Butterbur: Tesselation support for filling closed paths
[sdk] / deps / libtess / tess.c
diff --git a/deps/libtess/tess.c b/deps/libtess/tess.c
new file mode 100644 (file)
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+/*
+** License Applicability. Except to the extent portions of this file are
+** made subject to an alternative license as permitted in the SGI Free
+** Software License B, Version 1.1 (the "License"), the contents of this
+** file are subject only to the provisions of the License. You may not use
+** this file except in compliance with the License. You may obtain a copy
+** of the License at Silicon Graphics, Inc., attn: Legal Services, 1600
+** Amphitheatre Parkway, Mountain View, CA 94043-1351, or at:
+**
+** http://oss.sgi.com/projects/FreeB
+**
+** Note that, as provided in the License, the Software is distributed on an
+** "AS IS" basis, with ALL EXPRESS AND IMPLIED WARRANTIES AND CONDITIONS
+** DISCLAIMED, INCLUDING, WITHOUT LIMITATION, ANY IMPLIED WARRANTIES AND
+** CONDITIONS OF MERCHANTABILITY, SATISFACTORY QUALITY, FITNESS FOR A
+** PARTICULAR PURPOSE, AND NON-INFRINGEMENT.
+**
+** Original Code. The Original Code is: OpenGL Sample Implementation,
+** Version 1.2.1, released January 26, 2000, developed by Silicon Graphics,
+** Inc. The Original Code is Copyright (c) 1991-2000 Silicon Graphics, Inc.
+** Copyright in any portions created by third parties is as indicated
+** elsewhere herein. All Rights Reserved.
+**
+** Additional Notice Provisions: The application programming interfaces
+** established by SGI in conjunction with the Original Code are The
+** OpenGL(R) Graphics System: A Specification (Version 1.2.1), released
+** April 1, 1999; The OpenGL(R) Graphics System Utility Library (Version
+** 1.3), released November 4, 1998; and OpenGL(R) Graphics with the X
+** Window System(R) (Version 1.3), released October 19, 1998. This software
+** was created using the OpenGL(R) version 1.2.1 Sample Implementation
+** published by SGI, but has not been independently verified as being
+** compliant with the OpenGL(R) version 1.2.1 Specification.
+**
+*/
+/*
+** Author: Eric Veach, July 1994.
+**
+*/
+
+#include "gluos.h"
+#include <stddef.h>
+#include <assert.h>
+#include <setjmp.h>
+#include "memalloc.h"
+#include "tess.h"
+#include "mesh.h"
+#include "normal.h"
+#include "sweep.h"
+#include "tessmono.h"
+#include "render.h"
+
+#define GLU_TESS_DEFAULT_TOLERANCE 0.0
+#define GLU_TESS_MESH          100112  /* void (*)(GLUmesh *mesh)          */
+
+#define TRUE 1
+#define FALSE 0
+
+/*ARGSUSED*/ static void GLAPIENTRY noBegin( GLenum type ) {}
+/*ARGSUSED*/ static void GLAPIENTRY noEdgeFlag( GLboolean boundaryEdge ) {}
+/*ARGSUSED*/ static void GLAPIENTRY noVertex( void *data ) {}
+/*ARGSUSED*/ static void GLAPIENTRY noEnd( void ) {}
+/*ARGSUSED*/ static void GLAPIENTRY noError( GLenum errnum ) {}
+/*ARGSUSED*/ static void GLAPIENTRY noCombine( GLdouble coords[3], void *data[4],
+                                   GLfloat weight[4], void **dataOut ) {}
+/*ARGSUSED*/ static void GLAPIENTRY noMesh( GLUmesh *mesh ) {}
+
+
+/*ARGSUSED*/ void GLAPIENTRY __gl_noBeginData( GLenum type,
+                                            void *polygonData ) {}
+/*ARGSUSED*/ void GLAPIENTRY __gl_noEdgeFlagData( GLboolean boundaryEdge,
+                                      void *polygonData ) {}
+/*ARGSUSED*/ void GLAPIENTRY __gl_noVertexData( void *data,
+                                             void *polygonData ) {}
+/*ARGSUSED*/ void GLAPIENTRY __gl_noEndData( void *polygonData ) {}
+/*ARGSUSED*/ void GLAPIENTRY __gl_noErrorData( GLenum errnum,
+                                            void *polygonData ) {}
+/*ARGSUSED*/ void GLAPIENTRY __gl_noCombineData( GLdouble coords[3],
+                                              void *data[4],
+                                              GLfloat weight[4],
+                                              void **outData,
+                                              void *polygonData ) {}
+
+/* Half-edges are allocated in pairs (see mesh.c) */
+typedef struct { GLUhalfEdge e, eSym; } EdgePair;
+
+#undef MAX
+#define MAX(a,b)       ((a) > (b) ? (a) : (b))
+#define MAX_FAST_ALLOC (MAX(sizeof(EdgePair), \
+                         MAX(sizeof(GLUvertex),sizeof(GLUface))))
+
+
+GLUtesselator * GLAPIENTRY
+gluNewTess( void )
+{
+  GLUtesselator *tess;
+
+  /* Only initialize fields which can be changed by the api.  Other fields
+   * are initialized where they are used.
