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// Test my Plane2D constraint.
// Uses ode-0.35 collision API.
# include <stdio.h>
# include <stdlib.h>
# include <math.h>
# include <ode/ode.h>
# include <drawstuff/drawstuff.h>
# define drand48() ((double) (((double) rand()) / ((double) RAND_MAX)))
# define N_BODIES 40
# define STAGE_SIZE 8.0 // in m
# define TIME_STEP 0.01
# define K_SPRING 10.0
# define K_DAMP 10.0
static dWorld dyn_world;
static dBody dyn_bodies[N_BODIES];
static dReal bodies_sides[N_BODIES][3];
static dSpaceID coll_space_id;
static dJointID plane2d_joint_ids[N_BODIES];
static dJointGroup
coll_contacts;
static void cb_start ()
/*************************/
{
static float xyz[3] = { 0.5f*STAGE_SIZE, 0.5f*STAGE_SIZE, 0.65f*STAGE_SIZE};
static float hpr[3] = { 90.0f, -90.0f, 0 };
dsSetViewpoint (xyz, hpr);
}
static void cb_near_collision (void *data, dGeomID o1, dGeomID o2)
/********************************************************************/
{
dBodyID b1 = dGeomGetBody (o1);
dBodyID b2 = dGeomGetBody (o2);
dContact contact;
// exit without doing anything if the two bodies are static
if (b1 == 0 && b2 == 0)
return;
// exit without doing anything if the two bodies are connected by a joint
if (b1 && b2 && dAreConnected (b1, b2))
{
/* MTRAP; */
return;
}
contact.surface.mode = 0;
contact.surface.mu = 0; // frictionless
if (dCollide (o1, o2, 1, &contact.geom, sizeof (dContactGeom)))
{
dJointID c = dJointCreateContact (dyn_world.id(),
coll_contacts.id (), &contact);
dJointAttach (c, b1, b2);
}
}
static void track_to_pos (dBody &body, dJointID joint_id,
dReal target_x, dReal target_y)
/************************************************************************/
{
dReal curr_x = body.getPosition()[0];
dReal curr_y = body.getPosition()[1];
dJointSetPlane2DXParam (joint_id, dParamVel, 1 * (target_x - curr_x));
dJointSetPlane2DYParam (joint_id, dParamVel, 1 * (target_y - curr_y));
}
static void cb_sim_step (int pause)
/*************************************/
{
if (! pause)
{
static dReal angle = 0;
angle += REAL( 0.01 );
track_to_pos (dyn_bodies[0], plane2d_joint_ids[0],
dReal( STAGE_SIZE/2 + STAGE_SIZE/2.0 * cos (angle) ),
dReal( STAGE_SIZE/2 + STAGE_SIZE/2.0 * sin (angle) ));
/* double f0 = 0.001; */
/* for (int b = 0; b < N_BODIES; b ++) */
/* { */
/* double p = 1 + b / (double) N_BODIES; */
/* double q = 2 - b / (double) N_BODIES; */
/* dyn_bodies[b].addForce (f0 * cos (p*angle), f0 * sin (q*angle), 0); */
/* } */
/* dyn_bodies[0].addTorque (0, 0, 0.1); */
const int n = 10;
for (int i = 0; i < n; i ++)
{
dSpaceCollide (coll_space_id, 0, &cb_near_collision);
dyn_world.step (dReal(TIME_STEP/n));
coll_contacts.empty ();
}
}
# if 1 /* [ */
{
// @@@ hack Plane2D constraint error reduction here:
for (int b = 0; b < N_BODIES; b ++)
{
const dReal *rot = dBodyGetAngularVel (dyn_bodies[b].id());
const dReal *quat_ptr;
dReal quat[4],
quat_len;
quat_ptr = dBodyGetQuaternion (dyn_bodies[b].id());
quat[0] = quat_ptr[0];
quat[1] = 0;
quat[2] = 0;
quat[3] = quat_ptr[3];
quat_len = sqrt (quat[0] * quat[0] + quat[3] * quat[3]);
quat[0] /= quat_len;
quat[3] /= quat_len;
dBodySetQuaternion (dyn_bodies[b].id(), quat);
dBodySetAngularVel (dyn_bodies[b].id(), 0, 0, rot[2]);
