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| #include <complex.h>
#include "view.h"
#define PI 3.141592653589793
struct Polygon {
int nv;
coord * Vertices;
};
int ReadPolygon ( char * polyfile, struct Polygon * _Poly)
{
char buffer[200];
int nv;
FILE * fp;
double xv,yv;
if(!(fp = fopen (polyfile, "r")))
{
printf("Failed to open polygon file!\n");
return -1;
}
_Poly->Vertices = (coord *) malloc(0*sizeof(coord));
nv=0;
while ( fgets(buffer, 200, fp)!=NULL )
{
sscanf(buffer,"%lf %lf",&xv,&yv);
_Poly->Vertices = (coord *) realloc( _Poly->Vertices , (nv+1)*sizeof(coord));
(_Poly->Vertices)[nv].x = xv;
(_Poly->Vertices)[nv].y = yv;
nv++;
}
_Poly->nv = nv;
return(0);
}
bool isInPolygon(coord P, struct Polygon * _Poly )
{
int i;
coord Pcurr;
double complex zprev, zcurr;
double sum,dsum;
Pcurr = (_Poly->Vertices)[0];
zcurr = (Pcurr.x-P.x) + I*(Pcurr.y-P.y);
if(cabs(zcurr)<1e-6) // P almost coincides with current vertex, leave
return(true);
sum = 0.;
for(i=1;i<(_Poly->nv);i++)
{
zprev = zcurr;
Pcurr = (_Poly->Vertices)[i];
zcurr = (Pcurr.x-P.x) + I*(Pcurr.y-P.y);
if(cabs(zcurr)<1e-6) // P almost coincides with current vertex, leave
return(true);
dsum = cimag(clog(zcurr)-clog(zprev));
dsum += fabs(dsum)>PI ? -2.0*PI*dsum/fabs(dsum) : 0.;
sum += dsum;
}
// Ensure polygon is closed
i = (_Poly->nv)-1;
zprev = zcurr;
Pcurr = (_Poly->Vertices)[i];
zcurr = (Pcurr.x-P.x) + I*(Pcurr.y-P.y);
dsum = cimag(clog(zcurr)-clog(zprev));
dsum += fabs(dsum)>PI ? -2.0*PI*dsum/fabs(dsum) : 0.;
sum += dsum;
return( fabs(sum)>PI );
}
int draw_polygon ( struct Polygon * _Poly , float lc[3] = {0}, float lw = 1.)
{
bview * view = draw();
draw_lines (view, lc, lw) {
glBegin (GL_LINE_LOOP);
for(int k=1;k<(_Poly->nv);k++)
glvertex2d (view, (_Poly->Vertices)[k].x, (_Poly->Vertices)[k].y);
glEnd();
view->ni++;
}
return 0;
}
int draw_polygon_on_surface ( struct Polygon * _Poly , scalar s, float lc[3] = {0}, float lw = 1., float z_offset = 0.)
{
bview * view = draw();
draw_lines (view, lc, lw) {
glBegin (GL_LINE_LOOP);
for(int k=1;k<(_Poly->nv);k++)
{
Point point = locate ( (_Poly->Vertices)[k].x, (_Poly->Vertices)[k].y );
glvertex3d (view, x, y , s[] + z_offset);
}
glEnd();
view->ni++;
}
return 0;
}
|
