depth.c revision af69d88d 
1/*
2 * Mesa 3-D graphics library
3 *
4 * Copyright (C) 1999-2007  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 "imports.h"
28#include "context.h"
29#include "depth.h"
30#include "enums.h"
31#include "macros.h"
32#include "mtypes.h"
33
34
35/**********************************************************************/
36/*****                          API Functions                     *****/
37/**********************************************************************/
38
39
40
41void GLAPIENTRY
42_mesa_ClearDepth( GLclampd depth )
43{
44   GET_CURRENT_CONTEXT(ctx);
45
46   if (MESA_VERBOSE & VERBOSE_API)
47      _mesa_debug(ctx, "glClearDepth(%f)\n", depth);
48
49   ctx->Depth.Clear = CLAMP( depth, 0.0, 1.0 );
50}
51
52
53void GLAPIENTRY
54_mesa_ClearDepthf( GLclampf depth )
55{
56   _mesa_ClearDepth(depth);
57}
58
59
60void GLAPIENTRY
61_mesa_DepthFunc( GLenum func )
62{
63   GET_CURRENT_CONTEXT(ctx);
64
65   if (MESA_VERBOSE & VERBOSE_API)
66      _mesa_debug(ctx, "glDepthFunc %s\n", _mesa_lookup_enum_by_nr(func));
67
68   switch (func) {
69   case GL_LESS:    /* (default) pass if incoming z < stored z */
70   case GL_GEQUAL:
71   case GL_LEQUAL:
72   case GL_GREATER:
73   case GL_NOTEQUAL:
74   case GL_EQUAL:
75   case GL_ALWAYS:
76   case GL_NEVER:
77      break;
78   default:
79      _mesa_error( ctx, GL_INVALID_ENUM, "glDepth.Func" );
80      return;
81   }
82
83   if (ctx->Depth.Func == func)
84      return;
85
86   FLUSH_VERTICES(ctx, _NEW_DEPTH);
87   ctx->Depth.Func = func;
88
89   if (ctx->Driver.DepthFunc)
90      ctx->Driver.DepthFunc( ctx, func );
91}
92
93
94
95void GLAPIENTRY
96_mesa_DepthMask( GLboolean flag )
97{
98   GET_CURRENT_CONTEXT(ctx);
99
100   if (MESA_VERBOSE & VERBOSE_API)
101      _mesa_debug(ctx, "glDepthMask %d\n", flag);
102
103   /*
104    * GL_TRUE indicates depth buffer writing is enabled (default)
105    * GL_FALSE indicates depth buffer writing is disabled
106    */
107   if (ctx->Depth.Mask == flag)
108      return;
109
110   FLUSH_VERTICES(ctx, _NEW_DEPTH);
111   ctx->Depth.Mask = flag;
112
113   if (ctx->Driver.DepthMask)
114      ctx->Driver.DepthMask( ctx, flag );
115}
116
117
118
119/**
120 * Specified by the GL_EXT_depth_bounds_test extension.
121 */
122void GLAPIENTRY
123_mesa_DepthBoundsEXT( GLclampd zmin, GLclampd zmax )
124{
125   GET_CURRENT_CONTEXT(ctx);
126
127   if (MESA_VERBOSE & VERBOSE_API)
128      _mesa_debug(ctx, "glDepthBounds(%f, %f)\n", zmin, zmax);
129
130   if (zmin > zmax) {
131      _mesa_error(ctx, GL_INVALID_VALUE, "glDepthBoundsEXT(zmin > zmax)");
132      return;
133   }
134
135   zmin = CLAMP(zmin, 0.0, 1.0);
136   zmax = CLAMP(zmax, 0.0, 1.0);
137
138   if (ctx->Depth.BoundsMin == zmin && ctx->Depth.BoundsMax == zmax)
139      return;
140
141   FLUSH_VERTICES(ctx, _NEW_DEPTH);
142   ctx->Depth.BoundsMin = (GLfloat) zmin;
143   ctx->Depth.BoundsMax = (GLfloat) zmax;
144}
145
146
147/**********************************************************************/
148/*****                      Initialization                        *****/
149/**********************************************************************/
150
151
152/**
153 * Initialize the depth buffer attribute group in the given context.
154 */
155void
156_mesa_init_depth(struct gl_context *ctx)
157{
158   ctx->Depth.Test = GL_FALSE;
159   ctx->Depth.Clear = 1.0;
160   ctx->Depth.Func = GL_LESS;
161   ctx->Depth.Mask = GL_TRUE;
162}
163