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
|
/*************************************************************************
* *
* Open Dynamics Engine, Copyright (C) 2001,2002 Russell L. Smith. *
* All rights reserved. Email: russ@q12.org Web: www.q12.org *
* *
* This library is free software; you can redistribute it and/or *
* modify it under the terms of EITHER: *
* (1) The GNU Lesser General Public License as published by the Free *
* Software Foundation; either version 2.1 of the License, or (at *
* your option) any later version. The text of the GNU Lesser *
* General Public License is included with this library in the *
* file LICENSE.TXT. *
* (2) The BSD-style license that is included with this library in *
* the file LICENSE-BSD.TXT. *
* *
* This library is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the files *
* LICENSE.TXT and LICENSE-BSD.TXT for more details. *
* *
*************************************************************************/
#include <ode/ode.h>
#include <drawstuff/drawstuff.h>
#ifdef _MSC_VER
#pragma warning(disable:4244 4305) // for VC++, no precision loss complaints
#endif
// select correct drawing functions
#ifdef dDOUBLE
#define dsDrawBox dsDrawBoxD
#endif
// some constants
#define SIDE (0.5f) // side length of a box
#define MASS (1.0) // mass of a box
// dynamics and collision objects
static dWorldID world;
static dBodyID body[2];
static dJointID hinge;
// state set by keyboard commands
static int occasional_error = 0;
// start simulation - set viewpoint
static void start()
{
static float xyz[3] = {1.0382f,-1.0811f,1.4700f};
static float hpr[3] = {135.0000f,-19.5000f,0.0000f};
dsSetViewpoint (xyz,hpr);
printf ("Press 'e' to start/stop occasional error.\n");
}
// called when a key pressed
static void command (int cmd)
{
if (cmd == 'e' || cmd == 'E') {
occasional_error ^= 1;
}
}
// simulation loop
static void simLoop (int pause)
{
const dReal kd = -0.3; // angular damping constant
if (!pause) {
// add an oscillating torque to body 0, and also damp its rotational motion
static dReal a=0;
const dReal *w = dBodyGetAngularVel (body[0]);
dBodyAddTorque (body[0],kd*w[0],kd*w[1]+0.1*cos(a),kd*w[2]+0.1*sin(a));
dWorldStep (world,0.05);
a += 0.01;
// occasionally re-orient one of the bodies to create a deliberate error.
if (occasional_error) {
static int count = 0;
if ((count % 20)==0) {
// randomly adjust orientation of body[0]
const dReal *R1;
dMatrix3 R2,R3;
R1 = dBodyGetRotation (body[0]);
dRFromAxisAndAngle (R2,dRandReal()-0.5,dRandReal()-0.5,
dRandReal()-0.5,dRandReal()-0.5);
dMultiply0 (R3,R1,R2,3,3,3);
dBodySetRotation (body[0],R3);
// randomly adjust position of body[0]
const dReal *pos = dBodyGetPosition (body[0]);
dBodySetPosition (body[0],
pos[0]+0.2*(dRandReal()-0.5),
pos[1]+0.2*(dRandReal()-0.5),
pos[2]+0.2*(dRandReal()-0.5));
}
count++;
}
}
dReal sides1[3] = {SIDE,SIDE,SIDE};
dReal sides2[3] = {SIDE,SIDE,SIDE*0.8f};
dsSetTexture (DS_WOOD);
dsSetColor (1,1,0);
dsDrawBox (dBodyGetPosition(body[0]),dBodyGetRotation(body[0]),sides1);
dsSetColor (0,1,1);
dsDrawBox (dBodyGetPosition(body[1]),dBodyGetRotation(body[1]),sides2);
}
int main (int argc, char **argv)
{
// setup pointers to drawstuff callback functions
dsFunctions fn;
fn.version = DS_VERSION;
fn.start = &start;
fn.step = &simLoop;
fn.command = &command;
fn.stop = 0;
fn.path_to_textures = "../../drawstuff/textures";
if(argc==2)
{
fn.path_to_textures = argv[1];
}
// create world
dInitODE();
world = dWorldCreate();
dMass m;
dMassSetBox (&m,1,SIDE,SIDE,SIDE);
dMassAdjust (&m,MASS);
dQuaternion q;
dQFromAxisAndAngle (q,1,1,0,0.25*M_PI);
body[0] = dBodyCreate (world);
dBodySetMass (body[0],&m);
dBodySetPosition (body[0],0.5*SIDE,0.5*SIDE,1);
dBodySetQuaternion (body[0],q);
body[1] = dBodyCreate (world);
dBodySetMass (body[1],&m);
dBodySetPosition (body[1],-0.5*SIDE,-0.5*SIDE,1);
dBodySetQuaternion (body[1],q);
hinge = dJointCreateHinge (world,0);
dJointAttach (hinge,body[0],body[1]);
dJointSetHingeAnchor (hinge,0,0,1);
dJointSetHingeAxis (hinge,1,-1,1.41421356);
// run simulation
dsSimulationLoop (argc,argv,352,288,&fn);
dWorldDestroy (world);
dCloseODE();
return 0;
}
|
