--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/ode/src/util.cpp Tue Feb 02 01:00:49 2010 +0200
@@ -0,0 +1,375 @@
+/*************************************************************************
+ * *
+ * 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 "object.h"
+#include "joint.h"
+#include "util.h"
+#include <ode/lookup_tables.h>
+
+//#define ALLOCA dALLOCA16
+
+//****************************************************************************
+// Auto disabling
+
+void dInternalHandleAutoDisabling (dxWorld *world, dReal stepsize)
+{
+ dxBody *bb;
+ for ( bb=world->firstbody; bb; bb=(dxBody*)bb->next )
+ {
+ // don't freeze objects mid-air (patch 1586738)
+ if ( bb->firstjoint == NULL ) continue;
+
+ // nothing to do unless this body is currently enabled and has
+ // the auto-disable flag set
+ if ( (bb->flags & (dxBodyAutoDisable|dxBodyDisabled)) != dxBodyAutoDisable ) continue;
+
+ // if sampling / threshold testing is disabled, we can never sleep.
+ if ( bb->adis.average_samples == 0 ) continue;
+
+ //
+ // see if the body is idle
+ //
+
+#ifndef dNODEBUG
+ // sanity check
+ if ( bb->average_counter >= bb->adis.average_samples )
+ {
+
+ // something is going wrong, reset the average-calculations
+ bb->average_ready = 0; // not ready for average calculation
+ bb->average_counter = 0; // reset the buffer index
+ }
+#endif // dNODEBUG
+
+ // sample the linear and angular velocity
+ bb->average_lvel_buffer[bb->average_counter][0] = bb->lvel[0];
+ bb->average_lvel_buffer[bb->average_counter][1] = bb->lvel[1];
+ bb->average_lvel_buffer[bb->average_counter][2] = bb->lvel[2];
+ bb->average_avel_buffer[bb->average_counter][0] = bb->avel[0];
+ bb->average_avel_buffer[bb->average_counter][1] = bb->avel[1];
+ bb->average_avel_buffer[bb->average_counter][2] = bb->avel[2];
+ bb->average_counter++;
+
+ // buffer ready test
+ if ( bb->average_counter >= bb->adis.average_samples )
+ {
+ bb->average_counter = 0; // fill the buffer from the beginning
+ bb->average_ready = 1; // this body is ready now for average calculation
+ }
+
+ int idle = 0; // Assume it's in motion unless we have samples to disprove it.
+
+ // enough samples?
+ if ( bb->average_ready )
+ {
+ idle = 1; // Initial assumption: IDLE
+
+ // the sample buffers are filled and ready for calculation
+ dVector3 average_lvel, average_avel;
+
+ // Store first velocity samples
+ average_lvel[0] = bb->average_lvel_buffer[0][0];
+ average_avel[0] = bb->average_avel_buffer[0][0];
+ average_lvel[1] = bb->average_lvel_buffer[0][1];
+ average_avel[1] = bb->average_avel_buffer[0][1];
+ average_lvel[2] = bb->average_lvel_buffer[0][2];
+ average_avel[2] = bb->average_avel_buffer[0][2];
+
+ // If we're not in "instantaneous mode"
+ if ( bb->adis.average_samples > 1 )
+ {
+ // add remaining velocities together
+ for ( unsigned int i = 1; i < bb->adis.average_samples; ++i )
+ {
+ average_lvel[0] += bb->average_lvel_buffer[i][0];
+ average_avel[0] += bb->average_avel_buffer[i][0];
+ average_lvel[1] += bb->average_lvel_buffer[i][1];
+ average_avel[1] += bb->average_avel_buffer[i][1];
+ average_lvel[2] += bb->average_lvel_buffer[i][2];
+ average_avel[2] += bb->average_avel_buffer[i][2];
+ }
+
+ // make average
+ dReal r1 = dDIV(REAL( 1.0 ),REAL( bb->adis.average_samples ));
+
+ average_lvel[0] = dMUL(average_lvel[0],r1);
+ average_avel[0] = dMUL(average_avel[0],r1);
+ average_lvel[1] = dMUL(average_lvel[1],r1);
+ average_avel[1] = dMUL(average_avel[1],r1);
+ average_lvel[2] = dMUL(average_lvel[2],r1);
+ average_avel[2] = dMUL(average_avel[2],r1);
+ }
+
+ // threshold test
+ dReal av_lspeed, av_aspeed;
+ av_lspeed = dDOT( average_lvel, average_lvel );
+ if ( av_lspeed > bb->adis.linear_average_threshold )
+ {
+ idle = 0; // average linear velocity is too high for idle
+ }
+ else
+ {
+ av_aspeed = dDOT( average_avel, average_avel );
+ if ( av_aspeed > bb->adis.angular_average_threshold )
+ {
+ idle = 0; // average angular velocity is too high for idle
+ }
+ }
+ }
+
+ // if it's idle, accumulate steps and time.
