/usr/share/doc/python-box2d-doc/examples/cantilever.py is in python-box2d-doc 2.3.2~dfsg-2.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 | #!/usr/bin/env python
# -*- coding: utf-8 -*-
#
# C++ version Copyright (c) 2006-2007 Erin Catto http://www.box2d.org
# Python version by Ken Lauer / sirkne at gmail dot 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 .framework import (Framework, main)
from Box2D import (b2CircleShape, b2EdgeShape, b2FixtureDef, b2PolygonShape)
class Cantilever (Framework):
name = "Cantilever"
description = ""
numPlanks = 8
def __init__(self):
super(Cantilever, self).__init__()
# The ground
ground = self.world.CreateBody(
shapes=b2EdgeShape(vertices=[(-40, 0), (40, 0)]))
plank = b2FixtureDef(
shape=b2PolygonShape(box=(0.5, 0.125)),
friction=0.2,
density=20
)
# Create one cantilever (Only the left end is fixed)
prevBody = ground
for i in range(self.numPlanks):
body = self.world.CreateDynamicBody(
position=(-14.5 + i, 5),
fixtures=plank,
)
self.world.CreateWeldJoint(
bodyA=prevBody,
bodyB=body,
anchor=(-15 + i, 5),
)
prevBody = body
# Create another higher up
prevBody = ground
for i in range(self.numPlanks):
body = self.world.CreateDynamicBody(
position=(-14.5 + i, 15),
fixtures=plank,
)
self.world.CreateWeldJoint(
bodyA=prevBody,
bodyB=body,
anchor=(-15 + i, 15),
)
prevBody = body
# And the left-most unconnected one (technically not a cantilever)
prevBody = ground
for i in range(self.numPlanks):
body = self.world.CreateDynamicBody(
position=(-4.5 + i, 5),
fixtures=plank,
)
if i > 0: # skip the joint on the first one
self.world.CreateWeldJoint(
bodyA=prevBody,
bodyB=body,
anchor=(-5 + i, 5),
)
prevBody = body
# And the right-most unconnected one, using joint damping
prevBody = ground
for i in range(self.numPlanks):
body = self.world.CreateDynamicBody(
position=(5.5 + i, 10),
fixtures=plank,
)
if i > 0: # skip the joint on the first one
self.world.CreateWeldJoint(
bodyA=prevBody,
bodyB=body,
anchor=(5 + i, 10),
frequencyHz=8.0,
dampingRatio=0.7,
)
prevBody = body
# And a few random shapes to play with
# First a set of triangles,
fixture = b2FixtureDef(shape=b2PolygonShape(vertices=[(-0.5, 0.0),
(0.5, 0.0),
(0.0, 1.5),
]),
density=1.0)
for i in range(2):
self.world.CreateDynamicBody(
position=(-8 + 8 * i, 12),
fixtures=fixture,
)
# And then a few circles
fixture = b2FixtureDef(shape=b2CircleShape(radius=0.5), density=1)
for i in range(3):
self.world.CreateDynamicBody(
position=(-6 + 6 * i, 10),
fixtures=fixture,
)
if __name__ == "__main__":
main(Cantilever)
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