}
}
# endif /* ] */
# if 0 /* [ */
{
// @@@ friction
for (int b = 0; b < N_BODIES; b ++)
{
const dReal *vel = dBodyGetLinearVel (dyn_bodies[b].id()),
*rot = dBodyGetAngularVel (dyn_bodies[b].id());
dReal s = 1.00;
dReal t = 0.99;
dBodySetLinearVel (dyn_bodies[b].id(), s*vel[0],s*vel[1],s*vel[2]);
dBodySetAngularVel (dyn_bodies[b].id(),t*rot[0],t*rot[1],t*rot[2]);
}
}
# endif /* ] */
{
// ode drawstuff
dsSetTexture (DS_WOOD);
for (int b = 0; b < N_BODIES; b ++)
{
if (b == 0)
dsSetColor (1.0, 0.5, 1.0);
else
dsSetColor (0, 0.5, 1.0);
#ifdef dDOUBLE
dsDrawBoxD (dyn_bodies[b].getPosition(), dyn_bodies[b].getRotation(), bodies_sides[b]);
#else
dsDrawBox (dyn_bodies[b].getPosition(), dyn_bodies[b].getRotation(), bodies_sides[b]);
#endif
}
}
}
extern int main
/******************/
(
int argc,
char **argv
)
{
int b;
dsFunctions drawstuff_functions;
dInitODE();
// dynamic world
dReal cf_mixing;// = 1 / TIME_STEP * K_SPRING + K_DAMP;
dReal err_reduct;// = TIME_STEP * K_SPRING * cf_mixing;
err_reduct = REAL( 0.5 );
cf_mixing = REAL( 0.001 );
dWorldSetERP (dyn_world.id (), err_reduct);
dWorldSetCFM (dyn_world.id (), cf_mixing);
dyn_world.setGravity (0, 0.0, -1.0);
coll_space_id = dSimpleSpaceCreate (0);
// dynamic bodies
for (b = 0; b < N_BODIES; b ++)
{
int l = (int) (1 + sqrt ((double) N_BODIES));
dReal x = dReal( (0.5 + (b / l)) / l * STAGE_SIZE );
dReal y = dReal( (0.5 + (b % l)) / l * STAGE_SIZE );
dReal z = REAL( 1.0 ) + REAL( 0.1 ) * (dReal)drand48();
bodies_sides[b][0] = dReal( 5 * (0.2 + 0.7*drand48()) / sqrt((double)N_BODIES) );
bodies_sides[b][1] = dReal( 5 * (0.2 + 0.7*drand48()) / sqrt((double)N_BODIES) );
bodies_sides[b][2] = z;
dyn_bodies[b].create (dyn_world);
dyn_bodies[b].setPosition (x, y, z/2);
dyn_bodies[b].setData ((void*) (size_t)b);
dBodySetLinearVel (dyn_bodies[b].id (),
dReal( 3 * (drand48 () - 0.5) ),
dReal( 3 * (drand48 () - 0.5) ), 0);
dMass m;
m.setBox (1, bodies_sides[b][0],bodies_sides[b][1],bodies_sides[b][2]);
m.adjust (REAL(0.1) * bodies_sides[b][0] * bodies_sides[b][1]);
dyn_bodies[b].setMass (&m);
plane2d_joint_ids[b] = dJointCreatePlane2D (dyn_world.id (), 0);
dJointAttach (plane2d_joint_ids[b], dyn_bodies[b].id (), 0);
}
dJointSetPlane2DXParam (plane2d_joint_ids[0], dParamFMax, 10);
dJointSetPlane2DYParam (plane2d_joint_ids[0], dParamFMax, 10);
// collision geoms and joints
dCreatePlane (coll_space_id, 1, 0, 0, 0);
dCreatePlane (coll_space_id, -1, 0, 0, -STAGE_SIZE);
dCreatePlane (coll_space_id, 0, 1, 0, 0);
dCreatePlane (coll_space_id, 0, -1, 0, -STAGE_SIZE);
for (b = 0; b < N_BODIES; b ++)
{
dGeomID coll_box_id;
coll_box_id = dCreateBox (coll_space_id,
bodies_sides[b][0], bodies_sides[b][1], bodies_sides[b][2]);
dGeomSetBody (coll_box_id, dyn_bodies[b].id ());
}
coll_contacts.create (0);
{
// simulation loop (by drawstuff lib)
drawstuff_functions.version = DS_VERSION;
drawstuff_functions.start = &cb_start;
drawstuff_functions.step = &cb_sim_step;
drawstuff_functions.command = 0;
drawstuff_functions.stop = 0;
drawstuff_functions.path_to_textures = "../../drawstuff/textures";
dsSimulationLoop (argc, argv, 352,288,&drawstuff_functions);
}
dCloseODE();
return 0;
}
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