Import Geant4 11.0.0.beta source tree

source/externals/g4tools/include/tools/glutess/_glu

@@ -0,0 +1,140 @@
+/*
+   G.Barrand : glu.h of Mesa-7.8.1 but containing only tess related material.
+   We bring also the needed material from gl.h.
+ */
+
+#ifndef tools_glutess__glu
+#define tools_glutess__glu
+
+#include "rename"
+
+/* //////////////////////////////////////////////////////////////// */
+/* //////////////////////////////////////////////////////////////// */
+
+typedef unsigned int	GLUenum;
+typedef void		GLUvoid;
+typedef double		GLUdouble;
+
+typedef unsigned char	GLUboolean;
+typedef float		GLUfloat;	/* single precision float */
+typedef double		GLUclampd;	/* double precision float in [0,1] */
+
+/* //////////////////////////////////////////////////////////////// */
+/* //////////////////////////////////////////////////////////////// */
+/* //////////////////////////////////////////////////////////////// */
+
+/* TessCallback */
+#define GLU_TESS_BEGIN_DATA                100106
+#define GLU_TESS_VERTEX_DATA               100107
+#define GLU_TESS_END_DATA                  100108
+#define GLU_TESS_ERROR_DATA                100109
+#define GLU_TESS_COMBINE_DATA              100111
+
+/* TessProperty */
+#define GLU_TESS_WINDING_RULE              100140
+//#define GLU_TESS_TOLERANCE                 100142
+
+/* TessWinding */
+#define GLU_TESS_WINDING_ODD               100130
+#define GLU_TESS_WINDING_POSITIVE          100132
+#define GLU_TESS_WINDING_NEGATIVE          100133
+
+/*************************************************************/
+
+// mesa glu has the below for Windows.
+//#define GLUAPIENTRY __stdcall
+//typedef void (__stdcall* _GLUfuncptr)();
+
+#define GLUAPIENTRY
+typedef void (* _GLUfuncptr)();
+
+#define GLUAPI
+
+typedef struct GLUtesselator GLUtesselator;
+
+typedef GLUtesselator GLUtesselatorObj;
+typedef GLUtesselator GLUtriangulatorObj;
+
+  /*
+GLUAPI GLUtesselator* GLUAPIENTRY gluNewTess (void);
+GLUAPI void GLUAPIENTRY gluDeleteTess (GLUtesselator* tess);
+
+GLUAPI void GLUAPIENTRY gluTessBeginContour (GLUtesselator* tess);
+GLUAPI void GLUAPIENTRY gluTessBeginPolygon (GLUtesselator* tess, GLUvoid* data);
+GLUAPI void GLUAPIENTRY gluTessCallback (GLUtesselator* tess, GLUenum which, _GLUfuncptr CallBackFunc);
+GLUAPI void GLUAPIENTRY gluTessEndContour (GLUtesselator* tess);
+GLUAPI void GLUAPIENTRY gluTessEndPolygon (GLUtesselator* tess);
+GLUAPI void GLUAPIENTRY gluTessNormal (GLUtesselator* tess, GLUdouble valueX, GLUdouble valueY, GLUdouble valueZ);
+GLUAPI void GLUAPIENTRY gluTessProperty (GLUtesselator* tess, GLUenum which, GLUdouble data);
+GLUAPI void GLUAPIENTRY gluTessVertex (GLUtesselator* tess, GLUdouble *location, GLUvoid* data);
+  */
+
+#define GLU_MIN(x,y)	((x) <= (y) ? (x) : (y))
+#define GLU_MAX(x,y)	((x) >= (y) ? (x) : (y))
+#define GLU_ABS(x)	((x) < 0 ? -(x) : (x))
+
+/* //////////////////////////////////////////////////////////////// */
+/* //////////////////////////////////////////////////////////////// */
+/* //////////////////////////////////////////////////////////////// */
+
+/* Boolean values */
+#define TOOLS_GLU_FALSE   0x0
+#define TOOLS_GLU_TRUE    0x1
+
+/* Primitives */
+#define GLU_LINE_LOOP				0x0002
+#define GLU_TRIANGLES				0x0004
+#define GLU_TRIANGLE_STRIP			0x0005
+#define GLU_TRIANGLE_FAN			0x0006
+
+#define GLU_TESS_MAX_COORD 1.0e150
+
+/* ErrorCode */
+#define GLU_INVALID_ENUM                   100900
+#define GLU_INVALID_VALUE                  100901
+#define GLU_OUT_OF_MEMORY                  100902
+#define GLU_INCOMPATIBLE_GL_VERSION        100903
+#define GLU_INVALID_OPERATION              100904
+
+/* TessCallback */
+#define GLU_TESS_BEGIN                     100100
+#define GLU_TESS_VERTEX                    100101
+#define GLU_TESS_END                       100102
+#define GLU_TESS_ERROR                     100103
+#define GLU_TESS_EDGE_FLAG                 100104
+#define GLU_EDGE_FLAG                      100104
+#define GLU_TESS_COMBINE                   100105
+#define GLU_TESS_EDGE_FLAG_DATA            100110
+
+/* TessContour */
+#define GLU_CW                             100120
+#define GLU_CCW                            100121
+#define GLU_INTERIOR                       100122
+#define GLU_EXTERIOR                       100123
+#define GLU_UNKNOWN                        100124
+
+/* TessProperty */
+#define GLU_TESS_BOUNDARY_ONLY             100141
+#define GLU_TESS_TOLERANCE                 100142
+
+/* TessError */
+#define GLU_TESS_ERROR1                    100151
+#define GLU_TESS_ERROR2                    100152
+#define GLU_TESS_ERROR3                    100153
+#define GLU_TESS_ERROR4                    100154
+#define GLU_TESS_ERROR5                    100155
+#define GLU_TESS_ERROR6                    100156
+#define GLU_TESS_ERROR7                    100157
+#define GLU_TESS_ERROR8                    100158
+#define GLU_TESS_MISSING_BEGIN_POLYGON     100151
+#define GLU_TESS_MISSING_BEGIN_CONTOUR     100152
+#define GLU_TESS_MISSING_END_POLYGON       100153
+#define GLU_TESS_MISSING_END_CONTOUR       100154
+#define GLU_TESS_COORD_TOO_LARGE           100155
+#define GLU_TESS_NEED_COMBINE_CALLBACK     100156
+
+/* TessWinding */
+#define GLU_TESS_WINDING_NONZERO           100131
+#define GLU_TESS_WINDING_ABS_GEQ_TWO       100134
+
+#endif /* __glu_h__ */

source/externals/g4tools/include/tools/glutess/_tess

@@ -0,0 +1,133 @@
+// see license file for original license.
+
+#ifndef tools_glutess__tess
+#define tools_glutess__tess
+
+#include "mesh"
+#include "dict"
+#include "priorityq"
+
+#include <csetjmp>
+
+/* The begin/end calls must be properly nested.  We keep track of
+ * the current state to enforce the ordering.
+ */
+enum TessState { T_DORMANT, T_IN_POLYGON, T_IN_CONTOUR };
+
+/* We cache vertex data for single-contour polygons so that we can
+ * try a quick-and-dirty decomposition first.
+ */
+#define GLU_TESS_MAX_CACHE 100
+
+typedef struct CachedVertex {
+  GLUdouble	coords[3];
+  void		*data;
+} CachedVertex;
+
+struct GLUtesselator {
+
+  /*** state needed for collecting the input data ***/
+
+  enum TessState state;		/* what begin/end calls have we seen? */
+
+  GLUhalfEdge	*lastEdge;	/* lastEdge->Org is the most recent vertex */
+  GLUmesh	*mesh;		/* stores the input contours, and eventually
+                                   the tessellation itself */
+
+  void		(GLUAPIENTRY *callError)( GLUenum errnum );
+
+  /*** state needed for projecting onto the sweep plane ***/
+
+  GLUdouble	normal[3];	/* user-specified normal (if provided) */
+  GLUdouble	sUnit[3];	/* unit vector in s-direction (debugging) */
+  GLUdouble	tUnit[3];	/* unit vector in t-direction (debugging) */
+
+  /*** state needed for the line sweep ***/
+
+  GLUdouble	relTolerance;	/* tolerance for merging features */
+  GLUenum	windingRule;	/* rule for determining polygon interior */
+  GLUboolean	fatalError;	/* fatal error: needed combine callback */
+
+  Dict		*dict;		/* edge dictionary for sweep line */
+  PriorityQ	*pq;		/* priority queue of vertex events */
+  GLUvertex	*event;		/* current sweep event being processed */
+
+  void		(GLUAPIENTRY *callCombine)( GLUdouble coords[3], void *data[4],
+			        GLUfloat weight[4], void **outData );
+
+  /*** state needed for rendering callbacks (see render.c) ***/
+
+  GLUboolean	flagBoundary;	/* mark boundary edges (use EdgeFlag) */
+  GLUboolean	boundaryOnly;	/* Extract contours, not triangles */
+  GLUface	*lonelyTriList;
+    /* list of triangles which could not be rendered as strips or fans */
+
+  void		(GLUAPIENTRY *callBegin)( GLUenum type );
+  void		(GLUAPIENTRY *callEdgeFlag)( GLUboolean boundaryEdge );
+  void		(GLUAPIENTRY *callVertex)( void *data );
+  void		(GLUAPIENTRY *callEnd)( void );
+  void		(GLUAPIENTRY *callMesh)( GLUmesh *mesh );
+
+
+  /*** state needed to cache single-contour polygons for renderCache() */
+
+  GLUboolean	emptyCache;		/* empty cache on next vertex() call */
+  int		cacheCount;		/* number of cached vertices */
+  CachedVertex	cache[GLU_TESS_MAX_CACHE];	/* the vertex data */
+
+  /*** rendering callbacks that also pass polygon data  ***/ 
+  void		(GLUAPIENTRY *callBeginData)( GLUenum type, void *polygonData );
+  void		(GLUAPIENTRY *callEdgeFlagData)( GLUboolean boundaryEdge, 
+				     void *polygonData );
+  void		(GLUAPIENTRY *callVertexData)( void *data, void *polygonData );
+  void		(GLUAPIENTRY *callEndData)( void *polygonData );
+  void		(GLUAPIENTRY *callErrorData)( GLUenum errnum, void *polygonData );
+  void		(GLUAPIENTRY *callCombineData)( GLUdouble coords[3], void *data[4],
+				    GLUfloat weight[4], void **outData,
+				    void *polygonData );
+
+  jmp_buf env;			/* place to jump to when memAllocs fail */
+
+  void *polygonData;		/* client data for current polygon */
+};
+
+void GLUAPIENTRY __gl_noBeginData( GLUenum type, void *polygonData );
+void GLUAPIENTRY __gl_noEdgeFlagData( GLUboolean boundaryEdge, void *polygonData );
+void GLUAPIENTRY __gl_noVertexData( void *data, void *polygonData );
+void GLUAPIENTRY __gl_noEndData( void *polygonData );
+void GLUAPIENTRY __gl_noErrorData( GLUenum errnum, void *polygonData );
+void GLUAPIENTRY __gl_noCombineData( GLUdouble coords[3], void *data[4],
+			 GLUfloat weight[4], void **outData,
+			 void *polygonData );
+
+#define CALL_BEGIN_OR_BEGIN_DATA(a) \
+   if (tess->callBeginData != &__gl_noBeginData) \
+      (*tess->callBeginData)((a),tess->polygonData); \
+   else (*tess->callBegin)((a));
+
+#define CALL_VERTEX_OR_VERTEX_DATA(a) \
+   if (tess->callVertexData != &__gl_noVertexData) \
+      (*tess->callVertexData)((a),tess->polygonData); \
+   else (*tess->callVertex)((a));
+
+#define CALL_EDGE_FLAG_OR_EDGE_FLAG_DATA(a) \
+   if (tess->callEdgeFlagData != &__gl_noEdgeFlagData) \
+      (*tess->callEdgeFlagData)((a),tess->polygonData); \
+   else (*tess->callEdgeFlag)((a));
+
+#define CALL_END_OR_END_DATA() \
+   if (tess->callEndData != &__gl_noEndData) \
+      (*tess->callEndData)(tess->polygonData); \
+   else (*tess->callEnd)();
+
+#define CALL_COMBINE_OR_COMBINE_DATA(a,b,c,d) \
+   if (tess->callCombineData != &__gl_noCombineData) \
+      (*tess->callCombineData)((a),(b),(c),(d),tess->polygonData); \
+   else (*tess->callCombine)((a),(b),(c),(d));
+
+#define CALL_ERROR_OR_ERROR_DATA(a) \
+   if (tess->callErrorData != &__gl_noErrorData) \
+      (*tess->callErrorData)((a),tess->polygonData); \
+   else (*tess->callError)((a));
+
+#endif

source/externals/g4tools/include/tools/glutess/dict

@@ -0,0 +1,127 @@
+// see license file for original license.
+
+#ifndef tools_glutess_dict_list
+#define tools_glutess_dict_list
+
+/* Use #define's so that another heap implementation can use this one */
+
+#define DictKey		DictListKey
+#define Dict		DictList
+#define DictNode	DictListNode
+
+#define dictNewDict(frame,leq)		__gl_dictListNewDict(frame,leq)
+#define dictDeleteDict(dict)		__gl_dictListDeleteDict(dict)
+
+#define dictSearch(dict,key)		__gl_dictListSearch(dict,key)
+#define dictInsert(dict,key)		__gl_dictListInsert(dict,key)
+#define dictInsertBefore(dict,node,key)	__gl_dictListInsertBefore(dict,node,key)
+#define dictDelete(dict,node)		__gl_dictListDelete(dict,node)
+
+#define dictKey(n)			__gl_dictListKey(n)
+#define dictSucc(n)			__gl_dictListSucc(n)
+#define dictPred(n)			__gl_dictListPred(n)
+#define dictMin(d)			__gl_dictListMin(d)
+#define dictMax(d)			__gl_dictListMax(d)
+
+typedef void *DictKey;
+typedef struct Dict Dict;
+typedef struct DictNode DictNode;
+
+#define __gl_dictListKey(n)	((n)->key)
+#define __gl_dictListSucc(n)	((n)->next)
+#define	__gl_dictListPred(n)	((n)->prev)
+#define	__gl_dictListMin(d)	((d)->head.next)
+#define	__gl_dictListMax(d)	((d)->head.prev)
+#define __gl_dictListInsert(d,k) (dictInsertBefore((d),&(d)->head,(k)))
+
+/*** Private data structures ***/
+
+struct DictNode {
+  DictKey	key;
+  DictNode	*next;
+  DictNode	*prev;
+};
+
+struct Dict {
+  DictNode	head;
+  void		*frame;
+  int		(*leq)(void *frame, DictKey key1, DictKey key2);
+};
+
+////////////////////////////////////////////////////////
+/// inlined C code : ///////////////////////////////////
+////////////////////////////////////////////////////////
+#include <cstddef>
+#include "memalloc"
+
+inline Dict *dictNewDict( void *frame,int (*leq)(void *frame, DictKey key1, DictKey key2) ) {
+  Dict *dict = (Dict *) memAlloc( sizeof( Dict ));
+  DictNode *head;
+
+  if (dict == NULL) return NULL;
+
+  head = &dict->head;
+
+  head->key = NULL;
+  head->next = head;
+  head->prev = head;
+
+  dict->frame = frame;
+  dict->leq = leq;
+
+  return dict;
+}
+
+inline void dictDeleteDict( Dict *dict ) {
+  DictNode *node, *next;
+
+  for( node = dict->head.next; node != &dict->head; node = next ) {
+    next = node->next;
+    memFree( node );
+  }
+  memFree( dict );
+}
+
+/* Search returns the node with the smallest key greater than or equal
+ * to the given key.  If there is no such key, returns a node whose
+ * key is NULL.  Similarly, Succ(Max(d)) has a NULL key, etc.
+ */
+
+inline DictNode *dictInsertBefore( Dict *dict, DictNode *node, DictKey key ) {
+  DictNode *newNode;
+
+  do {
+    node = node->prev;
+  } while( node->key != NULL && ! (*dict->leq)(dict->frame, node->key, key));
+
+  newNode = (DictNode *) memAlloc( sizeof( DictNode ));
+  if (newNode == NULL) return NULL;
+
+  newNode->key = key;
+  newNode->next = node->next;
+  node->next->prev = newNode;
+  newNode->prev = node;
+  node->next = newNode;
+
+  return newNode;
+}
+
+inline void dictDelete( Dict * /*dict*/, DictNode *node ) /*ARGSUSED*/
+{
+  node->next->prev = node->prev;
+  node->prev->next = node->next;
+  memFree( node );
+}
+
+inline DictNode *dictSearch( Dict *dict, DictKey key )
+{
+  DictNode *node = &dict->head;
+
+  do {
+    node = node->next;
+  } while( node->key != NULL && ! (*dict->leq)(dict->frame, key, node->key));
+
+  return node;
+}
+
+#endif

