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
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
|
#!/usr/bin/env python
# -*- coding: utf-8 -*-
import unittest
import itertools
import sys
class testJoints (unittest.TestCase):
world = None
dbody1 = None
dbody2 = None
sbody1 = None
sbody2 = None
def _fail(self, s):
# This little function would save us from an AssertionError on garbage collection.
# It forces the gc to take care of the world early.
self.world = None
self.dbody1 = None
self.dbody2 = None
self.sbody1 = None
self.sbody2 = None
self.b2 = None
self.fail(s)
def setUp(self):
self.b2 = __import__('Box2D')
try:
self.world = self.b2.b2World(self.b2.b2Vec2(0.0, -10.0), True)
except Exception as ex:
self.fail("Failed to create world (%s)" % ex)
try:
self.dbody1 = self.create_body((-3, 12))
self.dbody1.userData = "dbody1"
self.dbody2 = self.create_body((0, 12))
self.dbody2.userData = "dbody2"
except Exception as ex:
self._fail("Failed to create dynamic bodies (%s)" % ex)
try:
self.sbody1 = self.create_body((0, 0), False)
self.sbody1.userData = "sbody1"
self.sbody2 = self.create_body((1, 4), False)
self.sbody2.userData = "sbody2"
except Exception as ex:
self._fail("Failed to create static bodies (%s)" % ex)
def create_body(self, position, dynamic=True):
bodyDef = self.b2.b2BodyDef()
fixtureDef = self.b2.b2FixtureDef()
if dynamic:
bodyDef.type = self.b2.b2_dynamicBody
fixtureDef.density = 1
else:
bodyDef.type = self.b2.b2_staticBody
fixtureDef.density = 0
bodyDef.position = position
body = self.world.CreateBody(bodyDef)
dynamicBox = self.b2.b2PolygonShape()
dynamicBox.SetAsBox(1, 1)
fixtureDef.shape = dynamicBox
fixtureDef.friction = 0.3
body.CreateFixture(fixtureDef)
return body
def create_circle_body(self, position, dynamic=True):
bodyDef = self.b2.b2BodyDef()
fixtureDef = self.b2.b2FixtureDef()
if dynamic:
bodyDef.type = self.b2.b2_dynamicBody
fixtureDef.density = 1
else:
bodyDef.type = self.b2.b2_staticBody
fixtureDef.density = 0
bodyDef.position = position
body = self.world.CreateBody(bodyDef)
body.CreateFixture(shape=self.b2.b2CircleShape(radius=1.0), density=1.0, friction=0.3)
return body
def step_world(self, steps=10):
timeStep = 1.0 / 60
vel_iters, pos_iters = 6, 2
for i in range(steps):
self.world.Step(timeStep, vel_iters, pos_iters)
def check(self, dfn, joint, prop, joint_prop=""):
a = getattr(dfn, prop)
if joint_prop:
b = getattr(joint, joint_prop)
else:
b = getattr(joint, prop)
self.assertEquals(a, b, "Property not equal from definition to joint: %s (dfn %s != joint %s)" % (prop, a, b) )
# ---- revolute joint ----
def revolute_definition(self, body1, body2, anchor):
dfn=self.b2.b2RevoluteJointDef()
dfn.Initialize(body1, body2, anchor)
dfn.motorSpeed = 1.0 * self.b2.b2_pi
dfn.maxMotorTorque = 10000.0
dfn.enableMotor = False
dfn.lowerAngle = -0.25 * self.b2.b2_pi
dfn.upperAngle = 0.5 * self.b2.b2_pi
dfn.enableLimit = True
dfn.collideConnected = True
return dfn
def revolute_asserts(self, dfn, joint):
self.check(dfn, joint, "motorSpeed")
self.check(dfn, joint, "lowerAngle", "lowerLimit")
