geometry.c

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#include "turtle.h"
#include "geometry.h"
#include "geometry_utilities.h"
#include "geometry_freememory.h"

POINT *new_point(long index,double x,double y,double z){
        POINT *P;

        P=(POINT *)malloc((sizeof(POINT)));
        if (!P) t_error("point was not allocated");
    P->index=index;
        P->x=x;
        P->y=y;
        P->z=z;
        //P->attributes=(attribute_point *)malloc((size_t)(sizeof(attribute_point)));
        //if (!P) t_error("attribute_point was not allocated");
        //P->attributes=attributes;

  return P;


}



LINE *new_line_from_points(long index, POINT *P1,POINT *P2){
        LINE *L;
        L=(LINE *)malloc((sizeof(LINE)));
        if (!L) t_error("line was not allocated");
        L->index=index;

        L->begin=new_point(P1->index,P1->x,P1->y,P1->z);
        L->end=new_point(P2->index,P2->x,P2->y,P2->z);
//      L->begin_point_index=P1->index;
//      L->end_point_index=P2->index;
//      L->attributes=(attribute_line *)malloc(sizeof(attribute_line));
//      if (!L->attributes) t_error("attribute_line was not allocated");
//      L->attributes=attributes;
        L->length2d=distance2D(P1,P2);


        return L;

}

LINEVECTOR *new_linevector(long nh){
        LINEVECTOR *lv;

        lv=(LINEVECTOR *)malloc(sizeof(LINEVECTOR));
        if (!lv) t_error("Linevector struct was not allocated");

        lv->isdynamic=isDynamic;
        lv->nl=NL;
        lv->nh=nh;


        lv->element=(LINE **)malloc((size_t)((nh-NL+1+NR_END)*sizeof(LINE *)));
        if (!lv->element) t_error("Linevector element struct was not allocated");

        return lv;

}


POLYGONVECTOR *new_polygonvector(long nh){
        POLYGONVECTOR *pv;

        pv=(POLYGONVECTOR *)malloc(sizeof(POLYGONVECTOR));
        if (!pv) t_error("Polygonvector struct was not allocated");

        pv->isdynamic=isDynamic;
        pv->nl=NL;
        pv->nh=nh;


        pv->element=(POLYGON **)malloc((size_t)((nh-NL+1+NR_END)*sizeof(POLYGON *)));
        if (!pv) t_error("Polygonvector element struct was not allocated");

        return pv;

}



POLYGON *new_polygon_from_a_linevector(LINEVECTOR *lines,POINT *centroid){
        POLYGON *PO;
        LONGVECTOR *lvertices;
        long i,j;
        //l,s,se,a;
        double area;

        PO=(POLYGON *)malloc(sizeof(POLYGON));
        if (!PO) t_error("polygon was not allocated");

        PO->centroid=new_point(centroid->index,centroid->x,centroid->y,centroid->z);

        PO->index=centroid->index;





        for (i=lines->nl;i<=lines->nh;i++){
                for (j=lines->nl;j<i;j++){
                         if (segment_intersection_occurence(lines->element[i],lines->element[j])!=0) {
                                 printf("Warning:the lines %ld and %ld (polyogon-internal numeration) share an internal point, the polygon %ld cannot be created!! \n",i,j,centroid->index);
                                 return PO;
                         }
                }
        }

        lvertices=new_longvector(lines->nh*2);


    for (i=lines->nl;i<=lines->nh;i++){
        lvertices->element[2*i-1]=lines->element[i]->begin->index;
        lvertices->element[2*i]=lines->element[i]->end->index;
        if (lines->element[i]->end->index==lines->element[i]->begin->index) {
                printf("Warning:the line %ld has the same extremes in index %ld, the polygon %ld cannot be created!!",i,lines->element[i]->begin->index,centroid->index);
            return PO;
        }
    }

  //  print_longvector_elements(lvertices,1);

    for (i=lines->nl;i<=lines->nh;i++){
        if(query_freq_longvector(lvertices,lines->element[i]->begin->index)!=2) {
                printf("Warning: problem in begin vertex of %ld, (%ld points in the same vertex) the polygon %ld cannot be created!! \n",lines->element[i]->begin->index,query_freq_longvector(lvertices,lines->element[i]->begin->index),centroid->index);

                return PO;
        }

        if(query_freq_longvector(lvertices,lines->element[i]->end->index)!=2) {
                printf("Warning: problem in end vertex of line %ld, (%ld points in the same vertex) the polygon %ld cannot be created!! \n",lines->element[i]->end->index,query_freq_longvector(lvertices,lines->element[i]->begin->index),centroid->index);

            return PO;
         }
    }

/* The polygon can be defined */
/* It calculates the area of a polygon */
/* It defines the edge of the polygon */
    area=0.0;

    PO->edge_indices=new_longvector(lines->nh);
    for (i=lines->nl;i<=lines->nh;i++){
        area=area+area2d(centroid,lines->element[i]->begin,lines->element[i]->end);

        PO->edge_indices->element[i]=lines->element[i]->index;


    }
    PO->area2D=area;



    free_longvector(lvertices);




        return PO;



}