source/externals/g4tools/include/tools/glutess/geom

@@ -0,0 +1,241 @@
+// see license file for original license.
+
+#ifndef tools_glutess_geom
+#define tools_glutess_geom
+
+#include "mesh"
+
+#define VertEq(u,v)	((u)->s == (v)->s && (u)->t == (v)->t)
+#define VertLeq(u,v)	(((u)->s < (v)->s) || ((u)->s == (v)->s && (u)->t <= (v)->t))
+
+#define EdgeEval(u,v,w) __gl_edgeEval(u,v,w)
+#define EdgeSign(u,v,w) __gl_edgeSign(u,v,w)
+
+/* Versions of VertLeq, EdgeSign, EdgeEval with s and t transposed. */
+
+#define TransLeq(u,v)	(((u)->t < (v)->t) || \
+                         ((u)->t == (v)->t && (u)->s <= (v)->s))
+#define TransEval(u,v,w)	__gl_transEval(u,v,w)
+#define TransSign(u,v,w)	__gl_transSign(u,v,w)
+
+
+#define EdgeGoesLeft(e) 	VertLeq( (e)->Dst, (e)->Org )
+#define EdgeGoesRight(e)	VertLeq( (e)->Org, (e)->Dst )
+
+#define VertL1dist(u,v) (GLU_ABS(u->s - v->s) + GLU_ABS(u->t - v->t))
+
+#define VertCCW(u,v,w)	__gl_vertCCW(u,v,w)
+
+////////////////////////////////////////////////////////
+/// inlined C code : ///////////////////////////////////
+////////////////////////////////////////////////////////
+
+inline int __gl_vertLeq( GLUvertex *u, GLUvertex *v )
+{
+  /* Returns TOOLS_GLU_TRUE if u is lexicographically <= v. */
+
+  return VertLeq( u, v );
+}
+
+inline GLUdouble __gl_edgeEval( GLUvertex *u, GLUvertex *v, GLUvertex *w )
+{
+  /* Given three vertices u,v,w such that VertLeq(u,v) && VertLeq(v,w),
+   * evaluates the t-coord of the edge uw at the s-coord of the vertex v.
+   * Returns v->t - (uw)(v->s), ie. the signed distance from uw to v.
+   * If uw is vertical (and thus passes thru v), the result is zero.
+   *
+   * The calculation is extremely accurate and stable, even when v
+   * is very close to u or w.  In particular if we set v->t = 0 and
+   * let r be the negated result (this evaluates (uw)(v->s)), then
+   * r is guaranteed to satisfy MIN(u->t,w->t) <= r <= MAX(u->t,w->t).
+   */
+  GLUdouble gapL, gapR;
+
+  assert( VertLeq( u, v ) && VertLeq( v, w ));
+  
+  gapL = v->s - u->s;
+  gapR = w->s - v->s;
+
+  if( gapL + gapR > 0 ) {
+    if( gapL < gapR ) {
+      return (v->t - u->t) + (u->t - w->t) * (gapL / (gapL + gapR));
+    } else {
+      return (v->t - w->t) + (w->t - u->t) * (gapR / (gapL + gapR));
+    }
+  }
+  /* vertical line */
+  return 0;
+}
+
+inline GLUdouble __gl_edgeSign( GLUvertex *u, GLUvertex *v, GLUvertex *w )
+{
+  /* Returns a number whose sign matches EdgeEval(u,v,w) but which
+   * is cheaper to evaluate.  Returns > 0, == 0 , or < 0
+   * as v is above, on, or below the edge uw.
+   */
+  GLUdouble gapL, gapR;
+
+  /*
+#define VertLeq(u,v)	(((u)->s < (v)->s) ||			\
+                         ((u)->s == (v)->s && (u)->t <= (v)->t))
+  */
+  assert( VertLeq( u, v ) && VertLeq( v, w ));
+  
+  gapL = v->s - u->s;
+  gapR = w->s - v->s;
+
+  if( gapL + gapR > 0 ) {
+    return (v->t - w->t) * gapL + (v->t - u->t) * gapR;
+  }
+  /* vertical line */
+  return 0;
+}
+
+
+/***********************************************************************
+ * Define versions of EdgeSign, EdgeEval with s and t transposed.
+ */
+
+inline GLUdouble __gl_transEval( GLUvertex *u, GLUvertex *v, GLUvertex *w )
+{
+  /* Given three vertices u,v,w such that TransLeq(u,v) && TransLeq(v,w),
+   * evaluates the t-coord of the edge uw at the s-coord of the vertex v.
+   * Returns v->s - (uw)(v->t), ie. the signed distance from uw to v.
+   * If uw is vertical (and thus passes thru v), the result is zero.
+   *
+   * The calculation is extremely accurate and stable, even when v
+   * is very close to u or w.  In particular if we set v->s = 0 and
+   * let r be the negated result (this evaluates (uw)(v->t)), then
+   * r is guaranteed to satisfy MIN(u->s,w->s) <= r <= MAX(u->s,w->s).
+   */
+  GLUdouble gapL, gapR;
+
+  assert( TransLeq( u, v ) && TransLeq( v, w ));
+  
+  gapL = v->t - u->t;
+  gapR = w->t - v->t;
+
+  if( gapL + gapR > 0 ) {
+    if( gapL < gapR ) {
+      return (v->s - u->s) + (u->s - w->s) * (gapL / (gapL + gapR));
+    } else {
+      return (v->s - w->s) + (w->s - u->s) * (gapR / (gapL + gapR));
+    }
+  }
+  /* vertical line */
+  return 0;
+}
+
+inline GLUdouble __gl_transSign( GLUvertex *u, GLUvertex *v, GLUvertex *w )
+{
+  /* Returns a number whose sign matches TransEval(u,v,w) but which
+   * is cheaper to evaluate.  Returns > 0, == 0 , or < 0
+   * as v is above, on, or below the edge uw.
+   */
+  GLUdouble gapL, gapR;
+
+  assert( TransLeq( u, v ) && TransLeq( v, w ));
+  
+  gapL = v->t - u->t;
+  gapR = w->t - v->t;
+
+  if( gapL + gapR > 0 ) {
+    return (v->s - w->s) * gapL + (v->s - u->s) * gapR;
+  }
+  /* vertical line */
+  return 0;
+}
+
+
+inline int __gl_vertCCW( GLUvertex *u, GLUvertex *v, GLUvertex *w )
+{
+  /* For almost-degenerate situations, the results are not reliable.
+   * Unless the floating-point arithmetic can be performed without
+   * rounding errors, *any* implementation will give incorrect results
+   * on some degenerate inputs, so the client must have some way to
+   * handle this situation.
+   */
+  return (u->s*(v->t - w->t) + v->s*(w->t - u->t) + w->s*(u->t - v->t)) >= 0;
+}
+
+/* Given parameters a,x,b,y returns the value (b*x+a*y)/(a+b),
+ * or (x+y)/2 if a==b==0.  It requires that a,b >= 0, and enforces
+ * this in the rare case that one argument is slightly negative.
+ * The implementation is extremely stable numerically.
+ * In particular it guarantees that the result r satisfies
+ * MIN(x,y) <= r <= MAX(x,y), and the results are very accurate
+ * even when a and b differ greatly in magnitude.
+ */
+#define Interpolate(a,x,b,y)			\
+  (a = (a < 0) ? 0 : a, b = (b < 0) ? 0 : b,		\
+  ((a <= b) ? ((b == 0) ? ((x+y) / 2)			\
+                        : (x + (y-x) * (a/(a+b))))	\
+            : (y + (x-y) * (b/(a+b)))))
+
+//#define Swap(a,b)	if (1) { GLUvertex *t = a; a = b; b = t; } else
+#define Swap(a,b)	do { GLUvertex *t = a; a = b; b = t; } while(false)
+
+inline void __gl_edgeIntersect( GLUvertex *o1, GLUvertex *d1,
+			 GLUvertex *o2, GLUvertex *d2,
+			 GLUvertex *v )
+/* Given edges (o1,d1) and (o2,d2), compute their point of intersection.
+ * The computed point is guaranteed to lie in the intersection of the
+ * bounding rectangles defined by each edge.
+ */
+{
+  GLUdouble z1, z2;
+
+  /* This is certainly not the most efficient way to find the intersection
+   * of two line segments, but it is very numerically stable.
+   *
+   * Strategy: find the two middle vertices in the VertLeq ordering,
+   * and interpolate the intersection s-value from these.  Then repeat
+   * using the TransLeq ordering to find the intersection t-value.
+   */
+
+  if( ! VertLeq( o1, d1 )) { Swap( o1, d1 ); }
+  if( ! VertLeq( o2, d2 )) { Swap( o2, d2 ); }
+  if( ! VertLeq( o1, o2 )) { Swap( o1, o2 ); Swap( d1, d2 ); }
+
+  if( ! VertLeq( o2, d1 )) {
+    /* Technically, no intersection -- do our best */
+    v->s = (o2->s + d1->s) / 2;
+  } else if( VertLeq( d1, d2 )) {
+    /* Interpolate between o2 and d1 */
+    z1 = EdgeEval( o1, o2, d1 );
+    z2 = EdgeEval( o2, d1, d2 );
+    if( z1+z2 < 0 ) { z1 = -z1; z2 = -z2; }
+    v->s = Interpolate( z1, o2->s, z2, d1->s );
+  } else {
+    /* Interpolate between o2 and d2 */
+    z1 = EdgeSign( o1, o2, d1 );
+    z2 = -EdgeSign( o1, d2, d1 );
+    if( z1+z2 < 0 ) { z1 = -z1; z2 = -z2; }
+    v->s = Interpolate( z1, o2->s, z2, d2->s );
+  }
+
+  /* Now repeat the process for t */
+
+  if( ! TransLeq( o1, d1 )) { Swap( o1, d1 ); }
+  if( ! TransLeq( o2, d2 )) { Swap( o2, d2 ); }
+  if( ! TransLeq( o1, o2 )) { Swap( o1, o2 ); Swap( d1, d2 ); }
+
+  if( ! TransLeq( o2, d1 )) {
+    /* Technically, no intersection -- do our best */
+    v->t = (o2->t + d1->t) / 2;
+  } else if( TransLeq( d1, d2 )) {
+    /* Interpolate between o2 and d1 */
+    z1 = TransEval( o1, o2, d1 );
+    z2 = TransEval( o2, d1, d2 );
+    if( z1+z2 < 0 ) { z1 = -z1; z2 = -z2; }
+    v->t = Interpolate( z1, o2->t, z2, d1->t );
+  } else {
+    /* Interpolate between o2 and d2 */
+    z1 = TransSign( o1, o2, d1 );
+    z2 = -TransSign( o1, d2, d1 );
+    if( z1+z2 < 0 ) { z1 = -z1; z2 = -z2; }
+    v->t = Interpolate( z1, o2->t, z2, d2->t );
+  }
+}
+
+#endif

source/externals/g4tools/include/tools/glutess/glutess

@@ -0,0 +1,619 @@
+// see license file for original license.
+
+#ifndef tools_glutess_glutess
+#define tools_glutess_glutess
+
+#include "_tess"
+
+GLUAPI GLUtesselator* GLUAPIENTRY gluNewTess (void);
+GLUAPI void GLUAPIENTRY gluDeleteTess (GLUtesselator* tess);
+
+GLUAPI void GLUAPIENTRY gluTessBeginContour (GLUtesselator* tess);
+GLUAPI void GLUAPIENTRY gluTessBeginPolygon (GLUtesselator* tess, GLUvoid* data);
+GLUAPI void GLUAPIENTRY gluTessCallback (GLUtesselator* tess, GLUenum which, _GLUfuncptr CallBackFunc);
+GLUAPI void GLUAPIENTRY gluTessEndContour (GLUtesselator* tess);
+GLUAPI void GLUAPIENTRY gluTessEndPolygon (GLUtesselator* tess);
+GLUAPI void GLUAPIENTRY gluTessNormal (GLUtesselator* tess, GLUdouble valueX, GLUdouble valueY, GLUdouble valueZ);
+GLUAPI void GLUAPIENTRY gluTessProperty (GLUtesselator* tess, GLUenum which, GLUdouble data);
+GLUAPI void GLUAPIENTRY gluTessVertex (GLUtesselator* tess, GLUdouble *location, GLUvoid* data);
+
+#include "mesh"
+#include "normal"
+#include "sweep"
+#include "tessmono"
+#include "render"
+
+#define GLU_TESS_DEFAULT_TOLERANCE 0.0
+#define GLU_TESS_MESH		100112	/* void (*)(GLUmesh *mesh)	    */
+
+/*ARGSUSED*/ inline/*static*/ void GLUAPIENTRY static_noBegin( GLUenum /*type*/ ) {}
+/*ARGSUSED*/ inline/*static*/ void GLUAPIENTRY static_noEdgeFlag( GLUboolean /*boundaryEdge*/ ) {}
+/*ARGSUSED*/ inline/*static*/ void GLUAPIENTRY static_noVertex( void * /*data*/ ) {}
+/*ARGSUSED*/ inline/*static*/ void GLUAPIENTRY static_noEnd( void ) {}
+/*ARGSUSED*/ inline/*static*/ void GLUAPIENTRY static_noError( GLUenum /*errnum*/ ) {}
+/*ARGSUSED*/ inline/*static*/ void GLUAPIENTRY static_noCombine( GLUdouble /*coords*/[3], void* /*data*/[4],
+								 GLUfloat /*weight*/[4], void** /*dataOut*/ ) {}
+/*ARGSUSED*/ inline/*static*/ void GLUAPIENTRY static_noMesh( GLUmesh* /*mesh*/ ) {}
+
+
+inline /*ARGSUSED*/ void GLUAPIENTRY __gl_noBeginData( GLUenum /*type*/, void* /*polygonData*/ ) {}
+inline /*ARGSUSED*/ void GLUAPIENTRY __gl_noEdgeFlagData( GLUboolean /*boundaryEdge*/, void* /*polygonData*/ ) {}
+inline /*ARGSUSED*/ void GLUAPIENTRY __gl_noVertexData( void* /*data*/, void* /*polygonData*/ ) {}
+inline /*ARGSUSED*/ void GLUAPIENTRY __gl_noEndData( void* /*polygonData*/ ) {}
+inline /*ARGSUSED*/ void GLUAPIENTRY __gl_noErrorData( GLUenum /*errnum*/, void* /*polygonData*/ ) {}
+inline /*ARGSUSED*/ void GLUAPIENTRY __gl_noCombineData( GLUdouble /*coords*/[3],
+							 void* /*data*/[4],
+							 GLUfloat /*weight*/[4],
+							 void** /*outData*/,
+							 void* /*polygonData*/ ) {}
+
+/* Half-edges are allocated in pairs (see mesh.c) */
+//typedef struct { GLUhalfEdge e, eSym; } EdgePair;
+
+inline size_t MAX_FAST_ALLOC() {
+  static const size_t s_value = (GLU_MAX(sizeof(EdgePair),GLU_MAX(sizeof(GLUvertex),sizeof(GLUface))));
+  return s_value;
+}
+
+inline GLUtesselator * GLUAPIENTRY
+gluNewTess( void )
+{
+  GLUtesselator *tess;
+
+  /* Only initialize fields which can be changed by the api.  Other fields
+   * are initialized where they are used.
+   */
+
+  if (memInit( MAX_FAST_ALLOC() ) == 0) {
+     return 0;			/* out of memory */
+  }
+  tess = (GLUtesselator *)memAlloc( sizeof( GLUtesselator ));
+  if (tess == NULL) {
+     return 0;			/* out of memory */
+  }
+
+  tess->state = T_DORMANT;
+
+  tess->normal[0] = 0;
+  tess->normal[1] = 0;
+  tess->normal[2] = 0;
+
+  tess->relTolerance = GLU_TESS_DEFAULT_TOLERANCE;
+  tess->windingRule = GLU_TESS_WINDING_ODD;
+  tess->flagBoundary = TOOLS_GLU_FALSE;
+  tess->boundaryOnly = TOOLS_GLU_FALSE;
+
+  tess->callBegin = &static_noBegin;
+  tess->callEdgeFlag = &static_noEdgeFlag;
+  tess->callVertex = &static_noVertex;
+  tess->callEnd = &static_noEnd;
+
+  tess->callError = &static_noError;
+  tess->callCombine = &static_noCombine;
+  tess->callMesh = &static_noMesh;
+
+  tess->callBeginData= &__gl_noBeginData;
+  tess->callEdgeFlagData= &__gl_noEdgeFlagData;
+  tess->callVertexData= &__gl_noVertexData;
+  tess->callEndData= &__gl_noEndData;
+  tess->callErrorData= &__gl_noErrorData;
+  tess->callCombineData= &__gl_noCombineData;
+
+  tess->polygonData= NULL;
+
+  return tess;
+}
+
+inline/*static*/ void static_MakeDormant( GLUtesselator *tess )
+{
+  /* Return the tessellator to its original dormant state. */
+
+  if( tess->mesh != NULL ) {
+    __gl_meshDeleteMesh( tess->mesh );
+  }
+  tess->state = T_DORMANT;
+  tess->lastEdge = NULL;
+  tess->mesh = NULL;
+}
+
+#define RequireState( tess, s )   if( tess->state != s ) static_GotoState(tess,s)
+
+inline/*static*/ void static_GotoState( GLUtesselator *tess, enum TessState newState )
+{
+  while( tess->state != newState ) {
+    /* We change the current state one level at a time, to get to
+     * the desired state.
+     */
+    if( tess->state < newState ) {
+      switch( tess->state ) {
+      case T_DORMANT:
+	CALL_ERROR_OR_ERROR_DATA( GLU_TESS_MISSING_BEGIN_POLYGON );
+	gluTessBeginPolygon( tess, NULL );
+	break;
+      case T_IN_POLYGON:
+	CALL_ERROR_OR_ERROR_DATA( GLU_TESS_MISSING_BEGIN_CONTOUR );
+	gluTessBeginContour( tess );
+	break;
+      default:
+	 ;
+      }
+    } else {
+      switch( tess->state ) {
+      case T_IN_CONTOUR:
+	CALL_ERROR_OR_ERROR_DATA( GLU_TESS_MISSING_END_CONTOUR );
+	gluTessEndContour( tess );
+	break;
+      case T_IN_POLYGON:
+	CALL_ERROR_OR_ERROR_DATA( GLU_TESS_MISSING_END_POLYGON );
+	/* gluTessEndPolygon( tess ) is too much work! */
+	static_MakeDormant( tess );
+	break;
+      default:
+	 ;
+      }
+    }
+  }
+}
+
+
+inline void GLUAPIENTRY
+gluDeleteTess( GLUtesselator *tess )
+{
+  RequireState( tess, T_DORMANT );
+  memFree( tess );
+}
+
+
+inline void GLUAPIENTRY
+gluTessProperty( GLUtesselator *tess, GLUenum which, GLUdouble value )
+{
+  GLUenum windingRule;
+
+  switch( which ) {
+  case GLU_TESS_TOLERANCE:
+    if( value < 0.0 || value > 1.0 ) break;
+    tess->relTolerance = value;
+    return;
+
+  case GLU_TESS_WINDING_RULE:
+    windingRule = (GLUenum) value;
+    if( windingRule != value ) break;	/* not an integer */
+
+    switch( windingRule ) {
+    case GLU_TESS_WINDING_ODD:
+    case GLU_TESS_WINDING_NONZERO:
+    case GLU_TESS_WINDING_POSITIVE:
+    case GLU_TESS_WINDING_NEGATIVE:
+    case GLU_TESS_WINDING_ABS_GEQ_TWO:
+      tess->windingRule = windingRule;
+      return;
+    default:
+      break;
+    }
+    return; //G.Barrand : add : seen with g++-8.1.0.
+
+  case GLU_TESS_BOUNDARY_ONLY:
+    tess->boundaryOnly = (value != 0);
+    return;
+
+  default:
+    CALL_ERROR_OR_ERROR_DATA( GLU_INVALID_ENUM );
+    return;
+  }
+  CALL_ERROR_OR_ERROR_DATA( GLU_INVALID_VALUE );
+}
+
+/* Returns tessellator property */
+inline void GLUAPIENTRY
+gluGetTessProperty( GLUtesselator *tess, GLUenum which, GLUdouble *value )
+{
+   switch (which) {
+   case GLU_TESS_TOLERANCE:
+      /* tolerance should be in range [0..1] */
+      assert(0.0 <= tess->relTolerance && tess->relTolerance <= 1.0);
+      *value= tess->relTolerance;
+      break;
+   case GLU_TESS_WINDING_RULE:
+      assert(tess->windingRule == GLU_TESS_WINDING_ODD ||
+	     tess->windingRule == GLU_TESS_WINDING_NONZERO ||
+	     tess->windingRule == GLU_TESS_WINDING_POSITIVE ||
+	     tess->windingRule == GLU_TESS_WINDING_NEGATIVE ||
+	     tess->windingRule == GLU_TESS_WINDING_ABS_GEQ_TWO);
+      *value= tess->windingRule;
+      break;
+   case GLU_TESS_BOUNDARY_ONLY:
+      assert(tess->boundaryOnly == TOOLS_GLU_TRUE || tess->boundaryOnly == TOOLS_GLU_FALSE);
+      *value= tess->boundaryOnly;
+      break;
+   default:
+      *value= 0.0;
+      CALL_ERROR_OR_ERROR_DATA( GLU_INVALID_ENUM );
+      break;
+   }
+} /* gluGetTessProperty() */
+
+inline void GLUAPIENTRY
+gluTessNormal( GLUtesselator *tess, GLUdouble x, GLUdouble y, GLUdouble z )
+{
+  tess->normal[0] = x;
+  tess->normal[1] = y;
+  tess->normal[2] = z;
+}
+
+// G.Barrand : begin : g++-8.1.0 : the five below functions introduced to avoid warnings :
+//                                   warning :cast between incompatible function types
+inline void GLUAPIENTRY
+gluTessCallback_GLU_TESS_VERTEX_DATA(GLUtesselator *tess,void (GLUAPIENTRY* a_fn)(void *, void *)) {
+  tess->callVertexData = (a_fn == NULL) ? &__gl_noVertexData : a_fn;
+}
+inline void GLUAPIENTRY
+gluTessCallback_GLU_TESS_BEGIN_DATA(GLUtesselator *tess,void (GLUAPIENTRY* a_fn)(GLUenum, void *)) {
+  tess->callBeginData = (a_fn == NULL) ? &__gl_noBeginData : a_fn;
+}
+inline void GLUAPIENTRY
+gluTessCallback_GLU_TESS_END_DATA(GLUtesselator *tess,void (GLUAPIENTRY* a_fn)(void *)) {
+  tess->callEndData = (a_fn == NULL) ? &__gl_noEndData : a_fn;
+}
+inline void GLUAPIENTRY
+gluTessCallback_GLU_TESS_ERROR_DATA(GLUtesselator *tess,void (GLUAPIENTRY* a_fn)(GLUenum, void *)) {
+  tess->callErrorData = (a_fn == NULL) ? &__gl_noErrorData : a_fn;
+}
+inline void GLUAPIENTRY
+gluTessCallback_GLU_TESS_COMBINE_DATA(GLUtesselator *tess,
+                                      void (GLUAPIENTRY* a_fn)(GLUdouble [3],void *[4],GLUfloat [4],void **,void *)) {
+  tess->callCombineData = (a_fn == NULL) ? &__gl_noCombineData : a_fn;
+}
+// G.Barrand : end : g++-8.1.0.
+
+inline void GLUAPIENTRY
+gluTessCallback( GLUtesselator *tess, GLUenum which, _GLUfuncptr fn)
+{
+  switch( which ) {
+  case GLU_TESS_BEGIN:
+    tess->callBegin = (fn == NULL) ? &static_noBegin : (void (GLUAPIENTRY *)(GLUenum)) fn;
+    return;
+  case GLU_TESS_BEGIN_DATA:
+    tess->callBeginData = (fn == NULL) ?
+	&__gl_noBeginData : (void (GLUAPIENTRY *)(GLUenum, void *)) fn;
+    return;
+  case GLU_TESS_EDGE_FLAG:
+    tess->callEdgeFlag = (fn == NULL) ? &static_noEdgeFlag :
+					(void (GLUAPIENTRY *)(GLUboolean)) fn;
+    /* If the client wants boundary edges to be flagged,
+     * we render everything as separate triangles (no strips or fans).
+     */
+    tess->flagBoundary = (fn != NULL);
+    return;
+  case GLU_TESS_EDGE_FLAG_DATA:
+    tess->callEdgeFlagData= (fn == NULL) ?
+	&__gl_noEdgeFlagData : (void (GLUAPIENTRY *)(GLUboolean, void *)) fn;
+    /* If the client wants boundary edges to be flagged,
+     * we render everything as separate triangles (no strips or fans).
+     */
+    tess->flagBoundary = (fn != NULL);
+    return;
+  case GLU_TESS_VERTEX:
+    tess->callVertex = (fn == NULL) ? &static_noVertex :
+				      (void (GLUAPIENTRY *)(void *)) fn;
+    return;
+  case GLU_TESS_VERTEX_DATA:
+    tess->callVertexData = (fn == NULL) ?
+	&__gl_noVertexData : (void (GLUAPIENTRY *)(void *, void *)) fn;
+    return;
+  case GLU_TESS_END:
+    tess->callEnd = (fn == NULL) ? &static_noEnd : (void (GLUAPIENTRY *)(void)) fn;
+    return;
+  case GLU_TESS_END_DATA:
+    tess->callEndData = (fn == NULL) ? &__gl_noEndData :
+				       (void (GLUAPIENTRY *)(void *)) fn;
+    return;
+  case GLU_TESS_ERROR:
+    tess->callError = (fn == NULL) ? &static_noError : (void (GLUAPIENTRY *)(GLUenum)) fn;
+    return;
+  case GLU_TESS_ERROR_DATA:
+    tess->callErrorData = (fn == NULL) ?
+	&__gl_noErrorData : (void (GLUAPIENTRY *)(GLUenum, void *)) fn;
+    return;
+  case GLU_TESS_COMBINE:
+    tess->callCombine = (fn == NULL) ? &static_noCombine :
+	(void (GLUAPIENTRY *)(GLUdouble [3],void *[4], GLUfloat [4], void ** )) fn;
+    return;
+  case GLU_TESS_COMBINE_DATA:
+    tess->callCombineData = (fn == NULL) ? &__gl_noCombineData :
+					   (void (GLUAPIENTRY *)(GLUdouble [3],
+						     void *[4],
+						     GLUfloat [4],
+						     void **,
+						     void *)) fn;
+    return;
+  case GLU_TESS_MESH:
+    tess->callMesh = (fn == NULL) ? &static_noMesh : (void (GLUAPIENTRY *)(GLUmesh *)) fn;
+    return;
+  default:
+    CALL_ERROR_OR_ERROR_DATA( GLU_INVALID_ENUM );
+    return;
+  }
+}
+
+inline/*static*/ int static_AddVertex( GLUtesselator *tess, GLUdouble coords[3], void *data )
+{
+  GLUhalfEdge *e;
+
+  e = tess->lastEdge;
+  if( e == NULL ) {
+    /* Make a self-loop (one vertex, one edge). */
+
+    e = __gl_meshMakeEdge( tess->mesh );
+    if (e == NULL) return 0;
+    if ( !__gl_meshSplice( e, e->Sym ) ) return 0;
+  } else {
+    /* Create a new vertex and edge which immediately follow e
+     * in the ordering around the left face.
+     */
+    if (__gl_meshSplitEdge( e ) == NULL) return 0;
+    e = e->Lnext;
+  }
+
+  /* The new vertex is now e->Org. */
+  e->Org->data = data;
+  e->Org->coords[0] = coords[0];
+  e->Org->coords[1] = coords[1];
+  e->Org->coords[2] = coords[2];
+
+  /* The winding of an edge says how the winding number changes as we
+   * cross from the edge''s right face to its left face.  We add the
+   * vertices in such an order that a CCW contour will add +1 to
+   * the winding number of the region inside the contour.
+   */
+  e->winding = 1;
+  e->Sym->winding = -1;
+
+  tess->lastEdge = e;
+
+  return 1;
+}
+
+
+inline/*static*/ void static_CacheVertex( GLUtesselator *tess, GLUdouble coords[3], void *data )
+{
+  CachedVertex *v = &tess->cache[tess->cacheCount];
+
+  v->data = data;
+  v->coords[0] = coords[0];
+  v->coords[1] = coords[1];
+  v->coords[2] = coords[2];
+  ++tess->cacheCount;
+}
+
+
+inline/*static*/ int static_EmptyCache( GLUtesselator *tess )
+{
+  CachedVertex *v = tess->cache;
+  CachedVertex *vLast;
+
+  tess->mesh = __gl_meshNewMesh();
+  if (tess->mesh == NULL) return 0;
+
+  for( vLast = v + tess->cacheCount; v < vLast; ++v ) {
+    if ( !static_AddVertex( tess, v->coords, v->data ) ) return 0;
+  }
+  tess->cacheCount = 0;
+  tess->emptyCache = TOOLS_GLU_FALSE;
+
+  return 1;
+}
+
+
+inline void GLUAPIENTRY
+gluTessVertex( GLUtesselator *tess, GLUdouble coords[3], void *data )
+{
+  int i, tooLarge = TOOLS_GLU_FALSE;
+  GLUdouble x, clamped[3];
+
+  RequireState( tess, T_IN_CONTOUR );
+
+  if( tess->emptyCache ) {
+    if ( !static_EmptyCache( tess ) ) {
+       CALL_ERROR_OR_ERROR_DATA( GLU_OUT_OF_MEMORY );
+       return;
+    }
+    tess->lastEdge = NULL;
+  }
+  for( i = 0; i < 3; ++i ) {
+    x = coords[i];
+    if( x < - GLU_TESS_MAX_COORD ) {
+      x = - GLU_TESS_MAX_COORD;
+      tooLarge = TOOLS_GLU_TRUE;
+    }
+    if( x > GLU_TESS_MAX_COORD ) {
+      x = GLU_TESS_MAX_COORD;
+      tooLarge = TOOLS_GLU_TRUE;
+    }
+    clamped[i] = x;
+  }
+  if( tooLarge ) {
+    CALL_ERROR_OR_ERROR_DATA( GLU_TESS_COORD_TOO_LARGE );
+  }
+
+  if( tess->mesh == NULL ) {
+    if( tess->cacheCount < GLU_TESS_MAX_CACHE ) {
+      static_CacheVertex( tess, clamped, data );
+      return;
+    }
+    if ( !static_EmptyCache( tess ) ) {
+       CALL_ERROR_OR_ERROR_DATA( GLU_OUT_OF_MEMORY );
+       return;
+    }
+  }
+  if ( !static_AddVertex( tess, clamped, data ) ) {
+       CALL_ERROR_OR_ERROR_DATA( GLU_OUT_OF_MEMORY );
+  }
+}
+
+
+inline void GLUAPIENTRY
+gluTessBeginPolygon( GLUtesselator *tess, void *data )
+{
+  RequireState( tess, T_DORMANT );
+
+  tess->state = T_IN_POLYGON;
+  tess->cacheCount = 0;
+  tess->emptyCache = TOOLS_GLU_FALSE;
+  tess->mesh = NULL;
+
+  tess->polygonData= data;
+}
+
+
+inline void GLUAPIENTRY
+gluTessBeginContour( GLUtesselator *tess )
+{
+  RequireState( tess, T_IN_POLYGON );
+
+  tess->state = T_IN_CONTOUR;
+  tess->lastEdge = NULL;
+  if( tess->cacheCount > 0 ) {
+    /* Just set a flag so we don't get confused by empty contours
+     * -- these can be generated accidentally with the obsolete
+     * NextContour() interface.
+     */
+    tess->emptyCache = TOOLS_GLU_TRUE;
+  }
+}
+
+
+inline void GLUAPIENTRY
+gluTessEndContour( GLUtesselator *tess )
+{
+  RequireState( tess, T_IN_CONTOUR );
+  tess->state = T_IN_POLYGON;
+}
+
+inline void GLUAPIENTRY
+gluTessEndPolygon( GLUtesselator *tess )
+{
+  GLUmesh *mesh;
+
+  if (setjmp(tess->env) != 0) { 
+     /* come back here if out of memory */
+     CALL_ERROR_OR_ERROR_DATA( GLU_OUT_OF_MEMORY );
+     return;
+  }
+
+  RequireState( tess, T_IN_POLYGON );
+  tess->state = T_DORMANT;
+
+  if( tess->mesh == NULL ) {
+    if( ! tess->flagBoundary && tess->callMesh == &static_noMesh ) {
+
+      /* Try some special code to make the easy cases go quickly
+       * (eg. convex polygons).  This code does NOT handle multiple contours,
+       * intersections, edge flags, and of course it does not generate
+       * an explicit mesh either.
+       */
+      if( __gl_renderCache( tess )) {
+	tess->polygonData= NULL;
+	return;
+      }
+    }
+    if ( !static_EmptyCache( tess ) ) longjmp(tess->env,1); /* could've used a label*/
+  }
+
+  /* Determine the polygon normal and project vertices onto the plane
+   * of the polygon.
+   */
+  __gl_projectPolygon( tess );
+
+  /* __gl_computeInterior( tess ) computes the planar arrangement specified
+   * by the given contours, and further subdivides this arrangement
+   * into regions.  Each region is marked "inside" if it belongs
+   * to the polygon, according to the rule given by tess->windingRule.
+   * Each interior region is guaranteed be monotone.
+   */
+  if ( !__gl_computeInterior( tess ) ) {
+     longjmp(tess->env,1);	/* could've used a label */
+  }
+
+  mesh = tess->mesh;
+  if( ! tess->fatalError ) {
+    int rc = 1;
+
+    /* If the user wants only the boundary contours, we throw away all edges
+     * except those which separate the interior from the exterior.
+     * Otherwise we tessellate all the regions marked "inside".
+     */
+    if( tess->boundaryOnly ) {
+      rc = __gl_meshSetWindingNumber( mesh, 1, TOOLS_GLU_TRUE );
+    } else {
+      rc = __gl_meshTessellateInterior( mesh );
+    }
+    if (rc == 0) longjmp(tess->env,1);	/* could've used a label */
+
+    __gl_meshCheckMesh( mesh );
+
+    if( tess->callBegin != &static_noBegin || tess->callEnd != &static_noEnd
+       || tess->callVertex != &static_noVertex || tess->callEdgeFlag != &static_noEdgeFlag
+       || tess->callBeginData != &__gl_noBeginData
+       || tess->callEndData != &__gl_noEndData
+       || tess->callVertexData != &__gl_noVertexData
+       || tess->callEdgeFlagData != &__gl_noEdgeFlagData )
+    {
+      if( tess->boundaryOnly ) {
+	__gl_renderBoundary( tess, mesh );  /* output boundary contours */
+      } else {
+	__gl_renderMesh( tess, mesh );	   /* output strips and fans */
+      }
+    }
+    if( tess->callMesh != &static_noMesh ) {
+
+      /* Throw away the exterior faces, so that all faces are interior.
+       * This way the user doesn't have to check the "inside" flag,
+       * and we don't need to even reveal its existence.  It also leaves
+       * the freedom for an implementation to not generate the exterior
+       * faces in the first place.
+       */
+      __gl_meshDiscardExterior( mesh );
+      (*tess->callMesh)( mesh );		/* user wants the mesh itself */
+      tess->mesh = NULL;
+      tess->polygonData= NULL;
+      return;
+    }
+  }
+  __gl_meshDeleteMesh( mesh );
+  tess->polygonData= NULL;
+  tess->mesh = NULL;
+}
+
+
+/*******************************************************/
+
+/* Obsolete calls -- for backward compatibility */
+
+/*
+inline void GLUAPIENTRY
+gluBeginPolygon( GLUtesselator *tess )
+{
+  gluTessBeginPolygon( tess, NULL );
+  gluTessBeginContour( tess );
+}
+
+
+inline void GLUAPIENTRY
+gluNextContour( GLUtesselator *tess, GLUenum type )
+{
+  gluTessEndContour( tess );
+  gluTessBeginContour( tess );
+}
+
+
+inline void GLUAPIENTRY
+gluEndPolygon( GLUtesselator *tess )
+{
+  gluTessEndContour( tess );
+  gluTessEndPolygon( tess );
+}
+*/
+
+#include "undef"
+
+#endif

