1 /*
2  * SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
3  * Copyright (C) 1991-2000 Silicon Graphics, Inc. All Rights Reserved.
4  *
5  * Permission is hereby granted, free of charge, to any person obtaining a
6  * copy of this software and associated documentation files (the "Software"),
7  * to deal in the Software without restriction, including without limitation
8  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9  * and/or sell copies of the Software, and to permit persons to whom the
10  * Software is furnished to do so, subject to the following conditions:
11  *
12  * The above copyright notice including the dates of first publication and
13  * either this permission notice or a reference to
14  * http://oss.sgi.com/projects/FreeB/
15  * shall be included 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  * SILICON GRAPHICS, INC. BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
21  * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
22  * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
23  * SOFTWARE.
24  *
25  * Except as contained in this notice, the name of Silicon Graphics, Inc.
26  * shall not be used in advertising or otherwise to promote the sale, use or
27  * other dealings in this Software without prior written authorization from
28  * Silicon Graphics, Inc.
29  */
30 /*
31 ** Author: Eric Veach, July 1994.
32 **
33 */
34 
35 #ifndef __tess_h_
36 #define __tess_h_
37 
38 // #include <GL/glu.h>
39 #include <osg/GLU>
40 
41 #if defined(_MSC_VER) && defined(OSG_DISABLE_MSVC_WARNINGS)
42     // disable: structure was padded due to __declspec(align())
43     #pragma warning( disable : 4324 )
44 
45     // disable: warning C4611: interaction between '_setjmp' and C++ object destruction is non-portable
46     #pragma warning( disable :  4611)
47 #endif
48 
49 #ifndef GLAPIENTRY
50     #define GLAPIENTRY GL_APIENTRY
51 #endif
52 
53 #include <setjmp.h>
54 #include "mesh.h"
55 #include "dict.h"
56 #include "priorityq.h"
57 
58 /* The begin/end calls must be properly nested.  We keep track of
59  * the current state to enforce the ordering.
60  */
61 enum TessState { T_DORMANT, T_IN_POLYGON, T_IN_CONTOUR };
62 
63 /* We cache vertex data for single-contour polygons so that we can
64  * try a quick-and-dirty decomposition first.
65  */
66 #define TESS_MAX_CACHE	100
67 
68 typedef struct CachedVertex {
69   GLdouble	coords[3];
70   void		*data;
71 } CachedVertex;
72 
73 struct osg::GLUtesselator {
74 
75   /*** state needed for collecting the input data ***/
76 
77   enum TessState state;		/* what begin/end calls have we seen? */
78 
79   GLUhalfEdge	*lastEdge;	/* lastEdge->Org is the most recent vertex */
80   GLUmesh	*mesh;		/* stores the input contours, and eventually
81                                    the tessellation itself */
82 
83   void		(GLAPIENTRY *callError)( GLenum errnum );
84 
85   /*** state needed for projecting onto the sweep plane ***/
86 
87   GLdouble	normal[3];	/* user-specified normal (if provided) */
88   GLdouble	sUnit[3];	/* unit vector in s-direction (debugging) */
89   GLdouble	tUnit[3];	/* unit vector in t-direction (debugging) */
90 
91   /*** state needed for the line sweep ***/
92 
93   GLdouble	relTolerance;	/* tolerance for merging features */
94   GLenum	windingRule;	/* rule for determining polygon interior */
95   GLboolean	fatalError;	/* fatal error: needed combine callback */
96 
97   Dict		*dict;		/* edge dictionary for sweep line */
98   PriorityQ	*pq;		/* priority queue of vertex events */
99   GLUvertex	*event;		/* current sweep event being processed */
100 
101   void		(GLAPIENTRY *callCombine)( GLdouble coords[3], void *data[4],
