Method isPointOnPath

src/core/objects/object.cpp:2440–2506

}

int PathObject::isPointOnPath(
        const MapCoordF& coord,
        qreal tolerance,
        bool treat_areas_as_paths,
        bool extended_selection) const
{
	auto side_tolerance = tolerance;
	if (extended_selection && map && (symbol->getType() == Symbol::Line || symbol->getType() == Symbol::Combined))
	{
		// TODO: precalculate largest line extent for all symbols to move it out of this time critical method?
		side_tolerance += symbol->calculateLargestLineExtent();
	}
	
	auto contained_types = symbol->getContainedTypes();
	if ((contained_types & Symbol::Line || treat_areas_as_paths) && tolerance > 0)
	{
		update();
		for (const auto& part : path_parts)
		{
			const auto& path_coords = part.path_coords;
			auto size = path_coords.size();
			for (PathCoordVector::size_type i = 0; i < size - 1; ++i)
			{
				Q_ASSERT(path_coords[i].index < coords.size());
				if (coords[path_coords[i].index].isHolePoint())
					continue;
				
				MapCoordF to_coord = coord - path_coords[i].pos;
				MapCoordF to_next = path_coords[i+1].pos - path_coords[i].pos;
				MapCoordF tangent = to_next;
				tangent.normalize();
				
				auto dist_along_line = MapCoordF::dotProduct(to_coord, tangent);
				if (dist_along_line < -tolerance)
					continue;
				
				if (dist_along_line < 0 && to_coord.lengthSquared() <= tolerance*tolerance)
					return Symbol::Line;
				
				auto line_length = qreal(path_coords[i+1].clen) - qreal(path_coords[i].clen);
				if (line_length < 1e-7)
					continue;
				
				if (dist_along_line > line_length + tolerance)
					continue;
				
				if (dist_along_line > line_length && coord.distanceSquaredTo(path_coords[i+1].pos) <= tolerance*tolerance)
					return Symbol::Line;
				
				auto right = tangent.perpRight();
				
				auto dist_from_line = qAbs(MapCoordF::dotProduct(right, to_coord));
				if (dist_from_line <= side_tolerance)
					return Symbol::Line;
			}
		}
	}