source/externals/g4tools/include/tools/glutess/license

@@ -0,0 +1,33 @@
+/*
+ * SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
+ * Copyright (C) 1991-2000 Silicon Graphics, Inc. All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice including the dates of first publication and
+ * either this permission notice or a reference to
+ * http://oss.sgi.com/projects/FreeB/
+ * shall be included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * SILICON GRAPHICS, INC. BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
+ * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * Except as contained in this notice, the name of Silicon Graphics, Inc.
+ * shall not be used in advertising or otherwise to promote the sale, use or
+ * other dealings in this Software without prior written authorization from
+ * Silicon Graphics, Inc.
+ */
+/*
+** Author: Eric Veach, July 1994.
+**
+*/

source/externals/g4tools/include/tools/glutess/memalloc

@@ -0,0 +1,45 @@
+// see license file for original license.
+
+#ifndef tools_glutess_memalloc
+#define tools_glutess_memalloc
+
+////////////////////////////////////////////////////////
+/// inlined C code : ///////////////////////////////////
+////////////////////////////////////////////////////////
+
+#ifdef TOOLS_MEM
+#include "../mem"
+#include <cstdlib>
+namespace tools {
+inline void* mem_alloc(size_t a_size){
+  mem::increment(tools::s_malloc().c_str());
+  return ::malloc(a_size);
+}
+inline void* mem_realloc(void* a_ptr,size_t a_size){
+  if(a_ptr==NULL) mem::increment(tools::s_malloc().c_str());
+  return ::realloc(a_ptr,a_size);
+}
+inline void mem_free(void* a_ptr){
+  if(a_ptr!=NULL) mem::decrement(tools::s_malloc().c_str());
+  ::free(a_ptr);
+}
+inline int mem_init( size_t /*maxFast*/) {return 1;}
+
+}
+#else
+#include <cstdlib>
+#include <cstring>
+namespace tools {
+inline void* mem_alloc(size_t a_size) {return ::memset( ::malloc( a_size ), 0xa5, a_size);}
+inline void* mem_realloc(void* a_ptr,size_t a_size){return ::realloc(a_ptr,a_size);}
+inline void mem_free(void* a_ptr){::free(a_ptr);}
+inline int mem_init( size_t /*maxFast*/) {return 1;}
+}
+#endif
+
+#define memAlloc	tools::mem_alloc
+#define memRealloc	tools::mem_realloc
+#define memFree		tools::mem_free
+#define memInit		tools::mem_init
+
+#endif

