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
34void 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
44void 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
54void 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      case GL_FOG_DISTANCE_MODE_NV:
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
82void GLAPIENTRY
83_mesa_Fogfv( GLenum pname, const GLfloat *params )
84{
85   GET_CURRENT_CONTEXT(ctx);
86   GLenum m;
87
88   switch (pname) {
89      case GL_FOG_MODE:
90         m = (GLenum) (GLint) *params;
91	 switch (m) {
92	 case GL_LINEAR:
93	    ctx->Fog._PackedMode = FOG_LINEAR;
94	    break;
95	 case GL_EXP:
96	    ctx->Fog._PackedMode = FOG_EXP;
97	    break;
98	 case GL_EXP2:
99	    ctx->Fog._PackedMode = FOG_EXP2;
100	    break;
101	 default:
102	    _mesa_error( ctx, GL_INVALID_ENUM, "glFog" );
103            return;
104	 }
105	 if (ctx->Fog.Mode == m)
106	    return;
107	 FLUSH_VERTICES(ctx, _NEW_FOG);
108	 ctx->Fog.Mode = m;
109	 ctx->Fog._PackedEnabledMode = ctx->Fog.Enabled ?
110				       ctx->Fog._PackedMode : FOG_NONE;
111	 break;
112      case GL_FOG_DENSITY:
113	 if (*params<0.0F) {
114	    _mesa_error( ctx, GL_INVALID_VALUE, "glFog" );
115            return;
116	 }
117	 if (ctx->Fog.Density == *params)
118	    return;
119	 FLUSH_VERTICES(ctx, _NEW_FOG);
120	 ctx->Fog.Density = *params;
121	 break;
122      case GL_FOG_START:
123         if (ctx->Fog.Start == *params)
124            return;
125         FLUSH_VERTICES(ctx, _NEW_FOG);
126         ctx->Fog.Start = *params;
127         break;
128      case GL_FOG_END:
129         if (ctx->Fog.End == *params)
130            return;
131         FLUSH_VERTICES(ctx, _NEW_FOG);
132         ctx->Fog.End = *params;
133         break;
134      case GL_FOG_INDEX:
135         if (ctx->API != API_OPENGL_COMPAT)
136            goto invalid_pname;
137 	 if (ctx->Fog.Index == *params)
138	    return;
139	 FLUSH_VERTICES(ctx, _NEW_FOG);
140 	 ctx->Fog.Index = *params;
141	 break;
142      case GL_FOG_COLOR:
143	 if (TEST_EQ_4V(ctx->Fog.Color, params))
144	    return;
145	 FLUSH_VERTICES(ctx, _NEW_FOG);
146	 ctx->Fog.ColorUnclamped[0] = params[0];
147	 ctx->Fog.ColorUnclamped[1] = params[1];
148	 ctx->Fog.ColorUnclamped[2] = params[2];
149	 ctx->Fog.ColorUnclamped[3] = params[3];
150	 ctx->Fog.Color[0] = CLAMP(params[0], 0.0F, 1.0F);
151	 ctx->Fog.Color[1] = CLAMP(params[1], 0.0F, 1.0F);
152	 ctx->Fog.Color[2] = CLAMP(params[2], 0.0F, 1.0F);
153	 ctx->Fog.Color[3] = CLAMP(params[3], 0.0F, 1.0F);
154         break;
155      case GL_FOG_COORDINATE_SOURCE_EXT: {
156	 GLenum p = (GLenum) (GLint) *params;
157         if (ctx->API != API_OPENGL_COMPAT ||
158             (p != GL_FOG_COORDINATE_EXT && p != GL_FRAGMENT_DEPTH_EXT)) {
159	    _mesa_error(ctx, GL_INVALID_ENUM, "glFog");
160	    return;
161	 }
162	 if (ctx->Fog.FogCoordinateSource == p)
163	    return;
164	 FLUSH_VERTICES(ctx, _NEW_FOG);
165	 ctx->Fog.FogCoordinateSource = p;
166	 break;
167      }
168      case GL_FOG_DISTANCE_MODE_NV: {
169	 GLenum p = (GLenum) (GLint) *params;
170         if (ctx->API != API_OPENGL_COMPAT || !ctx->Extensions.NV_fog_distance ||
171             (p != GL_EYE_RADIAL_NV && p != GL_EYE_PLANE && p != GL_EYE_PLANE_ABSOLUTE_NV)) {
172	    _mesa_error(ctx, GL_INVALID_ENUM, "glFog");
173	    return;
174	 }
175	 if (ctx->Fog.FogDistanceMode == p)
176	    return;
177	 FLUSH_VERTICES(ctx, _NEW_FOG);
178	 ctx->Fog.FogDistanceMode = p;
179	 break;
180      }
181      default:
182         goto invalid_pname;
183   }
184
185   if (ctx->Driver.Fogfv) {
186      ctx->Driver.Fogfv( ctx, pname, params );
187   }
188
189   return;
190
191invalid_pname:
192   _mesa_error( ctx, GL_INVALID_ENUM, "glFog" );
193   return;
194}
195
196
197/**********************************************************************/
198/*****                      Initialization                        *****/
199/**********************************************************************/
200
201void _mesa_init_fog( struct gl_context * ctx )
202{
203   /* Fog group */
204   ctx->Fog.Enabled = GL_FALSE;
205   ctx->Fog.Mode = GL_EXP;
206   ctx->Fog._PackedMode = FOG_EXP;
207   ctx->Fog._PackedEnabledMode = FOG_NONE;
208   ASSIGN_4V( ctx->Fog.Color, 0.0, 0.0, 0.0, 0.0 );
209   ASSIGN_4V( ctx->Fog.ColorUnclamped, 0.0, 0.0, 0.0, 0.0 );
210   ctx->Fog.Index = 0.0;
211   ctx->Fog.Density = 1.0;
212   ctx->Fog.Start = 0.0;
213   ctx->Fog.End = 1.0;
214   ctx->Fog.ColorSumEnabled = GL_FALSE;
215   ctx->Fog.FogCoordinateSource = GL_FRAGMENT_DEPTH_EXT;
216   ctx->Fog.FogDistanceMode = GL_EYE_PLANE_ABSOLUTE_NV;
217}
218