skyline.py 文件源码

def _placement_points_generator(self, skyline, width):
        """Returns a generator for the x coordinates of all the placement
        points on the skyline for a given rectangle.

        WARNING: In some cases could be duplicated points, but it is faster
        to compute them twice than to remove them.

        Arguments:
            skyline (list): Skyline HSegment list
            width (int, float): Rectangle width

        Returns:
            generator
        """ 
        skyline_r = skyline[-1].right
        skyline_l = skyline[0].left

        # Placements using skyline segment left point
        ppointsl = (s.left for s in skyline if s.left+width <= skyline_r)

        # Placements using skyline segment right point
        ppointsr = (s.right-width for s in skyline if s.right-width >= skyline_l)

        # Merge positions
        return heapq.merge(ppointsl, ppointsr)