+ // these counters won't overflow because this code doesn't run for disabled bodies.
+ if (idle) {
+ bb->adis_stepsleft--;
+ bb->adis_timeleft -= stepsize;
+ }
+ else {
+ // Reset countdowns
+ bb->adis_stepsleft = bb->adis.idle_steps;
+ bb->adis_timeleft = bb->adis.idle_time;
+ }
+
+ // disable the body if it's idle for a long enough time
+ if ( bb->adis_stepsleft <= 0 && bb->adis_timeleft <= 0 )
+ {
+ bb->flags |= dxBodyDisabled; // set the disable flag
+
+ // disabling bodies should also include resetting the velocity
+ // should prevent jittering in big "islands"
+ bb->lvel[0] = 0;
+ bb->lvel[1] = 0;
+ bb->lvel[2] = 0;
+ bb->avel[0] = 0;
+ bb->avel[1] = 0;
+ bb->avel[2] = 0;
+ }
+ }
+}
+
+
+//****************************************************************************
+// body rotation
+
+// return sin(x)/x. this has a singularity at 0 so special handling is needed
+// for small arguments.
+
+static inline dReal sinc (dReal x)
+{
+ // if |x| < 1e-4 then use a taylor series expansion. this two term expansion
+ // is actually accurate to one LS bit within this range if double precision
+ // is being used - so don't worry!
+ if (dFabs(x) < REAL(1.0e-4)) return REAL(1.0) - dMUL(dMUL(x,x),REAL(0.166666666666666666667));
+ else return dDIV(dSin(x),x);
+}
+
+
+// given a body b, apply its linear and angular rotation over the time
+// interval h, thereby adjusting its position and orientation.
+
+void dxStepBody (dxBody *b, dReal h)
+{
+ int j;
+
+ // handle linear velocity
+ for (j=0; j<3; j++) b->posr.pos[j] += dMUL(h,b->lvel[j]);
+
+ if (b->flags & dxBodyFlagFiniteRotation) {
+ dVector3 irv; // infitesimal rotation vector
+ dQuaternion q; // quaternion for finite rotation
+
+ if (b->flags & dxBodyFlagFiniteRotationAxis) {
+ // split the angular velocity vector into a component along the finite
+ // rotation axis, and a component orthogonal to it.
+ dVector3 frv; // finite rotation vector
+ dReal k = dDOT (b->finite_rot_axis,b->avel);
+ frv[0] = dMUL(b->finite_rot_axis[0],k);
+ frv[1] = dMUL(b->finite_rot_axis[1],k);
+ frv[2] = dMUL(b->finite_rot_axis[2],k);
+ irv[0] = b->avel[0] - frv[0];
+ irv[1] = b->avel[1] - frv[1];
+ irv[2] = b->avel[2] - frv[2];
+
+ // make a rotation quaternion q that corresponds to frv * h.
+ // compare this with the full-finite-rotation case below.
+ h = dMUL(h,REAL(0.5));
+ dReal theta = dMUL(k,h);
+ q[0] = dCos(theta);
+ dReal s = dMUL(sinc(theta),h);
+ q[1] = dMUL(frv[0],s);
+ q[2] = dMUL(frv[1],s);
+ q[3] = dMUL(frv[2],s);
+ }
+ else {
+ // make a rotation quaternion q that corresponds to w * h
+ dReal wlen = dSqrt (dMUL(b->avel[0],b->avel[0]) + dMUL(b->avel[1],b->avel[1]) +
+ dMUL(b->avel[2],b->avel[2]));
+ h = dMUL(h,REAL(0.5));
+ dReal theta = dMUL(wlen,h);
+ q[0] = dCos(theta);
+ dReal s = dMUL(sinc(theta),h);
+ q[1] = dMUL(b->avel[0],s);
+ q[2] = dMUL(b->avel[1],s);
+ q[3] = dMUL(b->avel[2],s);
+ }
+
+ // do the finite rotation
+ dQuaternion q2;
+ dQMultiply0 (q2,q,b->q);
+ for (j=0; j<4; j++) b->q[j] = q2[j];
+
+ // do the infitesimal rotation if required
+ if (b->flags & dxBodyFlagFiniteRotationAxis) {
+ dReal dq[4];
+ dWtoDQ (irv,b->q,dq);
+ for (j=0; j<4; j++) b->q[j] += dMUL(h,dq[j]);
+ }
+ }
+ else {
+ // the normal way - do an infitesimal rotation
+ dReal dq[4];
+ dWtoDQ (b->avel,b->q,dq);
+ for (j=0; j<4; j++) b->q[j] += dMUL(h,dq[j]);
+ }
+
+ // normalize the quaternion and convert it to a rotation matrix
+ dNormalize4 (b->q);
+ dQtoR (b->q,b->posr.R);
+
+ // notify all attached geoms that this body has moved
+ for (dxGeom *geom = b->geom; geom; geom = dGeomGetBodyNext (geom))
+ dGeomMoved (geom);
+}
+
+//****************************************************************************
+// island processing
+
+// this groups all joints and bodies in a world into islands. all objects
+// in an island are reachable by going through connected bodies and joints.
