clip.c revision 19dff5efc1e348d037b1b3cdfb9ac91020ecde4d 
1/*
2 * Mesa 3-D graphics library
3 * Version:  6.3
4 *
5 * Copyright (C) 1999-2005  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 "clip.h"
28#include "context.h"
29#include "macros.h"
30#include "mtypes.h"
31
32#include "math/m_matrix.h"
33
34
35
36/**********************************************************************/
37/*                     Get/Set User clip-planes.                      */
38/**********************************************************************/
39
40
41
42void GLAPIENTRY
43_mesa_ClipPlane( GLenum plane, const GLdouble *eq )
44{
45   GET_CURRENT_CONTEXT(ctx);
46   GLint p;
47   GLfloat equation[4];
48   ASSERT_OUTSIDE_BEGIN_END(ctx);
49
50   p = (GLint) plane - (GLint) GL_CLIP_PLANE0;
51   if (p < 0 || p >= (GLint) ctx->Const.MaxClipPlanes) {
52      _mesa_error( ctx, GL_INVALID_ENUM, "glClipPlane" );
53      return;
54   }
55
56   equation[0] = (GLfloat) eq[0];
57   equation[1] = (GLfloat) eq[1];
58   equation[2] = (GLfloat) eq[2];
59   equation[3] = (GLfloat) eq[3];
60
61   /*
62    * The equation is transformed by the transpose of the inverse of the
63    * current modelview matrix and stored in the resulting eye coordinates.
64    *
65    * KW: Eqn is then transformed to the current clip space, where user
66    * clipping now takes place.  The clip-space equations are recalculated
67    * whenever the projection matrix changes.
68    */
69   if (_math_matrix_is_dirty(ctx->ModelviewMatrixStack.Top))
70      _math_matrix_analyse( ctx->ModelviewMatrixStack.Top );
71
72   _mesa_transform_vector( equation, equation,
73                           ctx->ModelviewMatrixStack.Top->inv );
74
75   if (TEST_EQ_4V(ctx->Transform.EyeUserPlane[p], equation))
76      return;
77
78   FLUSH_VERTICES(ctx, _NEW_TRANSFORM);
79   COPY_4FV(ctx->Transform.EyeUserPlane[p], equation);
80
81   /* Update derived state.  This state also depends on the projection
82    * matrix, and is recalculated on changes to the projection matrix by
83    * code in _mesa_update_state().
84    */
85   if (ctx->Transform.ClipPlanesEnabled & (1 << p)) {
86      if (_math_matrix_is_dirty(ctx->ProjectionMatrixStack.Top))
87         _math_matrix_analyse( ctx->ProjectionMatrixStack.Top );
88
89      _mesa_transform_vector( ctx->Transform._ClipUserPlane[p],
90			   ctx->Transform.EyeUserPlane[p],
91			   ctx->ProjectionMatrixStack.Top->inv );
92   }
93
94   if (ctx->Driver.ClipPlane)
95      ctx->Driver.ClipPlane( ctx, plane, equation );
96}
97
98
99void GLAPIENTRY
100_mesa_GetClipPlane( GLenum plane, GLdouble *equation )
101{
102   GET_CURRENT_CONTEXT(ctx);
103   GLint p;
104   ASSERT_OUTSIDE_BEGIN_END(ctx);
105
106   p = (GLint) (plane - GL_CLIP_PLANE0);
107   if (p < 0 || p >= (GLint) ctx->Const.MaxClipPlanes) {
108      _mesa_error( ctx, GL_INVALID_ENUM, "glGetClipPlane" );
109      return;
110   }
111
112   equation[0] = (GLdouble) ctx->Transform.EyeUserPlane[p][0];
113   equation[1] = (GLdouble) ctx->Transform.EyeUserPlane[p][1];
114   equation[2] = (GLdouble) ctx->Transform.EyeUserPlane[p][2];
115   equation[3] = (GLdouble) ctx->Transform.EyeUserPlane[p][3];
116}
117
118void GLAPIENTRY
119_mesa_CullParameterfvEXT (GLenum cap, GLfloat *v)
120{
121   GET_CURRENT_CONTEXT(ctx);
122   ASSERT_OUTSIDE_BEGIN_END(ctx);
123
124   switch (cap) {
125   case GL_CULL_VERTEX_EYE_POSITION_EXT:
126      FLUSH_VERTICES(ctx, _NEW_TRANSFORM);
127      COPY_4FV(ctx->Transform.CullEyePos, v);
128
129      _mesa_transform_vector( ctx->Transform.CullObjPos,
130			      ctx->Transform.CullEyePos,
131			      ctx->ModelviewMatrixStack.Top->inv );
132      break;
133
134   case GL_CULL_VERTEX_OBJECT_POSITION_EXT:
135      FLUSH_VERTICES(ctx, _NEW_TRANSFORM);
136      COPY_4FV(ctx->Transform.CullObjPos, v);
137
138      _mesa_transform_vector( ctx->Transform.CullEyePos,
139			      ctx->Transform.CullObjPos,
140			      ctx->ModelviewMatrixStack.Top->m );
141     break;
142   default:
143      _mesa_error( ctx, GL_INVALID_ENUM, "glCullParameterfvEXT" );
144   }
145}
146
147void GLAPIENTRY
148_mesa_CullParameterdvEXT (GLenum cap, GLdouble *v)
149{
150   GLfloat f[4];
151
152   f[0] = (GLfloat)v[0];
153   f[1] = (GLfloat)v[1];
154   f[2] = (GLfloat)v[2];
155   f[3] = (GLfloat)v[3];
156
157   _mesa_CullParameterfvEXT(cap, f);
158}
159
160