src/mesa/main/fog.c

   1 /* $Id: fog.c,v 1.36 2002/10/24 23:57:20 brianp Exp $ */
   2
   3 /*
   4  * Mesa 3-D graphics library
   5  * Version:  3.5
   6  *
   7  * Copyright (C) 1999-2001  Brian Paul   All Rights Reserved.
   8  *
   9  * Permission is hereby granted, free of charge, to any person obtaining a
  10  * copy of this software and associated documentation files (the "Software"),
  11  * to deal in the Software without restriction, including without limitation
  12  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  13  * and/or sell copies of the Software, and to permit persons to whom the
  14  * Software is furnished to do so, subject to the following conditions:
  15  *
  16  * The above copyright notice and this permission notice shall be included
  17  * in all copies or substantial portions of the Software.
  18  *
  19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  20  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  21  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  22  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  23  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  24  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  */
  26
  27
  28 #include "glheader.h"
  29 #include "colormac.h"
  30 #include "context.h"
  31 #include "fog.h"
  32 #include "mtypes.h"
  33
  34
  35
  36 void
  37 _mesa_Fogf(GLenum pname, GLfloat param)
  38 {
  39    _mesa_Fogfv(pname, &param);
  40 }
  41
  42
  43 void
  44 _mesa_Fogi(GLenum pname, GLint param )
  45 {
  46    GLfloat fparam = (GLfloat) param;
  47    _mesa_Fogfv(pname, &fparam);
  48 }
  49
  50
  51 void
  52 _mesa_Fogiv(GLenum pname, const GLint *params )
  53 {
  54    GLfloat p[4];
  55    switch (pname) {
  56       case GL_FOG_MODE:
  57       case GL_FOG_DENSITY:
  58       case GL_FOG_START:
  59       case GL_FOG_END:
  60       case GL_FOG_INDEX:
  61       case GL_FOG_COORDINATE_SOURCE_EXT:
  62          p[0] = (GLfloat) *params;
  63          break;
  64       case GL_FOG_COLOR:
  65          p[0] = INT_TO_FLOAT( params[0] );
  66          p[1] = INT_TO_FLOAT( params[1] );
  67          p[2] = INT_TO_FLOAT( params[2] );
  68          p[3] = INT_TO_FLOAT( params[3] );
  69          break;
  70       default:
  71          /* Error will be caught later in _mesa_Fogfv */
  72          ;
  73    }
  74    _mesa_Fogfv(pname, p);
  75 }
  76
  77
  78 void
  79 _mesa_Fogfv( GLenum pname, const GLfloat *params )
  80 {
  81    GET_CURRENT_CONTEXT(ctx);
  82    GLenum m;
  83    ASSERT_OUTSIDE_BEGIN_END(ctx);
  84
  85    switch (pname) {
  86       case GL_FOG_MODE:
  87          m = (GLenum) (GLint) *params;
  88          switch (m) {
  89          case GL_LINEAR:
  90          case GL_EXP:
  91          case GL_EXP2:
  92             break;
  93          default:
  94             _mesa_error( ctx, GL_INVALID_ENUM, "glFog" );
  95             return;
  96          }
  97          if (ctx->Fog.Mode == m)
  98             return;
  99          FLUSH_VERTICES(ctx, _NEW_FOG);
 100          ctx->Fog.Mode = m;
 101          break;
 102       case GL_FOG_DENSITY:
 103          if (*params<0.0) {
 104             _mesa_error( ctx, GL_INVALID_VALUE, "glFog" );
 105             return;
 106          }
 107          if (ctx->Fog.Density == *params)
 108             return;
 109          FLUSH_VERTICES(ctx, _NEW_FOG);
 110          ctx->Fog.Density = *params;
 111          break;
 112       case GL_FOG_START:
 113          if (ctx->Fog.Start == *params)
 114             return;
 115          FLUSH_VERTICES(ctx, _NEW_FOG);
 116          ctx->Fog.Start = *params;
 117          break;
 118       case GL_FOG_END:
 119          if (ctx->Fog.End == *params)
 120             return;
 121          FLUSH_VERTICES(ctx, _NEW_FOG);
 122          ctx->Fog.End = *params;
 123          break;
 124       case GL_FOG_INDEX:
 125          if (ctx->Fog.Index == *params)
 126             return;
 127          FLUSH_VERTICES(ctx, _NEW_FOG);
 128          ctx->Fog.Index = *params;
 129          break;
 130       case GL_FOG_COLOR:
 131          if (TEST_EQ_4V(ctx->Fog.Color, params))
 132             return;
 133          FLUSH_VERTICES(ctx, _NEW_FOG);
 134          ctx->Fog.Color[0] = params[0];
 135          ctx->Fog.Color[1] = params[1];
 136          ctx->Fog.Color[2] = params[2];
 137          ctx->Fog.Color[3] = params[3];
 138          break;
 139       case GL_FOG_COORDINATE_SOURCE_EXT: {
 140          GLenum p = (GLenum) (GLint) *params;
 141          if (!ctx->Extensions.EXT_fog_coord ||
 142              (p != GL_FOG_COORDINATE_EXT && p != GL_FRAGMENT_DEPTH_EXT)) {
 143             _mesa_error(ctx, GL_INVALID_ENUM, "glFog");
 144             return;
 145          }
 146          if (ctx->Fog.FogCoordinateSource == p)
 147             return;
 148          FLUSH_VERTICES(ctx, _NEW_FOG);
 149          ctx->Fog.FogCoordinateSource = p;
 150          break;
 151       }
 152       default:
 153          _mesa_error( ctx, GL_INVALID_ENUM, "glFog" );
 154          return;
 155    }
 156
 157    if (ctx->Driver.Fogfv) {
 158       (*ctx->Driver.Fogfv)( ctx, pname, params );
 159    }
 160 }