reactos/dll/opengl/mesa/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 "macros.h"
  31 #include "mtypes.h"
  32
  33
  34
  35 void GLAPIENTRY
  36 _mesa_Fogf(GLenum pname, GLfloat param)
  37 {
  38    GLfloat fparam[4];
  39    fparam[0] = param;
  40    fparam[1] = fparam[2] = fparam[3] = 0.0F;
  41    _mesa_Fogfv(pname, fparam);
  42 }
  43
  44
  45 void GLAPIENTRY
  46 _mesa_Fogi(GLenum pname, GLint param )
  47 {
  48    GLfloat fparam[4];
  49    fparam[0] = (GLfloat) param;
  50    fparam[1] = fparam[2] = fparam[3] = 0.0F;
  51    _mesa_Fogfv(pname, fparam);
  52 }
  53
  54
  55 void GLAPIENTRY
  56 _mesa_Fogiv(GLenum pname, const GLint *params )
  57 {
  58    GLfloat p[4];
  59    switch (pname) {
  60       case GL_FOG_MODE:
  61       case GL_FOG_DENSITY:
  62       case GL_FOG_START:
  63       case GL_FOG_END:
  64       case GL_FOG_INDEX:
  65       case GL_FOG_COORDINATE_SOURCE_EXT:
  66          p[0] = (GLfloat) *params;
  67          break;
  68       case GL_FOG_COLOR:
  69          p[0] = INT_TO_FLOAT( params[0] );
  70          p[1] = INT_TO_FLOAT( params[1] );
  71          p[2] = INT_TO_FLOAT( params[2] );
  72          p[3] = INT_TO_FLOAT( params[3] );
  73          break;
  74       default:
  75          /* Error will be caught later in _mesa_Fogfv */
  76          ASSIGN_4V(p, 0.0F, 0.0F, 0.0F, 0.0F);
  77    }
  78    _mesa_Fogfv(pname, p);
  79 }
  80
  81
  82 /**
  83  * Update the gl_fog_attrib::_Scale field.
  84  */
  85 static void
  86 update_fog_scale(struct gl_context *ctx)
  87 {
  88    if (ctx->Fog.End == ctx->Fog.Start)
  89       ctx->Fog._Scale = 1.0f;
  90    else
  91       ctx->Fog._Scale = 1.0f / (ctx->Fog.End - ctx->Fog.Start);
  92 }
  93
  94
  95 void GLAPIENTRY
  96 _mesa_Fogfv( GLenum pname, const GLfloat *params )
  97 {
  98    GET_CURRENT_CONTEXT(ctx);
  99    GLenum m;
 100    ASSERT_OUTSIDE_BEGIN_END(ctx);
 101
 102    switch (pname) {
 103       case GL_FOG_MODE:
 104          m = (GLenum) (GLint) *params;
 105          switch (m) {
 106          case GL_LINEAR:
 107          case GL_EXP:
 108          case GL_EXP2:
 109             break;
 110          default:
 111             _mesa_error( ctx, GL_INVALID_ENUM, "glFog" );
 112             return;
 113          }
 114          if (ctx->Fog.Mode == m)
 115             return;
 116          FLUSH_VERTICES(ctx, _NEW_FOG);
 117          ctx->Fog.Mode = m;
 118          break;
 119       case GL_FOG_DENSITY:
 120          if (*params<0.0) {
 121             _mesa_error( ctx, GL_INVALID_VALUE, "glFog" );
 122             return;
 123          }
 124          if (ctx->Fog.Density == *params)
 125             return;
 126          FLUSH_VERTICES(ctx, _NEW_FOG);
 127          ctx->Fog.Density = *params;
 128          break;
 129       case GL_FOG_START:
 130          if (ctx->Fog.Start == *params)
 131             return;
 132          FLUSH_VERTICES(ctx, _NEW_FOG);
 133          ctx->Fog.Start = *params;
 134          update_fog_scale(ctx);
 135          break;
 136       case GL_FOG_END:
 137          if (ctx->Fog.End == *params)
 138             return;
 139          FLUSH_VERTICES(ctx, _NEW_FOG);
 140          ctx->Fog.End = *params;
 141          update_fog_scale(ctx);
 142          break;
 143       case GL_FOG_INDEX:
 144          if (ctx->Fog.Index == *params)
 145             return;
 146          FLUSH_VERTICES(ctx, _NEW_FOG);
 147          ctx->Fog.Index = *params;
 148          break;
 149       case GL_FOG_COLOR:
 150          if (TEST_EQ_4V(ctx->Fog.Color, params))
 151             return;
 152          FLUSH_VERTICES(ctx, _NEW_FOG);
 153          ctx->Fog.Color[0] = params[0];
 154          ctx->Fog.Color[1] = params[1];
 155          ctx->Fog.Color[2] = params[2];
 156          ctx->Fog.Color[3] = params[3];
 157          break;
 158       case GL_FOG_COORDINATE_SOURCE_EXT: {
 159          GLenum p = (GLenum) (GLint) *params;
 160          if (!ctx->Extensions.EXT_fog_coord ||
 161              (p != GL_FOG_COORDINATE_EXT && p != GL_FRAGMENT_DEPTH_EXT)) {
 162             _mesa_error(ctx, GL_INVALID_ENUM, "glFog");
 163             return;
 164          }
 165          if (ctx->Fog.FogCoordinateSource == p)
 166             return;
 167          FLUSH_VERTICES(ctx, _NEW_FOG);
 168          ctx->Fog.FogCoordinateSource = p;
 169          break;
 170       }
 171       case GL_FOG_DISTANCE_MODE_NV: {
 172          GLenum p = (GLenum) (GLint) *params;
 173          if (!ctx->Extensions.NV_fog_distance ||
 174              (p != GL_EYE_RADIAL_NV && p != GL_EYE_PLANE && p != GL_EYE_PLANE_ABSOLUTE_NV)) {
 175             _mesa_error(ctx, GL_INVALID_ENUM, "glFog");
 176             return;
 177          }
 178          if (ctx->Fog.FogDistanceMode == p)
 179             return;
 180          FLUSH_VERTICES(ctx, _NEW_FOG);
 181          ctx->Fog.FogDistanceMode = p;
 182          break;
 183       }
 184       default:
 185          _mesa_error( ctx, GL_INVALID_ENUM, "glFog" );
 186          return;
 187    }
 188
 189    if (ctx->Driver.Fogfv) {
 190       (*ctx->Driver.Fogfv)( ctx, pname, params );
 191    }
 192 }
 193
 194
 195 /**********************************************************************/
 196 /*****                      Initialization                        *****/
 197 /**********************************************************************/
 198
 199 void _mesa_init_fog( struct gl_context * ctx )
 200 {
 201    /* Fog group */
 202    ctx->Fog.Enabled = GL_FALSE;
 203    ctx->Fog.Mode = GL_EXP;
 204    ASSIGN_4V( ctx->Fog.Color, 0.0, 0.0, 0.0, 0.0 );
 205    ctx->Fog.Index = 0.0;
 206    ctx->Fog.Density = 1.0;
 207    ctx->Fog.Start = 0.0;
 208    ctx->Fog.End = 1.0;
 209    ctx->Fog.ColorSumEnabled = GL_FALSE;
 210    ctx->Fog.FogCoordinateSource = GL_FRAGMENT_DEPTH_EXT;
 211    ctx->Fog._Scale = 1.0f;
 212    ctx->Fog.FogDistanceMode = GL_EYE_PLANE_ABSOLUTE_NV;
 213 }