source/externals/g4tools/include/tools/glutess/mesh

@@ -0,0 +1,973 @@
+// see license file for original license.
+
+#ifndef tools_glutess_mesh
+#define tools_glutess_mesh
+
+#include "_glu"
+
+typedef struct GLUmesh GLUmesh; 
+
+typedef struct GLUvertex GLUvertex;
+typedef struct GLUface GLUface;
+typedef struct GLUhalfEdge GLUhalfEdge;
+
+typedef struct ActiveRegion ActiveRegion;	/* Internal data */
+
+/* The mesh structure is similar in spirit, notation, and operations
+ * to the "quad-edge" structure (see L. Guibas and J. Stolfi, Primitives
+ * for the manipulation of general subdivisions and the computation of
+ * Voronoi diagrams, ACM Transactions on Graphics, 4(2):74-123, April 1985).
+ * For a simplified description, see the course notes for CS348a,
+ * "Mathematical Foundations of Computer Graphics", available at the
+ * Stanford bookstore (and taught during the fall quarter).
+ * The implementation also borrows a tiny subset of the graph-based approach
+ * use in Mantyla's Geometric Work Bench (see M. Mantyla, An Introduction
+ * to Sold Modeling, Computer Science Press, Rockville, Maryland, 1988).
+ *
+ * The fundamental data structure is the "half-edge".  Two half-edges
+ * go together to make an edge, but they point in opposite directions.
+ * Each half-edge has a pointer to its mate (the "symmetric" half-edge Sym),
+ * its origin vertex (Org), the face on its left side (Lface), and the
+ * adjacent half-edges in the CCW direction around the origin vertex
+ * (Onext) and around the left face (Lnext).  There is also a "next"
+ * pointer for the global edge list (see below).
+ *
+ * The notation used for mesh navigation:
+ *	Sym   = the mate of a half-edge (same edge, but opposite direction)
+ *	Onext = edge CCW around origin vertex (keep same origin)
+ *	Dnext = edge CCW around destination vertex (keep same dest)
+ *	Lnext = edge CCW around left face (dest becomes new origin)
+ *	Rnext = edge CCW around right face (origin becomes new dest)
+ *
+ * "prev" means to substitute CW for CCW in the definitions above.
+ *
+ * The mesh keeps global lists of all vertices, faces, and edges,
+ * stored as doubly-linked circular lists with a dummy header node.
+ * The mesh stores pointers to these dummy headers (vHead, fHead, eHead).
+ *
+ * The circular edge list is special; since half-edges always occur
+ * in pairs (e and e->Sym), each half-edge stores a pointer in only
+ * one direction.  Starting at eHead and following the e->next pointers
+ * will visit each *edge* once (ie. e or e->Sym, but not both).
+ * e->Sym stores a pointer in the opposite direction, thus it is
+ * always true that e->Sym->next->Sym->next == e.
+ *
+ * Each vertex has a pointer to next and previous vertices in the
+ * circular list, and a pointer to a half-edge with this vertex as
+ * the origin (NULL if this is the dummy header).  There is also a
+ * field "data" for client data.
+ *
+ * Each face has a pointer to the next and previous faces in the
+ * circular list, and a pointer to a half-edge with this face as
+ * the left face (NULL if this is the dummy header).  There is also
+ * a field "data" for client data.
+ *
+ * Note that what we call a "face" is really a loop; faces may consist
+ * of more than one loop (ie. not simply connected), but there is no
+ * record of this in the data structure.  The mesh may consist of
+ * several disconnected regions, so it may not be possible to visit
+ * the entire mesh by starting at a half-edge and traversing the edge
+ * structure.
+ *
+ * The mesh does NOT support isolated vertices; a vertex is deleted along
+ * with its last edge.  Similarly when two faces are merged, one of the
+ * faces is deleted (see __gl_meshDelete below).  For mesh operations,
+ * all face (loop) and vertex pointers must not be NULL.  However, once
+ * mesh manipulation is finished, __gl_MeshZapFace can be used to delete
+ * faces of the mesh, one at a time.  All external faces can be "zapped"
+ * before the mesh is returned to the client; then a NULL face indicates
+ * a region which is not part of the output polygon.
+ */
+
+struct GLUvertex {
+  GLUvertex	*next;		/* next vertex (never NULL) */
+  GLUvertex	*prev;		/* previous vertex (never NULL) */
+  GLUhalfEdge	*anEdge;	/* a half-edge with this origin */
+  void		*data;		/* client's data */
+
+  /* Internal data (keep hidden) */
+  GLUdouble	coords[3];	/* vertex location in 3D */
+  GLUdouble	s, t;		/* projection onto the sweep plane */
+  long		pqHandle;	/* to allow deletion from priority queue */
+};
+
+struct GLUface {
+  GLUface	*next;		/* next face (never NULL) */
+  GLUface	*prev;		/* previous face (never NULL) */
+  GLUhalfEdge	*anEdge;	/* a half edge with this left face */
+  void		*data;		/* room for client's data */
+
+  /* Internal data (keep hidden) */
+  GLUface	*trail;		/* "stack" for conversion to strips */
+  GLUboolean	marked;		/* flag for conversion to strips */
+  GLUboolean	inside;		/* this face is in the polygon interior */
+};
+
+struct GLUhalfEdge {
+  GLUhalfEdge	*next;		/* doubly-linked list (prev==Sym->next) */
+  GLUhalfEdge	*Sym;		/* same edge, opposite direction */
+  GLUhalfEdge	*Onext;		/* next edge CCW around origin */
+  GLUhalfEdge	*Lnext;		/* next edge CCW around left face */
+  GLUvertex	*Org;		/* origin vertex (Overtex too long) */
+  GLUface	*Lface;		/* left face */
+
+  /* Internal data (keep hidden) */
+  ActiveRegion	*activeRegion;	/* a region with this upper edge (sweep.c) */
+  int		winding;	/* change in winding number when crossing
+                                   from the right face to the left face */
+};
+
+#define	Rface	Sym->Lface
+#define Dst	Sym->Org
+
+#define Oprev	Sym->Lnext
+#define Lprev   Onext->Sym
+#define Dprev	Lnext->Sym
+#define Rprev	Sym->Onext
+#define Dnext	Rprev->Sym	/* 3 pointers */
+#define Rnext	Oprev->Sym	/* 3 pointers */
+
+
+struct GLUmesh {
+  GLUvertex	vHead;		/* dummy header for vertex list */
+  GLUface	fHead;		/* dummy header for face list */
+  GLUhalfEdge	eHead;		/* dummy header for edge list */
+  GLUhalfEdge	eHeadSym;	/* and its symmetric counterpart */
+};
+
+/* The mesh operations below have three motivations: completeness,
+ * convenience, and efficiency.  The basic mesh operations are MakeEdge,
+ * Splice, and Delete.  All the other edge operations can be implemented
+ * in terms of these.  The other operations are provided for convenience
+ * and/or efficiency.
+ *
+ * When a face is split or a vertex is added, they are inserted into the
+ * global list *before* the existing vertex or face (ie. e->Org or e->Lface).
+ * This makes it easier to process all vertices or faces in the global lists
+ * without worrying about processing the same data twice.  As a convenience,
+ * when a face is split, the "inside" flag is copied from the old face.
+ * Other internal data (v->data, v->activeRegion, f->data, f->marked,
+ * f->trail, e->winding) is set to zero.
+ *
+ * ********************** Basic Edge Operations **************************
+ *
+ * __gl_meshMakeEdge( mesh ) creates one edge, two vertices, and a loop.
+ * The loop (face) consists of the two new half-edges.
+ *
+ * __gl_meshSplice( eOrg, eDst ) is the basic operation for changing the
+ * mesh connectivity and topology.  It changes the mesh so that
+ *	eOrg->Onext <- OLD( eDst->Onext )
+ *	eDst->Onext <- OLD( eOrg->Onext )
+ * where OLD(...) means the value before the meshSplice operation.
+ *
+ * This can have two effects on the vertex structure:
+ *  - if eOrg->Org != eDst->Org, the two vertices are merged together
+ *  - if eOrg->Org == eDst->Org, the origin is split into two vertices
+ * In both cases, eDst->Org is changed and eOrg->Org is untouched.
+ *
+ * Similarly (and independently) for the face structure,
+ *  - if eOrg->Lface == eDst->Lface, one loop is split into two
+ *  - if eOrg->Lface != eDst->Lface, two distinct loops are joined into one
+ * In both cases, eDst->Lface is changed and eOrg->Lface is unaffected.
+ *
+ * __gl_meshDelete( eDel ) removes the edge eDel.  There are several cases:
+ * if (eDel->Lface != eDel->Rface), we join two loops into one; the loop
+ * eDel->Lface is deleted.  Otherwise, we are splitting one loop into two;
+ * the newly created loop will contain eDel->Dst.  If the deletion of eDel
+ * would create isolated vertices, those are deleted as well.
+ *
+ * ********************** Other Edge Operations **************************
+ *
+ * __gl_meshAddEdgeVertex( eOrg ) creates a new edge eNew such that
+ * eNew == eOrg->Lnext, and eNew->Dst is a newly created vertex.
+ * eOrg and eNew will have the same left face.
+ *
+ * __gl_meshSplitEdge( eOrg ) splits eOrg into two edges eOrg and eNew,
+ * such that eNew == eOrg->Lnext.  The new vertex is eOrg->Dst == eNew->Org.
+ * eOrg and eNew will have the same left face.
+ *
+ * __gl_meshConnect( eOrg, eDst ) creates a new edge from eOrg->Dst
+ * to eDst->Org, and returns the corresponding half-edge eNew.
+ * If eOrg->Lface == eDst->Lface, this splits one loop into two,
+ * and the newly created loop is eNew->Lface.  Otherwise, two disjoint
+ * loops are merged into one, and the loop eDst->Lface is destroyed.
+ *
+ * ************************ Other Operations *****************************
+ *
+ * __gl_meshNewMesh() creates a new mesh with no edges, no vertices,
+ * and no loops (what we usually call a "face").
+ *
+ * __gl_meshUnion( mesh1, mesh2 ) forms the union of all structures in
+ * both meshes, and returns the new mesh (the old meshes are destroyed).
+ *
+ * __gl_meshDeleteMesh( mesh ) will free all storage for any valid mesh.
+ *
+ * __gl_meshZapFace( fZap ) destroys a face and removes it from the
+ * global face list.  All edges of fZap will have a NULL pointer as their
+ * left face.  Any edges which also have a NULL pointer as their right face
+ * are deleted entirely (along with any isolated vertices this produces).
+ * An entire mesh can be deleted by zapping its faces, one at a time,
+ * in any order.  Zapped faces cannot be used in further mesh operations!
+ *
+ * __gl_meshCheckMesh( mesh ) checks a mesh for self-consistency.
+ */
+
+////////////////////////////////////////////////////////
+/// inlined C code : ///////////////////////////////////
+////////////////////////////////////////////////////////
+
+//#include "gluos"
+#include <cstddef>
+#include <cassert>
+#include "memalloc"
+
+inline/*static*/ GLUvertex *static_allocVertex()
+{
+   return (GLUvertex *)memAlloc( sizeof( GLUvertex ));
+}
+
+inline/*static*/ GLUface *static_allocFace()
+{
+   return (GLUface *)memAlloc( sizeof( GLUface ));
+}
+
+/************************ Utility Routines ************************/
+
+/* Allocate and free half-edges in pairs for efficiency.
+ * The *only* place that should use this fact is allocation/free.
+ */
+typedef struct { GLUhalfEdge e, eSym; } EdgePair;
+
+/* MakeEdge creates a new pair of half-edges which form their own loop.
+ * No vertex or face structures are allocated, but these must be assigned
+ * before the current edge operation is completed.
+ */
+inline/*static*/ GLUhalfEdge *static_MakeEdge( GLUhalfEdge *eNext )
+{
+  GLUhalfEdge *e;
+  GLUhalfEdge *eSym;
+  GLUhalfEdge *ePrev;
+  EdgePair *pair = (EdgePair *)memAlloc( sizeof( EdgePair ));
+  if (pair == NULL) return NULL;
+
+  e = &pair->e;
+  eSym = &pair->eSym;
+
+  /* Make sure eNext points to the first edge of the edge pair */
+  if( eNext->Sym < eNext ) { eNext = eNext->Sym; }
+
+  /* Insert in circular doubly-linked list before eNext.
+   * Note that the prev pointer is stored in Sym->next.
+   */
+  ePrev = eNext->Sym->next;
+  eSym->next = ePrev;
+  ePrev->Sym->next = e;
+  e->next = eNext;
+  eNext->Sym->next = eSym;
+
+  e->Sym = eSym;
+  e->Onext = e;
+  e->Lnext = eSym;
+  e->Org = NULL;
+  e->Lface = NULL;
+  e->winding = 0;
+  e->activeRegion = NULL;
+
+  eSym->Sym = e;
+  eSym->Onext = eSym;
+  eSym->Lnext = e;
+  eSym->Org = NULL;
+  eSym->Lface = NULL;
+  eSym->winding = 0;
+  eSym->activeRegion = NULL;
+
+  return e;
+}
+
+/* Splice( a, b ) is best described by the Guibas/Stolfi paper or the
+ * CS348a notes (see mesh.h).  Basically it modifies the mesh so that
+ * a->Onext and b->Onext are exchanged.  This can have various effects
+ * depending on whether a and b belong to different face or vertex rings.
+ * For more explanation see __gl_meshSplice() below.
+ */
+inline/*static*/ void static_Splice( GLUhalfEdge *a, GLUhalfEdge *b )
+{
+  GLUhalfEdge *aOnext = a->Onext;
+  GLUhalfEdge *bOnext = b->Onext;
+
+  aOnext->Sym->Lnext = b;
+  bOnext->Sym->Lnext = a;
+  a->Onext = bOnext;
+  b->Onext = aOnext;
+}
+
+/* MakeVertex( newVertex, eOrig, vNext ) attaches a new vertex and makes it the
+ * origin of all edges in the vertex loop to which eOrig belongs. "vNext" gives
+ * a place to insert the new vertex in the global vertex list.  We insert
+ * the new vertex *before* vNext so that algorithms which walk the vertex
+ * list will not see the newly created vertices.
+ */
+inline/*static*/ void static_MakeVertex( GLUvertex *newVertex, 
+			GLUhalfEdge *eOrig, GLUvertex *vNext )
+{
+  GLUhalfEdge *e;
+  GLUvertex *vPrev;
+  GLUvertex *vNew = newVertex;
+
+  assert(vNew != NULL);
+
+  /* insert in circular doubly-linked list before vNext */
+  vPrev = vNext->prev;
+  vNew->prev = vPrev;
+  vPrev->next = vNew;
+  vNew->next = vNext;
+  vNext->prev = vNew;
+
+  vNew->anEdge = eOrig;
+  vNew->data = NULL;
+  /* leave coords, s, t undefined */
+
+  /* fix other edges on this vertex loop */
+  e = eOrig;
+  do {
+    e->Org = vNew;
+    e = e->Onext;
+  } while( e != eOrig );
+}
+
+/* MakeFace( newFace, eOrig, fNext ) attaches a new face and makes it the left
+ * face of all edges in the face loop to which eOrig belongs.  "fNext" gives
+ * a place to insert the new face in the global face list.  We insert
+ * the new face *before* fNext so that algorithms which walk the face
+ * list will not see the newly created faces.
+ */
+inline/*static*/ void static_MakeFace( GLUface *newFace, GLUhalfEdge *eOrig, GLUface *fNext )
+{
+  GLUhalfEdge *e;
+  GLUface *fPrev;
+  GLUface *fNew = newFace;
+
+  assert(fNew != NULL); 
+
+  /* insert in circular doubly-linked list before fNext */
+  fPrev = fNext->prev;
+  fNew->prev = fPrev;
+  fPrev->next = fNew;
+  fNew->next = fNext;
+  fNext->prev = fNew;
+
+  fNew->anEdge = eOrig;
+  fNew->data = NULL;
+  fNew->trail = NULL;
+  fNew->marked = TOOLS_GLU_FALSE;
+
+  /* The new face is marked "inside" if the old one was.  This is a
+   * convenience for the common case where a face has been split in two.
+   */
+  fNew->inside = fNext->inside;
+
+  /* fix other edges on this face loop */
+  e = eOrig;
+  do {
+    e->Lface = fNew;
+    e = e->Lnext;
+  } while( e != eOrig );
+}
+
+/* KillEdge( eDel ) destroys an edge (the half-edges eDel and eDel->Sym),
+ * and removes from the global edge list.
+ */
+inline/*static*/ void static_KillEdge( GLUhalfEdge *eDel )
+{
+  GLUhalfEdge *ePrev, *eNext;
+
+  /* Half-edges are allocated in pairs, see EdgePair above */
+  if( eDel->Sym < eDel ) { eDel = eDel->Sym; }
+
+  /* delete from circular doubly-linked list */
+  eNext = eDel->next;
+  ePrev = eDel->Sym->next;
+  eNext->Sym->next = ePrev;
+  ePrev->Sym->next = eNext;
+
+  memFree( eDel );
+}
+
+
+/* KillVertex( vDel ) destroys a vertex and removes it from the global
+ * vertex list.  It updates the vertex loop to point to a given new vertex.
+ */
+inline/*static*/ void static_KillVertex( GLUvertex *vDel, GLUvertex *newOrg )
+{
+  GLUhalfEdge *e, *eStart = vDel->anEdge;
+  GLUvertex *vPrev, *vNext;
+
+  /* change the origin of all affected edges */
+  e = eStart;
+  do {
+    e->Org = newOrg;
+    e = e->Onext;
+  } while( e != eStart );
+
+  /* delete from circular doubly-linked list */
+  vPrev = vDel->prev;
+  vNext = vDel->next;
+  vNext->prev = vPrev;
+  vPrev->next = vNext;
+
+  memFree( vDel );
+}
+
+/* KillFace( fDel ) destroys a face and removes it from the global face
+ * list.  It updates the face loop to point to a given new face.
+ */
+inline/*static*/ void static_KillFace( GLUface *fDel, GLUface *newLface )
+{
+  GLUhalfEdge *e, *eStart = fDel->anEdge;
+  GLUface *fPrev, *fNext;
+
+  /* change the left face of all affected edges */
+  e = eStart;
+  do {
+    e->Lface = newLface;
+    e = e->Lnext;
+  } while( e != eStart );
+
+  /* delete from circular doubly-linked list */
+  fPrev = fDel->prev;
+  fNext = fDel->next;
+  fNext->prev = fPrev;
+  fPrev->next = fNext;
+
+  memFree( fDel );
+}
+
+
+/****************** Basic Edge Operations **********************/
+
+/* __gl_meshMakeEdge creates one edge, two vertices, and a loop (face).
+ * The loop consists of the two new half-edges.
+ */
+inline GLUhalfEdge *__gl_meshMakeEdge( GLUmesh *mesh )
+{
+  GLUvertex *newVertex1= static_allocVertex();
+  GLUvertex *newVertex2= static_allocVertex();
+  GLUface *newFace= static_allocFace();
+  GLUhalfEdge *e;
+
+  /* if any one is null then all get freed */
+  if (newVertex1 == NULL || newVertex2 == NULL || newFace == NULL) {
+     if (newVertex1 != NULL) memFree(newVertex1);
+     if (newVertex2 != NULL) memFree(newVertex2);
+     if (newFace != NULL) memFree(newFace);     
+     return NULL;
+  } 
+
+  e = static_MakeEdge( &mesh->eHead );
+  if (e == NULL) {
+     memFree(newVertex1);
+     memFree(newVertex2);
+     memFree(newFace);
+     return NULL;
+  }
+
+  static_MakeVertex( newVertex1, e, &mesh->vHead );
+  static_MakeVertex( newVertex2, e->Sym, &mesh->vHead );
+  static_MakeFace( newFace, e, &mesh->fHead );
+  return e;
+}
+  
+
+/* __gl_meshSplice( eOrg, eDst ) is the basic operation for changing the
+ * mesh connectivity and topology.  It changes the mesh so that
+ *	eOrg->Onext <- OLD( eDst->Onext )
+ *	eDst->Onext <- OLD( eOrg->Onext )
+ * where OLD(...) means the value before the meshSplice operation.
+ *
+ * This can have two effects on the vertex structure:
+ *  - if eOrg->Org != eDst->Org, the two vertices are merged together
+ *  - if eOrg->Org == eDst->Org, the origin is split into two vertices
+ * In both cases, eDst->Org is changed and eOrg->Org is untouched.
+ *
+ * Similarly (and independently) for the face structure,
+ *  - if eOrg->Lface == eDst->Lface, one loop is split into two
+ *  - if eOrg->Lface != eDst->Lface, two distinct loops are joined into one
+ * In both cases, eDst->Lface is changed and eOrg->Lface is unaffected.
+ *
+ * Some special cases:
+ * If eDst == eOrg, the operation has no effect.
+ * If eDst == eOrg->Lnext, the new face will have a single edge.
+ * If eDst == eOrg->Lprev, the old face will have a single edge.
+ * If eDst == eOrg->Onext, the new vertex will have a single edge.
+ * If eDst == eOrg->Oprev, the old vertex will have a single edge.
+ */
+inline int __gl_meshSplice( GLUhalfEdge *eOrg, GLUhalfEdge *eDst )
+{
+  int joiningLoops = TOOLS_GLU_FALSE;
+  int joiningVertices = TOOLS_GLU_FALSE;
+
+  if( eOrg == eDst ) return 1;
+
+  if( eDst->Org != eOrg->Org ) {
+    /* We are merging two disjoint vertices -- destroy eDst->Org */
+    joiningVertices = TOOLS_GLU_TRUE;
+    static_KillVertex( eDst->Org, eOrg->Org );
+  }
+  if( eDst->Lface != eOrg->Lface ) {
+    /* We are connecting two disjoint loops -- destroy eDst->Lface */
+    joiningLoops = TOOLS_GLU_TRUE;
+    static_KillFace( eDst->Lface, eOrg->Lface );
+  }
+
+  /* Change the edge structure */
+  static_Splice( eDst, eOrg );
+
+  if( ! joiningVertices ) {
+    GLUvertex *newVertex= static_allocVertex();
+    if (newVertex == NULL) return 0;
+
+    /* We split one vertex into two -- the new vertex is eDst->Org.
+     * Make sure the old vertex points to a valid half-edge.
+     */
+    static_MakeVertex( newVertex, eDst, eOrg->Org );
+    eOrg->Org->anEdge = eOrg;
+  }
+  if( ! joiningLoops ) {
+    GLUface *newFace= static_allocFace();  
+    if (newFace == NULL) return 0;
+
+    /* We split one loop into two -- the new loop is eDst->Lface.
+     * Make sure the old face points to a valid half-edge.
+     */
+    static_MakeFace( newFace, eDst, eOrg->Lface );
+    eOrg->Lface->anEdge = eOrg;
+  }
+
+  return 1;
+}
+
+
+/* __gl_meshDelete( eDel ) removes the edge eDel.  There are several cases:
+ * if (eDel->Lface != eDel->Rface), we join two loops into one; the loop
+ * eDel->Lface is deleted.  Otherwise, we are splitting one loop into two;
+ * the newly created loop will contain eDel->Dst.  If the deletion of eDel
+ * would create isolated vertices, those are deleted as well.
+ *
+ * This function could be implemented as two calls to __gl_meshSplice
+ * plus a few calls to memFree, but this would allocate and delete
+ * unnecessary vertices and faces.
+ */
+inline int __gl_meshDelete( GLUhalfEdge *eDel )
+{
+  GLUhalfEdge *eDelSym = eDel->Sym;
+  int joiningLoops = TOOLS_GLU_FALSE;
+
+  /* First step: disconnect the origin vertex eDel->Org.  We make all
+   * changes to get a consistent mesh in this "intermediate" state.
+   */
+  if( eDel->Lface != eDel->Rface ) {
+    /* We are joining two loops into one -- remove the left face */
+    joiningLoops = TOOLS_GLU_TRUE;
+    static_KillFace( eDel->Lface, eDel->Rface );
+    /* G.Barrand : note : Coverity says that there is a problem using eDel->Lface->anEdge in the below,
+       but it appears that at the out of the upper static_KillFace() call (then here), eDel->Lface before
+       (the pointer freeed) is not the same than after (then here). */
+  }
+
+  if( eDel->Onext == eDel ) {
+    static_KillVertex( eDel->Org, NULL );
+  } else {
+    /* Make sure that eDel->Org and eDel->Rface point to valid half-edges */
+    eDel->Rface->anEdge = eDel->Oprev;
+    eDel->Org->anEdge = eDel->Onext;
+
+    static_Splice( eDel, eDel->Oprev );
+    if( ! joiningLoops ) {
+      GLUface *newFace= static_allocFace();
+      if (newFace == NULL) return 0; 
+
+      /* We are splitting one loop into two -- create a new loop for eDel. */
+      static_MakeFace( newFace, eDel, eDel->Lface );
+    }
+  }
+
+  /* Claim: the mesh is now in a consistent state, except that eDel->Org
+   * may have been deleted.  Now we disconnect eDel->Dst.
+   */
+  if( eDelSym->Onext == eDelSym ) {
+    static_KillVertex( eDelSym->Org, NULL );
+    static_KillFace( eDelSym->Lface, NULL );
+  } else {
+    /* Make sure that eDel->Dst and eDel->Lface point to valid half-edges */
+    eDel->Lface->anEdge = eDelSym->Oprev;
+    eDelSym->Org->anEdge = eDelSym->Onext;
+    static_Splice( eDelSym, eDelSym->Oprev );
+  }
+
+  /* Any isolated vertices or faces have already been freed. */
+  static_KillEdge( eDel );
+
+  return 1;
+}
+
+
+/******************** Other Edge Operations **********************/
+
+/* All these routines can be implemented with the basic edge
+ * operations above.  They are provided for convenience and efficiency.
+ */
+
+
+/* __gl_meshAddEdgeVertex( eOrg ) creates a new edge eNew such that
+ * eNew == eOrg->Lnext, and eNew->Dst is a newly created vertex.
+ * eOrg and eNew will have the same left face.
+ */
+inline GLUhalfEdge *__gl_meshAddEdgeVertex( GLUhalfEdge *eOrg )
+{
+  GLUhalfEdge *eNewSym;
+  GLUhalfEdge *eNew = static_MakeEdge( eOrg );
+  if (eNew == NULL) return NULL;
+
+  eNewSym = eNew->Sym;
+
+  /* Connect the new edge appropriately */
+  static_Splice( eNew, eOrg->Lnext );
+
+  /* Set the vertex and face information */
+  eNew->Org = eOrg->Dst;
+  {
+    GLUvertex *newVertex= static_allocVertex();
+    if (newVertex == NULL) return NULL;
+
+    static_MakeVertex( newVertex, eNewSym, eNew->Org );
+  }
+  eNew->Lface = eNewSym->Lface = eOrg->Lface;
+
+  return eNew;
+}
+
+
+/* __gl_meshSplitEdge( eOrg ) splits eOrg into two edges eOrg and eNew,
+ * such that eNew == eOrg->Lnext.  The new vertex is eOrg->Dst == eNew->Org.
+ * eOrg and eNew will have the same left face.
+ */
+inline GLUhalfEdge *__gl_meshSplitEdge( GLUhalfEdge *eOrg )
+{
+  GLUhalfEdge *eNew;
+  GLUhalfEdge *tempHalfEdge= __gl_meshAddEdgeVertex( eOrg );
+  if (tempHalfEdge == NULL) return NULL;
+
+  eNew = tempHalfEdge->Sym;
+
+  /* Disconnect eOrg from eOrg->Dst and connect it to eNew->Org */
+  static_Splice( eOrg->Sym, eOrg->Sym->Oprev );
+  static_Splice( eOrg->Sym, eNew );
+
+  /* Set the vertex and face information */
+  eOrg->Dst = eNew->Org;
+  eNew->Dst->anEdge = eNew->Sym;	/* may have pointed to eOrg->Sym */
+  eNew->Rface = eOrg->Rface;
+  eNew->winding = eOrg->winding;	/* copy old winding information */
+  eNew->Sym->winding = eOrg->Sym->winding;
+
+  return eNew;
+}
+
+
+/* __gl_meshConnect( eOrg, eDst ) creates a new edge from eOrg->Dst
+ * to eDst->Org, and returns the corresponding half-edge eNew.
+ * If eOrg->Lface == eDst->Lface, this splits one loop into two,
+ * and the newly created loop is eNew->Lface.  Otherwise, two disjoint
+ * loops are merged into one, and the loop eDst->Lface is destroyed.
+ *
+ * If (eOrg == eDst), the new face will have only two edges.
+ * If (eOrg->Lnext == eDst), the old face is reduced to a single edge.
+ * If (eOrg->Lnext->Lnext == eDst), the old face is reduced to two edges.
+ */
+inline GLUhalfEdge *__gl_meshConnect( GLUhalfEdge *eOrg, GLUhalfEdge *eDst )
+{
+  GLUhalfEdge *eNewSym;
+  int joiningLoops = TOOLS_GLU_FALSE;  
+  GLUhalfEdge *eNew = static_MakeEdge( eOrg );
+  if (eNew == NULL) return NULL;
+
+  eNewSym = eNew->Sym;
+
+  if( eDst->Lface != eOrg->Lface ) {
+    /* We are connecting two disjoint loops -- destroy eDst->Lface */
+    joiningLoops = TOOLS_GLU_TRUE;
+    static_KillFace( eDst->Lface, eOrg->Lface );
+  }
+
+  /* Connect the new edge appropriately */
+  static_Splice( eNew, eOrg->Lnext );
+  static_Splice( eNewSym, eDst );
+
+  /* Set the vertex and face information */
+  eNew->Org = eOrg->Dst;
+  eNewSym->Org = eDst->Org;
+  eNew->Lface = eNewSym->Lface = eOrg->Lface;
+
+  /* Make sure the old face points to a valid half-edge */
+  eOrg->Lface->anEdge = eNewSym;
+
+  if( ! joiningLoops ) {
+    GLUface *newFace= static_allocFace();
+    if (newFace == NULL) return NULL;
+
+    /* We split one loop into two -- the new loop is eNew->Lface */
+    static_MakeFace( newFace, eNew, eOrg->Lface );
+  }
+  return eNew;
+}
+
+
+/******************** Other Operations **********************/
+
+/* __gl_meshZapFace( fZap ) destroys a face and removes it from the
+ * global face list.  All edges of fZap will have a NULL pointer as their
+ * left face.  Any edges which also have a NULL pointer as their right face
+ * are deleted entirely (along with any isolated vertices this produces).
+ * An entire mesh can be deleted by zapping its faces, one at a time,
+ * in any order.  Zapped faces cannot be used in further mesh operations!
+ */
+inline void __gl_meshZapFace( GLUface *fZap )
+{
+  GLUhalfEdge *eStart = fZap->anEdge;
+  GLUhalfEdge *e, *eNext, *eSym;
+  GLUface *fPrev, *fNext;
+
+  /* walk around face, deleting edges whose right face is also NULL */
+  eNext = eStart->Lnext;
+  do {
+    e = eNext;
+    eNext = e->Lnext;
+
+    e->Lface = NULL;
+    if( e->Rface == NULL ) {
+      /* delete the edge -- see __gl_MeshDelete above */
+
+      if( e->Onext == e ) {
+	static_KillVertex( e->Org, NULL );
+      } else {
+	/* Make sure that e->Org points to a valid half-edge */
+	e->Org->anEdge = e->Onext;
+	static_Splice( e, e->Oprev );
+      }
+      eSym = e->Sym;
+      if( eSym->Onext == eSym ) {
+	static_KillVertex( eSym->Org, NULL );
+      } else {
+	/* Make sure that eSym->Org points to a valid half-edge */
+	eSym->Org->anEdge = eSym->Onext;
+	static_Splice( eSym, eSym->Oprev );
+      }
+      static_KillEdge( e );
+    }
+  } while( e != eStart );
+
+  /* delete from circular doubly-linked list */
+  fPrev = fZap->prev;
+  fNext = fZap->next;
+  fNext->prev = fPrev;
+  fPrev->next = fNext;
+
+  memFree( fZap );
+}
+
+
+/* __gl_meshNewMesh() creates a new mesh with no edges, no vertices,
+ * and no loops (what we usually call a "face").
+ */
+inline GLUmesh *__gl_meshNewMesh( void )
+{
+  GLUvertex *v;
+  GLUface *f;
+  GLUhalfEdge *e;
+  GLUhalfEdge *eSym;
+  GLUmesh *mesh = (GLUmesh *)memAlloc( sizeof( GLUmesh ));
+  if (mesh == NULL) {
+     return NULL;
+  }
+  
+  v = &mesh->vHead;
+  f = &mesh->fHead;
+  e = &mesh->eHead;
+  eSym = &mesh->eHeadSym;
+
+  v->next = v->prev = v;
+  v->anEdge = NULL;
+  v->data = NULL;
+
+  f->next = f->prev = f;
+  f->anEdge = NULL;
+  f->data = NULL;
+  f->trail = NULL;
+  f->marked = TOOLS_GLU_FALSE;
+  f->inside = TOOLS_GLU_FALSE;
+
+  e->next = e;
+  e->Sym = eSym;
+  e->Onext = NULL;
+  e->Lnext = NULL;
+  e->Org = NULL;
+  e->Lface = NULL;
+  e->winding = 0;
+  e->activeRegion = NULL;
+
+  eSym->next = eSym;
+  eSym->Sym = e;
+  eSym->Onext = NULL;
+  eSym->Lnext = NULL;
+  eSym->Org = NULL;
+  eSym->Lface = NULL;
+  eSym->winding = 0;
+  eSym->activeRegion = NULL;
+
+  return mesh;
+}
+
+
+/* __gl_meshUnion( mesh1, mesh2 ) forms the union of all structures in
+ * both meshes, and returns the new mesh (the old meshes are destroyed).
+ */
+inline GLUmesh *__gl_meshUnion( GLUmesh *mesh1, GLUmesh *mesh2 )
+{
+  GLUface *f1 = &mesh1->fHead;
+  GLUvertex *v1 = &mesh1->vHead;
+  GLUhalfEdge *e1 = &mesh1->eHead;
+  GLUface *f2 = &mesh2->fHead;
+  GLUvertex *v2 = &mesh2->vHead;
+  GLUhalfEdge *e2 = &mesh2->eHead;
+
+  /* Add the faces, vertices, and edges of mesh2 to those of mesh1 */
+  if( f2->next != f2 ) {
+    f1->prev->next = f2->next;
+    f2->next->prev = f1->prev;
+    f2->prev->next = f1;
+    f1->prev = f2->prev;
+  }
+
+  if( v2->next != v2 ) {
+    v1->prev->next = v2->next;
+    v2->next->prev = v1->prev;
+    v2->prev->next = v1;
+    v1->prev = v2->prev;
+  }
+
+  if( e2->next != e2 ) {
+    e1->Sym->next->Sym->next = e2->next;
+    e2->next->Sym->next = e1->Sym->next;
+    e2->Sym->next->Sym->next = e1;
+    e1->Sym->next = e2->Sym->next;
+  }
+
+  memFree( mesh2 );
+  return mesh1;
+}
+
+
+#ifdef DELETE_BY_ZAPPING
+
+/* __gl_meshDeleteMesh( mesh ) will free all storage for any valid mesh.
+ */
+inline void __gl_meshDeleteMesh( GLUmesh *mesh )
+{
+  GLUface *fHead = &mesh->fHead;
+
+  while( fHead->next != fHead ) {
+    __gl_meshZapFace( fHead->next );
+  }
+  assert( mesh->vHead.next == &mesh->vHead );
+
+  memFree( mesh );
+}
+
+#else
+
+/* __gl_meshDeleteMesh( mesh ) will free all storage for any valid mesh.
+ */
+inline void __gl_meshDeleteMesh( GLUmesh *mesh )
+{
+  GLUface *f, *fNext;
+  GLUvertex *v, *vNext;
+  GLUhalfEdge *e, *eNext;
+
+  for( f = mesh->fHead.next; f != &mesh->fHead; f = fNext ) {
+    fNext = f->next;
+    memFree( f );
+  }
+
+  for( v = mesh->vHead.next; v != &mesh->vHead; v = vNext ) {
+    vNext = v->next;
+    memFree( v );
+  }
+
+  for( e = mesh->eHead.next; e != &mesh->eHead; e = eNext ) {
+    /* One call frees both e and e->Sym (see EdgePair above) */
+    eNext = e->next;
+    memFree( e );
+  }
+
+  memFree( mesh );
+}
+
+#endif
+
+inline void __gl_meshCheckMesh( GLUmesh *mesh )
+{
+  GLUface *fHead = &mesh->fHead;
+  GLUvertex *vHead = &mesh->vHead;
+  GLUhalfEdge *eHead = &mesh->eHead;
+  GLUface *f, *fPrev;
+  GLUvertex *v, *vPrev;
+  GLUhalfEdge *e, *ePrev;
+
+  fPrev = fHead;
+  for( fPrev = fHead ; (f = fPrev->next) != fHead; fPrev = f) {
+    assert( f->prev == fPrev );
+    e = f->anEdge;
+    do {
+      assert( e->Sym != e );
+      assert( e->Sym->Sym == e );
+      assert( e->Lnext->Onext->Sym == e );
+      assert( e->Onext->Sym->Lnext == e );
+      assert( e->Lface == f );
+      e = e->Lnext;
+    } while( e != f->anEdge );
+  }
+  assert( f->prev == fPrev && f->anEdge == NULL && f->data == NULL );
+
+  vPrev = vHead;
+  for( vPrev = vHead ; (v = vPrev->next) != vHead; vPrev = v) {
+    assert( v->prev == vPrev );
+    e = v->anEdge;
+    do {
+      assert( e->Sym != e );
+      assert( e->Sym->Sym == e );
+      assert( e->Lnext->Onext->Sym == e );
+      assert( e->Onext->Sym->Lnext == e );
+      assert( e->Org == v );
+      e = e->Onext;
+    } while( e != v->anEdge );
+  }
+  assert( v->prev == vPrev && v->anEdge == NULL && v->data == NULL );
+
+  ePrev = eHead;
+  for( ePrev = eHead ; (e = ePrev->next) != eHead; ePrev = e) {
+    assert( e->Sym->next == ePrev->Sym );
+    assert( e->Sym != e );
+    assert( e->Sym->Sym == e );
+    assert( e->Org != NULL );
+    assert( e->Dst != NULL );
+    assert( e->Lnext->Onext->Sym == e );
+    assert( e->Onext->Sym->Lnext == e );
+  }
+  assert( e->Sym->next == ePrev->Sym
+       && e->Sym == &mesh->eHeadSym
+       && e->Sym->Sym == e
+       && e->Org == NULL && e->Dst == NULL
+       && e->Lface == NULL && e->Rface == NULL );
+}
+
+#endif

