/*************************************************************************
* *
* 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. *
* *
*************************************************************************/
// Test for breaking joints, by Bram Stolk
#include <ode/config.h>
#include <assert.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <ode/ode.h>
#include <drawstuff/drawstuff.h>
#ifdef _MSC_VER
#pragma warning(disable:4244 4305) // for VC++, no precision loss complaints
#endif
#ifdef dDOUBLE
#define dsDrawBox dsDrawBoxD
#define dsDrawCylinder dsDrawCylinderD
#endif
// dynamics and collision objects (chassis, 3 wheels, environment)
static dWorldID world;
static dSpaceID space;
static const int STACKCNT=10; // nr of weights on bridge
static const int SEGMCNT=16; // nr of segments in bridge
static const float SEGMDIM[3] = { 0.9, 4, 0.1 };
static dGeomID groundgeom;
static dBodyID segbodies[SEGMCNT];
static dGeomID seggeoms[SEGMCNT];
static dBodyID stackbodies[STACKCNT];
static dGeomID stackgeoms[STACKCNT];
static dJointID hinges[SEGMCNT-1];
static dJointID sliders[2];
static dJointFeedback jfeedbacks[SEGMCNT-1];
static dReal colours[SEGMCNT];
static int stress[SEGMCNT-1];
static dJointGroupID contactgroup;
// this is called by dSpaceCollide when two objects in space are
// potentially colliding.
static void nearCallback (void *data, dGeomID o1, dGeomID o2)
{
assert(o1);
assert(o2);
if (dGeomIsSpace(o1) || dGeomIsSpace(o2))
{
fprintf(stderr,"testing space %p %p\n", o1,o2);
// colliding a space with something
dSpaceCollide2(o1,o2,data,&nearCallback);
// Note we do not want to test intersections within a space,
// only between spaces.
return;
}
const int N = 32;
dContact contact[N];
int n = dCollide (o1,o2,N,&(contact[0].geom),sizeof(dContact));
if (n > 0)
{
for (int i=0; i<n; i++)
{
contact[i].surface.mode = dContactSoftERP | dContactSoftCFM | dContactApprox1;
contact[i].surface.mu = 100.0;
contact[i].surface.soft_erp = 0.96;
contact[i].surface.soft_cfm = 0.02;
dJointID c = dJointCreateContact (world,contactgroup,&contact[i]);
dJointAttach (c,
dGeomGetBody(contact[i].geom.g1),
dGeomGetBody(contact[i].geom.g2));
}
}
}
// start simulation - set viewpoint
static void start()
{
static float xyz[3] = { -6, 8, 6};
static float hpr[3] = { -65.0f, -27.0f, 0.0f};
dsSetViewpoint (xyz,hpr);
}
// called when a key pressed
static void command (int cmd)
{
}
void drawGeom (dGeomID g)
{
const dReal *pos = dGeomGetPosition(g);
const dReal *R = dGeomGetRotation(g);
int type = dGeomGetClass (g);
if (type == dBoxClass)
{
dVector3 sides;
dGeomBoxGetLengths (g, sides);
dsDrawBox (pos,R,sides);
}
if (type == dCylinderClass)
{
dReal r,l;
dGeomCylinderGetParams(g, &r, &l);
dsDrawCylinder (pos, R, l, r);
}
}
static void inspectJoints(void)
{
const dReal forcelimit = 2000.0;
int i;
for (i=0; i<SEGMCNT-1; i++)
{
if (dJointGetBody(hinges[i], 0))
{
// This joint has not snapped already... inspect it.
dReal l0 = dLENGTH(jfeedbacks[i].f1);
dReal l1 = dLENGTH(jfeedbacks[i].f2);
colours[i+0] = 0.95*colours[i+0] + 0.05 * l0/forcelimit;
colours[i+1] = 0.95*colours[i+1] + 0.05 * l1/forcelimit;
if (l0 > forcelimit || l1 > forcelimit)
stress[i]++;
else
stress[i]=0;
if (stress[i]>4)
{
// Low-pass filter the noisy feedback data.
