source: issm/trunk-jpl/src/c/shared/TriMesh/OrderSegments.cpp@ 11202

/*
 * OrderSegments.c: 
 * reorder segments so that their normals point outside the domain outline.
 */
#include "./trimesh.h"

int OrderSegments(double** psegments,int nseg, double* index,int nel){
        
        /*Error management: */
        int i;
        int noerr=1;

        /*Input: */
        double* segments=NULL;

        /*vertex indices: */
        double A,B;
        /*element indices: */
        int el;


        /*Recover segments: */
        segments=*psegments;

        for (i=0;i<nseg;i++){
                A=segments[3*i+0];
                B=segments[3*i+1];
                el=(int)segments[3*i+2]-1; //after AssociateSegmentToElement, el was a matlab index, we need the c index now.

                if (index[3*el+0]==A){
                        if (index[3*el+2]==B){
                                segments[3*i+0]=B;
                                segments[3*i+1]=A;
                        }
                }
                else if (index[3*el+1]==A){
                        if (index[3*el+0]==B){
                                segments[3*i+0]=B;
                                segments[3*i+1]=A;
                        }
                }
                else{
                        if (index[3*el+1]==B){
                                segments[3*i+0]=B;
                                segments[3*i+1]=A;
                        }
                }
        }

        /*Assign output pointers: */
        *psegments=segments;
        return noerr;
}