src/mesa/main/fog.c

   1 /* $Id: fog.c,v 1.31 2000/12/26 05:09:28 keithw Exp $ */
   2
   3 /*
   4  * Mesa 3-D graphics library
   5  * Version:  3.5
   6  *
   7  * Copyright (C) 1999-2000  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 #ifdef PC_HEADER
  29 #include "all.h"
  30 #else
  31 #include "glheader.h"
  32 #include "colormac.h"
  33 #include "context.h"
  34 #include "fog.h"
  35 #include "mtypes.h"
  36 #endif
  37
  38
  39
  40 void
  41 _mesa_Fogf(GLenum pname, GLfloat param)
  42 {
  43    _mesa_Fogfv(pname, &param);
  44 }
  45
  46
  47 void
  48 _mesa_Fogi(GLenum pname, GLint param )
  49 {
  50    GLfloat fparam = (GLfloat) param;
  51    _mesa_Fogfv(pname, &fparam);
  52 }
  53
  54
  55 void
  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          ;
  77    }
  78    _mesa_Fogfv(pname, p);
  79 }
  80
  81
  82 void
  83 _mesa_Fogfv( GLenum pname, const GLfloat *params )
  84 {
  85    GET_CURRENT_CONTEXT(ctx);
  86    GLenum m;
  87    ASSERT_OUTSIDE_BEGIN_END(ctx);
  88
  89    switch (pname) {
  90       case GL_FOG_MODE:
  91          m = (GLenum) (GLint) *params;
  92          if (ctx->Fog.Mode == m)
  93             return;
  94          switch (m) {
  95          case GL_LINEAR:
  96          case GL_EXP:
  97          case GL_EXP2:
  98             break;
  99          default:
 100             gl_error( ctx, GL_INVALID_ENUM, "glFog" );
 101             return;
 102          }
 103          FLUSH_VERTICES(ctx, _NEW_FOG);
 104          ctx->Fog.Mode = m;
 105          break;
 106       case GL_FOG_DENSITY:
 107          if (*params<0.0) {
 108             gl_error( ctx, GL_INVALID_VALUE, "glFog" );
 109             return;
 110          }
 111          if (ctx->Fog.Density == *params)
 112             return;
 113          FLUSH_VERTICES(ctx, _NEW_FOG);
 114          ctx->Fog.Density = *params;
 115          break;
 116       case GL_FOG_START:
 117          if (ctx->Fog.Start == *params)
 118             return;
 119          FLUSH_VERTICES(ctx, _NEW_FOG);
 120          ctx->Fog.Start = *params;
 121          break;
 122       case GL_FOG_END:
 123          if (ctx->Fog.End == *params)
 124             return;
 125          FLUSH_VERTICES(ctx, _NEW_FOG);
 126          ctx->Fog.End = *params;
 127          break;
 128       case GL_FOG_INDEX:
 129          if (ctx->Fog.Index == *params)
 130             return;
 131          FLUSH_VERTICES(ctx, _NEW_FOG);
 132          ctx->Fog.Index = *params;
 133          break;
 134       case GL_FOG_COLOR:
 135          if (TEST_EQ_4V(ctx->Fog.Color, params))
 136             return;
 137          FLUSH_VERTICES(ctx, _NEW_FOG);
 138          ctx->Fog.Color[0] = params[0];
 139          ctx->Fog.Color[1] = params[1];
 140          ctx->Fog.Color[2] = params[2];
 141          ctx->Fog.Color[3] = params[3];
 142          break;
 143       case GL_FOG_COORDINATE_SOURCE_EXT: {
 144          GLenum p = (GLenum)(GLint) *params;
 145          if (ctx->Fog.FogCoordinateSource == p)
 146             return;
 147          if (p != GL_FOG_COORDINATE_EXT && p != GL_FRAGMENT_DEPTH_EXT) {
 148             gl_error( ctx, GL_INVALID_ENUM, "glFog" );
 149             return;
 150          }
 151          FLUSH_VERTICES(ctx, _NEW_FOG);
 152          ctx->Fog.FogCoordinateSource = p;
 153          break;
 154       }
 155       default:
 156          gl_error( ctx, GL_INVALID_ENUM, "glFog" );
 157          return;
 158    }
 159
 160    if (ctx->Driver.Fogfv) {
 161       (*ctx->Driver.Fogfv)( ctx, pname, params );
 162    }
 163
 164    ctx->NewState |= _NEW_FOG;
 165 }
 166
 167