0,0,1> )     // Precompute
 *       ENDIF
 *   ENDIF
 *
 * Functions:
 *   Normalize( v ) = normalized vector v
 *   Magnitude( v ) = length of vector v
 */



/*
 * Whenever the spotlight exponent for a light changes we must call
 * this function to recompute the exponent lookup table.
 */
void
_mesa_invalidate_spot_exp_table( struct gl_light *l )
{
   l->_SpotExpTable[0][0] = -1;
}


static void
validate_spot_exp_table( struct gl_light *l )
{
   GLint i;
   GLdouble exponent = l->SpotExponent;
   GLdouble tmp = 0;
   GLint clamp = 0;

   l->_SpotExpTable[0][0] = 0.0;

   for (i = EXP_TABLE_SIZE - 1; i > 0 ;i--) {
      if (clamp == 0) {
         tmp = _mesa_pow(i / (GLdouble) (EXP_TABLE_SIZE - 1), exponent);
         if (tmp < FLT_MIN * 100.0) {
            tmp = 0.0;
            clamp = 1;
         }
      }
      l->_SpotExpTable[i][0] = (GLfloat) tmp;
   }
   for (i = 0; i < EXP_TABLE_SIZE - 1; i++) {
      l->_SpotExpTable[i][1] = (l->_SpotExpTable[i+1][0] -
                                l->_SpotExpTable[i][0]);
   }
   l->_SpotExpTable[EXP_TABLE_SIZE-1][1] = 0.0;
}



/* Calculate a new shine table.  Doing this here saves a branch in
 * lighting, and the cost of doing it early may be partially offset
 * by keeping a MRU cache of shine tables for various shine values.
 */
void
_mesa_invalidate_shine_table( GLcontext *ctx, GLuint side )
{
   ASSERT(side < 2);
   if (ctx->_ShineTable[side])
      ctx->_ShineTable[side]->refcount--;
   ctx->_ShineTable[side] = NULL;
}


static void
validate_shine_table( GLcontext *ctx, GLuint side, GLfloat shininess )
{
   struct gl_shine_tab *list = ctx->_ShineTabList;
   struct gl_shine_tab *s;

   ASSERT(side < 2);

   foreach(s, list)
      if ( s->shininess == shininess )
         break;

   if (s == list) {
      GLint j;
      GLfloat *m;

      foreach(s, list)
         if (s->refcount == 0)
            break;

      m = s->tab;
      m[0] = 0.0;
      if (shininess == 0.0) {
         for (j = 1 ; j <= SHINE_TABLE_SIZE ; j++)
            m[j] = 1.0;
      }
      else {
         for (j = 1 ; j < SHINE_TABLE_SIZE ; j++) {
            GLdouble t, x = j / (GLfloat) (SHINE_TABLE_SIZE - 1);
            if (x < 0.005) /* underflow check */
               x = 0.005;
            t = _mesa_pow(x, shininess);
            if (t > 1e-20)
               m[j] = (GLfloat) t;
            else
               m[j] = 0.0;
         }
         m[SHINE_TABLE_SIZE] = 1.0;
      }

      s->shininess = shininess;
   }

   if (ctx->_ShineTable[side])
      ctx->_ShineTable[side]->refcount--;

   ctx->_ShineTable[side] = s;
   move_to_tail( list, s );
   s->refcount++;
}


void
_mesa_validate_all_lighting_tables( GLcontext *ctx )
{
   GLuint i;
   GLfloat shininess;
   
   shininess = ctx->Light.Material.Attrib[MAT_ATTRIB_FRONT_SHININESS][0];
   if (!ctx->_ShineTable[0] || ctx->_ShineTable[0]->shininess != shininess)
      validate_shine_table( ctx, 0, shininess );

   shininess = ctx->Light.Material.Attrib[MAT_ATTRIB_BACK_SHININESS][0];
   if (!ctx->_ShineTable[1] || ctx->_ShineTable[1]->shininess != shininess)
      validate_shine_table( ctx, 1, shininess );

   for (i = 0; i < ctx->Const.MaxLights; i++)
      if (ctx->Light.Light[i]._SpotExpTable[0][0] == -1)
         validate_spot_exp_table( &ctx->Light.Light[i] );
}


