src/mesa/main/fog.c

   1 /*
   2  * Mesa 3-D graphics library
   3  *
   4  * Copyright (C) 1999-2003  Brian Paul   All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the "Software"),
   8  * to deal in the Software without restriction, including without limitation
   9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  10  * and/or sell copies of the Software, and to permit persons to whom the
  11  * Software is furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included
  14  * in all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  17  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  20  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  21  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  22  * OTHER DEALINGS IN THE SOFTWARE.
  23  */
  24
  25
  26 #include "glheader.h"
  27 #include "context.h"
  28 #include "fog.h"
  29 #include "macros.h"
  30 #include "mtypes.h"
  31
  32
  33
  34 void GLAPIENTRY
  35 _mesa_Fogf(GLenum pname, GLfloat param)
  36 {
  37    GLfloat fparam[4];
  38    fparam[0] = param;
  39    fparam[1] = fparam[2] = fparam[3] = 0.0F;
  40    _mesa_Fogfv(pname, fparam);
  41 }
  42
  43
  44 void GLAPIENTRY
  45 _mesa_Fogi(GLenum pname, GLint param )
  46 {
  47    GLfloat fparam[4];
  48    fparam[0] = (GLfloat) param;
  49    fparam[1] = fparam[2] = fparam[3] = 0.0F;
  50    _mesa_Fogfv(pname, fparam);
  51 }
  52
  53
  54 void GLAPIENTRY
  55 _mesa_Fogiv(GLenum pname, const GLint *params )
  56 {
  57    GLfloat p[4];
  58    switch (pname) {
  59       case GL_FOG_MODE:
  60       case GL_FOG_DENSITY:
  61       case GL_FOG_START:
  62       case GL_FOG_END:
  63       case GL_FOG_INDEX:
  64       case GL_FOG_COORDINATE_SOURCE_EXT:
  65          p[0] = (GLfloat) *params;
  66          break;
  67       case GL_FOG_COLOR:
  68          p[0] = INT_TO_FLOAT( params[0] );
  69          p[1] = INT_TO_FLOAT( params[1] );
  70          p[2] = INT_TO_FLOAT( params[2] );
  71          p[3] = INT_TO_FLOAT( params[3] );
  72          break;
  73       default:
  74          /* Error will be caught later in _mesa_Fogfv */
  75          ASSIGN_4V(p, 0.0F, 0.0F, 0.0F, 0.0F);
  76    }
  77    _mesa_Fogfv(pname, p);
  78 }
  79
  80
  81 void GLAPIENTRY
  82 _mesa_Fogfv( GLenum pname, const GLfloat *params )
  83 {
  84    GET_CURRENT_CONTEXT(ctx);
  85    GLenum m;
  86
  87    switch (pname) {
  88       case GL_FOG_MODE:
  89          m = (GLenum) (GLint) *params;
  90          switch (m) {
  91          case GL_LINEAR:
  92             ctx->Fog._PackedMode = FOG_LINEAR;
  93             break;
  94          case GL_EXP:
  95             ctx->Fog._PackedMode = FOG_EXP;
  96             break;
  97          case GL_EXP2:
  98             ctx->Fog._PackedMode = FOG_EXP2;
  99             break;
 100          default:
 101             _mesa_error( ctx, GL_INVALID_ENUM, "glFog" );
 102             return;
 103          }
 104          if (ctx->Fog.Mode == m)
 105             return;
 106          FLUSH_VERTICES(ctx, _NEW_FOG);
 107          ctx->Fog.Mode = m;
 108          ctx->Fog._PackedEnabledMode = ctx->Fog.Enabled ?