source/externals/g4tools/include/tools/glutess/normal

@@ -0,0 +1,209 @@
+// see license file for original license.
+
+#ifndef tools_glutess_normal
+#define tools_glutess_normal
+
+#include "_tess"
+
+/* __gl_projectPolygon( tess ) determines the polygon normal
+ * and project vertices onto the plane of the polygon.
+ */
+//void __gl_projectPolygon( GLUtesselator *tess );
+
+////////////////////////////////////////////////////////
+/// inlined C code : ///////////////////////////////////
+////////////////////////////////////////////////////////
+#include <cmath>
+
+#define Dot(u,v)	(u[0]*v[0] + u[1]*v[1] + u[2]*v[2])
+
+inline/*static*/ int static_LongAxis( GLUdouble v[3] )
+{
+  int i = 0;
+
+  if( GLU_ABS(v[1]) > GLU_ABS(v[0]) ) { i = 1; }
+  if( GLU_ABS(v[2]) > GLU_ABS(v[i]) ) { i = 2; }
+  return i;
+}
+
+inline/*static*/ void static_ComputeNormal( GLUtesselator *tess, GLUdouble norm[3] )
+{
+  GLUvertex *v, *v1, *v2;
+  GLUdouble c, tLen2, maxLen2;
+  GLUdouble maxVal[3], minVal[3], d1[3], d2[3], tNorm[3];
+  GLUvertex *maxVert[3], *minVert[3];
+  GLUvertex *vHead = &tess->mesh->vHead;
+  int i;
+
+  maxVal[0] = maxVal[1] = maxVal[2] = -2 * GLU_TESS_MAX_COORD;
+  minVal[0] = minVal[1] = minVal[2] = 2 * GLU_TESS_MAX_COORD;
+  
+  minVert[0] = 0;minVert[1] = 0;minVert[2] = 0; //G.Barrand : to quiet Coverity.
+  maxVert[0] = 0;maxVert[1] = 0;maxVert[2] = 0; //G.Barrand : to quiet Coverity.
+
+  for( v = vHead->next; v != vHead; v = v->next ) {
+    for( i = 0; i < 3; ++i ) {
+      c = v->coords[i];
+      if( c < minVal[i] ) { minVal[i] = c; minVert[i] = v; }
+      if( c > maxVal[i] ) { maxVal[i] = c; maxVert[i] = v; }
+    }
+  }
+
+  /* Find two vertices separated by at least 1/sqrt(3) of the maximum
+   * distance between any two vertices
+   */
+  i = 0;
+  if( maxVal[1] - minVal[1] > maxVal[0] - minVal[0] ) { i = 1; }
+  if( maxVal[2] - minVal[2] > maxVal[i] - minVal[i] ) { i = 2; }
+  if( minVal[i] >= maxVal[i] ) {
+    /* All vertices are the same -- normal doesn't matter */
+    norm[0] = 0; norm[1] = 0; norm[2] = 1;
+    return;
+  }
+
+  /* Look for a third vertex which forms the triangle with maximum area
+   * (Length of normal == twice the triangle area)
+   */
+  maxLen2 = 0;
+  v1 = minVert[i];
+  v2 = maxVert[i];
+  if( !v1 || !v2 ) {norm[0] = 0; norm[1] = 0; norm[2] = 1;return;} //G.Barrand.
+  d1[0] = v1->coords[0] - v2->coords[0];
+  d1[1] = v1->coords[1] - v2->coords[1];
+  d1[2] = v1->coords[2] - v2->coords[2];
+  for( v = vHead->next; v != vHead; v = v->next ) {
+    d2[0] = v->coords[0] - v2->coords[0];
+    d2[1] = v->coords[1] - v2->coords[1];
+    d2[2] = v->coords[2] - v2->coords[2];
+    tNorm[0] = d1[1]*d2[2] - d1[2]*d2[1];
+    tNorm[1] = d1[2]*d2[0] - d1[0]*d2[2];
+    tNorm[2] = d1[0]*d2[1] - d1[1]*d2[0];
+    tLen2 = tNorm[0]*tNorm[0] + tNorm[1]*tNorm[1] + tNorm[2]*tNorm[2];
+    if( tLen2 > maxLen2 ) {
+      maxLen2 = tLen2;
+      norm[0] = tNorm[0];
+      norm[1] = tNorm[1];
+      norm[2] = tNorm[2];
+    }
+  }
+
+  if( maxLen2 <= 0 ) {
+    /* All points lie on a single line -- any decent normal will do */
+    norm[0] = norm[1] = norm[2] = 0;
+    norm[static_LongAxis(d1)] = 1;
+  }
+}
+
+
+inline/*static*/ void static_CheckOrientation( GLUtesselator *tess )
+{
+  GLUdouble area;
+  GLUface *f, *fHead = &tess->mesh->fHead;
+  GLUvertex *v, *vHead = &tess->mesh->vHead;
+  GLUhalfEdge *e;
+
+  /* When we compute the normal automatically, we choose the orientation
+   * so that the sum of the signed areas of all contours is non-negative.
+   */
+  area = 0;
+  for( f = fHead->next; f != fHead; f = f->next ) {
+    e = f->anEdge;
+    if( e->winding <= 0 ) continue;
+    do {
+      area += (e->Org->s - e->Dst->s) * (e->Org->t + e->Dst->t);
+      e = e->Lnext;
+    } while( e != f->anEdge );
+  }
+  if( area < 0 ) {
+    /* Reverse the orientation by flipping all the t-coordinates */
+    for( v = vHead->next; v != vHead; v = v->next ) {
+      v->t = - v->t;
+    }
+    tess->tUnit[0] = - tess->tUnit[0];
+    tess->tUnit[1] = - tess->tUnit[1];
+    tess->tUnit[2] = - tess->tUnit[2];
+  }
+}
+
+#if defined(SLANTED_SWEEP)
+/* The "feature merging" is not intended to be complete.  There are
+ * special cases where edges are nearly parallel to the sweep line
+ * which are not implemented.  The algorithm should still behave
+ * robustly (ie. produce a reasonable tesselation) in the presence
+ * of such edges, however it may miss features which could have been
+ * merged.  We could minimize this effect by choosing the sweep line
+ * direction to be something unusual (ie. not parallel to one of the
+ * coordinate axes).
+ */
+#define S_UNIT_X	0.50941539564955385	/* Pre-normalized */
+#define S_UNIT_Y	0.86052074622010633
+#else
+#define S_UNIT_X	1.0
+#define S_UNIT_Y	0.0
+#endif
+
+/* Determine the polygon normal and project vertices onto the plane
+ * of the polygon.
+ */
+inline void __gl_projectPolygon( GLUtesselator *tess )
+{
+  GLUvertex *v, *vHead = &tess->mesh->vHead;
+  GLUdouble norm[3];
+  GLUdouble *sUnit, *tUnit;
+  int i, computedNormal = TOOLS_GLU_FALSE;
+
+  norm[0] = tess->normal[0];
+  norm[1] = tess->normal[1];
+  norm[2] = tess->normal[2];
+  if( norm[0] == 0 && norm[1] == 0 && norm[2] == 0 ) {
+    static_ComputeNormal( tess, norm );
+    computedNormal = TOOLS_GLU_TRUE;
+  }
+  sUnit = tess->sUnit;
+  tUnit = tess->tUnit;
+  i = static_LongAxis( norm );
+
+#if defined(FOR_TRITE_TEST_PROGRAM) || defined(TRUE_PROJECT)
+  /* Choose the initial sUnit vector to be approximately perpendicular
+   * to the normal.
+   */
+  Normalize( norm );
+
+  sUnit[i] = 0;
+  sUnit[(i+1)%3] = S_UNIT_X;
+  sUnit[(i+2)%3] = S_UNIT_Y;
+
+  /* Now make it exactly perpendicular */
+  w = Dot( sUnit, norm );
+  sUnit[0] -= w * norm[0];
+  sUnit[1] -= w * norm[1];
+  sUnit[2] -= w * norm[2];
+  Normalize( sUnit );
+
+  /* Choose tUnit so that (sUnit,tUnit,norm) form a right-handed frame */
+  tUnit[0] = norm[1]*sUnit[2] - norm[2]*sUnit[1];
+  tUnit[1] = norm[2]*sUnit[0] - norm[0]*sUnit[2];
+  tUnit[2] = norm[0]*sUnit[1] - norm[1]*sUnit[0];
+  Normalize( tUnit );
+#else
+  /* Project perpendicular to a coordinate axis -- better numerically */
+  sUnit[i] = 0;
+  sUnit[(i+1)%3] = S_UNIT_X;
+  sUnit[(i+2)%3] = S_UNIT_Y;
+
+  tUnit[i] = 0;
+  tUnit[(i+1)%3] = (norm[i] > 0) ? -S_UNIT_Y : S_UNIT_Y;
+  tUnit[(i+2)%3] = (norm[i] > 0) ? S_UNIT_X : -S_UNIT_X;
+#endif
+
+  /* Project the vertices onto the sweep plane */
+  for( v = vHead->next; v != vHead; v = v->next ) {
+    v->s = Dot( v->coords, sUnit );
+    v->t = Dot( v->coords, tUnit );
+  }
+  if( computedNormal ) {
+    static_CheckOrientation( tess );
+  }
+}
+
+#endif