/**
 * Examine current lighting parameters to determine if the optimized lighting
 * function can be used.
 * Also, precompute some lighting values such as the products of light
 * source and material ambient, diffuse and specular coefficients.
 */
void
_mesa_update_lighting( GLcontext *ctx )
{
   struct gl_light *light;
   ctx->Light._NeedEyeCoords = GL_FALSE;
   ctx->Light._Flags = 0;

   if (!ctx->Light.Enabled)
      return;

   foreach(light, &ctx->Light.EnabledList) {
      ctx->Light._Flags |= light->_Flags;
   }

   ctx->Light._NeedVertices =
      ((ctx->Light._Flags & (LIGHT_POSITIONAL|LIGHT_SPOT)) ||
       ctx->Light.Model.ColorControl == GL_SEPARATE_SPECULAR_COLOR ||
       ctx->Light.Model.LocalViewer);

   ctx->Light._NeedEyeCoords = ((ctx->Light._Flags & LIGHT_POSITIONAL) ||
                                ctx->Light.Model.LocalViewer);

   /* XXX: This test is overkill & needs to be fixed both for software and
    * hardware t&l drivers.  The above should be sufficient & should
    * be tested to verify this.
    */
   if (ctx->Light._NeedVertices)
      ctx->Light._NeedEyeCoords = GL_TRUE;

   /* Precompute some shading values.  Although we reference
    * Light.Material here, we can get away without flushing
    * FLUSH_UPDATE_CURRENT, as when any outstanding material changes
    * are flushed, they will update the derived state at that time.
    */
   if (ctx->Visual.rgbMode) {
      if (ctx->Light.Model.TwoSide)
         _mesa_update_material( ctx, 
                                MAT_BIT_FRONT_EMISSION |
                                MAT_BIT_FRONT_AMBIENT |
                                MAT_BIT_FRONT_DIFFUSE | 
                                MAT_BIT_FRONT_SPECULAR |
                                MAT_BIT_BACK_EMISSION |
                                MAT_BIT_BACK_AMBIENT |
                                MAT_BIT_BACK_DIFFUSE | 
                                MAT_BIT_BACK_SPECULAR);
      else
         _mesa_update_material( ctx, 
                                MAT_BIT_FRONT_EMISSION |
                                MAT_BIT_FRONT_AMBIENT |
                                MAT_BIT_FRONT_DIFFUSE | 
                                MAT_BIT_FRONT_SPECULAR);
   }
   else {
      static const GLfloat ci[3] = { .30F, .59F, .11F };
      foreach(light, &ctx->Light.EnabledList) {
         light->_dli = DOT3(ci, light->Diffuse);
         light->_sli = DOT3(ci, light->Specular);
      }
   }
}


/**
 * Update state derived from light position, spot direction.
 * Called upon:
 *   _NEW_MODELVIEW
 *   _NEW_LIGHT
 *   _TNL_NEW_NEED_EYE_COORDS
 *
 * Update on (_NEW_MODELVIEW | _NEW_LIGHT) when lighting is enabled.
 * Also update on lighting space changes.
 */
static void
compute_light_positions( GLcontext *ctx )
{
   struct gl_light *light;
   static const GLfloat eye_z[3] = { 0, 0, 1 };

   if (!ctx->Light.Enabled)
      return;

   if (ctx->_NeedEyeCoords) {
      COPY_3V( ctx->_EyeZDir, eye_z );
   }
   else {
      TRANSFORM_NORMAL( ctx->_EyeZDir, eye_z, ctx->ModelviewMatrixStack.Top->m );
   }