+// each island can be simulated separately.
+// note that joints that are not attached to anything will not be included
+// in any island, an so they do not affect the simulation.
+//
+// this function starts new island from unvisited bodies. however, it will
+// never start a new islands from a disabled body. thus islands of disabled
+// bodies will not be included in the simulation. disabled bodies are
+// re-enabled if they are found to be part of an active island.
+
+void dxProcessIslands (dxWorld *world, dReal stepsize, dstepper_fn_t stepper)
+{
+ dxBody *b,*bb,**body;
+ dxJoint *j,**joint;
+
+ // nothing to do if no bodies
+ if (world->nb <= 0) return;
+
+ // handle auto-disabling of bodies
+ dInternalHandleAutoDisabling (world,stepsize);
+
+ // make arrays for body and joint lists (for a single island) to go into
+ body = (dxBody**) malloc (world->nb * sizeof(dxBody*));
+ if(body == NULL){
+ return;
+ }
+ joint = (dxJoint**) malloc (world->nj * sizeof(dxJoint*));
+ if(joint == NULL){
+ free(body);
+ return;
+ }
+ int bcount = 0; // number of bodies in `body'
+ int jcount = 0; // number of joints in `joint'
+
+ // set all body/joint tags to 0
+ for (b=world->firstbody; b; b=(dxBody*)b->next) b->tag = 0;
+ for (j=world->firstjoint; j; j=(dxJoint*)j->next) j->tag = 0;
+
+ // allocate a stack of unvisited bodies in the island. the maximum size of
+ // the stack can be the lesser of the number of bodies or joints, because
+ // new bodies are only ever added to the stack by going through untagged
+ // joints. all the bodies in the stack must be tagged!
+ int stackalloc = (world->nj < world->nb) ? world->nj : world->nb;
+ dxBody **stack = (dxBody**) malloc (stackalloc * sizeof(dxBody*));
+ if(stack == NULL){
+ free(body);
+ free(joint);
+ return;
+ }
+
+ for (bb=world->firstbody; bb; bb=(dxBody*)bb->next) {
+ // get bb = the next enabled, untagged body, and tag it
+ if (bb->tag || (bb->flags & dxBodyDisabled)) continue;
+ bb->tag = 1;
+
+ // tag all bodies and joints starting from bb.
+ int stacksize = 0;
+ int firsttime = 1;
+
+ b = bb;
+ body[0] = bb;
+ bcount = 1;
+ jcount = 0;
+
+ while (stacksize > 0 || firsttime)
+ {
+ if (!firsttime)
+ {
+ b = stack[--stacksize]; // pop body off stack
+ body[bcount++] = b; // put body on body list
+ }
+ else
+ {
+ firsttime = 0;
+ }
+
+ // traverse and tag all body's joints, add untagged connected bodies
+ // to stack
+ for (dxJointNode *n=b->firstjoint; n; n=n->next) {
+ if (!n->joint->tag) {
+ n->joint->tag = 1;
+ joint[jcount++] = n->joint;
+ if (n->body && !n->body->tag) {
+ n->body->tag = 1;
+ stack[stacksize++] = n->body;
+ }
+ }
+ }
+ }
+
+ // now do something with body and joint lists
+ stepper (world,body,bcount,joint,jcount,stepsize);
+
+ // what we've just done may have altered the body/joint tag values.
+ // we must make sure that these tags are nonzero.
+ // also make sure all bodies are in the enabled state.
+ int i;
+ for (i=0; i<bcount; i++) {
+ body[i]->tag = 1;
+ body[i]->flags &= ~dxBodyDisabled;
+ }
+ for (i=0; i<jcount; i++) joint[i]->tag = 1;
+ }
+
+ free(body);
+ free(joint);
+ free(stack);
+
+}