bouncing_chain.py

import time
import pyglet
import pymunk
import pymunk.pyglet_util
import sys

window = pyglet.window.Window(width = 800, height = 600)

space = pymunk.Space()
space.gravity = 0, -980

ball_body = pymunk.Body(1, 100)
ball_body.position = 400, 300
ball_body.angular_velocity = 10
ball_shape = pymunk.Circle(ball_body, 15)
ball_shape.friction = 0.5
ball_shape.elasticity = 0.9
ball_shape.color = (0,255,0)
space.add(ball_body, ball_shape)


static_lines = [pymunk.Segment(space.static_body, (20,20), (780,20), 12),
                pymunk.Segment(space.static_body, (20,1160), (780,1160), 12),
                pymunk.Segment(space.static_body, (20,20), (20,1160), 12),
                pymunk.Segment(space.static_body, (780,20), (780,1160), 12)]

for static_line in static_lines:
    static_line.color = (255,255,255)
    static_line.elasticity = 0.9
    static_line.friction = 1

space.add(static_lines)


i = 0
prev_body = pymunk.Body(10, 10000)
prev_body.position = (400, 570)
chain_fix_point = pymunk.Body(body_type = pymunk.Body.KINEMATIC)
chain_fix_point.position = (400, prev_body.position[1])

while i < 12:
    # rotation_center_body = pymunk.Body()
    # rotation_center_body.position = (400, prev_body.position[1] - 20)

    body = pymunk.Body(1, 1)
    body.position = (400, prev_body.position[1] - 10)

    line = pymunk.Circle(body, 5)
    line.elasticity = 0
    line.friction = 1
    if i == 0:
        rotation_center_joint = pymunk.PinJoint(body, chain_fix_point)
    else:
        rotation_center_joint = pymunk.PinJoint(body, prev_body)

    space.add(line, body, rotation_center_joint)

    prev_body = body

    i += 1

blob_body = pymunk.Body(5, 10000)
blob_body.position = prev_body.position[0], prev_body.position[1] + 30
blob_shape = pymunk.Circle(blob_body, 20)
rotation_center_joint = pymunk.PinJoint(blob_body, prev_body)
space.add(blob_body, blob_shape, rotation_center_joint)

box_body = pymunk.Body(1,10000)
box_body.position = 600, 200
box_vertices = [(570, 170),(570, 230),(630,230),(630,170)]
box_shape = pymunk.Poly(box_body, box_vertices, radius=1) #.create_box(box_body, size = (60,60))
box_shape.friction = 0.5
box_shape.elasticity = 0.9
box_shape.color = (255,0,0)
space.add(box_body, box_shape)

draw_options = pymunk.pyglet_util.DrawOptions()

def update(dt):
    #if ball_body.angle != 0:
    #    angle += ball_body.angular_velocity
    #for x in range(10):
    space.step(1/60.0)
    # img = pygame.transform.rotate(appleimg, angle)


@window.event
def on_key_press(symbol, modifiers):
    # Symbolic names:
    if symbol == pyglet.window.key.SPACE:
        ball_body.apply_impulse_at_local_point((1000, 1000))


@window.event
def on_draw():
    window.clear()
    space.debug_draw(draw_options)


pyglet.clock.schedule(update)
pyglet.app.run()