   foreach (light, &ctx->Light.EnabledList) {

      if (ctx->_NeedEyeCoords) {
         /* _Position is in eye coordinate space */
         COPY_4FV( light->_Position, light->EyePosition );
      }
      else {
         /* _Position is in object coordinate space */
         TRANSFORM_POINT( light->_Position, ctx->ModelviewMatrixStack.Top->inv,
                          light->EyePosition );
      }

      if (!(light->_Flags & LIGHT_POSITIONAL)) {
         /* VP (VP) = Normalize( Position ) */
         COPY_3V( light->_VP_inf_norm, light->_Position );
         NORMALIZE_3FV( light->_VP_inf_norm );

         if (!ctx->Light.Model.LocalViewer) {
            /* _h_inf_norm = Normalize( V_to_P + <0,0,1> ) */
            ADD_3V( light->_h_inf_norm, light->_VP_inf_norm, ctx->_EyeZDir);
            NORMALIZE_3FV( light->_h_inf_norm );
         }
         light->_VP_inf_spot_attenuation = 1.0;
      }
      else {
         /* positional light w/ homogeneous coordinate, divide by W */
         GLfloat wInv = (GLfloat)1.0 / light->_Position[3];
         light->_Position[0] *= wInv;
         light->_Position[1] *= wInv;
         light->_Position[2] *= wInv;
      }

      if (light->_Flags & LIGHT_SPOT) {
         /* Note: we normalize the spot direction now */

         if (ctx->_NeedEyeCoords) {
            COPY_3V( light->_NormSpotDirection, light->SpotDirection );
            NORMALIZE_3FV( light->_NormSpotDirection );
         }
         else {
            GLfloat spotDir[3];
            COPY_3V(spotDir, light->SpotDirection);
            NORMALIZE_3FV(spotDir);
            TRANSFORM_NORMAL( light->_NormSpotDirection,
                              spotDir,
                              ctx->ModelviewMatrixStack.Top->m);
         }

         NORMALIZE_3FV( light->_NormSpotDirection );

         if (!(light->_Flags & LIGHT_POSITIONAL)) {
            GLfloat PV_dot_dir = - DOT3(light->_VP_inf_norm,
                                        light->_NormSpotDirection);

            if (PV_dot_dir > light->_CosCutoff) {
               double x = PV_dot_dir * (EXP_TABLE_SIZE-1);
               int k = (int) x;
               light->_VP_inf_spot_attenuation =
                  (GLfloat) (light->_SpotExpTable[k][0] +
                   (x-k)*light->_SpotExpTable[k][1]);
            }
            else {
               light->_VP_inf_spot_attenuation = 0;
            }
         }
      }
   }
}



static void
update_modelview_scale( GLcontext *ctx )
{
   ctx->_ModelViewInvScale = 1.0F;
   if (!_math_matrix_is_length_preserving(ctx->ModelviewMatrixStack.Top)) {
      const GLfloat *m = ctx->ModelviewMatrixStack.Top->inv;
      GLfloat f = m[2] * m[2] + m[6] * m[6] + m[10] * m[10];
      if (f < 1e-12) f = 1.0;
      if (ctx->_NeedEyeCoords)
         ctx->_ModelViewInvScale = (GLfloat) INV_SQRTF(f);
      else
         ctx->_ModelViewInvScale = (GLfloat) SQRTF(f);
   }
}


/**
 * Bring up to date any state that relies on _NeedEyeCoords.
 */
void
_mesa_update_tnl_spaces( GLcontext *ctx, GLuint new_state )
{
   const GLuint oldneedeyecoords = ctx->_NeedEyeCoords;

   (void) new_state;
   ctx->_NeedEyeCoords = GL_FALSE;

   if (ctx->_ForceEyeCoords ||
       (ctx->Texture._GenFlags & TEXGEN_NEED_EYE_COORD) ||
       ctx->Point._Attenuated ||
       ctx->Light._NeedEyeCoords)
      ctx->_NeedEyeCoords = GL_TRUE;

   if (ctx->Light.Enabled &&
       !_math_matrix_is_length_preserving(ctx->ModelviewMatrixStack.Top))
      ctx->_NeedEyeCoords = GL_TRUE;

