bool DropCapsid::onContactAstroObj(ContactInfo& cinfo)
{
if (cinfo.contact.getEventCode() == PhysicsContact::EventCode::POSTSOLVE) {
if (cpArbiter* arb = static_cast<cpArbiter*>(cinfo.contact.getContactInfo())) {
cpContactPointSet cps = cpArbiterGetContactPointSet(arb);
bool moving = false;
for (int i = 0; i < cps.count; ++i) {
cpVect va = cpBodyGetVelocityAtWorldPoint(arb->body_a, cps.points[i].pointA);
cpVect vb = cpBodyGetVelocityAtWorldPoint(arb->body_b, cps.points[i].pointB);
cpVect rv = cpvsub(va, vb);
cpFloat wa = cpBodyGetAngularVelocity(arb->body_a);
cpFloat wb = cpBodyGetAngularVelocity(arb->body_b);
cpFloat rw = wa - wb;
//if (cpvlengthsq(rv) > 1e-6 || fabs(rw) > 0.5) {
if (cpvlengthsq(rv) > 1.0 || fabs(rw) > 5) {
moving = true;
break;
}
}
if (!moving) {
Unit* created = onLandCreate(_game);
Player* player = _player;
replaceWith(created); // this is destroyed
float up = (cinfo.thisBody->getPosition() - cinfo.thatBody->getPosition()).getAngle() / (M_PI / 180.0);
created->getNode()->getPhysicsBody()->setRotation(90 - up);
created->setPlayer(player);
// CCLOG("LANDING up# %f", up);
return true;
}
}
}
return true;
}
/*
* @return [Chipmunk2d::ContactPointSet]
*/
static mrb_value
arbiter_get_contact_point_set(mrb_state* mrb, mrb_value self)
{
cpArbiter* arbiter;
cpContactPointSet contact_point_set;
arbiter = mrb_cp_get_arbiter_ptr(mrb, self);
contact_point_set = cpArbiterGetContactPointSet(arbiter);
return mrb_cp_contact_point_set_value(mrb, &contact_point_set);
}
static cpBool
StickyPreSolve(cpArbiter *arb, cpSpace *space, void *data)
{
// We want to fudge the collisions a bit to allow shapes to overlap more.
// This simulates their squishy sticky surface, and more importantly
// keeps them from separating and destroying the joint.
// Track the deepest collision point and use that to determine if a rigid collision should occur.
cpFloat deepest = INFINITY;
// Grab the contact set and iterate over them.
cpContactPointSet contacts = cpArbiterGetContactPointSet(arb);
for(int i=0; i<contacts.count; i++){
// Increase the distance (negative means overlaping) of the
// collision to allow them to overlap more.
// This value is used only for fixing the positions of overlapping shapes.
cpFloat dist = contacts.points[i].dist + 2.0f*STICK_SENSOR_THICKNESS;
contacts.points[i].dist = cpfmin(0.0f, dist);
deepest = cpfmin(deepest, dist);
}
// Set the new contact point data.
cpArbiterSetContactPointSet(arb, &contacts);
// If the shapes are overlapping enough, then create a
// joint that sticks them together at the first contact point.
if(!cpArbiterGetUserData(arb) && deepest <= 0.0f){
CP_ARBITER_GET_BODIES(arb, bodyA, bodyB);
// Create a joint at the contact point to hold the body in place.
cpConstraint *joint = cpPivotJointNew(bodyA, bodyB, contacts.points[0].point);
// Give it a finite force for the stickyness.
cpConstraintSetMaxForce(joint, 3e3);
// Schedule a post-step() callback to add the joint.
cpSpaceAddPostStepCallback(space, PostStepAddJoint, joint, NULL);
// Store the joint on the arbiter so we can remove it later.
cpArbiterSetUserData(arb, joint);
}
// Position correction and velocity are handled separately so changing
// the overlap distance alone won't prevent the collision from occuring.
// Explicitly the collision for this frame if the shapes don't overlap using the new distance.
return (deepest <= 0.0f);
// Lots more that you could improve upon here as well:
// * Modify the joint over time to make it plastic.
// * Modify the joint in the post-step to make it conditionally plastic (like clay).
// * Track a joint for the deepest contact point instead of the first.
// * Track a joint for each contact point. (more complicated since you only get one data pointer).
}
static World_CollisionInfo _collisionInfoForArbiter(cpArbiter *aArbiter)
{
cpBody *bodyA, *bodyB;
cpArbiterGetBodies(aArbiter, &bodyA, &bodyB);
WorldEntity_t *a = bodyA->data;
dynamo_assert(a != NULL, "Incomplete collision");
WorldEntity_t *b = bodyB->data;
dynamo_assert(b != NULL, "Incomplete collision");
cpContactPointSet cpPointSet = cpArbiterGetContactPointSet(aArbiter);
World_ContactPointSet pointSet = *(World_ContactPointSet *)&cpPointSet;
return (World_CollisionInfo) {
a, b,
cpArbiterIsFirstContact(aArbiter),
pointSet,
aArbiter
};
}
cpContactPointSet cArbiter::ContactPointSet() {
return cpArbiterGetContactPointSet( mArbiter );
}