self.check(dfn, joint, "upperAngle", "upperLimit")
self.check(dfn, joint, "enableMotor", "motorEnabled")
self.check(dfn, joint, "enableLimit", "limitEnabled")
self.check(dfn, joint, "bodyA")
self.check(dfn, joint, "bodyB")
def revolute_checks(self, dfn, joint):
# check to make sure they are at least accessible
joint.GetReactionForce(1.0)
joint.GetReactionTorque(1.0)
joint.GetMotorTorque(1.0)
i = joint.angle
i = joint.speed
i = joint.anchorA
i = joint.anchorB
joint.upperLimit = 2
joint.maxMotorTorque = 10.0
joint.foobar = 2
# ---- prismatic joint ----
def prismatic_definition(self, body1, body2, anchor, axis):
dfn=self.b2.b2PrismaticJointDef()
dfn.Initialize(body1, body2, anchor, axis)
dfn.motorSpeed = 10
dfn.maxMotorForce = 1000.0
dfn.enableMotor = True
dfn.lowerTranslation = 0
dfn.upperTranslation = 20
dfn.enableLimit = True
return dfn
def prismatic_asserts(self, dfn, joint):
self.check(dfn, joint, "motorSpeed")
self.check(dfn, joint, "lowerTranslation", "lowerLimit")
self.check(dfn, joint, "upperTranslation", "upperLimit")
self.check(dfn, joint, "enableMotor", "motorEnabled")
self.check(dfn, joint, "enableLimit", "limitEnabled")
self.check(dfn, joint, "bodyA")
self.check(dfn, joint, "bodyB")
self.check(dfn, joint, "maxMotorForce")
def prismatic_checks(self, dfn, joint):
# check to make sure they are at least accessible
i = joint.GetMotorForce(1.0)
i = joint.anchorA
i = joint.anchorB
i = joint.speed
i = joint.translation
joint.GetReactionForce(1.0)
joint.GetReactionTorque(1.0)
# ---- distance joint ----
def distance_definition(self, body1, body2, anchorA, anchorB):
dfn=self.b2.b2DistanceJointDef()
dfn.Initialize(body1, body2, anchorA, anchorB)
dfn.length = (self.b2.b2Vec2(*anchorA) - self.b2.b2Vec2(*anchorB)).length
dfn.frequencyHz = 4.0
dfn.dampingRatio = 0.5
return dfn
def distance_asserts(self, dfn, joint):
self.check(dfn, joint, "bodyA")
self.check(dfn, joint, "bodyB")
self.check(dfn, joint, "length")
self.check(dfn, joint, "frequencyHz", "frequency")
self.check(dfn, joint, "dampingRatio")
def distance_checks(self, dfn, joint):
joint.GetReactionForce(1.0)
joint.GetReactionTorque(1.0)
# ---- Rope joint ----
def rope_definition(self, body1, body2, anchorA, anchorB, maxLength):
dfn=self.b2.b2RopeJointDef(bodyA=body1, bodyB=body2, anchorA=anchorA, \
anchorB=anchorB, maxLength=maxLength)
return dfn
def rope_asserts(self, dfn, joint):
self.check(dfn, joint, "bodyA")
self.check(dfn, joint, "bodyB")
self.check(dfn, joint, "maxLength")
def rope_checks(self, dfn, joint):
joint.GetReactionForce(1.0)
joint.GetReactionTorque(1.0)
joint.limitState
# ---- pulley joint ----
def pulley_definition(self, body1, body2):
if body2.mass == 0 or body1.mass == 0:
body1 = self.dbody2
body2 = self.dbody1
dfn=self.b2.b2PulleyJointDef()
a, b = 2, 4
y, L = 16, 12
anchor1 =(body1.position.x, y + b)
anchor2 =(body1.position.x, y + b)
groundAnchor1=(body1.position.x, y + b + L)
groundAnchor2=(body1.position.x, y + b + L)
dfn.Initialize(body1, body2, groundAnchor1, groundAnchor2, anchor1, anchor2, 2.0)
return dfn
def pulley_asserts(self, dfn, joint):
