#!/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)