Function polygonToPathPart

src/core/objects/boolean_tool.cpp:611–778

}

void polygonToPathPart(const ClipperLib::Path& polygon, const PolyMap& polymap, PathObject* object)
{
	auto num_points = polygon.size();
	if (num_points < 3)
		return;
	
	// Index of first used point in polygon
	auto part_start_index = 0u;
	auto cur_info = PathCoordInfo{ nullptr, nullptr };
	
	// Check if we can find either an unknown intersection point
	// or a path coord with parameter 0.
	// This gives a starting point to search for curves to rebuild
	// (because we cannot start in the middle of a curve)
	for (; part_start_index < num_points; ++part_start_index)
	{
		auto current_point = polygon.at(part_start_index);
		if (!polymap.contains(current_point))
			break;
		
		if (polymap.value(current_point).second->param == 0.0)
		{
			cur_info = polymap.value(current_point);
			break;
		}
	}
	
	if (part_start_index == num_points)
	{
		// Did not find a valid starting point. Return the part as a polygon.
		for (auto i = 0u; i < num_points; ++i)
			object->addCoordinate(MapCoord::fromNative64(polygon.at(i).X, polygon.at(i).Y), i == 0);
		object->parts().back().setClosed(true, true);
		return;
	}
	
	// Add the first point to the object
	rebuildCoordinate(part_start_index, polygon, polymap, object, true);
	
	
	// Index of first segment point in polygon
	auto segment_start_index = part_start_index;
	bool have_sequence = false;
	bool sequence_increasing = false;
	bool stop_before = false;
	
	// Advance along the boundary and rebuild the curve for every sequence
	// of path coord pointers with the same path and index.
	auto i = part_start_index;
	do
	{
		++i;
		if (i >= num_points)
			i = 0;
		
		PathCoordInfo new_info{ nullptr, nullptr };
		auto new_point = polygon.at(i);
		if (polymap.contains(new_point))