void
cpDampedSpring(cpBody *a, cpBody *b, cpVect anchr1, cpVect anchr2, cpFloat rlen, cpFloat k, cpFloat dmp, cpFloat dt)
{
// Calculate the world space anchor coordinates.
cpVect r1 = cpvrotate(anchr1, a->rot);
cpVect r2 = cpvrotate(anchr2, b->rot);
cpVect delta = cpvsub(cpvadd(b->p, r2), cpvadd(a->p, r1));
cpFloat dist = cpvlength(delta);
cpVect n = dist ? cpvmult(delta, 1.0f/dist) : cpvzero;
cpFloat f_spring = (dist - rlen)*k;
// Calculate the world relative velocities of the anchor points.
cpVect v1 = cpvadd(a->v, cpvmult(cpvperp(r1), a->w));
cpVect v2 = cpvadd(b->v, cpvmult(cpvperp(r2), b->w));
// Calculate the damping force.
// This really should be in the impulse solver and can produce problems when using large damping values.
cpFloat vrn = cpvdot(cpvsub(v2, v1), n);
cpFloat f_damp = vrn*cpfmin(dmp, 1.0f/(dt*(a->m_inv + b->m_inv)));
// Apply!
cpVect f = cpvmult(n, f_spring + f_damp);
cpBodyApplyForce(a, f, r1);
cpBodyApplyForce(b, cpvneg(f), r2);
}
static int cpBody_applyForce (lua_State *L){
cpBody *b = check_cpBody(L, 1);
cpVect f = check_cpVect(L, 2);
cpVect r = check_cpVect(L, 4);
cpBodyApplyForce(b, f, r);
return 0;
}
void PhysicsBody::applyForce(const Vect& force, const Vec2& offset)
{
if (_dynamic && _mass != PHYSICS_INFINITY)
{
cpBodyApplyForce(_info->getBody(), PhysicsHelper::point2cpv(force), PhysicsHelper::point2cpv(offset));
}
}
Value * tumble ( std::list<Value *> * args, Scope * s ) {
World * world = current_gro_program->get_world();
std::list<Value *>::iterator i = args->begin();
float vel = (*i)->num_value();
if ( current_cell != NULL ) {
float a = current_cell->get_theta();
cpBody * body = current_cell->get_body();
cpVect v = cpBodyGetVel ( body );
cpFloat adot = cpBodyGetAngVel ( body );
cpBodySetTorque ( body, vel - adot ); // apply torque
cpBodyApplyForce ( // damp translation
current_cell->get_shape()->body,
cpv (
- v.x * world->get_sim_dt(),
- v.y * world->get_sim_dt()
),
cpv ( 0, 0 ) );
} else
printf ( "Warning: Tried to emit signal from outside a cell program. No action taken\n" );
return new Value ( Value::UNIT );
}
void cBody::ApplyForce( const cVect f, const cVect r ) {
cpBodyApplyForce( mBody, tocpv( f ), tocpv( r ) );
}
// apply a lasting external force to the center of gravity.
// also apply lasting forces perpendicluar to vectors from the c.o.g.
// (in other words, push and rotate the object)
// these need to be subtracted later to stop their effect
void applyforces(struct objnode *player, struct forces f)
{
cpBodyApplyForce(player->b, f.force, cpvzero);
cpBodyApplyForce(player->b, f.tforce, cpv(RLEN, 0));
cpBodyApplyForce(player->b, cpvneg(f.tforce), cpv(-RLEN, 0));
}
void bmx_cpbody_applyforce(cpBody * body, cpVect * force, cpVect * offset) {
cpBodyApplyForce(body, *force, *offset);
}
void PhysicsBody::applyForce(Point force, Point offset)
{
cpBodyApplyForce(_info->body, PhysicsHelper::point2cpv(force), PhysicsHelper::point2cpv(offset));
}
void wrBodyApplyForce(cpBody *b, cpVect *f, cpVect *p) {
cpBodyApplyForce(b, *f, *p);
}
static VALUE
rb_cpBodyApplyForce(VALUE self, VALUE f, VALUE r) {
cpBodyApplyForce(BODY(self), *VGET(f), *VGET(r));
return self;
}
void PhysicsBody::applyForce(const Vect& force, const Point& offset)
{
cpBodyApplyForce(_info->getBody(), PhysicsHelper::point2cpv(force), PhysicsHelper::point2cpv(offset));
}
void physics_apply_force_at(Entity ent, Vec2 force, Vec2 at)
{
PhysicsInfo *info = entitypool_get(pool, ent);
error_assert(info);
cpBodyApplyForce(info->body, cpv_of_vec2(force), cpv_of_vec2(at));
}
void worldEnt_applyForce(WorldEntity_t *aEntity, vec2_t aForce, vec2_t aOffset)
{
cpBodyApplyForce(aEntity->cpBody, VEC2_TO_CPV(aForce), VEC2_TO_CPV(aOffset));
}
void Body::applyForce(const cp::Vect& f,const cp::Vect& r)
{
cpBodyApplyForce(body,f,r);
}