102 			        GLfloat weight[4], void **outData );
103 
104   /*** state needed for rendering callbacks (see render.c) ***/
105 
106   GLboolean	flagBoundary;	/* mark boundary edges (use EdgeFlag) */
107   GLboolean	boundaryOnly;	/* Extract contours, not triangles */
108   GLUface	*lonelyTriList;
109     /* list of triangles which could not be rendered as strips or fans */
110 
111   void		(GLAPIENTRY *callBegin)( GLenum type );
112   void		(GLAPIENTRY *callEdgeFlag)( GLboolean boundaryEdge );
113   void		(GLAPIENTRY *callVertex)( void *data );
114   void		(GLAPIENTRY *callEnd)( void );
115   void		(GLAPIENTRY *callMesh)( GLUmesh *mesh );
116 
117 
118   /*** state needed to cache single-contour polygons for renderCache() */
119 
120   GLboolean	emptyCache;		/* empty cache on next vertex() call */
121   int		cacheCount;		/* number of cached vertices */
122   CachedVertex	cache[TESS_MAX_CACHE];	/* the vertex data */
123 
124   /*** rendering callbacks that also pass polygon data  ***/
125   void		(GLAPIENTRY *callBeginData)( GLenum type, void *polygonData );
126   void		(GLAPIENTRY *callEdgeFlagData)( GLboolean boundaryEdge,
127 				     void *polygonData );
128   void		(GLAPIENTRY *callVertexData)( void *data, void *polygonData );
129   void		(GLAPIENTRY *callEndData)( void *polygonData );
130   void		(GLAPIENTRY *callErrorData)( GLenum errnum, void *polygonData );
131   void		(GLAPIENTRY *callCombineData)( GLdouble coords[3], void *data[4],
132 				    GLfloat weight[4], void **outData,
133 				    void *polygonData );
134 
135   jmp_buf env;			/* place to jump to when memAllocs fail */
136 
137   void *polygonData;		/* client data for current polygon */
138 };
139 
140 void GLAPIENTRY __gl_noBeginData( GLenum type, void *polygonData );
141 void GLAPIENTRY __gl_noEdgeFlagData( GLboolean boundaryEdge, void *polygonData );
142 void GLAPIENTRY __gl_noVertexData( void *data, void *polygonData );
143 void GLAPIENTRY __gl_noEndData( void *polygonData );
144 void GLAPIENTRY __gl_noErrorData( GLenum errnum, void *polygonData );
145 void GLAPIENTRY __gl_noCombineData( GLdouble coords[3], void *data[4],
146 			 GLfloat weight[4], void **outData,
147 			 void *polygonData );
148 
149 #define CALL_BEGIN_OR_BEGIN_DATA(a) \
150    if (tess->callBeginData != &__gl_noBeginData) \
151       (*tess->callBeginData)((a),tess->polygonData); \
152    else (*tess->callBegin)((a));
153 
154 #define CALL_VERTEX_OR_VERTEX_DATA(a) \
155    if (tess->callVertexData != &__gl_noVertexData) \
156       (*tess->callVertexData)((a),tess->polygonData); \
157    else (*tess->callVertex)((a));
158 
159 #define CALL_EDGE_FLAG_OR_EDGE_FLAG_DATA(a) \
160    if (tess->callEdgeFlagData != &__gl_noEdgeFlagData) \
161       (*tess->callEdgeFlagData)((a),tess->polygonData); \
162    else (*tess->callEdgeFlag)((a));
163 
164 #define CALL_END_OR_END_DATA() \
165    if (tess->callEndData != &__gl_noEndData) \
166       (*tess->callEndData)(tess->polygonData); \
167    else (*tess->callEnd)();
168 
169 #define CALL_COMBINE_OR_COMBINE_DATA(a,b,c,d) \
170    if (tess->callCombineData != &__gl_noCombineData) \
171       (*tess->callCombineData)((a),(b),(c),(d),tess->polygonData); \
172    else (*tess->callCombine)((a),(b),(c),(d));
173 
174 #define CALL_ERROR_OR_ERROR_DATA(a) \
175    if (tess->callErrorData != &__gl_noErrorData) \
176       (*tess->callErrorData)((a),tess->polygonData); \
177    else (*tess->callError)((a));
178 
179 // make it easy to introduce the namespace osg for the public functions and typedefs
180 using osg::GLUtesselator;
181 using osg::_GLUfuncptr;
182 
183 
184 #endif
185