   /* Check if the truth-value interpretations of the bitfields have
    * changed:
    */
   if (oldneedeyecoords != ctx->_NeedEyeCoords) {
      /* Recalculate all state that depends on _NeedEyeCoords.
       */
      update_modelview_scale(ctx);
      compute_light_positions( ctx );

      if (ctx->Driver.LightingSpaceChange)
         ctx->Driver.LightingSpaceChange( ctx );
   }
   else {
      GLuint new_state2 = ctx->NewState;

      /* Recalculate that same state only if it has been invalidated
       * by other statechanges.
       */
      if (new_state2 & _NEW_MODELVIEW)
         update_modelview_scale(ctx);

      if (new_state2 & (_NEW_LIGHT|_NEW_MODELVIEW))
         compute_light_positions( ctx );
   }
}


/**
 * Drivers may need this if the hardware tnl unit doesn't support the
 * light-in-modelspace optimization.  It's also useful for debugging.
 */
void
_mesa_allow_light_in_model( GLcontext *ctx, GLboolean flag )
{
   ctx->_ForceEyeCoords = !flag;
   ctx->NewState |= _NEW_POINT; /* one of the bits from
                                 * _MESA_NEW_NEED_EYE_COORDS.
                                 */
}



/**********************************************************************/
/*****                      Initialization                        *****/
/**********************************************************************/

/**
 * Initialize the n-th light data structure.
 *
 * \param l pointer to the gl_light structure to be initialized.
 * \param n number of the light. 
 * \note The defaults for light 0 are different than the other lights.
 */
static void
init_light( struct gl_light *l, GLuint n )
{
   make_empty_list( l );

   ASSIGN_4V( l->Ambient, 0.0, 0.0, 0.0, 1.0 );
   if (n==0) {
      ASSIGN_4V( l->Diffuse, 1.0, 1.0, 1.0, 1.0 );
      ASSIGN_4V( l->Specular, 1.0, 1.0, 1.0, 1.0 );
   }
   else {
      ASSIGN_4V( l->Diffuse, 0.0, 0.0, 0.0, 1.0 );
      ASSIGN_4V( l->Specular, 0.0, 0.0, 0.0, 1.0 );
   }
   ASSIGN_4V( l->EyePosition, 0.0, 0.0, 1.0, 0.0 );
   ASSIGN_3V( l->SpotDirection, 0.0, 0.0, -1.0 );
   l->SpotExponent = 0.0;
   _mesa_invalidate_spot_exp_table( l );
   l->SpotCutoff = 180.0;
   l->_CosCutoffNeg = -1.0f;
   l->_CosCutoff = 0.0;         /* KW: -ve values not admitted */
   l->ConstantAttenuation = 1.0;
   l->LinearAttenuation = 0.0;
   l->QuadraticAttenuation = 0.0;
   l->Enabled = GL_FALSE;
}


/**
 * Initialize the light model data structure.
 *
 * \param lm pointer to the gl_lightmodel structure to be initialized.
 */
static void
init_lightmodel( struct gl_lightmodel *lm )
{
   ASSIGN_4V( lm->Ambient, 0.2F, 0.2F, 0.2F, 1.0F );
   lm->LocalViewer = GL_FALSE;
   lm->TwoSide = GL_FALSE;
   lm->ColorControl = GL_SINGLE_COLOR;
}


/**
 * Initialize the material data structure.
 * 
 * \param m pointer to the gl_material structure to be initialized.
 */
static void
init_material( struct gl_material *m )
{
   ASSIGN_4V( m->Attrib[MAT_ATTRIB_FRONT_AMBIENT],  0.2F, 0.2F, 0.2F, 1.0F );
   ASSIGN_4V( m->Attrib[MAT_ATTRIB_FRONT_DIFFUSE],  0.8F, 0.8F, 0.8F, 1.0F );
   ASSIGN_4V( m->Attrib[MAT_ATTRIB_FRONT_SPECULAR], 0.0F, 0.0F, 0.0F, 1.0F );
   ASSIGN_4V( m->Attrib[MAT_ATTRIB_FRONT_EMISSION], 0.0F, 0.0F, 0.0F, 1.0F );
   ASSIGN_4V( m->Attrib[MAT_ATTRIB_FRONT_SHININESS], 0.0F, 0.0F, 0.0F, 0.0F );
   ASSIGN_4V( m->Attrib[MAT_ATTRIB_FRONT_INDEXES], 0.0F, 1.0F, 1.0F, 0.0F );
 
