src/mesa/main/depth.c

   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  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  21  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  22  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  23  * OTHER DEALINGS IN THE SOFTWARE.
  24  */
  25
  26
  27 #include "glheader.h"
  28 #include "imports.h"
  29 #include "context.h"
  30 #include "depth.h"
  31 #include "enums.h"
  32 #include "macros.h"
  33 #include "mtypes.h"
  34
  35
  36 /**********************************************************************/
  37 /*****                          API Functions                     *****/
  38 /**********************************************************************/
  39
  40
  41
  42 void GLAPIENTRY
  43 _mesa_ClearDepth( GLclampd depth )
  44 {
  45    GET_CURRENT_CONTEXT(ctx);
  46
  47    if (MESA_VERBOSE & VERBOSE_API)
  48       _mesa_debug(ctx, "glClearDepth(%f)\n", depth);
  49
  50    ctx->Depth.Clear = CLAMP( depth, 0.0, 1.0 );
  51 }
  52
  53
  54 void GLAPIENTRY
  55 _mesa_ClearDepthf( GLclampf depth )
  56 {
  57    _mesa_ClearDepth(depth);
  58 }
  59
  60
  61 void GLAPIENTRY
  62 _mesa_DepthFunc( GLenum func )
  63 {
  64    GET_CURRENT_CONTEXT(ctx);
  65
  66    if (MESA_VERBOSE & VERBOSE_API)
  67       _mesa_debug(ctx, "glDepthFunc %s\n", _mesa_lookup_enum_by_nr(func));
  68
  69    switch (func) {
  70    case GL_LESS:    /* (default) pass if incoming z < stored z */
  71    case GL_GEQUAL:
  72    case GL_LEQUAL:
  73    case GL_GREATER:
  74    case GL_NOTEQUAL:
  75    case GL_EQUAL:
  76    case GL_ALWAYS:
  77    case GL_NEVER:
  78       break;
  79    default:
  80       _mesa_error( ctx, GL_INVALID_ENUM, "glDepth.Func" );
  81       return;
  82    }
  83
  84    if (ctx->Depth.Func == func)
  85       return;
  86
  87    FLUSH_VERTICES(ctx, _NEW_DEPTH);
  88    ctx->Depth.Func = func;
  89
  90    if (ctx->Driver.DepthFunc)
  91       ctx->Driver.DepthFunc( ctx, func );
  92 }
  93
  94
  95
  96 void GLAPIENTRY
  97 _mesa_DepthMask( GLboolean flag )
  98 {
  99    GET_CURRENT_CONTEXT(ctx);
 100
 101    if (MESA_VERBOSE & VERBOSE_API)
 102       _mesa_debug(ctx, "glDepthMask %d\n", flag);
 103
 104    /*
 105     * GL_TRUE indicates depth buffer writing is enabled (default)
 106     * GL_FALSE indicates depth buffer writing is disabled
 107     */
 108    if (ctx->Depth.Mask == flag)
 109       return;
 110
 111    FLUSH_VERTICES(ctx, _NEW_DEPTH);
 112    ctx->Depth.Mask = flag;
 113
 114    if (ctx->Driver.DepthMask)
 115       ctx->Driver.DepthMask( ctx, flag );
 116 }
 117
 118
 119
 120 /**
 121  * Specified by the GL_EXT_depth_bounds_test extension.
 122  */
 123 void GLAPIENTRY
 124 _mesa_DepthBoundsEXT( GLclampd zmin, GLclampd zmax )
 125 {
 126    GET_CURRENT_CONTEXT(ctx);
 127
 128    if (MESA_VERBOSE & VERBOSE_API)
 129       _mesa_debug(ctx, "glDepthBounds(%f, %f)\n", zmin, zmax);
 130
 131    if (zmin > zmax) {
 132       _mesa_error(ctx, GL_INVALID_VALUE, "glDepthBoundsEXT(zmin > zmax)");
 133       return;
 134    }
 135
 136    zmin = CLAMP(zmin, 0.0, 1.0);
 137    zmax = CLAMP(zmax, 0.0, 1.0);
 138
 139    if (ctx->Depth.BoundsMin == zmin && ctx->Depth.BoundsMax == zmax)
 140       return;
 141
 142    FLUSH_VERTICES(ctx, _NEW_DEPTH);
 143    ctx->Depth.BoundsMin = (GLfloat) zmin;
 144    ctx->Depth.BoundsMax = (GLfloat) zmax;
 145 }
 146
 147
 148 /**********************************************************************/
 149 /*****                      Initialization                        *****/
 150 /**********************************************************************/
 151
 152
 153 /**
 154  * Initialize the depth buffer attribute group in the given context.
 155  */
 156 void
 157 _mesa_init_depth(struct gl_context *ctx)
 158 {
 159    ctx->Depth.Test = GL_FALSE;
 160    ctx->Depth.Clear = 1.0;
 161    ctx->Depth.Func = GL_LESS;
 162    ctx->Depth.Mask = GL_TRUE;
 163 }