Subversion Repositories shark

Rev

Rev 55 | Details | Compare with Previous | Last modification | View Log | RSS feed

Rev Author Line No. Line
55 pj 1
/* $Id: clip.c,v 1.1 2003-02-28 11:41:58 pj Exp $ */
2
 
3
/*
4
 * Mesa 3-D graphics library
5
 * Version:  3.5
6
 *
7
 * Copyright (C) 1999-2001  Brian Paul   All Rights Reserved.
8
 *
9
 * Permission is hereby granted, free of charge, to any person obtaining a
10
 * copy of this software and associated documentation files (the "Software"),
11
 * to deal in the Software without restriction, including without limitation
12
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
13
 * and/or sell copies of the Software, and to permit persons to whom the
14
 * Software is furnished to do so, subject to the following conditions:
15
 *
16
 * The above copyright notice and this permission notice shall be included
17
 * in all copies or substantial portions of the Software.
18
 *
19
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
20
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
21
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
22
 * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
23
 * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
24
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
25
 */
26
 
27
 
28
#include "glheader.h"
29
#include "clip.h"
30
#include "context.h"
31
#include "macros.h"
32
#include "mmath.h"
33
#include "mtypes.h"
34
 
35
#include "math/m_xform.h"
36
#include "math/m_matrix.h"
37
 
38
 
39
 
40
/**********************************************************************/
41
/*                     Get/Set User clip-planes.                      */
42
/**********************************************************************/
43
 
44
 
45
 
46
void
47
_mesa_ClipPlane( GLenum plane, const GLdouble *eq )
48
{
49
   GET_CURRENT_CONTEXT(ctx);
50
   GLint p;
51
   GLfloat equation[4];
52
   ASSERT_OUTSIDE_BEGIN_END(ctx);
53
 
54
   p = (GLint) plane - (GLint) GL_CLIP_PLANE0;
55
   if (p < 0 || p >= (GLint) ctx->Const.MaxClipPlanes) {
56
      _mesa_error( ctx, GL_INVALID_ENUM, "glClipPlane" );
57
      return;
58
   }
59
 
60
   equation[0] = (GLfloat) eq[0];
61
   equation[1] = (GLfloat) eq[1];
62
   equation[2] = (GLfloat) eq[2];
63
   equation[3] = (GLfloat) eq[3];
64
 
65
   /*
66
    * The equation is transformed by the transpose of the inverse of the
67
    * current modelview matrix and stored in the resulting eye coordinates.
68
    *
69
    * KW: Eqn is then transformed to the current clip space, where user
70
    * clipping now takes place.  The clip-space equations are recalculated
71
    * whenever the projection matrix changes.
72
    */
73
   if (ctx->ModelviewMatrixStack.Top->flags & MAT_DIRTY)
74
      _math_matrix_analyse( ctx->ModelviewMatrixStack.Top );
75
 
76
   _mesa_transform_vector( equation, equation,
77
                           ctx->ModelviewMatrixStack.Top->inv );
78
 
79
   if (TEST_EQ_4V(ctx->Transform.EyeUserPlane[p], equation))
80
      return;
81
 
82
   FLUSH_VERTICES(ctx, _NEW_TRANSFORM);
83
   COPY_4FV(ctx->Transform.EyeUserPlane[p], equation);
84
 
85
   /* Update derived state.  This state also depends on the projection
86
    * matrix, and is recalculated on changes to the projection matrix by
87
    * code in _mesa_update_state().
88
    */
89
   if (ctx->Transform.ClipPlanesEnabled & (1 << p)) {
90
      if (ctx->ProjectionMatrixStack.Top->flags & MAT_DIRTY)
91
         _math_matrix_analyse( ctx->ProjectionMatrixStack.Top );
92
 
93
      _mesa_transform_vector( ctx->Transform._ClipUserPlane[p],
94
                           ctx->Transform.EyeUserPlane[p],
95
                           ctx->ProjectionMatrixStack.Top->inv );
96
   }
97
 
98
   if (ctx->Driver.ClipPlane)
99
      ctx->Driver.ClipPlane( ctx, plane, equation );
100
}
101
 
102
 
103
void
104
_mesa_GetClipPlane( GLenum plane, GLdouble *equation )
105
{
106
   GET_CURRENT_CONTEXT(ctx);
107
   GLint p;
108
   ASSERT_OUTSIDE_BEGIN_END(ctx);
109
 
110
   p = (GLint) (plane - GL_CLIP_PLANE0);
111
   if (p < 0 || p >= (GLint) ctx->Const.MaxClipPlanes) {
112
      _mesa_error( ctx, GL_INVALID_ENUM, "glGetClipPlane" );
113
      return;
114
   }
115
 
116
   equation[0] = (GLdouble) ctx->Transform.EyeUserPlane[p][0];
117
   equation[1] = (GLdouble) ctx->Transform.EyeUserPlane[p][1];
118
   equation[2] = (GLdouble) ctx->Transform.EyeUserPlane[p][2];
119
   equation[3] = (GLdouble) ctx->Transform.EyeUserPlane[p][3];
120
}