+   */
+
+  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 = FALSE;
+  tess->boundaryOnly = FALSE;
+
+  tess->callBegin = &noBegin;
+  tess->callEdgeFlag = &noEdgeFlag;
+  tess->callVertex = &noVertex;
+  tess->callEnd = &noEnd;
+
+  tess->callError = &noError;
+  tess->callCombine = &noCombine;
+  tess->callMesh = &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;
+}
+
+static void 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 ) GotoState(tess,s)
+
+static void 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! */
+       MakeDormant( tess );
+       break;
+      default:
+        ;
+      }
+    }
+  }
+}
+
+
+void GLAPIENTRY
+gluDeleteTess( GLUtesselator *tess )
+{
+  RequireState( tess, T_DORMANT );
+  memFree( tess );
+}
+
+
+void GLAPIENTRY
+gluTessProperty( GLUtesselator *tess, GLenum which, GLdouble value )
+{
+  GLenum 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 = (GLenum) 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;
+    }
+
+  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 */
+void GLAPIENTRY
+gluGetTessProperty( GLUtesselator *tess, GLenum which, GLdouble *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 == TRUE || tess->boundaryOnly == FALSE);
+      *value= tess->boundaryOnly;
+      break;
+   default:
+      *value= 0.0;
+      CALL_ERROR_OR_ERROR_DATA( GLU_INVALID_ENUM );
+      break;
+   }
+} /* gluGetTessProperty() */
+
+void GLAPIENTRY
+gluTessNormal( GLUtesselator *tess, GLdouble x, GLdouble y, GLdouble z )
+{
+  tess->normal[0] = x;
+  tess->normal[1] = y;
+  tess->normal[2] = z;
+}
+
+void GLAPIENTRY
+gluTessCallback( GLUtesselator *tess, GLenum which, _GLUfuncptr fn)
+{
+  switch( which ) {
+  case GLU_TESS_BEGIN:
+    tess->callBegin = (fn == NULL) ? &noBegin : (void (GLAPIENTRY *)(GLenum)) fn;
+    return;
+  case GLU_TESS_BEGIN_DATA:
+    tess->callBeginData = (fn == NULL) ?
+       &__gl_noBeginData : (void (GLAPIENTRY *)(GLenum, void *)) fn;
+    return;
+  case GLU_TESS_EDGE_FLAG:
+    tess->callEdgeFlag = (fn == NULL) ? &noEdgeFlag :
+                                       (void (GLAPIENTRY *)(GLboolean)) 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 (GLAPIENTRY *)(GLboolean, 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) ? &noVertex :
+                                     (void (GLAPIENTRY *)(void *)) fn;
+    return;
+  case GLU_TESS_VERTEX_DATA:
+    tess->callVertexData = (fn == NULL) ?
+       &__gl_noVertexData : (void (GLAPIENTRY *)(void *, void *)) fn;
+    return;
+  case GLU_TESS_END:
+    tess->callEnd = (fn == NULL) ? &noEnd : (void (GLAPIENTRY *)(void)) fn;
+    return;
+  case GLU_TESS_END_DATA:
+    tess->callEndData = (fn == NULL) ? &__gl_noEndData :
+                                      (void (GLAPIENTRY *)(void *)) fn;
+    return;
+  case GLU_TESS_ERROR:
+    tess->callError = (fn == NULL) ? &noError : (void (GLAPIENTRY *)(GLenum)) fn;
+    return;
+  case GLU_TESS_ERROR_DATA:
+    tess->callErrorData = (fn == NULL) ?