 109                                        ctx->Fog._PackedMode : FOG_NONE;
 110          break;
 111       case GL_FOG_DENSITY:
 112          if (*params<0.0F) {
 113             _mesa_error( ctx, GL_INVALID_VALUE, "glFog" );
 114             return;
 115          }
 116          if (ctx->Fog.Density == *params)
 117             return;
 118          FLUSH_VERTICES(ctx, _NEW_FOG);
 119          ctx->Fog.Density = *params;
 120          break;
 121       case GL_FOG_START:
 122          if (ctx->Fog.Start == *params)
 123             return;
 124          FLUSH_VERTICES(ctx, _NEW_FOG);
 125          ctx->Fog.Start = *params;
 126          break;
 127       case GL_FOG_END:
 128          if (ctx->Fog.End == *params)
 129             return;
 130          FLUSH_VERTICES(ctx, _NEW_FOG);
 131          ctx->Fog.End = *params;
 132          break;
 133       case GL_FOG_INDEX:
 134          if (ctx->API != API_OPENGL_COMPAT)
 135             goto invalid_pname;
 136          if (ctx->Fog.Index == *params)
 137             return;
 138          FLUSH_VERTICES(ctx, _NEW_FOG);
 139          ctx->Fog.Index = *params;
 140          break;
 141       case GL_FOG_COLOR:
 142          if (TEST_EQ_4V(ctx->Fog.Color, params))
 143             return;
 144          FLUSH_VERTICES(ctx, _NEW_FOG);
 145          ctx->Fog.ColorUnclamped[0] = params[0];
 146          ctx->Fog.ColorUnclamped[1] = params[1];
 147          ctx->Fog.ColorUnclamped[2] = params[2];
 148          ctx->Fog.ColorUnclamped[3] = params[3];
 149          ctx->Fog.Color[0] = CLAMP(params[0], 0.0F, 1.0F);
 150          ctx->Fog.Color[1] = CLAMP(params[1], 0.0F, 1.0F);
 151          ctx->Fog.Color[2] = CLAMP(params[2], 0.0F, 1.0F);
 152          ctx->Fog.Color[3] = CLAMP(params[3], 0.0F, 1.0F);
 153          break;
 154       case GL_FOG_COORDINATE_SOURCE_EXT: {
 155          GLenum p = (GLenum) (GLint) *params;
 156          if (ctx->API != API_OPENGL_COMPAT ||
 157              (p != GL_FOG_COORDINATE_EXT && p != GL_FRAGMENT_DEPTH_EXT)) {
 158             _mesa_error(ctx, GL_INVALID_ENUM, "glFog");
 159             return;
 160          }
 161          if (ctx->Fog.FogCoordinateSource == p)
 162             return;
 163          FLUSH_VERTICES(ctx, _NEW_FOG);
 164          ctx->Fog.FogCoordinateSource = p;
 165          break;
 166       }
 167       case GL_FOG_DISTANCE_MODE_NV: {
 168          GLenum p = (GLenum) (GLint) *params;
 169          if (ctx->API != API_OPENGL_COMPAT || !ctx->Extensions.NV_fog_distance ||
 170              (p != GL_EYE_RADIAL_NV && p != GL_EYE_PLANE && p != GL_EYE_PLANE_ABSOLUTE_NV)) {
 171             _mesa_error(ctx, GL_INVALID_ENUM, "glFog");
 172             return;
 173          }
 174          if (ctx->Fog.FogDistanceMode == p)
 175             return;
 176          FLUSH_VERTICES(ctx, _NEW_FOG);
 177          ctx->Fog.FogDistanceMode = p;
 178          break;
 179       }
 180       default:
 181          goto invalid_pname;
 182    }
 183
 184    if (ctx->Driver.Fogfv) {
 185       ctx->Driver.Fogfv( ctx, pname, params );
 186    }
 187
 188    return;
 189
 190 invalid_pname:
 191    _mesa_error( ctx, GL_INVALID_ENUM, "glFog" );
 192    return;
 193 }
 194
 195
 196 /**********************************************************************/
 197 /*****                      Initialization                        *****/
 198 /**********************************************************************/
 199
 200 void _mesa_init_fog( struct gl_context * ctx )
 201 {
 202    /* Fog group */
 203    ctx->Fog.Enabled = GL_FALSE;
 204    ctx->Fog.Mode = GL_EXP;
 205    ctx->Fog._PackedMode = FOG_EXP;
 206    ctx->Fog._PackedEnabledMode = FOG_NONE;
 207    ASSIGN_4V( ctx->Fog.Color, 0.0, 0.0, 0.0, 0.0 );
 208    ASSIGN_4V( ctx->Fog.ColorUnclamped, 0.0, 0.0, 0.0, 0.0 );
 209    ctx->Fog.Index = 0.0;
 210    ctx->Fog.Density = 1.0;
 211    ctx->Fog.Start = 0.0;
 212    ctx->Fog.End = 1.0;
 213    ctx->Fog.ColorSumEnabled = GL_FALSE;
 214    ctx->Fog.FogCoordinateSource = GL_FRAGMENT_DEPTH_EXT;
 215    ctx->Fog.FogDistanceMode = GL_EYE_PLANE_ABSOLUTE_NV;
 216 }