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#!/usr/bin/python
#
# C++ version Copyright (c) 2006-2007 Erin Catto http://www.gphysics.com
# Python version Copyright (c) 2008 kne / sirkne at gmail dot com
#
# Implemented using the pybox2d SWIG interface for Box2D (pybox2d.googlecode.com)
#
# This software is provided 'as-is', without any express or implied
# warranty. In no event will the authors be held liable for any damages
# arising from the use of this software.
# Permission is granted to anyone to use this software for any purpose,
# including commercial applications, and to alter it and redistribute it
# freely, subject to the following restrictions:
# 1. The origin of this software must not be misrepresented; you must not
# claim that you wrote the original software. If you use this software
# in a product, an acknowledgment in the product documentation would be
# appreciated but is not required.
# 2. Altered source versions must be plainly marked as such, and must not be
# misrepresented as being the original software.
# 3. This notice may not be removed or altered from any source distribution.
from test_main import *
from math import atan2
# C++ version by Smartcode
# See http://www.box2d.org/forum/viewtopic.php?f=3&t=2280
class Belt (Framework):
name="Belt"
def __init__(self):
super(Belt, self).__init__()
bd=box2d.b2BodyDef()
# static body
bd.position=(0.0, 0.0)
stat_c = self.world.CreateBody(bd)
# first circle
bd.position=(-5, 10)
c1 = self.world.CreateBody(bd)
sd=box2d.b2CircleDef()
sd.radius = 4.3
sd.density = 3.0
sd.friction = 0.8
sd.restitution = 0.4
c1.CreateShape(sd)
c1.SetMassFromShapes()
# first joint
rjd=box2d.b2RevoluteJointDef()
rjd.Initialize(stat_c, c1, c1.GetWorldCenter())
self.world.CreateJoint(rjd) #.getAsType() use getAsType if you want to refer to this joint
# second circle
bd.position=(10, 15)
c2 = self.world.CreateBody(bd)
sd.radius = 2.2
c2.CreateShape(sd)
c2.SetMassFromShapes()
# second joint
rjd.Initialize(stat_c, c2, c2.GetWorldCenter())
self.world.CreateJoint(rjd)
# create belt from the table of points
tuple_points = [
(-5.97, 14.91), (-3.17, 15.46), (-0.38, 16.01), ( 2.42, 16.56), ( 5.22, 17.11),
(8.01, 17.67 ), (10.82, 17.88), (12.83, 16.01), (12.46, 13.29), (10.12, 11.73),
(7.56, 10.49 ), ( 4.99, 9.26), ( 2.42, 8.02), (-0.15, 6.79), (-2.72, 5.55),
(-5.48, 5.02), (-8.09, 6.07), (-9.72, 8.36), (-9.86, 11.17), (-8.46, 13.61) ]
points = [box2d.b2Vec2(*t) for t in tuple_points]
pd=box2d.b2PolygonDef()
jd=box2d.b2RevoluteJointDef()
pd.density = 3.0
pd.friction = 0.8
thickness = 1.0
first_body= None
prev_body = None
next_body = None
for i in range(20):
v = points[(i+1)%20] - points[i]
angle = atan2(v.y, v.x)
bd.position = points[i] + 0.5 * v
next_body = self.world.CreateBody(bd)
if i == 0:
first_body = next_body # remember the body of first fragment
pd.SetAsBox(0.5 * v.Length() + thickness / 2.0, thickness / 2.0, (0,0), angle)
shape = next_body.CreateShape(pd)
next_body.SetMassFromShapes()
if prev_body: # if we have previous body, create joint
local_anchor=points[i]
jd.Initialize(prev_body, next_body, local_anchor)
self.world.CreateJoint(jd)
prev_body = next_body
# last anchor between last and first element
jd.Initialize(prev_body, first_body, points[0])
self.world.CreateJoint(jd)
if __name__=="__main__":
main(Belt)
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