self.check(dfn, joint, "bodyA")
self.check(dfn, joint, "bodyB")
self.check(dfn, joint, "groundAnchorA")
self.check(dfn, joint, "groundAnchorB")
self.check(dfn, joint, "ratio")
def pulley_checks(self, dfn, joint):
joint.GetReactionForce(1.0)
joint.GetReactionTorque(1.0)
# ---- mouse joint ----
def mouse_definition(self, body1, body2):
dfn=self.b2.b2MouseJointDef()
if body2.mass == 0:
body2 = self.dbody1
if body2 == body1:
body1 = self.sbody1
dfn.bodyA = body1
dfn.bodyB = body2
dfn.target = (2, 1)
dfn.maxForce = 10
return dfn
def mouse_asserts(self, dfn, joint):
self.check(dfn, joint, "target")
self.check(dfn, joint, "maxForce")
self.check(dfn, joint, "frequencyHz", "frequency")
self.check(dfn, joint, "dampingRatio")
def mouse_checks(self, dfn, joint):
joint.GetReactionForce(1.0)
joint.GetReactionTorque(1.0)
# ---- wheel joint ----
def wheel_definition(self, body1, body2, anchor, axis):
dfn=self.b2.b2WheelJointDef()
dfn.Initialize(body1, body2, anchor, axis)
dfn.motorSpeed = 0
dfn.maxMotorForce = 100.0
dfn.enableMotor = True
dfn.lowerTranslation = -4.0
dfn.upperTranslation = 4.0
dfn.enableLimit = True
return dfn
def wheel_asserts(self, dfn, joint):
self.check(dfn, joint, "motorSpeed")
self.check(dfn, joint, "maxMotorTorque")
self.check(dfn, joint, "enableMotor", "motorEnabled")
self.check(dfn, joint, "bodyA")
self.check(dfn, joint, "bodyB")
self.check(dfn, joint, "frequencyHz", "springFrequencyHz")
self.check(dfn, joint, "dampingRatio", "springDampingRatio")
def wheel_checks(self, dfn, joint):
# check to make sure they are at least accessible
i = joint.anchorA
i = joint.anchorB
i = joint.speed
i = joint.translation
joint.GetReactionForce(1.0)
joint.GetReactionTorque(1.0)
# ---- weld joint ----
def weld_definition(self, body1, body2):
dfn=self.b2.b2WeldJointDef()
dfn.bodyA = body1
dfn.bodyB = body2
return dfn
def weld_asserts(self, dfn, joint):
pass
def weld_checks(self, dfn, joint):
joint.GetReactionForce(1.0)
joint.GetReactionTorque(1.0)
# ---- friction joint ----
def friction_definition(self, body1, body2):
dfn=self.b2.b2FrictionJointDef()
dfn.bodyA = body1
dfn.bodyB = body2
dfn.localAnchorA = dfn.localAnchorB = (0,0)
dfn.collideConnected = True
dfn.maxForce = 10.0
dfn.maxTorque = 20.0
return dfn
def friction_asserts(self, dfn, joint):
self.check(dfn, joint, "maxForce")
self.check(dfn, joint, "maxTorque")
def friction_checks(self, dfn, joint):
joint.GetReactionForce(1.0)
joint.GetReactionTorque(1.0)
def do_joint(self, name, init_args):
'''test a joint by name'''
get_dfn = getattr(self, "%s_definition"%name)
asserts = getattr(self, "%s_asserts"%name)
checks = getattr(self, "%s_checks"%name)
create_name=getattr(self.world, "Create%sJoint" % (name.capitalize()))
for bodyA, bodyB in itertools.permutations( ( self.sbody1, self.sbody2, self.dbody1, self.dbody2), 2 ):
try:
dfn = get_dfn(body1=bodyA, body2=bodyB, **init_args)
except Exception as ex:
self._fail("%s: Failed on bodies %s and %s, joint definition (%s)" % (name, bodyA.userData, bodyB.userData, ex))
kw_args = {}
try:
kw_args = dfn.to_kwargs()
joint = create_name(**kw_args)
