BOOL8
C_OUTLINE::operator< ( //winding number
const C_OUTLINE & other //other outline
) const
{
inT16 count = 0; //winding count
ICOORD pos; //position of point
inT32 stepindex; //index to cstep
if (!box.overlap (other.box))
return FALSE; //can't be contained
if (stepcount == 0)
return other.box.contains(this->box);
pos = start;
for (stepindex = 0; stepindex < stepcount
&& (count = other.winding_number (pos)) == INTERSECTING; stepindex++)
pos += step (stepindex); //try all points
if (count == INTERSECTING) {
//all intersected
pos = other.start;
for (stepindex = 0; stepindex < other.stepcount
&& (count = winding_number (pos)) == INTERSECTING; stepindex++)
//try other way round
pos += other.step (stepindex);
return count == INTERSECTING || count == 0;
}
return count != 0;
}
BOOL8
OUTLINE::operator< ( //winding number
OUTLINE & other //other outline
) {
inT16 count; //winding count
POLYPT_IT it = &outline; //iterator
if (!box.overlap (other.box))
return FALSE; //can't be contained
do {
count = other.winding_number (FCOORD (it.data ()->pos));
//get winding number
if (count != INTERSECTING)
return count != 0;
it.forward ();
}
while (!it.at_first ());
//switch lists
it.set_to_list (&other.outline);
do {
//try other way round
count = winding_number (FCOORD (it.data ()->pos));
if (count != INTERSECTING)
return count == 0;
it.forward ();
}
while (!it.at_first ());
return TRUE;
}
static int is_inside_polygon( Point P, Point *polygon, long n) {
int cleanup_needed=0;
int wn;
Point *copy=malloc((n+1)*sizeof(Point));
memcpy(copy,polygon,n*sizeof(Point));
/* as we are searching for inclusion, close the polygon...*/
if ( (copy[0].lat == copy[n-1].lat) && (copy[0].lon == copy[n-1].lon) ) {
n--;
} else {
copy[n].lat= copy[0].lat;
copy[n].lon= copy[0].lon;
}
if ( (P.lat != 0.0) || (P.lon != 0.0) ) {
copy= shift_polygon(P,copy,n);
}
wn= winding_number(copy,n);
free(copy);
if (wn == 0) {
return 0;
} else {
return 1;
}
}
BOOL8 POLY_BLOCK::overlap( // do polys overlap
POLY_BLOCK *other) {
inT16 count; //winding count
ICOORDELT_IT it = &vertices; //iterator
ICOORD vertex;
if (!box.overlap (*(other->bounding_box ())))
return FALSE; //can't be any overlap
/* see if a vertex of this is inside other */
do {
vertex = *it.data ();
//get winding number
count = other->winding_number (vertex);
if (count != INTERSECTING)
if (count != 0)
return (TRUE);
it.forward ();
}
while (!it.at_first ());
/* see if a vertex of other is inside this */
//switch lists
it.set_to_list (other->points ());
do {
vertex = *it.data ();
//try other way round
count = winding_number (vertex);
if (count != INTERSECTING)
if (count != 0)
return (TRUE);
it.forward ();
}
while (!it.at_first ());
return FALSE;
}
BOOL8 POLY_BLOCK::contains( //other outline
POLY_BLOCK *other) {
inT16 count; //winding count
ICOORDELT_IT it = &vertices; //iterator
ICOORD vertex;
if (!box.overlap (*(other->bounding_box ())))
return FALSE; //can't be contained
/* check that no vertex of this is inside other */
do {
vertex = *it.data ();
//get winding number
count = other->winding_number (vertex);
if (count != INTERSECTING)
if (count != 0)
return (FALSE);
it.forward ();
}
while (!it.at_first ());
/* check that all vertices of other are inside this */
//switch lists
it.set_to_list (other->points ());
do {
vertex = *it.data ();
//try other way round
count = winding_number (vertex);
if (count != INTERSECTING)
if (count == 0)
return (FALSE);
it.forward ();
}
while (!it.at_first ());
return TRUE;
}