   ASSIGN_4V( m->Attrib[MAT_ATTRIB_BACK_AMBIENT],  0.2F, 0.2F, 0.2F, 1.0F );
   ASSIGN_4V( m->Attrib[MAT_ATTRIB_BACK_DIFFUSE],  0.8F, 0.8F, 0.8F, 1.0F );
   ASSIGN_4V( m->Attrib[MAT_ATTRIB_BACK_SPECULAR], 0.0F, 0.0F, 0.0F, 1.0F );
   ASSIGN_4V( m->Attrib[MAT_ATTRIB_BACK_EMISSION], 0.0F, 0.0F, 0.0F, 1.0F );
   ASSIGN_4V( m->Attrib[MAT_ATTRIB_BACK_SHININESS], 0.0F, 0.0F, 0.0F, 0.0F );
   ASSIGN_4V( m->Attrib[MAT_ATTRIB_BACK_INDEXES], 0.0F, 1.0F, 1.0F, 0.0F );
}


/**
 * Initialize all lighting state for the given context.
 */
void
_mesa_init_lighting( GLcontext *ctx )
{
   GLuint i;

   /* Lighting group */
   for (i = 0; i < MAX_LIGHTS; i++) {
      init_light( &ctx->Light.Light[i], i );
   }
   make_empty_list( &ctx->Light.EnabledList );

   init_lightmodel( &ctx->Light.Model );
   init_material( &ctx->Light.Material );
   ctx->Light.ShadeModel = GL_SMOOTH;
   ctx->Light.ProvokingVertex = GL_LAST_VERTEX_CONVENTION_EXT;
   ctx->Light.Enabled = GL_FALSE;
   ctx->Light.ColorMaterialFace = GL_FRONT_AND_BACK;
   ctx->Light.ColorMaterialMode = GL_AMBIENT_AND_DIFFUSE;
   ctx->Light.ColorMaterialBitmask = _mesa_material_bitmask( ctx,
                                               GL_FRONT_AND_BACK,
                                               GL_AMBIENT_AND_DIFFUSE, ~0,
                                               NULL );

   ctx->Light.ColorMaterialEnabled = GL_FALSE;
   ctx->Light.ClampVertexColor = GL_TRUE;

   /* Lighting miscellaneous */
   ctx->_ShineTabList = MALLOC_STRUCT( gl_shine_tab );
   make_empty_list( ctx->_ShineTabList );
   /* Allocate 10 (arbitrary) shininess lookup tables */
   for (i = 0 ; i < 10 ; i++) {
      struct gl_shine_tab *s = MALLOC_STRUCT( gl_shine_tab );
      s->shininess = -1;
      s->refcount = 0;
      insert_at_tail( ctx->_ShineTabList, s );
   }

   /* Miscellaneous */
   ctx->Light._NeedEyeCoords = GL_FALSE;
   ctx->_NeedEyeCoords = GL_FALSE;
   ctx->_ForceEyeCoords = GL_FALSE;
   ctx->_ModelViewInvScale = 1.0;
}


/**
 * Deallocate malloc'd lighting state attached to given context.
 */
void
_mesa_free_lighting_data( GLcontext *ctx )
{
   struct gl_shine_tab *s, *tmps;

   /* Free lighting shininess exponentiation table */
   foreach_s( s, tmps, ctx->_ShineTabList ) {
      _mesa_free( s );
   }
   _mesa_free( ctx->_ShineTabList );
}