1 files changed, 314 insertions, 0 deletions

diff --git a/libraries/ode-0.9/ode/demo/demo_feedback.cpp b/libraries/ode-0.9/ode/demo/demo_feedback.cpp
new file mode 100644
index 0000000..fd49278
--- /dev/null
+++ b/libraries/ode-0.9/ode/demo/demo_feedback.cpp
@@ -0,0 +1,314 @@
+/*************************************************************************
+ *                                                                       *
+ * 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;
+}
+