spotlight.py

import os
import sys
import pygame as pg

CAPTION="SPOTLIGHT GAME"
screen_size=(1000,650)
color_key=(255,0,255)
ellipse_size=(400,400)

class Control(object):
    def __init__(self):
        self.screen=pg.display.get_surface()
        self.screen_rect=self.screen.get_rect()
        self.clock=pg.time.Clock()
        self.fps=60.0
        self.done=False
        self.keys=pg.key.get_pressed()
        self.background=FRACTAL
        self.ellipse_rect=pg.Rect((0,0),ellipse_size)

    def event_loop(self):
        for event in pg.event.get():
            self.keys=pg.key.get_pressed()
            if event.type == pg.QUIT or self.keys[pg.K_ESCAPE]:
                self.done = True

    def make_hole(self):
        hole=pg.Surface(self.screen_rect.size).convert()
        hole.set_colorkey(color_key)
        hole.fill((0,0,0))
        pg.draw.ellipse(hole,color_key,self.ellipse_rect)
        return hole

    def make_hole_alpha(self):
        hole=pg.Surface(self.screen_rect.size).convert_alpha()
        hole.fill((255,255,200))
        pg.draw.ellipse(hole,(0,0,0,0),self.ellipse_rect)
        return hole

    def update(self):
        self.ellipse_rect.center=pg.mouse.get_pos()
        self.hole=self.make_hole()

    def draw(self):
        self.screen.blit(self.background,(0,0))
        self.screen.blit(self.hole,(0,0))

    def display_fps(self):
        caption="{} - FPS: {:.2f}".format(CAPTION,self.clock.get_fps())
        pg.display.set_caption(caption)

    def main_loop(self):
        while not self.done:
            self.event_loop()
            self.update()
            self.draw()
            pg.display.update()
            self.clock.tick(self.fps)
            self.display_fps()

    if __name__=="__main__":
        os.environ['SDL_VIDEO_CENTERED']='1'
        pg.init()
        pg.display.set_mode(screen_size)
        FRACTAL=pg.image.load("background.jpg").convert()
        run_it=Control()
        run_it.main_loop()
        pg.quit()
        sys.exit()