+       &__gl_noErrorData : (void (GLAPIENTRY *)(GLenum, void *)) fn;
+    return;
+  case GLU_TESS_COMBINE:
+    tess->callCombine = (fn == NULL) ? &noCombine :
+       (void (GLAPIENTRY *)(GLdouble [3],void *[4], GLfloat [4], void ** )) fn;
+    return;
+  case GLU_TESS_COMBINE_DATA:
+    tess->callCombineData = (fn == NULL) ? &__gl_noCombineData :
+                                          (void (GLAPIENTRY *)(GLdouble [3],
+                                                    void *[4],
+                                                    GLfloat [4],
+                                                    void **,
+                                                    void *)) fn;
+    return;
+  case GLU_TESS_MESH:
+    tess->callMesh = (fn == NULL) ? &noMesh : (void (GLAPIENTRY *)(GLUmesh *)) fn;
+    return;
+  default:
+    CALL_ERROR_OR_ERROR_DATA( GLU_INVALID_ENUM );
+    return;
+  }
+}
+
+static int AddVertex( GLUtesselator *tess, GLdouble 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;
+}
+
+
+static void CacheVertex( GLUtesselator *tess, GLdouble 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;
+}
+
+
+static int 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 ( !AddVertex( tess, v->coords, v->data ) ) return 0;
+  }
+  tess->cacheCount = 0;
+  tess->emptyCache = FALSE;
+
+  return 1;
+}
+
+
+void GLAPIENTRY
+gluTessVertex( GLUtesselator *tess, GLdouble coords[3], void *data )
+{
+  int i, tooLarge = FALSE;
+  GLdouble x, clamped[3];
+
+  RequireState( tess, T_IN_CONTOUR );
+
+  if( tess->emptyCache ) {
+    if ( !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 = TRUE;
+    }
+    if( x > GLU_TESS_MAX_COORD ) {
+      x = GLU_TESS_MAX_COORD;
+      tooLarge = TRUE;
+    }
+    clamped[i] = x;
+  }
+  if( tooLarge ) {
+    CALL_ERROR_OR_ERROR_DATA( GLU_TESS_COORD_TOO_LARGE );
+  }
+
+  if( tess->mesh == NULL ) {
+    if( tess->cacheCount < TESS_MAX_CACHE ) {
+      CacheVertex( tess, clamped, data );
+      return;
+    }
+    if ( !EmptyCache( tess ) ) {
+       CALL_ERROR_OR_ERROR_DATA( GLU_OUT_OF_MEMORY );
+       return;
+    }
+  }
+  if ( !AddVertex( tess, clamped, data ) ) {
+       CALL_ERROR_OR_ERROR_DATA( GLU_OUT_OF_MEMORY );
+  }
+}
+
+
+void GLAPIENTRY
+gluTessBeginPolygon( GLUtesselator *tess, void *data )
+{
+  RequireState( tess, T_DORMANT );
+
+  tess->state = T_IN_POLYGON;
+  tess->cacheCount = 0;
+  tess->emptyCache = FALSE;
+  tess->mesh = NULL;
+
+  tess->polygonData= data;
+}
+
+
+void GLAPIENTRY
+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 = TRUE;
+  }
+}
+
+
+void GLAPIENTRY
+gluTessEndContour( GLUtesselator *tess )
+{
+  RequireState( tess, T_IN_CONTOUR );
+  tess->state = T_IN_POLYGON;
+}
+
+void GLAPIENTRY
+gluTessEndPolygon( GLUtesselator *tess )
+{
+  GLUmesh *mesh;
+
+  /*  No idea why, but setjmp() has suddenly started to crash...
+  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 == &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 ( !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, TRUE );
+    } else {
+      rc = __gl_meshTessellateInterior( mesh );
+    }
+    if (rc == 0) longjmp(tess->env,1); /* could've used a label */
+
+    __gl_meshCheckMesh( mesh );
+
+    if( tess->callBegin != &noBegin || tess->callEnd != &noEnd
+       || tess->callVertex != &noVertex || tess->callEdgeFlag != &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 != &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;
+}
+
+
+/*XXXblythe unused function*/
+#if 0
+void GLAPIENTRY
+gluDeleteMesh( GLUmesh *mesh )
+{
+  __gl_meshDeleteMesh( mesh );
+}
+#endif
+
+
+
+/*******************************************************/
+
+/* Obsolete calls -- for backward compatibility */
+
+void GLAPIENTRY
+gluBeginPolygon( GLUtesselator *tess )
+{
+  gluTessBeginPolygon( tess, NULL );
+  gluTessBeginContour( tess );
+}
+
+
+/*ARGSUSED*/
+void GLAPIENTRY
+gluNextContour( GLUtesselator *tess, GLenum type )
+{
+  gluTessEndContour( tess );
+  gluTessBeginContour( tess );
+}
+
+
+void GLAPIENTRY
+gluEndPolygon( GLUtesselator *tess )
+{
+  gluTessEndContour( tess );
+  gluTessEndPolygon( tess );
+}