reactos/lib/mesa32/src/main/fog.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  5.1
   4  *
   5  * Copyright (C) 1999-2003  Brian Paul   All Rights Reserved.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a
   8  * copy of this software and associated documentation files (the "Software"),
   9  * to deal in the Software without restriction, including without limitation
  10  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  11  * and/or sell copies of the Software, and to permit persons to whom the
  12  * Software is furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included
  15  * in all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  18  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  20  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  21  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  22  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  23  */
  24
  25
  26 #include "glheader.h"
  27 #include "colormac.h"
  28 #include "context.h"
  29 #include "fog.h"
  30 #include "mtypes.h"
  31
  32
  33
  34 void GLAPIENTRY
  35 _mesa_Fogf(GLenum pname, GLfloat param)
  36 {
  37    _mesa_Fogfv(pname, &param);
  38 }
  39
  40
  41 void GLAPIENTRY
  42 _mesa_Fogi(GLenum pname, GLint param )
  43 {
  44    GLfloat fparam = (GLfloat) param;
  45    _mesa_Fogfv(pname, &fparam);
  46 }
  47
  48
  49 void GLAPIENTRY
  50 _mesa_Fogiv(GLenum pname, const GLint *params )
  51 {
  52    GLfloat p[4];
  53    switch (pname) {
  54       case GL_FOG_MODE:
  55       case GL_FOG_DENSITY:
  56       case GL_FOG_START:
  57       case GL_FOG_END:
  58       case GL_FOG_INDEX:
  59       case GL_FOG_COORDINATE_SOURCE_EXT:
  60          p[0] = (GLfloat) *params;
  61          break;
  62       case GL_FOG_COLOR:
  63          p[0] = INT_TO_FLOAT( params[0] );
  64          p[1] = INT_TO_FLOAT( params[1] );
  65          p[2] = INT_TO_FLOAT( params[2] );
  66          p[3] = INT_TO_FLOAT( params[3] );
  67          break;
  68       default:
  69          /* Error will be caught later in _mesa_Fogfv */
  70          ;
  71    }
  72    _mesa_Fogfv(pname, p);
  73 }
  74
  75
  76 void GLAPIENTRY
  77 _mesa_Fogfv( GLenum pname, const GLfloat *params )
  78 {
  79    GET_CURRENT_CONTEXT(ctx);
  80    GLenum m;
  81    ASSERT_OUTSIDE_BEGIN_END(ctx);
  82
  83    switch (pname) {
  84       case GL_FOG_MODE:
  85          m = (GLenum) (GLint) *params;
  86          switch (m) {
  87          case GL_LINEAR:
  88          case GL_EXP:
  89          case GL_EXP2:
  90             break;
  91          default:
  92             _mesa_error( ctx, GL_INVALID_ENUM, "glFog" );
  93             return;
  94          }
  95          if (ctx->Fog.Mode == m)
  96             return;
  97          FLUSH_VERTICES(ctx, _NEW_FOG);
  98          ctx->Fog.Mode = m;
  99          break;
 100       case GL_FOG_DENSITY:
 101          if (*params<0.0) {
 102             _mesa_error( ctx, GL_INVALID_VALUE, "glFog" );
 103             return;
 104          }
 105          if (ctx->Fog.Density == *params)
 106             return;
 107          FLUSH_VERTICES(ctx, _NEW_FOG);
 108          ctx->Fog.Density = *params;
 109          break;
 110       case GL_FOG_START:
 111          if (ctx->Fog.Start == *params)
 112             return;
 113          FLUSH_VERTICES(ctx, _NEW_FOG);
 114          ctx->Fog.Start = *params;
 115          break;
 116       case GL_FOG_END:
 117          if (ctx->Fog.End == *params)
 118             return;
 119          FLUSH_VERTICES(ctx, _NEW_FOG);
 120          ctx->Fog.End = *params;
 121          break;
 122       case GL_FOG_INDEX:
 123          if (ctx->Fog.Index == *params)
 124             return;
 125          FLUSH_VERTICES(ctx, _NEW_FOG);
 126          ctx->Fog.Index = *params;
 127          break;
 128       case GL_FOG_COLOR:
 129          if (TEST_EQ_4V(ctx->Fog.Color, params))
 130             return;
 131          FLUSH_VERTICES(ctx, _NEW_FOG);
 132          ctx->Fog.Color[0] = CLAMP(params[0], 0.0F, 1.0F);
 133          ctx->Fog.Color[1] = CLAMP(params[1], 0.0F, 1.0F);
 134          ctx->Fog.Color[2] = CLAMP(params[2], 0.0F, 1.0F);
 135          ctx->Fog.Color[3] = CLAMP(params[3], 0.0F, 1.0F);
 136          break;
 137       case GL_FOG_COORDINATE_SOURCE_EXT: {
 138          GLenum p = (GLenum) (GLint) *params;
 139          if (!ctx->Extensions.EXT_fog_coord ||
 140              (p != GL_FOG_COORDINATE_EXT && p != GL_FRAGMENT_DEPTH_EXT)) {
 141             _mesa_error(ctx, GL_INVALID_ENUM, "glFog");
 142             return;
 143          }
 144          if (ctx->Fog.FogCoordinateSource == p)
 145             return;
 146          FLUSH_VERTICES(ctx, _NEW_FOG);
 147          ctx->Fog.FogCoordinateSource = p;
 148          break;
 149       }
 150       default:
 151          _mesa_error( ctx, GL_INVALID_ENUM, "glFog" );
 152          return;
 153    }
 154
 155    if (ctx->Driver.Fogfv) {
 156       (*ctx->Driver.Fogfv)( ctx, pname, params );
 157    }
 158 }
 159
 160
 161 /**********************************************************************/
 162 /*****                      Initialization                        *****/
 163 /**********************************************************************/
 164
 165 void _mesa_init_fog( GLcontext * ctx )
 166 {
 167    /* Fog group */
 168    ctx->Fog.Enabled = GL_FALSE;
 169    ctx->Fog.Mode = GL_EXP;
 170    ASSIGN_4V( ctx->Fog.Color, 0.0, 0.0, 0.0, 0.0 );
 171    ctx->Fog.Index = 0.0;
 172    ctx->Fog.Density = 1.0;
 173    ctx->Fog.Start = 0.0;
 174    ctx->Fog.End = 1.0;
 175    ctx->Fog.ColorSumEnabled = GL_FALSE;
 176    ctx->Fog.FogCoordinateSource = GL_FRAGMENT_DEPTH_EXT;
 177 }