// Only after 4 consecutive timesteps with excessive load, snap.
fprintf(stderr,"SNAP! (that was the sound of joint %d breaking)\n", i);
dJointAttach (hinges[i], 0, 0);
}
}
}
}
// simulation loop
static void simLoop (int pause)
{
int i;
double simstep = 0.005; // 5ms simulation steps
double dt = dsElapsedTime();
int nrofsteps = (int) ceilf(dt/simstep);
for (i=0; i<nrofsteps && !pause; i++)
{
dSpaceCollide (space,0,&nearCallback);
dWorldQuickStep (world, simstep);
dJointGroupEmpty (contactgroup);
inspectJoints();
}
for (i=0; i<SEGMCNT; i++)
{
float r=0,g=0,b=0.2;
float v = colours[i];
if (v>1.0) v=1.0;
if (v<0.5)
{
r=2*v;
g=1.0;
}
else
{
r=1.0;
g=2*(1.0-v);
}
dsSetColor (r,g,b);
drawGeom(seggeoms[i]);
}
dsSetColor (1,1,1);
for (i=0; i<STACKCNT; i++)
drawGeom(stackgeoms[i]);
}
int main (int argc, char **argv)
{
dMass m;
// 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();
space = dHashSpaceCreate (0);
contactgroup = dJointGroupCreate (0);
dWorldSetGravity (world,0,0,-9.8);
dWorldSetQuickStepNumIterations (world, 20);
int i;
for (i=0; i<SEGMCNT; i++)
{
segbodies[i] = dBodyCreate (world);
dBodySetPosition(segbodies[i], i - SEGMCNT/2.0, 0, 5);
dMassSetBox (&m, 1, SEGMDIM[0], SEGMDIM[1], SEGMDIM[2]);
dBodySetMass (segbodies[i], &m);
seggeoms[i] = dCreateBox (0, SEGMDIM[0], SEGMDIM[1], SEGMDIM[2]);
dGeomSetBody (seggeoms[i], segbodies[i]);
dSpaceAdd (space, seggeoms[i]);
}
for (i=0; i<SEGMCNT-1; i++)
{
hinges[i] = dJointCreateHinge (world,0);
dJointAttach (hinges[i], segbodies[i],segbodies[i+1]);
dJointSetHingeAnchor (hinges[i], i + 0.5 - SEGMCNT/2.0, 0, 5);
dJointSetHingeAxis (hinges[i], 0,1,0);
dJointSetHingeParam (hinges[i],dParamFMax, 8000.0);
// NOTE:
// Here we tell ODE where to put the feedback on the forces for this hinge
dJointSetFeedback (hinges[i], jfeedbacks+i);
stress[i]=0;
}
for (i=0; i<STACKCNT; i++)
{
stackbodies[i] = dBodyCreate(world);
dMassSetBox (&m, 2.0, 2, 2, 0.6);
dBodySetMass(stackbodies[i],&m);
stackgeoms[i] = dCreateBox(0, 2, 2, 0.6);
dGeomSetBody(stackgeoms[i], stackbodies[i]);
dBodySetPosition(stackbodies[i], 0,0,8+2*i);
dSpaceAdd(space, stackgeoms[i]);
}
sliders[0] = dJointCreateSlider (world,0);
dJointAttach(sliders[0], segbodies[0], 0);
dJointSetSliderAxis (sliders[0], 1,0,0);
dJointSetSliderParam (sliders[0],dParamFMax, 4000.0);
dJointSetSliderParam (sliders[0],dParamLoStop, 0.0);
dJointSetSliderParam (sliders[0],dParamHiStop, 0.2);
sliders[1] = dJointCreateSlider (world,0);
dJointAttach(sliders[1], segbodies[SEGMCNT-1], 0);
dJointSetSliderAxis (sliders[1], 1,0,0);
dJointSetSliderParam (sliders[1],dParamFMax, 4000.0);
dJointSetSliderParam (sliders[1],dParamLoStop, 0.0);
dJointSetSliderParam (sliders[1],dParamHiStop, -0.2);
groundgeom = dCreatePlane(space, 0,0,1,0);
for (i=0; i<SEGMCNT; i++)
colours[i]=0.0;
// run simulation
dsSimulationLoop (argc,argv,352,288,&fn);
dJointGroupEmpty (contactgroup);
dJointGroupDestroy (contactgroup);
// First destroy seggeoms, then space, then the world.
for (i=0; i<SEGMCNT; i++)
dGeomDestroy (seggeoms[i]);
for (i=0; i<STACKCNT; i++)
dGeomDestroy (stackgeoms[i]);
dSpaceDestroy(space);
dWorldDestroy (world);
dCloseODE();
return 0;
}