src/mesa/main/depth.c

   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
  41 void 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
  53 void GLAPIENTRY
  54 _mesa_ClearDepthf( GLclampf depth )
  55 {
  56    _mesa_ClearDepth(depth);
  57 }
  58
  59
  60 void 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    if (ctx->Depth.Func == func)
  69       return;
  70
  71    switch (func) {
  72    case GL_LESS:    /* (default) pass if incoming z < stored z */
  73    case GL_GEQUAL:
  74    case GL_LEQUAL:
  75    case GL_GREATER:
  76    case GL_NOTEQUAL:
  77    case GL_EQUAL:
  78    case GL_ALWAYS:
  79    case GL_NEVER:
  80       break;
  81    default:
  82       _mesa_error( ctx, GL_INVALID_ENUM, "glDepth.Func" );
  83       return;
  84    }
  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
  95 void 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  */
 122 void 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  */
 155 void
 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 }