pyglet--旋转的矩形

展示怎么制作动画。。。。

#-*- coding:utf-8 -*-
from pyglet.gl import *
from pyglet import clock

def draw_rect(x, y,z,width, height,ang):
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
    glLoadIdentity()
    glTranslatef(x+width/2,y+height/2,0.0)
    glRotatef(ang,0.0,0.0,1.0)
    glBegin(GL_LINE_LOOP)
    glColor3f(1.0,0.0,0.0)
    glVertex3f(x, y,z)
    glColor3f(1.0,0.0,0.0)
    glVertex3f(x + width, y,z)
    glColor3f(1.0,0.0,0.0)
    glVertex3f(x + width, y + height,z)
    glColor3f(1.0,0.0,0.0)
    glVertex3f(x, y + height,z)
    glEnd()

class Button():
    x=y=z=0
    width=height=10.0
    ang=0
    def draw(self):
        draw_rect(self.x,self.y,self.z,self.width,self.height,self.ang)

class MyWindow(pyglet.window.Window):
    def __init__(self):
        super(MyWindow,self).__init__()
        #按钮
        self.button=Button()
        self.button.x=10
        self.button.y=10
        self.button.z=0
        self.button.width=self.width/2
        self.button.height=self.height/2
        self.button.ang=0

        self.need_draw=[
                self.button,
                            ]
    def on_draw(self):
        self.clear()
        for draw_object in self.need_draw:
            draw_object.draw()
    def value_change(self,dt):
        self.button.ang+=0.5

if __name__ == "__main__":
    wn=MyWindow()
    clock.schedule_interval(wn.value_change,0.5)
pyglet.app.run()