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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.
+**
+*/
+/*
+*/
+
+#include <stdlib.h>
+#include <stdio.h>
+
+#include "partitionX.h"
+
+#define CONCAVITY_ZERO 1.0e-6 //this number is used to test whether a vertex is concave (refelx)
+ //or not. The test needs to compute the area of the three adjacent
+ //vertices to see if the are is positive or negative.
+
+Int isCuspX(directedLine *v)
+{
+ //if v->prev <= v && v->next <= v
+ //|| v->prev >= v && v->next >= v
+ Real* T = v->head();
+ Real* P = v->getPrev()->head();
+ Real* N = v->getNext()->head();
+ if(
+ (compV2InX(T,P) != -1 &&
+ compV2InX(T,N) != -1
+ ) ||
+ (compV2InX(T,P) != 1 &&
+ compV2InX(T,N) != 1
+ )
+ )
+ return 1;
+ else
+ return 0;
+}
+
+Int isReflexX(directedLine* v)
+{
+ Real* A = v->getPrev()->head();
+ Real* B = v->head();
+ Real* C = v->tail();
+ Real Bx,By, Cx, Cy;
+ //scale them in case they are too small
+ Bx = 10*(B[0] - A[0]);
+ By = 10*(B[1] - A[1]);
+ Cx = 10*(C[0] - A[0]);
+ Cy = 10*(C[1] - A[1]);
+
+ if(Bx*Cy - Cx*By < -CONCAVITY_ZERO) return 1;
+ else return 0;
+}
+
+
+/*return
+ *0: not-cusp
+ *1: interior cusp
+ *2: exterior cusp
+ */
+Int cuspTypeX(directedLine *v)
+{
+ if(! isCuspX(v)) return 0;
+ else
+ {
+//printf("isCusp,%f,%f\n", v->head()[0], v->head()[1]);
+ if(isReflexX(v))
+ {
+// printf("isReflex\n");
+ return 1;
+ }
+ else
+ {
+// printf("not isReflex\n");
+ return 2;
+ }
+ }
+}
+
+Int numInteriorCuspsX(directedLine *polygon)
+{
+ directedLine *temp;
+ int ret = 0;
+ if(cuspTypeX(polygon) == 1)
+ ret++;
+ for(temp = polygon->getNext(); temp != polygon; temp = temp->getNext())
+ if(cuspTypeX(temp) == 1)
+ ret++;
+ return ret;
+}
+
+
+void findInteriorCuspsX(directedLine *polygon, Int& ret_n_interior_cusps,
+ directedLine** ret_interior_cusps)
+{
+ directedLine *temp;
+ ret_n_interior_cusps = 0;
+ if(cuspTypeX(polygon) == 1)
+ {
+ ret_interior_cusps[ret_n_interior_cusps++] = polygon;
+ }
+ for(temp = polygon->getNext(); temp != polygon; temp = temp->getNext())
+ if(cuspTypeX(temp) == 1)
+ {
+ ret_interior_cusps[ret_n_interior_cusps++] = temp;
+ }
+}
+
+directedLine* findDiagonal_singleCuspX(directedLine* cusp)
+{
+ directedLine* temp;
+ Int is_minimal = ((compV2InX(cusp->head(), cusp->tail()) == -1)? 1:0);
+
+ if(is_minimal)
+ for(temp = cusp->getNext(); temp != cusp; temp = temp->getNext())
+ {
+ if(compV2InX(cusp->head(), temp->head()) == 1)
+ {
+ return temp;
+ }
+ }
+ else //is maxmal
+ for(temp = cusp->getNext(); temp != cusp; temp = temp->getNext())
+ {
+ if(compV2InX(cusp->head(), temp->head()) == -1)
+ {
+ return temp;
+ }
+ }
+ return NULL;
+}
+
+
+