box2d_viewer.py 文件源码

def _Keyboard_Event(self, key, down=True):
        """
        Internal keyboard event, don't override this.

        Checks for the initial keydown of the basic testbed keys. Passes the
        unused ones onto the test via the Keyboard() function.
        """
        if down:
            if key == pygame.K_z:       # Zoom in
                self.viewZoom = min(2 * self.viewZoom, 500.0)
            elif key == pygame.K_x:     # Zoom out
                self.viewZoom = max(0.9 * self.viewZoom, 0.02)