polygon::polygon(const reshp::shp::polygon& poly)
{
for(int32_t part = 0; part < poly.num_parts; ++part)
{
reshp::polygon::ring ring;
int32_t first_index = poly.parts[part];
reshp::point first(poly.points[first_index].x, poly.points[first_index].y);
for(int32_t p = first_index + 1; p < poly.num_points; ++p)
{
reshp::segment segment(reshp::point(poly.points[p - 1].x, poly.points[p - 1].y),
reshp::point(poly.points[p].x, poly.points[p].y));
ring.segments.push_back(segment);
if(segment.end == first)
break;
}
int sum = 0;
for(unsigned s = 0; s < ring.segments.size(); ++s)
sum += (ring.segments[s].end.x - ring.segments[s].start.x) * (ring.segments[s].end.y + ring.segments[s].start.y);
// Clockwise: Outer, Counter-clockwise: Inner
ring.type = (sum > 0 ? ring::outer : ring::inner);
ring.calculate_aabb();
rings.push_back(ring);
}
calculate_aabb();
}
const AABB &RenderObject::aabb() {
if(aabb_dirty()) calculate_aabb();
return aabb_;
}