source/externals/g4tools/include/tools/glutess/priorityq

@@ -0,0 +1,572 @@
+// see license file for original license.
+
+#ifndef tools_glutess_priorityq
+#define tools_glutess_priorityq
+
+#include <climits>		/* LONG_MAX */
+#include "memalloc"
+
+/* Include all the code for the regular heap-based queue here. */
+
+/////////////////////////////////////////////////////////////////
+//#include "priorityq-heap.ic"
+//#include "priorityq-heap"
+
+/* Use #define's so that another heap implementation can use this one */
+
+#define PQkey			PQHeapKey
+#define PQhandle		PQHeapHandle
+#define PriorityQ		PriorityQHeap
+
+#define pqNewPriorityQ(leq)	__gl_pqHeapNewPriorityQ(leq)
+#define pqDeletePriorityQ(pq)	__gl_pqHeapDeletePriorityQ(pq)
+
+/* The basic operations are insertion of a new key (pqInsert),
+ * and examination/extraction of a key whose value is minimum
+ * (pqMinimum/pqExtractMin).  Deletion is also allowed (pqDelete);
+ * for this purpose pqInsert returns a "handle" which is supplied
+ * as the argument.
+ *
+ * An initial heap may be created efficiently by calling pqInsert
+ * repeatedly, then calling pqInit.  In any case pqInit must be called
+ * before any operations other than pqInsert are used.
+ *
+ * If the heap is empty, pqMinimum/pqExtractMin will return a NULL key.
+ * This may also be tested with pqIsEmpty.
+ */
+#define pqInit(pq)		__gl_pqHeapInit(pq)
+#define pqInsert(pq,key)	__gl_pqHeapInsert(pq,key)
+#define pqMinimum(pq)		__gl_pqHeapMinimum(pq)
+#define pqExtractMin(pq)	__gl_pqHeapExtractMin(pq)
+#define pqDelete(pq,handle)	__gl_pqHeapDelete(pq,handle)
+#define pqIsEmpty(pq)		__gl_pqHeapIsEmpty(pq)
+
+/* Since we support deletion the data structure is a little more
+ * complicated than an ordinary heap.  "nodes" is the heap itself;
+ * active nodes are stored in the range 1..pq->size.  When the
+ * heap exceeds its allocated size (pq->max), its size doubles.
+ * The children of node i are nodes 2i and 2i+1.
+ *
+ * Each node stores an index into an array "handles".  Each handle
+ * stores a key, plus a pointer back to the node which currently
+ * represents that key (ie. nodes[handles[i].node].handle == i).
+ */
+
+typedef void *PQkey;
+typedef long PQhandle;
+typedef struct PriorityQ PriorityQ;
+
+typedef struct { PQhandle handle; } PQnode;
+typedef struct { PQkey key; PQhandle node; } PQhandleElem;
+
+struct PriorityQ {
+  PQnode	*nodes;
+  PQhandleElem	*handles;
+  long		size, max;
+  PQhandle	freeList;
+  int		initialized;
+  int		(*leq)(PQkey key1, PQkey key2);
+};
+  
+#define __gl_pqHeapMinimum(pq)	((pq)->handles[(pq)->nodes[1].handle].key)
+#define __gl_pqHeapIsEmpty(pq)	((pq)->size == 0)
+
+/////////////////////////////////////////////////////////////////
+/////////////////////////////////////////////////////////////////
+//#define INIT_SIZE 32
+inline long INIT_SIZE() {
+  static const long s_value = 32;
+  return s_value;
+}
+
+/* Violates modularity, but a little faster */
+#include "geom"
+#define LEQ(x,y)	VertLeq((GLUvertex *)x, (GLUvertex *)y)
+
+/* really __gl_pqHeapNewPriorityQ */
+inline PriorityQ *pqNewPriorityQ( int (*leq)(PQkey key1, PQkey key2) )
+{
+  PriorityQ *pq = (PriorityQ *)memAlloc( sizeof( PriorityQ ));
+  if (pq == NULL) return NULL;
+
+  pq->size = 0;
+  pq->max = INIT_SIZE();
+  pq->nodes = (PQnode *)memAlloc( (INIT_SIZE() + 1) * sizeof(pq->nodes[0]) );
+  if (pq->nodes == NULL) {
+     memFree(pq);
+     return NULL;
+  }
+
+  pq->handles = (PQhandleElem *)memAlloc( (INIT_SIZE() + 1) * sizeof(pq->handles[0]) );
+  if (pq->handles == NULL) {
+     memFree(pq->nodes);
+     memFree(pq);
+     return NULL;
+  }
+
+  pq->initialized = TOOLS_GLU_FALSE;
+  pq->freeList = 0;
+  pq->leq = leq;
+
+  pq->nodes[1].handle = 1;	/* so that Minimum() returns NULL */
+  pq->handles[1].key = NULL;
+  return pq;
+}
+
+/* really __gl_pqHeapDeletePriorityQ */
+inline void pqDeletePriorityQ( PriorityQ *pq )
+{
+  memFree( pq->handles );
+  memFree( pq->nodes );
+  memFree( pq );
+}
+
+
+inline/*static*/ void static_FloatDown( PriorityQ *pq, long curr )
+{
+  PQnode *n = pq->nodes;
+  PQhandleElem *h = pq->handles;
+  PQhandle hCurr, hChild;
+  long child;
+
+  hCurr = n[curr].handle;
+  for( ;; ) {
+    child = curr << 1;
+    if( child < pq->size && LEQ( h[n[child+1].handle].key,
+				 h[n[child].handle].key )) {
+      ++child;
+    }
+
+    assert(child <= pq->max);
+
+    hChild = n[child].handle;
+    if( child > pq->size || LEQ( h[hCurr].key, h[hChild].key )) {
+      n[curr].handle = hCurr;
+      h[hCurr].node = curr;
+      break;
+    }
+    n[curr].handle = hChild;
+    h[hChild].node = curr;
+    curr = child;
+  }
+}
+
+
+inline/*static*/ void static_FloatUp( PriorityQ *pq, long curr )
+{
+  PQnode *n = pq->nodes;
+  PQhandleElem *h = pq->handles;
+  PQhandle hCurr, hParent;
+  long parent;
+
+  hCurr = n[curr].handle;
+  for( ;; ) {
+    parent = curr >> 1;
+    hParent = n[parent].handle;
+    if( parent == 0 || LEQ( h[hParent].key, h[hCurr].key )) {
+      n[curr].handle = hCurr;
+      h[hCurr].node = curr;
+      break;
+    }
+    n[curr].handle = hParent;
+    h[hParent].node = curr;
+    curr = parent;
+  }
+}
+
+/* really __gl_pqHeapInit */
+inline void pqInit( PriorityQ *pq )
+{
+  long i;
+
+  /* This method of building a heap is O(n), rather than O(n lg n). */
+
+  for( i = pq->size; i >= 1; --i ) {
+    static_FloatDown( pq, i );
+  }
+  pq->initialized = TOOLS_GLU_TRUE;
+}
+
+/* really __gl_pqHeapInsert */
+/* returns LONG_MAX iff out of memory */
+inline PQhandle pqInsert( PriorityQ *pq, PQkey keyNew )
+{
+  long curr;
+  PQhandle free;
+
+  curr = ++ pq->size;
+  if( (curr*2) > pq->max ) {
+    PQnode *saveNodes= pq->nodes;
+    PQhandleElem *saveHandles= pq->handles;
+
+    /* If the heap overflows, double its size. */
+    pq->max <<= 1;
+    pq->nodes = (PQnode *)memRealloc( pq->nodes, 
+				     (size_t) 
+				     ((pq->max + 1) * sizeof( pq->nodes[0] )));
+    if (pq->nodes == NULL) {
+       pq->nodes = saveNodes;	/* restore ptr to free upon return */
+       return LONG_MAX;
+    }
+    pq->handles = (PQhandleElem *)memRealloc( pq->handles,
+			                     (size_t)
+			                      ((pq->max + 1) * 
+					       sizeof( pq->handles[0] )));
+    if (pq->handles == NULL) {
+       pq->handles = saveHandles; /* restore ptr to free upon return */
+       return LONG_MAX;
+    }
+  }
+
+  if( pq->freeList == 0 ) {
+    free = curr;
+  } else {
+    free = pq->freeList;
+    pq->freeList = pq->handles[free].node;
+  }
+
+  pq->nodes[curr].handle = free;
+  pq->handles[free].node = curr;
+  pq->handles[free].key = keyNew;
+
+  if( pq->initialized ) {
+    static_FloatUp( pq, curr );
+  }
+  assert(free != LONG_MAX);
+  return free;
+}
+
+/* really __gl_pqHeapExtractMin */
+inline PQkey pqExtractMin( PriorityQ *pq )
+{
+  PQnode *n = pq->nodes;
+  PQhandleElem *h = pq->handles;
+  PQhandle hMin = n[1].handle;
+  PQkey min = h[hMin].key;
+
+  if( pq->size > 0 ) {
+    n[1].handle = n[pq->size].handle;
+    h[n[1].handle].node = 1;
+
+    h[hMin].key = NULL;
+    h[hMin].node = pq->freeList;
+    pq->freeList = hMin;
+
+    if( -- pq->size > 0 ) {
+      static_FloatDown( pq, 1 );
+    }
+  }
+  return min;
+}
+
+/* really __gl_pqHeapDelete */
+inline void pqDelete( PriorityQ *pq, PQhandle hCurr )
+{
+  PQnode *n = pq->nodes;
+  PQhandleElem *h = pq->handles;
+  long curr;
+
+  assert( hCurr >= 1 && hCurr <= pq->max && h[hCurr].key != NULL );
+
+  curr = h[hCurr].node;
+  n[curr].handle = n[pq->size].handle;
+  h[n[curr].handle].node = curr;
+
+  if( curr <= -- pq->size ) {
+    if( curr <= 1 || LEQ( h[n[curr>>1].handle].key, h[n[curr].handle].key )) {
+      static_FloatDown( pq, curr );
+    } else {
+      static_FloatUp( pq, curr );
+    }
+  }
+  h[hCurr].key = NULL;
+  h[hCurr].node = pq->freeList;
+  pq->freeList = hCurr;
+}
+
+/* Now redefine all the function names to map to their "Sort" versions. */
+
+/////////////////////////////////////////////////////////////////
+//#include "priorityq-sort"
+
+#undef PQkey
+#undef PQhandle
+#undef PriorityQ
+#undef pqNewPriorityQ
+#undef pqDeletePriorityQ
+#undef pqInit
+#undef pqInsert
+#undef pqMinimum
+#undef pqExtractMin
+#undef pqDelete
+#undef pqIsEmpty
+
+/* Use #define's so that another heap implementation can use this one */
+
+#define PQkey			PQSortKey
+#define PQhandle		PQSortHandle
+#define PriorityQ		PriorityQSort
+
+#define pqNewPriorityQ(leq)	__gl_pqSortNewPriorityQ(leq)
+#define pqDeletePriorityQ(pq)	__gl_pqSortDeletePriorityQ(pq)
+
+/* The basic operations are insertion of a new key (pqInsert),
+ * and examination/extraction of a key whose value is minimum
+ * (pqMinimum/pqExtractMin).  Deletion is also allowed (pqDelete);
+ * for this purpose pqInsert returns a "handle" which is supplied
+ * as the argument.
+ *
+ * An initial heap may be created efficiently by calling pqInsert
+ * repeatedly, then calling pqInit.  In any case pqInit must be called
+ * before any operations other than pqInsert are used.
+ *
+ * If the heap is empty, pqMinimum/pqExtractMin will return a NULL key.
+ * This may also be tested with pqIsEmpty.
+ */
+#define pqInit(pq)		__gl_pqSortInit(pq)
+#define pqInsert(pq,key)	__gl_pqSortInsert(pq,key)
+#define pqMinimum(pq)		__gl_pqSortMinimum(pq)
+#define pqExtractMin(pq)	__gl_pqSortExtractMin(pq)
+#define pqDelete(pq,handle)	__gl_pqSortDelete(pq,handle)
+#define pqIsEmpty(pq)		__gl_pqSortIsEmpty(pq)
+
+
+/* Since we support deletion the data structure is a little more
+ * complicated than an ordinary heap.  "nodes" is the heap itself;
+ * active nodes are stored in the range 1..pq->size.  When the
+ * heap exceeds its allocated size (pq->max), its size doubles.
+ * The children of node i are nodes 2i and 2i+1.
+ *
+ * Each node stores an index into an array "handles".  Each handle
+ * stores a key, plus a pointer back to the node which currently
+ * represents that key (ie. nodes[handles[i].node].handle == i).
+ */
+
+typedef PQHeapKey PQkey;
+typedef PQHeapHandle PQhandle;
+typedef struct PriorityQ PriorityQ;
+
+struct PriorityQ {
+  PriorityQHeap	*heap;
+  PQkey		*keys;
+  PQkey		**order;
+  PQhandle	size, max;
+  int		initialized;
+  int		(*leq)(PQkey key1, PQkey key2);
+};
+  
+/* really __gl_pqSortNewPriorityQ */
+inline PriorityQ *pqNewPriorityQ( int (*leq)(PQkey key1, PQkey key2) )
+{
+  PriorityQ *pq = (PriorityQ *)memAlloc( sizeof( PriorityQ ));
+  if (pq == NULL) return NULL;
+
+  pq->heap = __gl_pqHeapNewPriorityQ( leq );
+  if (pq->heap == NULL) {
+     memFree(pq);
+     return NULL;
+  }
+
+  pq->keys = (PQHeapKey *)memAlloc( INIT_SIZE() * sizeof(pq->keys[0]) );
+  if (pq->keys == NULL) {
+     __gl_pqHeapDeletePriorityQ(pq->heap);
+     memFree(pq);
+     return NULL;
+  }
+
+  pq->size = 0;
+  pq->max = INIT_SIZE();
+  pq->initialized = TOOLS_GLU_FALSE;
+  pq->leq = leq;
+  return pq;
+}
+
+/* really __gl_pqSortDeletePriorityQ */
+inline void pqDeletePriorityQ( PriorityQ *pq )
+{
+  assert(pq != NULL); 
+  if (pq->heap != NULL) __gl_pqHeapDeletePriorityQ( pq->heap );
+  if (pq->order != NULL) memFree( pq->order );
+  if (pq->keys != NULL) memFree( pq->keys );
+  memFree( pq );
+}
+
+
+#define LT(x,y)		(! LEQ(y,x))
+#define GT(x,y)		(! LEQ(x,y))
+//#define pq_Swap(a,b)	if(1){PQkey *tmp = *a; *a = *b; *b = tmp;}else
+#define pq_Swap(a,b)	do{PQkey *tmp = *a; *a = *b; *b = tmp;} while(false)
+
+/* really __gl_pqSortInit */
+inline int pqInit( PriorityQ *pq )
+{
+  PQkey **p, **r, **i, **j, *piv;
+  struct { PQkey **p, **r; } Stack[50], *top = Stack;
+  unsigned long seed = 2016473283;
+
+  /* Create an array of indirect pointers to the keys, so that we
+   * the handles we have returned are still valid.
+   */
+/*
+  pq->order = (PQHeapKey **)memAlloc( (size_t)
+                                  (pq->size * sizeof(pq->order[0])) );
+*/
+  pq->order = (PQHeapKey **)memAlloc( (size_t)
+                                  ((pq->size+1) * sizeof(pq->order[0])) );
+/* the previous line is a patch to compensate for the fact that IBM */
+/* machines return a null on a malloc of zero bytes (unlike SGI),   */
+/* so we have to put in this defense to guard against a memory      */
+/* fault four lines down. from fossum@austin.ibm.com.               */
+  if (pq->order == NULL) return 0;
+
+  p = pq->order;
+  r = p + pq->size - 1;
+  for( piv = pq->keys, i = p; i <= r; ++piv, ++i ) {
+    *i = piv;
+  }
+
+  /* Sort the indirect pointers in descending order,
+   * using randomized Quicksort
+   */
+  top->p = p; top->r = r; ++top;
+  while( --top >= Stack ) {
+    p = top->p;
+    r = top->r;
+    while( r > p + 10 ) {
+      seed = seed * 1539415821 + 1;
+      i = p + seed % (r - p + 1);
+      piv = *i;
+      *i = *p;
+      *p = piv;
+      i = p - 1;
+      j = r + 1;
+      do {
+	do { ++i; } while( GT( **i, *piv ));
+	do { --j; } while( LT( **j, *piv ));
+	pq_Swap( i, j );
+      } while( i < j );
+      pq_Swap( i, j );	/* Undo last swap */
+      if( i - p < r - j ) {
+	top->p = j+1; top->r = r; ++top;
+	r = i-1;
+      } else {
+	top->p = p; top->r = i-1; ++top;
+	p = j+1;
+      }
+    }
+    /* Insertion sort small lists */
+    for( i = p+1; i <= r; ++i ) {
+      piv = *i;
+      for( j = i; j > p && LT( **(j-1), *piv ); --j ) {
+	*j = *(j-1);
+      }
+      *j = piv;
+    }
+  }
+  pq->max = pq->size;
+  pq->initialized = TOOLS_GLU_TRUE;
+  __gl_pqHeapInit( pq->heap );	/* always succeeds */
+
+#ifndef NDEBUG
+  p = pq->order;
+  r = p + pq->size - 1;
+  for( i = p; i < r; ++i ) {
+    assert( LEQ( **(i+1), **i ));
+  }
+#endif
+
+  return 1;
+}
+
+/* really __gl_pqSortInsert */
+/* returns LONG_MAX iff out of memory */ 
+inline PQhandle pqInsert( PriorityQ *pq, PQkey keyNew )
+{
+  long curr;
+
+  if( pq->initialized ) {
+    return __gl_pqHeapInsert( pq->heap, keyNew );
+  }
+  curr = pq->size;
+  if( ++ pq->size >= pq->max ) {
+    PQkey *saveKey= pq->keys;
+
+    /* If the heap overflows, double its size. */
+    pq->max <<= 1;
+    pq->keys = (PQHeapKey *)memRealloc( pq->keys, 
+	 	                        (size_t)
+	                                 (pq->max * sizeof( pq->keys[0] )));
+    if (pq->keys == NULL) {	
+       pq->keys = saveKey;	/* restore ptr to free upon return */
+       return LONG_MAX;
+    }
+  }
+  assert(curr != LONG_MAX);	
+  pq->keys[curr] = keyNew;
+
+  /* Negative handles index the sorted array. */
+  return -(curr+1);
+}
+
+/* really __gl_pqSortExtractMin */
+inline PQkey pqExtractMin( PriorityQ *pq )
+{
+  PQkey sortMin, heapMin;
+
+  if( pq->size == 0 ) {
+    return __gl_pqHeapExtractMin( pq->heap );
+  }
+  sortMin = *(pq->order[pq->size-1]);
+  if( ! __gl_pqHeapIsEmpty( pq->heap )) {
+    heapMin = __gl_pqHeapMinimum( pq->heap );
+    if( LEQ( heapMin, sortMin )) {
+      return __gl_pqHeapExtractMin( pq->heap );
+    }
+  }
+  do {
+    -- pq->size;
+  } while( pq->size > 0 && *(pq->order[pq->size-1]) == NULL );
+  return sortMin;
+}
+
+/* really __gl_pqSortMinimum */
+inline PQkey pqMinimum( PriorityQ *pq )
+{
+  PQkey sortMin, heapMin;
+
+  if( pq->size == 0 ) {
+    return __gl_pqHeapMinimum( pq->heap );
+  }
+  sortMin = *(pq->order[pq->size-1]);
+  if( ! __gl_pqHeapIsEmpty( pq->heap )) {
+    heapMin = __gl_pqHeapMinimum( pq->heap );
+    if( LEQ( heapMin, sortMin )) {
+      return heapMin;
+    }
+  }
+  return sortMin;
+}
+
+/* really __gl_pqSortIsEmpty */
+inline int pqIsEmpty( PriorityQ *pq )
+{
+  return (pq->size == 0) && __gl_pqHeapIsEmpty( pq->heap );
+}
+
+/* really __gl_pqSortDelete */
+inline void pqDelete( PriorityQ *pq, PQhandle curr )
+{
+  if( curr >= 0 ) {
+    __gl_pqHeapDelete( pq->heap, curr );
+    return;
+  }
+  curr = -(curr+1);
+  assert( curr < pq->max && pq->keys[curr] != NULL );
+
+  pq->keys[curr] = NULL;
+  while( pq->size > 0 && *(pq->order[pq->size-1]) == NULL ) {
+    -- pq->size;
+  }
+}
+
+#endif

