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# ODE Demo
import sys
import pygame
from pygame.locals import *
import ode
import xode.parser
doc = '''<?xml version="1.0" encoding="iso-8859-1"?>
<xode>
<world name="world">
<space>
<body name="body1">
<transform>
<position x="1" y="2" z="0"/>
</transform>
<mass>
<mass_shape density="2500">
<sphere radius="0.05"/>
</mass_shape>
</mass>
</body>
<body name="body2">
<transform>
<position x="2" y="2" z="0"/>
</transform>
<mass>
<mass_shape density="2500">
<sphere radius="0.05"/>
</mass_shape>
</mass>
<joint name="joint2">
<link1 body="body1"/>
<ball>
<anchor x="1" y="2" z="0"/>
</ball>
</joint>
</body>
<joint name="joint1">
<link1 body="body1"/>
<ball>
<anchor x="0" y="2" z="0"/>
</ball>
</joint>
</space>
</world>
</xode>'''
def coord(x,y):
"Convert world coordinates to pixel coordinates."
return 320+170*x, 400-170*y
def buildObjects():
world = ode.World()
world.setGravity((0,-9.81,0))
body1 = ode.Body(world)
M = ode.Mass()
M.setSphere(2500, 0.05)
body1.setMass(M)
body1.setPosition((1,2,0))
body2 = ode.Body(world)
M = ode.Mass()
M.setSphere(2500, 0.05)
body2.setMass(M)
body2.setPosition((2,2,0))
j1 = ode.BallJoint(world)
j1.attach(body1, ode.environment)
j1.setAnchor( (0,2,0) )
#j1 = ode.HingeJoint(world)
#j1.attach(body1, ode.environment)
#j1.setAnchor( (0,2,0) )
#j1.setAxis( (0,0,1) )
#j1.setParam(ode.ParamVel, 3)
#j1.setParam(ode.ParamFMax, 22)
j2 = ode.BallJoint(world)
j2.attach(body1, body2)
j2.setAnchor( (1,2,0) )
return world, body1, body2, j1, j2
def buildObjectsXODE():
p = xode.parser.Parser()
root = p.parseString(doc)
world = root.namedChild('world').getODEObject()
body1 = root.namedChild('body1').getODEObject()
body2 = root.namedChild('body2').getODEObject()
j1 = root.namedChild('joint1').getODEObject()
j2 = root.namedChild('joint2').getODEObject()
world.setGravity((0,-9.81,0))
#body1.setPosition((1,2,0))
#body2.setPosition((2,2,0))
#j1 = ode.BallJoint(world)
#j1.attach(body1, ode.environment)
#j1.setAnchor( (0,2,0) )
#j2 = ode.BallJoint(world)
#j2.attach(body1, body2)
#j2.setAnchor( (1,2,0) )
return world, body1, body2, j1, j2
def simulate(world, body1, body2):
# Initialize pygame
pygame.init()
# Open a display
srf = pygame.display.set_mode((640,480))
clk = pygame.time.Clock()
# Keep the window open and wait for a key
fps = 50
dt = 1.0/fps
loopFlag = True
while loopFlag:
events = pygame.event.get()
for e in events:
if e.type==QUIT:
loopFlag=False
# Clear the screen
srf.fill((255,255,255))
x1,y1,z1 = body1.getPosition()
x2,y2,z2 = body2.getPosition()
pygame.draw.circle(srf, (55,0,200), coord(x1,y1), 20, 0)
pygame.draw.line(srf, (55,0,200), coord(0,2), coord(x1,y1), 2)
pygame.draw.circle(srf, (55,0,200), coord(x2,y2), 20, 0)
pygame.draw.line(srf, (55,0,200), coord(x1,y1), coord(x2,y2), 2)
pygame.display.flip()
world.step(dt)
clk.tick(fps)
#print "fps: %2.1f dt:%d rawdt:%d"%(clk.get_fps(), clk.get_time(), clk.get_rawtime())
world, body1, body2, j1, j2 = buildObjectsXODE()
simulate(world, body1, body2)
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