self.world.DestroyJoint(joint)
except Exception as ex:
self._fail("%s: Failed on bodies %s and %s, joint creation by kwargs (%s) kw=%s" % (name, bodyA.userData, bodyB.userData, ex, kw_args))
try:
joint = self.world.CreateJoint(dfn)
except Exception as ex:
self._fail("%s: Failed on bodies %s and %s, joint creation (%s)" % (name, bodyA.userData, bodyB.userData, ex))
try:
asserts(dfn, joint)
except Exception as ex:
self.world.DestroyJoint(joint)
raise
try:
checks(dfn, joint)
except Exception as ex:
self.world.DestroyJoint(joint)
self._fail("%s: Failed on bodies %s and %s, joint checks (%s)" % (name, bodyA.userData, bodyB.userData, ex))
try:
self.step_world(5)
except Exception as ex:
# self.world.DestroyJoint(joint) # -> locked
try:
# Ok, this will cause an assertion to go off during unwinding (in the b2StackAllocator deconstructor),
# so do it once, catch that, and then fail finally
self.fail()
except AssertionError as ex:
self._fail("%s: Failed on bodies %s and %s, joint simulation (%s)" % (name, bodyA.userData, bodyB.userData, ex))
try:
self.world.DestroyJoint(joint)
except Exception as ex:
s=sys.exc_info()[1]
self._fail("%s: Failed on bodies %s and %s joint deletion (%s)" % (name, bodyA.userData, bodyB.userData, s))
# --- the actual tests ---
def test_revolute(self):
self.do_joint("revolute", { 'anchor' : (0, 12) })
def test_prismatic(self):
self.do_joint("prismatic", { 'anchor' : (0, 0), 'axis' : (1,0) })
def test_distance(self):
self.do_joint("distance", { 'anchorA' : (-10, 0), 'anchorB' : (-0.5,-0.5) })
def test_rope(self):
self.do_joint("rope", { 'anchorA' : (-10, 0), 'anchorB' : (-0.5,-0.5), 'maxLength' : 5.0 })
def test_pulley(self):
self.do_joint("pulley", {} )
def test_mouse(self):
self.do_joint("mouse", {} )
def test_wheel(self):
self.do_joint("wheel", { 'anchor' : (0, 8.5), 'axis' : (2,1) })
def test_weld(self):
self.do_joint("weld", {} )
def test_friction(self):
self.do_joint("friction", {} )
def test_emptyjoint(self):
try:
self.world.CreateJoint( self.b2.b2RevoluteJointDef() )
except ValueError:
pass # good
else:
raise Exception('Empty joint should have raised an exception')
def test_gear(self):
# creates 2 revolute joints and then joins them, so it's done separately
ground=self.world.CreateBody( self.b2.b2BodyDef() )
shape=self.b2.b2EdgeShape(vertices=((50.0, 0.0), (-50.0, 0.0)))
ground.CreateFixturesFromShapes(shapes=shape)
body1=self.create_circle_body((-3, 12))
body2=self.create_circle_body(( 0, 12))
jd1=self.b2.b2RevoluteJointDef()
jd1.Initialize(ground, body1, body1.position)
joint1 = self.world.CreateJoint(jd1)
jd2=self.b2.b2RevoluteJointDef()
jd2.Initialize(ground, body2, body2.position)
joint2 = self.world.CreateJoint(jd2)
gjd=self.b2.b2GearJointDef()
gjd.bodyA = body1
gjd.bodyB = body2
gjd.joint1 = joint1
gjd.joint2 = joint2
gjd.ratio = 2.0
gj = self.world.CreateJoint(gjd)
self.step_world(10)
self.check(gjd, gj, "ratio")
gj.GetReactionForce(1.0)
gj.GetReactionTorque(1.0)
self.world.DestroyJoint(gj)
self.world.DestroyJoint(joint2)
self.world.DestroyJoint(joint1)
if __name__ == '__main__':
unittest.main()
|