source/externals/g4tools/include/tools/glutess/rename

@@ -0,0 +1,80 @@
+#ifndef tools_glutess_rename
+#define tools_glutess_rename
+
+/* G.Barrand : name space protection : */
+
+#define gluTessBeginContour tools_gluTessBeginContour
+#define gluTessBeginPolygon tools_gluTessBeginPolygon
+#define gluTessCallback     tools_gluTessCallback
+#define gluTessEndContour   tools_gluTessEndContour
+#define gluTessEndPolygon   tools_gluTessEndPolygon
+#define gluTessNormal       tools_gluTessNormal
+#define gluTessProperty     tools_gluTessProperty
+#define gluTessVertex       tools_gluTessVertex
+
+/* internal */
+#define gluBeginPolygon     tools_gluBeginPolygon
+#define gluDeleteTess       tools_gluDeleteTess
+#define gluEndPolygon       tools_gluEndPolygon
+#define gluGetTessProperty  tools_gluGetTessProperty
+#define gluNewTess          tools_gluNewTess
+#define gluNextContour      tools_gluNextContour
+
+#define __gl_computeInterior      tools__gl_computeInterior
+#define __gl_dictListDelete       tools__gl_dictListDelete
+#define __gl_dictListDeleteDict   tools__gl_dictListDeleteDict
+#define __gl_dictListInsertBefore tools__gl_dictListInsertBefore
+#define __gl_dictListNewDict      tools__gl_dictListNewDict
+#define __gl_dictListSearch       tools__gl_dictListSearch
+
+#define __gl_edgeEval      tools__gl_edgeEval
+#define __gl_edgeIntersect tools__gl_edgeIntersect
+#define __gl_edgeSign      tools__gl_edgeSign
+/* done in memalloc.h :
+#define __gl_memInit       tools__gl_memInit
+*/
+#define __gl_meshAddEdgeVertex        tools__gl_meshAddEdgeVertex
+#define __gl_meshCheckMesh            tools__gl_meshCheckMesh
+#define __gl_meshConnect              tools__gl_meshConnect
+#define __gl_meshDelete               tools__gl_meshDelete
+#define __gl_meshDeleteMesh           tools__gl_meshDeleteMesh
+#define __gl_meshDiscardExterior      tools__gl_meshDiscardExterior
+#define __gl_meshMakeEdge             tools__gl_meshMakeEdge
+#define __gl_meshNewMesh              tools__gl_meshNewMesh
+#define __gl_meshSetWindingNumber     tools__gl_meshSetWindingNumber
+#define __gl_meshSplice               tools__gl_meshSplice
+#define __gl_meshSplitEdge            tools__gl_meshSplitEdge
+#define __gl_meshTessellateInterior   tools__gl_meshTessellateInterior
+#define __gl_meshTessellateMonoRegion tools__gl_meshTessellateMonoRegion
+#define __gl_meshUnion                tools__gl_meshUnion
+#define __gl_meshZapFace              tools__gl_meshZapFace
+#define __gl_noBeginData              tools__gl_noBeginData
+#define __gl_noCombineData            tools__gl_noCombineData
+#define __gl_noEdgeFlagData           tools__gl_noEdgeFlagData
+#define __gl_noEndData                tools__gl_noEndData
+#define __gl_noErrorData              tools__gl_noErrorData
+#define __gl_noVertexData             tools__gl_noVertexData
+#define __gl_pqHeapDelete             tools__gl_pqHeapDelete
+#define __gl_pqHeapDeletePriorityQ    tools__gl_pqHeapDeletePriorityQ
+#define __gl_pqHeapExtractMin         tools__gl_pqHeapExtractMin
+#define __gl_pqHeapInit               tools__gl_pqHeapInit
+#define __gl_pqHeapInsert             tools__gl_pqHeapInsert
+#define __gl_pqHeapNewPriorityQ       tools__gl_pqHeapNewPriorityQ
+#define __gl_pqSortDelete             tools__gl_pqSortDelete
+#define __gl_pqSortDeletePriorityQ    tools__gl_pqSortDeletePriorityQ
+#define __gl_pqSortExtractMin         tools__gl_pqSortExtractMin
+#define __gl_pqSortInit               tools__gl_pqSortInit
+#define __gl_pqSortInsert             tools__gl_pqSortInsert
+#define __gl_pqSortIsEmpty            tools__gl_pqSortIsEmpty
+#define __gl_pqSortMinimum            tools__gl_pqSortMinimum
+#define __gl_pqSortNewPriorityQ       tools__gl_pqSortNewPriorityQ
+#define __gl_projectPolygon           tools__gl_projectPolygon
+#define __gl_renderBoundary           tools__gl_renderBoundary
+#define __gl_renderCache              tools__gl_renderCache
+#define __gl_renderMesh               tools__gl_renderMesh
+#define __gl_transEval                tools__gl_transEval
+#define __gl_transSign                tools__gl_transSign
+#define __gl_vertCCW                  tools__gl_vertCCW
+#define __gl_vertLeq                  tools__gl_vertLeq
+   
+#endif

source/externals/g4tools/include/tools/glutess/render

@@ -0,0 +1,481 @@
+// see license file for original license.
+
+#ifndef tools_glutess_render
+#define tools_glutess_render
+
+#include "mesh"
+
+/* __gl_renderMesh( tess, mesh ) takes a mesh and breaks it into triangle
+ * fans, strips, and separate triangles.  A substantial effort is made
+ * to use as few rendering primitives as possible (ie. to make the fans
+ * and strips as large as possible).
+ *
+ * The rendering output is provided as callbacks (see the api).
+ */
+//void __gl_renderMesh( GLUtesselator *tess, GLUmesh *mesh );
+//void __gl_renderBoundary( GLUtesselator *tess, GLUmesh *mesh );
+
+//GLUboolean __gl_renderCache( GLUtesselator *tess );
+
+////////////////////////////////////////////////////////
+/// inlined C code : ///////////////////////////////////
+////////////////////////////////////////////////////////
+
+#include "_tess"
+
+/* This structure remembers the information we need about a primitive
+ * to be able to render it later, once we have determined which
+ * primitive is able to use the most triangles.
+ */
+struct FaceCount {
+  long		size;		/* number of triangles used */
+  GLUhalfEdge	*eStart;	/* edge where this primitive starts */
+  void		(*render)(GLUtesselator *, GLUhalfEdge *, long);
+                                /* routine to render this primitive */
+};
+
+inline/*static*/ struct FaceCount static_MaximumFan( GLUhalfEdge *eOrig );
+inline/*static*/ struct FaceCount static_MaximumStrip( GLUhalfEdge *eOrig );
+
+inline/*static*/ void static_RenderFan( GLUtesselator *tess, GLUhalfEdge *eStart, long size );
+inline/*static*/ void static_RenderStrip( GLUtesselator *tess, GLUhalfEdge *eStart, long size );
+inline/*static*/ void static_RenderTriangle( GLUtesselator *tess, GLUhalfEdge *eStart,
+			    long size );
+
+inline/*static*/ void static_RenderMaximumFaceGroup( GLUtesselator *tess, GLUface *fOrig );
+inline/*static*/ void static_RenderLonelyTriangles( GLUtesselator *tess, GLUface *head );
+
+
+
+/************************ Strips and Fans decomposition ******************/
+
+/* __gl_renderMesh( tess, mesh ) takes a mesh and breaks it into triangle
+ * fans, strips, and separate triangles.  A substantial effort is made
+ * to use as few rendering primitives as possible (ie. to make the fans
+ * and strips as large as possible).
+ *
+ * The rendering output is provided as callbacks (see the api).
+ */
+inline void __gl_renderMesh( GLUtesselator *tess, GLUmesh *mesh )
+{
+  GLUface *f;
+
+  /* Make a list of separate triangles so we can render them all at once */
+  tess->lonelyTriList = NULL;
+
+  for( f = mesh->fHead.next; f != &mesh->fHead; f = f->next ) {
+    f->marked = TOOLS_GLU_FALSE;
+  }
+  for( f = mesh->fHead.next; f != &mesh->fHead; f = f->next ) {
+
+    /* We examine all faces in an arbitrary order.  Whenever we find
+     * an unprocessed face F, we output a group of faces including F
+     * whose size is maximum.
+     */
+    if( f->inside && ! f->marked ) {
+      static_RenderMaximumFaceGroup( tess, f );
+      assert( f->marked );
+    }
+  }
+  if( tess->lonelyTriList != NULL ) {
+    static_RenderLonelyTriangles( tess, tess->lonelyTriList );
+    tess->lonelyTriList = NULL;
+  }
+}
+
+
+inline/*static*/ void static_RenderMaximumFaceGroup( GLUtesselator *tess, GLUface *fOrig )
+{
+  /* We want to find the largest triangle fan or strip of unmarked faces
+   * which includes the given face fOrig.  There are 3 possible fans
+   * passing through fOrig (one centered at each vertex), and 3 possible
+   * strips (one for each CCW permutation of the vertices).  Our strategy
+   * is to try all of these, and take the primitive which uses the most
+   * triangles (a greedy approach).
+   */
+  GLUhalfEdge *e = fOrig->anEdge;
+  struct FaceCount max, newFace;
+
+  max.size = 1;
+  max.eStart = e;
+  max.render = &static_RenderTriangle;
+
+  if( ! tess->flagBoundary ) {
+    newFace = static_MaximumFan( e ); if( newFace.size > max.size ) { max = newFace; }
+    newFace = static_MaximumFan( e->Lnext ); if( newFace.size > max.size ) { max = newFace; }
+    newFace = static_MaximumFan( e->Lprev ); if( newFace.size > max.size ) { max = newFace; }
+
+    newFace = static_MaximumStrip( e ); if( newFace.size > max.size ) { max = newFace; }
+    newFace = static_MaximumStrip( e->Lnext ); if( newFace.size > max.size ) { max = newFace; }
+    newFace = static_MaximumStrip( e->Lprev ); if( newFace.size > max.size ) { max = newFace; }
+  }
+  (*(max.render))( tess, max.eStart, max.size );
+}
+
+
+/* Macros which keep track of faces we have marked temporarily, and allow
+ * us to backtrack when necessary.  With triangle fans, this is not
+ * really necessary, since the only awkward case is a loop of triangles
+ * around a single origin vertex.  However with strips the situation is
+ * more complicated, and we need a general tracking method like the
+ * one here.
+ */
+#define Marked(f)	(! (f)->inside || (f)->marked)
+
+#define AddToTrail(f,t)	((f)->trail = (t), (t) = (f), (f)->marked = TOOLS_GLU_TRUE)
+
+//#define FreeTrail(t)	if( 1 ) { while( (t) != NULL ) { (t)->marked = TOOLS_GLU_FALSE; t = (t)->trail; } } else
+#define FreeTrail(t)	do { while( (t) != NULL ) { (t)->marked = TOOLS_GLU_FALSE; t = (t)->trail; } } while(false)
+
+inline/*static*/ struct FaceCount static_MaximumFan( GLUhalfEdge *eOrig )
+{
+  /* eOrig->Lface is the face we want to render.  We want to find the size
+   * of a maximal fan around eOrig->Org.  To do this we just walk around
+   * the origin vertex as far as possible in both directions.
+   */
+  struct FaceCount newFace = { 0, NULL, &static_RenderFan };
+  GLUface *trail = NULL;
+  GLUhalfEdge *e;
+
+  for( e = eOrig; ! Marked( e->Lface ); e = e->Onext ) {
+    AddToTrail( e->Lface, trail );
+    ++newFace.size;
+  }
+  for( e = eOrig; ! Marked( e->Rface ); e = e->Oprev ) {
+    AddToTrail( e->Rface, trail );
+    ++newFace.size;
+  }
+  newFace.eStart = e;
+  /*LINTED*/
+  FreeTrail( trail );
+  return newFace;
+}
+
+
+#define IsEven(n)	(((n) & 1) == 0)
+
+inline/*static*/ struct FaceCount static_MaximumStrip( GLUhalfEdge *eOrig )
+{
+  /* Here we are looking for a maximal strip that contains the vertices
+   * eOrig->Org, eOrig->Dst, eOrig->Lnext->Dst (in that order or the
+   * reverse, such that all triangles are oriented CCW).
+   *
+   * Again we walk forward and backward as far as possible.  However for
+   * strips there is a twist: to get CCW orientations, there must be
+   * an *even* number of triangles in the strip on one side of eOrig.
+   * We walk the strip starting on a side with an even number of triangles;
+   * if both side have an odd number, we are forced to shorten one side.
+   */
+  struct FaceCount newFace = { 0, NULL, &static_RenderStrip };
+  long headSize = 0, tailSize = 0;
+  GLUface *trail = NULL;
+  GLUhalfEdge *e, *eTail, *eHead;
+
+  for( e = eOrig; ! Marked( e->Lface ); ++tailSize, e = e->Onext ) {
+    AddToTrail( e->Lface, trail );
+    ++tailSize;
+    e = e->Dprev;
+    if( Marked( e->Lface )) break;
+    AddToTrail( e->Lface, trail );
+  }
+  eTail = e;
+
+  for( e = eOrig; ! Marked( e->Rface ); ++headSize, e = e->Dnext ) {
+    AddToTrail( e->Rface, trail );
+    ++headSize;
+    e = e->Oprev;
+    if( Marked( e->Rface )) break;
+    AddToTrail( e->Rface, trail );
+  }
+  eHead = e;
+
+  newFace.size = tailSize + headSize;
+  if( IsEven( tailSize )) {
+    newFace.eStart = eTail->Sym;
+  } else if( IsEven( headSize )) {
+    newFace.eStart = eHead;
+  } else {
+    /* Both sides have odd length, we must shorten one of them.  In fact,
+     * we must start from eHead to guarantee inclusion of eOrig->Lface.
+     */
+    --newFace.size;
+    newFace.eStart = eHead->Onext;
+  }
+  /*LINTED*/
+  FreeTrail( trail );
+  return newFace;
+}
+
+
+inline/*static*/ void static_RenderTriangle( GLUtesselator *tess, GLUhalfEdge *e, long size )
+{
+  /* Just add the triangle to a triangle list, so we can render all
+   * the separate triangles at once.
+   */
+  assert( size == 1 );
+  AddToTrail( e->Lface, tess->lonelyTriList );
+  (void)size;
+}
+
+
+inline/*static*/ void static_RenderLonelyTriangles( GLUtesselator *tess, GLUface *f )
+{
+  /* Now we render all the separate triangles which could not be
+   * grouped into a triangle fan or strip.
+   */
+  GLUhalfEdge *e;
+  int newState;
+  int edgeState = -1;	/* force edge state output for first vertex */
+
+  CALL_BEGIN_OR_BEGIN_DATA( GLU_TRIANGLES );
+
+  for( ; f != NULL; f = f->trail ) {
+    /* Loop once for each edge (there will always be 3 edges) */
+
+    e = f->anEdge;
+    do {
+      if( tess->flagBoundary ) {
+	/* Set the "edge state" to TOOLS_GLU_TRUE just before we output the
+	 * first vertex of each edge on the polygon boundary.
+	 */
+	newState = ! e->Rface->inside;
+	if( edgeState != newState ) {
+	  edgeState = newState;
+          CALL_EDGE_FLAG_OR_EDGE_FLAG_DATA( edgeState );
+	}
+      }
+      CALL_VERTEX_OR_VERTEX_DATA( e->Org->data );
+
+      e = e->Lnext;
+    } while( e != f->anEdge );
+  }
+  CALL_END_OR_END_DATA();
+}
+
+
+inline/*static*/ void static_RenderFan( GLUtesselator *tess, GLUhalfEdge *e, long size )
+{
+  /* Render as many CCW triangles as possible in a fan starting from
+   * edge "e".  The fan *should* contain exactly "size" triangles
+   * (otherwise we've goofed up somewhere).
+   */
+  CALL_BEGIN_OR_BEGIN_DATA( GLU_TRIANGLE_FAN ); 
+  CALL_VERTEX_OR_VERTEX_DATA( e->Org->data ); 
+  CALL_VERTEX_OR_VERTEX_DATA( e->Dst->data ); 
+
+  while( ! Marked( e->Lface )) {
+    e->Lface->marked = TOOLS_GLU_TRUE;
+    --size;
+    e = e->Onext;
+    CALL_VERTEX_OR_VERTEX_DATA( e->Dst->data ); 
+  }
+
+  assert( size == 0 );
+  CALL_END_OR_END_DATA();
+}
+
+
+inline/*static*/ void static_RenderStrip( GLUtesselator *tess, GLUhalfEdge *e, long size )
+{
+  /* Render as many CCW triangles as possible in a strip starting from
+   * edge "e".  The strip *should* contain exactly "size" triangles
+   * (otherwise we've goofed up somewhere).
+   */
+  CALL_BEGIN_OR_BEGIN_DATA( GLU_TRIANGLE_STRIP );
+  CALL_VERTEX_OR_VERTEX_DATA( e->Org->data ); 
+  CALL_VERTEX_OR_VERTEX_DATA( e->Dst->data ); 
+
+  while( ! Marked( e->Lface )) {
+    e->Lface->marked = TOOLS_GLU_TRUE;
+    --size;
+    e = e->Dprev;
+    CALL_VERTEX_OR_VERTEX_DATA( e->Org->data ); 
+    if( Marked( e->Lface )) break;
+
+    e->Lface->marked = TOOLS_GLU_TRUE;
+    --size;
+    e = e->Onext;
+    CALL_VERTEX_OR_VERTEX_DATA( e->Dst->data ); 
+  }
+
+  assert( size == 0 );
+  CALL_END_OR_END_DATA();
+}
+
+
+/************************ Boundary contour decomposition ******************/
+
+/* __gl_renderBoundary( tess, mesh ) takes a mesh, and outputs one
+ * contour for each face marked "inside".  The rendering output is
+ * provided as callbacks (see the api).
+ */
+inline void __gl_renderBoundary( GLUtesselator *tess, GLUmesh *mesh )
+{
+  GLUface *f;
+  GLUhalfEdge *e;
+
+  for( f = mesh->fHead.next; f != &mesh->fHead; f = f->next ) {
+    if( f->inside ) {
+      CALL_BEGIN_OR_BEGIN_DATA( GLU_LINE_LOOP );
+      e = f->anEdge;
+      do {
+        CALL_VERTEX_OR_VERTEX_DATA( e->Org->data ); 
+	e = e->Lnext;
+      } while( e != f->anEdge );
+      CALL_END_OR_END_DATA();
+    }
+  }
+}
+
+
+/************************ Quick-and-dirty decomposition ******************/
+
+//#define SIGN_INCONSISTENT 2
+inline int SIGN_INCONSISTENT() {
+  static const int s_value = 2;
+  return s_value;
+}
+
+inline/*static*/ int static_ComputeNormal( GLUtesselator *tess, GLUdouble norm[3], int check )
+/*
+ * If check==TOOLS_GLU_FALSE, we compute the polygon normal and place it in norm[].
+ * If check==TOOLS_GLU_TRUE, we check that each triangle in the fan from v0 has a
+ * consistent orientation with respect to norm[].  If triangles are
+ * consistently oriented CCW, return 1; if CW, return -1; if all triangles
+ * are degenerate return 0; otherwise (no consistent orientation) return
+ * SIGN_INCONSISTENT.
+ */
+{
+  CachedVertex *v0 = tess->cache;
+  CachedVertex *vn = v0 + tess->cacheCount;
+  CachedVertex *vc;
+  GLUdouble dot, xc, yc, zc, xp, yp, zp, n[3];
+  int sign = 0;
+
+  /* Find the polygon normal.  It is important to get a reasonable
+   * normal even when the polygon is self-intersecting (eg. a bowtie).
+   * Otherwise, the computed normal could be very tiny, but perpendicular
+   * to the true plane of the polygon due to numerical noise.  Then all
+   * the triangles would appear to be degenerate and we would incorrectly
+   * decompose the polygon as a fan (or simply not render it at all).
+   *
+   * We use a sum-of-triangles normal algorithm rather than the more
+   * efficient sum-of-trapezoids method (used in CheckOrientation()
+   * in normal.c).  This lets us explicitly reverse the signed area
+   * of some triangles to get a reasonable normal in the self-intersecting
+   * case.
+   */
+  if( ! check ) {
+    norm[0] = norm[1] = norm[2] = 0.0;
+  }
+
+  vc = v0 + 1;
+  xc = vc->coords[0] - v0->coords[0];
+  yc = vc->coords[1] - v0->coords[1];
+  zc = vc->coords[2] - v0->coords[2];
+  while( ++vc < vn ) {
+    xp = xc; yp = yc; zp = zc;
+    xc = vc->coords[0] - v0->coords[0];
+    yc = vc->coords[1] - v0->coords[1];
+    zc = vc->coords[2] - v0->coords[2];
+
+    /* Compute (vp - v0) cross (vc - v0) */
+    n[0] = yp*zc - zp*yc;
+    n[1] = zp*xc - xp*zc;
+    n[2] = xp*yc - yp*xc;
+
+    dot = n[0]*norm[0] + n[1]*norm[1] + n[2]*norm[2];
+    if( ! check ) {
+      /* Reverse the contribution of back-facing triangles to get
+       * a reasonable normal for self-intersecting polygons (see above)
+       */
+      if( dot >= 0 ) {
+	norm[0] += n[0]; norm[1] += n[1]; norm[2] += n[2];
+      } else {
+	norm[0] -= n[0]; norm[1] -= n[1]; norm[2] -= n[2];
+      }
+    } else if( dot != 0 ) {
+      /* Check the new orientation for consistency with previous triangles */
+      if( dot > 0 ) {
+	if( sign < 0 ) return SIGN_INCONSISTENT();
+	sign = 1;
+      } else {
+	if( sign > 0 ) return SIGN_INCONSISTENT();
+	sign = -1;
+      }
+    }
+  }
+  return sign;
+}
+
+/* __gl_renderCache( tess ) takes a single contour and tries to render it
+ * as a triangle fan.  This handles convex polygons, as well as some
+ * non-convex polygons if we get lucky.
+ *
+ * Returns TOOLS_GLU_TRUE if the polygon was successfully rendered.  The rendering
+ * output is provided as callbacks (see the api).
+ */
+inline GLUboolean __gl_renderCache( GLUtesselator *tess )
+{
+  CachedVertex *v0 = tess->cache;
+  CachedVertex *vn = v0 + tess->cacheCount;
+  CachedVertex *vc;
+  GLUdouble norm[3];
+  int sign;
+
+  if( tess->cacheCount < 3 ) {
+    /* Degenerate contour -- no output */
+    return TOOLS_GLU_TRUE;
+  }
+
+  norm[0] = tess->normal[0];
+  norm[1] = tess->normal[1];
+  norm[2] = tess->normal[2];
+  if( norm[0] == 0 && norm[1] == 0 && norm[2] == 0 ) {
+    static_ComputeNormal( tess, norm, TOOLS_GLU_FALSE );
+  }
+
+  sign = static_ComputeNormal( tess, norm, TOOLS_GLU_TRUE );
+  if( sign == SIGN_INCONSISTENT() ) {
+    /* Fan triangles did not have a consistent orientation */
+    return TOOLS_GLU_FALSE;
+  }
+  if( sign == 0 ) {
+    /* All triangles were degenerate */
+    return TOOLS_GLU_TRUE;
+  }
+
+  /* Make sure we do the right thing for each winding rule */
+  switch( tess->windingRule ) {
+  case GLU_TESS_WINDING_ODD:
+  case GLU_TESS_WINDING_NONZERO:
+    break;
+  case GLU_TESS_WINDING_POSITIVE:
+    if( sign < 0 ) return TOOLS_GLU_TRUE;
+    break;
+  case GLU_TESS_WINDING_NEGATIVE:
+    if( sign > 0 ) return TOOLS_GLU_TRUE;
+    break;
+  case GLU_TESS_WINDING_ABS_GEQ_TWO:
+    return TOOLS_GLU_TRUE;
+  }
+
+  CALL_BEGIN_OR_BEGIN_DATA( tess->boundaryOnly ? GLU_LINE_LOOP
+			  : (tess->cacheCount > 3) ? GLU_TRIANGLE_FAN
+			  : GLU_TRIANGLES );
+
+  CALL_VERTEX_OR_VERTEX_DATA( v0->data ); 
+  if( sign > 0 ) {
+    for( vc = v0+1; vc < vn; ++vc ) {
+      CALL_VERTEX_OR_VERTEX_DATA( vc->data ); 
+    }
+  } else {
+    for( vc = vn-1; vc > v0; --vc ) {
+      CALL_VERTEX_OR_VERTEX_DATA( vc->data ); 
+    }
+  }
+  CALL_END_OR_END_DATA();
+  return TOOLS_GLU_TRUE;
+}
+
+#endif

