lru_cache is fast

intersection.py

    @lru_cache(maxsize=4096)
    def intersection(self, region: Region) -> Region:
        """Get the overlapping portion of the two regions.

        Args:
            region (Region): A region that overlaps this region.

        Returns:
            Region: A new region that covers when the two regions overlap.
        """
        # Unrolled because this method is used a lot
        x1, y1, w1, h1 = self
        cx1, cy1, w2, h2 = region
        x2 = x1 + w1
        y2 = y1 + h1
        cx2 = cx1 + w2
        cy2 = cy1 + h2

        rx1 = cx2 if x1 > cx2 else (cx1 if x1 < cx1 else x1)
        ry1 = cy2 if y1 > cy2 else (cy1 if y1 < cy1 else y1)
        rx2 = cx2 if x2 > cx2 else (cx1 if x2 < cx1 else x2)
        ry2 = cy2 if y2 > cy2 else (cy1 if y2 < cy1 else y2)

        return Region(rx1, ry1, rx2 - rx1, ry2 - ry1)