depth.c revision 3464ebd5 
1/*
2 * Mesa 3-D graphics library
3 * Version:  7.1
4 *
5 * Copyright (C) 1999-2007  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 "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   ASSERT_OUTSIDE_BEGIN_END(ctx);
46
47   if (MESA_VERBOSE & VERBOSE_API)
48      _mesa_debug(ctx, "glClearDepth(%f)\n", depth);
49
50   depth = CLAMP( depth, 0.0, 1.0 );
51
52   if (ctx->Depth.Clear == depth)
53      return;
54
55   FLUSH_VERTICES(ctx, _NEW_DEPTH);
56   ctx->Depth.Clear = depth;
57   if (ctx->Driver.ClearDepth)
58      (*ctx->Driver.ClearDepth)( ctx, ctx->Depth.Clear );
59}
60
61
62void GLAPIENTRY
63_mesa_ClearDepthf( GLclampf depth )
64{
65   _mesa_ClearDepth(depth);
66}
67
68
69void GLAPIENTRY
70_mesa_DepthFunc( GLenum func )
71{
72   GET_CURRENT_CONTEXT(ctx);
73   ASSERT_OUTSIDE_BEGIN_END(ctx);
74
75   if (MESA_VERBOSE & VERBOSE_API)
76      _mesa_debug(ctx, "glDepthFunc %s\n", _mesa_lookup_enum_by_nr(func));
77
78   switch (func) {
79   case GL_LESS:    /* (default) pass if incoming z < stored z */
80   case GL_GEQUAL:
81   case GL_LEQUAL:
82   case GL_GREATER:
83   case GL_NOTEQUAL:
84   case GL_EQUAL:
85   case GL_ALWAYS:
86   case GL_NEVER:
87      break;
88   default:
89      _mesa_error( ctx, GL_INVALID_ENUM, "glDepth.Func" );
90      return;
91   }
92
93   if (ctx->Depth.Func == func)
94      return;
95
96   FLUSH_VERTICES(ctx, _NEW_DEPTH);
97   ctx->Depth.Func = func;
98
99   if (ctx->Driver.DepthFunc)
100      ctx->Driver.DepthFunc( ctx, func );
101}
102
103
104
105void GLAPIENTRY
106_mesa_DepthMask( GLboolean flag )
107{
108   GET_CURRENT_CONTEXT(ctx);
109   ASSERT_OUTSIDE_BEGIN_END(ctx);
110
111   if (MESA_VERBOSE & VERBOSE_API)
112      _mesa_debug(ctx, "glDepthMask %d\n", flag);
113
114   /*
115    * GL_TRUE indicates depth buffer writing is enabled (default)
116    * GL_FALSE indicates depth buffer writing is disabled
117    */
118   if (ctx->Depth.Mask == flag)
119      return;
120
121   FLUSH_VERTICES(ctx, _NEW_DEPTH);
122   ctx->Depth.Mask = flag;
123
124   if (ctx->Driver.DepthMask)
125      ctx->Driver.DepthMask( ctx, flag );
126}
127
128
129
130/**
131 * Specified by the GL_EXT_depth_bounds_test extension.
132 */
133void GLAPIENTRY
134_mesa_DepthBoundsEXT( GLclampd zmin, GLclampd zmax )
135{
136   GET_CURRENT_CONTEXT(ctx);
137   ASSERT_OUTSIDE_BEGIN_END(ctx);
138
139   if (MESA_VERBOSE & VERBOSE_API)
140      _mesa_debug(ctx, "glDepthBounds(%f, %f)\n", zmin, zmax);
141
142   if (zmin > zmax) {
143      _mesa_error(ctx, GL_INVALID_VALUE, "glDepthBoundsEXT(zmin > zmax)");
144      return;
145   }
146
147   zmin = CLAMP(zmin, 0.0, 1.0);
148   zmax = CLAMP(zmax, 0.0, 1.0);
149
150   if (ctx->Depth.BoundsMin == zmin && ctx->Depth.BoundsMax == zmax)
151      return;
152
153   FLUSH_VERTICES(ctx, _NEW_DEPTH);
154   ctx->Depth.BoundsMin = (GLfloat) zmin;
155   ctx->Depth.BoundsMax = (GLfloat) zmax;
156}
157
158
159/**********************************************************************/
160/*****                      Initialization                        *****/
161/**********************************************************************/
162
163
164/**
165 * Initialize the depth buffer attribute group in the given context.
166 */
167void
168_mesa_init_depth(struct gl_context *ctx)
169{
170   ctx->Depth.Test = GL_FALSE;
171   ctx->Depth.Clear = 1.0;
172   ctx->Depth.Func = GL_LESS;
173   ctx->Depth.Mask = GL_TRUE;
174}
175