source/externals/g4tools/include/tools/glutess/tessmono

@@ -0,0 +1,203 @@
+// see license file for original license.
+
+#ifndef tools_glutess_tessmono
+#define tools_glutess_tessmono
+
+/* __gl_meshTessellateMonoRegion( face ) tessellates a monotone region
+ * (what else would it do??)  The region must consist of a single
+ * loop of half-edges (see mesh.h) oriented CCW.  "Monotone" in this
+ * case means that any vertical line intersects the interior of the
+ * region in a single interval.  
+ *
+ * Tessellation consists of adding interior edges (actually pairs of
+ * half-edges), to split the region into non-overlapping triangles.
+ *
+ * __gl_meshTessellateInterior( mesh ) tessellates each region of
+ * the mesh which is marked "inside" the polygon.  Each such region
+ * must be monotone.
+ *
+ * __gl_meshDiscardExterior( mesh ) zaps (ie. sets to NULL) all faces
+ * which are not marked "inside" the polygon.  Since further mesh operations
+ * on NULL faces are not allowed, the main purpose is to clean up the
+ * mesh so that exterior loops are not represented in the data structure.
+ *
+ * __gl_meshSetWindingNumber( mesh, value, keepOnlyBoundary ) resets the
+ * winding numbers on all edges so that regions marked "inside" the
+ * polygon have a winding number of "value", and regions outside
+ * have a winding number of 0.
+ *
+ * If keepOnlyBoundary is TOOLS_GLU_TRUE, it also deletes all edges which do not
+ * separate an interior region from an exterior one.
+ */
+
+//int __gl_meshTessellateMonoRegion( GLUface *face );
+//int __gl_meshTessellateInterior( GLUmesh *mesh );
+//void __gl_meshDiscardExterior( GLUmesh *mesh );
+//int __gl_meshSetWindingNumber( GLUmesh *mesh, int value,
+//			        GLUboolean keepOnlyBoundary );
+
+////////////////////////////////////////////////////////
+/// inlined C code : ///////////////////////////////////
+////////////////////////////////////////////////////////
+#include "geom"
+#include "mesh"
+
+/* __gl_meshTessellateMonoRegion( face ) tessellates a monotone region
+ * (what else would it do??)  The region must consist of a single
+ * loop of half-edges (see mesh.h) oriented CCW.  "Monotone" in this
+ * case means that any vertical line intersects the interior of the
+ * region in a single interval.  
+ *
+ * Tessellation consists of adding interior edges (actually pairs of
+ * half-edges), to split the region into non-overlapping triangles.
+ *
+ * The basic idea is explained in Preparata and Shamos (which I don''t
+ * have handy right now), although their implementation is more
+ * complicated than this one.  The are two edge chains, an upper chain
+ * and a lower chain.  We process all vertices from both chains in order,
+ * from right to left.
+ *
+ * The algorithm ensures that the following invariant holds after each
+ * vertex is processed: the untessellated region consists of two
+ * chains, where one chain (say the upper) is a single edge, and
+ * the other chain is concave.  The left vertex of the single edge
+ * is always to the left of all vertices in the concave chain.
+ *
+ * Each step consists of adding the rightmost unprocessed vertex to one
+ * of the two chains, and forming a fan of triangles from the rightmost
+ * of two chain endpoints.  Determining whether we can add each triangle
+ * to the fan is a simple orientation test.  By making the fan as large
+ * as possible, we restore the invariant (check it yourself).
+ */
+inline int __gl_meshTessellateMonoRegion( GLUface *face )
+{
+  GLUhalfEdge *up, *lo;
+
+  /* All edges are oriented CCW around the boundary of the region.
+   * First, find the half-edge whose origin vertex is rightmost.
+   * Since the sweep goes from left to right, face->anEdge should
+   * be close to the edge we want.
+   */
+  up = face->anEdge;
+  assert( up->Lnext != up && up->Lnext->Lnext != up );
+
+  for( ; VertLeq( up->Dst, up->Org ); up = up->Lprev )
+    ;
+  for( ; VertLeq( up->Org, up->Dst ); up = up->Lnext )
+    ;
+  lo = up->Lprev;
+
+  while( up->Lnext != lo ) {
+    if( VertLeq( up->Dst, lo->Org )) {
+      /* up->Dst is on the left.  It is safe to form triangles from lo->Org.
+       * The EdgeGoesLeft test guarantees progress even when some triangles
+       * are CW, given that the upper and lower chains are truly monotone.
+       */
+      while( lo->Lnext != up && (EdgeGoesLeft( lo->Lnext )
+	     || EdgeSign( lo->Org, lo->Dst, lo->Lnext->Dst ) <= 0 )) {
+	GLUhalfEdge *tempHalfEdge= __gl_meshConnect( lo->Lnext, lo );
+	if (tempHalfEdge == NULL) return 0;
+	lo = tempHalfEdge->Sym;
+      }
+      lo = lo->Lprev;
+    } else {
+      /* lo->Org is on the left.  We can make CCW triangles from up->Dst. */
+      while( lo->Lnext != up && (EdgeGoesRight( up->Lprev )
+	     || EdgeSign( up->Dst, up->Org, up->Lprev->Org ) >= 0 )) {
+	GLUhalfEdge *tempHalfEdge= __gl_meshConnect( up, up->Lprev );
+	if (tempHalfEdge == NULL) return 0;
+	up = tempHalfEdge->Sym;
+      }
+      up = up->Lnext;
+    }
+  }
+
+  /* Now lo->Org == up->Dst == the leftmost vertex.  The remaining region
+   * can be tessellated in a fan from this leftmost vertex.
+   */
+  assert( lo->Lnext != up );
+  while( lo->Lnext->Lnext != up ) {
+    GLUhalfEdge *tempHalfEdge= __gl_meshConnect( lo->Lnext, lo );
+    if (tempHalfEdge == NULL) return 0;
+    lo = tempHalfEdge->Sym;
+  }
+
+  return 1;
+}
+
+
+/* __gl_meshTessellateInterior( mesh ) tessellates each region of
+ * the mesh which is marked "inside" the polygon.  Each such region
+ * must be monotone.
+ */
+inline int __gl_meshTessellateInterior( GLUmesh *mesh )
+{
+  GLUface *f, *next;
+
+  /*LINTED*/
+  for( f = mesh->fHead.next; f != &mesh->fHead; f = next ) {
+    /* Make sure we don''t try to tessellate the new triangles. */
+    next = f->next;
+    if( f->inside ) {
+      if ( !__gl_meshTessellateMonoRegion( f ) ) return 0;
+    }
+  }
+
+  return 1;
+}
+
+
+/* __gl_meshDiscardExterior( mesh ) zaps (ie. sets to NULL) all faces
+ * which are not marked "inside" the polygon.  Since further mesh operations
+ * on NULL faces are not allowed, the main purpose is to clean up the
+ * mesh so that exterior loops are not represented in the data structure.
+ */
+inline void __gl_meshDiscardExterior( GLUmesh *mesh )
+{
+  GLUface *f, *next;
+
+  /*LINTED*/
+  for( f = mesh->fHead.next; f != &mesh->fHead; f = next ) {
+    /* Since f will be destroyed, save its next pointer. */
+    next = f->next;
+    if( ! f->inside ) {
+      __gl_meshZapFace( f );
+    }
+  }
+}
+
+//#define MARKED_FOR_DELETION	0x7fffffff
+
+/* __gl_meshSetWindingNumber( mesh, value, keepOnlyBoundary ) resets the
+ * winding numbers on all edges so that regions marked "inside" the
+ * polygon have a winding number of "value", and regions outside
+ * have a winding number of 0.
+ *
+ * If keepOnlyBoundary is TOOLS_GLU_TRUE, it also deletes all edges which do not
+ * separate an interior region from an exterior one.
+ */
+inline int __gl_meshSetWindingNumber( GLUmesh *mesh, int value,
+			        GLUboolean keepOnlyBoundary )
+{
+  GLUhalfEdge *e, *eNext;
+
+  for( e = mesh->eHead.next; e != &mesh->eHead; e = eNext ) {
+    eNext = e->next;
+    if( e->Rface->inside != e->Lface->inside ) {
+
+      /* This is a boundary edge (one side is interior, one is exterior). */
+      e->winding = (e->Lface->inside) ? value : -value;
+    } else {
+
+      /* Both regions are interior, or both are exterior. */
+      if( ! keepOnlyBoundary ) {
+	e->winding = 0;
+      } else {
+	if ( !__gl_meshDelete( e ) ) return 0;
+      }
+    }
+  }
+  return 1;
+}
+
+#endif

source/externals/g4tools/include/tools/glutess/undef

@@ -0,0 +1,231 @@
+#ifndef tools_glutess_undef
+#define tools_glutess_undef
+
+#undef GLU_TESS_MAX_CACHE
+#undef CALL_BEGIN_OR_BEGIN_DATA
+#undef CALL_VERTEX_OR_VERTEX_DATA
+#undef CALL_EDGE_FLAG_OR_EDGE_FLAG_DATA
+#undef CALL_END_OR_END_DATA
+#undef CALL_COMBINE_OR_COMBINE_DATA
+#undef CALL_ERROR_OR_ERROR_DATA
+#undef __gl_dictListDelete
+#undef __gl_dictListDeleteDict
+#undef __gl_dictListInsertBefore
+#undef __gl_dictListNewDict
+#undef __gl_dictListSearch
+#undef DictKey
+#undef Dict
+#undef DictNode
+#undef dictNewDict
+#undef dictDeleteDict
+#undef dictSearch
+#undef dictInsert
+#undef dictInsertBefore
+#undef dictDelete
+#undef dictKey
+#undef dictSucc
+#undef dictPred
+#undef dictMin
+#undef dictMax
+#undef __gl_dictListKey
+#undef __gl_dictListSucc
+#undef __gl_dictListPred
+#undef __gl_dictListMin
+#undef __gl_dictListMax
+#undef __gl_dictListInsert
+#undef VertEq
+#undef VertLeq
+#undef EdgeEval
+#undef EdgeSign
+#undef TransLeq
+#undef TransEval
+#undef TransSign
+#undef EdgeGoesLeft
+#undef EdgeGoesRight
+#undef VertL1dist
+#undef VertCCW
+#undef VertLeq
+#undef Interpolate
+#undef Swap
+#undef GLUAPI
+/*
+#undef GLUAPIENTRY
+#undef GLU_TESS_BEGIN_DATA
+#undef GLU_TESS_VERTEX_DATA
+#undef GLU_TESS_END_DATA
+#undef GLU_TESS_ERROR_DATA
+#undef GLU_TESS_COMBINE_DATA
+#undef GLU_TESS_WINDING_RULE
+#undef GLU_TESS_WINDING_ODD
+#undef GLU_TESS_WINDING_POSITIVE
+#undef GLU_TESS_WINDING_NEGATIVE
+*/
+#undef GLU_MIN
+#undef GLU_MAX
+#undef GLU_ABS
+#undef TOOLS_GLU_FALSE
+#undef TOOLS_GLU_TRUE
+#undef GLU_LINE_LOOP
+#undef GLU_TRIANGLES
+#undef GLU_TRIANGLE_STRIP
+#undef GLU_TRIANGLE_FAN
+#undef GLU_TESS_MAX_COORD
+#undef GLU_INVALID_ENUM
+#undef GLU_INVALID_VALUE
+#undef GLU_OUT_OF_MEMORY
+#undef GLU_INCOMPATIBLE_GL_VERSION
+#undef GLU_INVALID_OPERATION
+#undef GLU_TESS_BEGIN
+#undef GLU_TESS_VERTEX
+#undef GLU_TESS_END
+#undef GLU_TESS_ERROR
+#undef GLU_TESS_EDGE_FLAG
+#undef GLU_EDGE_FLAG
+#undef GLU_TESS_COMBINE
+#undef GLU_TESS_EDGE_FLAG_DATA
+#undef GLU_CW
+#undef GLU_CCW
+#undef GLU_INTERIOR
+#undef GLU_EXTERIOR
+#undef GLU_UNKNOWN
+#undef GLU_TESS_BOUNDARY_ONLY
+#undef GLU_TESS_TOLERANCE
+#undef GLU_TESS_ERROR1
+#undef GLU_TESS_ERROR2
+#undef GLU_TESS_ERROR3
+#undef GLU_TESS_ERROR4
+#undef GLU_TESS_ERROR5
+#undef GLU_TESS_ERROR6
+#undef GLU_TESS_ERROR7
+#undef GLU_TESS_ERROR8
+#undef GLU_TESS_MISSING_BEGIN_POLYGON
+#undef GLU_TESS_MISSING_BEGIN_CONTOUR
+#undef GLU_TESS_MISSING_END_POLYGON
+#undef GLU_TESS_MISSING_END_CONTOUR
+#undef GLU_TESS_COORD_TOO_LARGE
+#undef GLU_TESS_NEED_COMBINE_CALLBACK
+#undef GLU_TESS_WINDING_NONZERO
+#undef GLU_TESS_WINDING_ABS_GEQ_TWO
+#undef memAlloc
+#undef memRealloc
+#undef memFree
+#undef memInit
+#undef Rface
+#undef Dst
+#undef Oprev
+#undef Lprev
+#undef Dprev
+#undef Rprev
+#undef Dnext
+#undef Rnext
+#undef Dot
+#undef S_UNIT_X
+#undef S_UNIT_Y
+#undef PQkey
+#undef PQhandle
+#undef PriorityQ
+#undef pqNewPriorityQ
+#undef pqDeletePriorityQ
+#undef pqInit
+#undef pqInsert
+#undef pqMinimum
+#undef pqExtractMin
+#undef pqDelete
+#undef pqIsEmpty
+#undef __gl_pqHeapMinimum
+#undef __gl_pqHeapIsEmpty
+#undef LEQ
+#undef PQkey
+#undef PQhandle
+#undef PriorityQ
+#undef pqNewPriorityQ
+#undef pqDeletePriorityQ
+#undef pqInit
+#undef pqInsert
+#undef pqMinimum
+#undef pqExtractMin
+#undef pqDelete
+#undef pqIsEmpty
+#undef LT
+#undef GT
+#undef pq_Swap
+//#undef gluTessBeginContour
+//#undef gluTessBeginPolygon
+//#undef gluTessCallback
+//#undef gluTessEndContour
+//#undef gluTessEndPolygon
+//#undef gluTessNormal
+//#undef gluTessProperty
+//#undef gluTessVertex
+//#undef gluBeginPolygon
+//#undef gluDeleteTess
+//#undef gluEndPolygon
+//#undef gluGetTessProperty
+//#undef gluNewTess
+//#undef gluNextContour
+#undef __gl_computeInterior
+#undef __gl_dictListDelete
+#undef __gl_dictListDeleteDict
+#undef __gl_dictListInsertBefore
+#undef __gl_dictListNewDict
+#undef __gl_dictListSearch
+#undef __gl_edgeEval
+#undef __gl_edgeIntersect
+#undef __gl_edgeSign
+#undef __gl_memInit
+#undef __gl_meshAddEdgeVertex
+#undef __gl_meshCheckMesh
+#undef __gl_meshConnect
+#undef __gl_meshDelete
+#undef __gl_meshDeleteMesh
+#undef __gl_meshDiscardExterior
+#undef __gl_meshMakeEdge
+#undef __gl_meshNewMesh
+#undef __gl_meshSetWindingNumber
+#undef __gl_meshSplice
+#undef __gl_meshSplitEdge
+#undef __gl_meshTessellateInterior
+#undef __gl_meshTessellateMonoRegion
+#undef __gl_meshUnion
+#undef __gl_meshZapFace
+#undef __gl_noBeginData
+#undef __gl_noCombineData
+#undef __gl_noEdgeFlagData
+#undef __gl_noEndData
+#undef __gl_noErrorData
+#undef __gl_noVertexData
+#undef __gl_pqHeapDelete
+#undef __gl_pqHeapDeletePriorityQ
+#undef __gl_pqHeapExtractMin
+#undef __gl_pqHeapInit
+#undef __gl_pqHeapInsert
+#undef __gl_pqHeapNewPriorityQ
+#undef __gl_pqSortDelete
+#undef __gl_pqSortDeletePriorityQ
+#undef __gl_pqSortExtractMin
+#undef __gl_pqSortInit
+#undef __gl_pqSortInsert
+#undef __gl_pqSortIsEmpty
+#undef __gl_pqSortMinimum
+#undef __gl_pqSortNewPriorityQ
+#undef __gl_projectPolygon
+#undef __gl_renderBoundary
+#undef __gl_renderCache
+#undef __gl_renderMesh
+#undef __gl_transEval
+#undef __gl_transSign
+#undef __gl_vertCCW
+#undef __gl_vertLeq
+#undef Marked
+#undef AddToTrail
+#undef FreeTrail
+#undef IsEven
+#undef RegionBelow
+#undef RegionAbove
+#undef DebugEvent
+#undef AddWinding
+#undef GLU_TESS_DEFAULT_TOLERANCE
+#undef GLU_TESS_MESH
+#undef RequireState
+
+#endif