public void PhysicsSimulateCycle(float dTime)
{
// maximum number of static counts
var staticCnts = PhysicsConstants.StaticCnts;
// it's okay to have this code outside of the inner loop, as the
// ball hitrects already include the maximum distance they can
// travel in that timespan
_hitOcTreeDynamic.Update();
while (dTime > 0)
{
var hitTime = dTime;
// find earliest time where a flipper collides with its stop
foreach (var flipperMover in _flipperMovers)
{
var flipperHitTime = flipperMover.GetHitTime();
if (flipperHitTime > 0 && flipperHitTime < hitTime)
{
//!! >= 0.F causes infinite loop
hitTime = flipperHitTime;
}
}
RecordContacts = true;
Contacts.Clear();
foreach (var ball in Balls)
{
var ballHit = ball.Hit;
// don't play with frozen balls
if (!ball.State.IsFrozen)
{
// search upto current hit time
ballHit.Coll.HitTime = hitTime;
ballHit.Coll.Clear();
// always check for playfield and top glass
if (!_table.HasMeshAsPlayfield)
{
_hitPlayfield.DoHitTest(ball, ball.Coll, this);
}
_hitTopGlass.DoHitTest(ball, ball.Coll, this);
// swap order of dynamic and static obj checks randomly
if (MathF.Random() < 0.5)
{
_hitOcTreeDynamic.HitTestBall(ball, ball.Coll, this); // dynamic objects
_hitOcTree.HitTestBall(ball, ball.Coll, this); // find the hit objects and hit times
}
else
{
_hitOcTree.HitTestBall(ball, ball.Coll, this); // find the hit objects and hit times
_hitOcTreeDynamic.HitTestBall(ball, ball.Coll, this); // dynamic objects
}
// this ball's hit time
var htz = ball.Coll.HitTime;
if (htz < 0)
{
// no negative time allowed
ball.Coll.Clear();
}
if (ball.Coll.HasHit)
{
// smaller hit time?
if (htz <= hitTime)
{
// record actual event time
hitTime = htz;
// less than static time interval
if (htz < PhysicsConstants.StaticTime)
{
if (--staticCnts < 0)
{
staticCnts = 0; // keep from wrapping
hitTime = PhysicsConstants.StaticTime;
}
}
}
}
}
} // end loop over all balls
RecordContacts = false;
// hit time now set... or full frame if no hit
// now update displacements to collide-contact or end of physics frame
if (hitTime > PhysicsConstants.StaticTime)
{
// allow more zeros next round
staticCnts = PhysicsConstants.StaticCnts;
}
foreach (var mover in _movers)
{
// step 2: move the objects about according to velocities
// (spinner, gate, flipper, plunger, ball)
mover.UpdateDisplacements(hitTime);
}
// find balls that need to be collided and scripted (generally
// there will be one, but more are possible)
for (var i = 0; i < Balls.Count; i++)
{
var ball = Balls[i];
var hitObject = ball.Coll.Obj; // object that ball hit in trials
// find balls with hit objects and minimum time
if (hitObject != null && ball.Coll.HitTime <= hitTime)
{
// now collision, contact and script reactions on active ball (object)
ActiveBall = ball; // For script that wants the ball doing the collision
hitObject.Collide(ball.Coll, this); // collision on active ball
ball.Coll.Clear(); // remove trial hit object pointer
// Collide may have changed the velocity of the ball,
// and therefore the bounding box for the next hit cycle
if (Balls[i] != ball) // Ball still exists? may have been deleted from list
// collision script deleted the ball, back up one count
{
--i;
}
else
{
ball.Hit.CalcHitBBox(); // do new boundings
}
}
}
// Now handle contacts.
//
// At this point UpdateDisplacements() was already called, so the state is different
// from that at HitTest(). However, contacts have zero relative velocity, so
// hopefully nothing catastrophic has happened in the meanwhile.
//
// Maybe a two-phase setup where we first process only contacts, then only collisions
// could also work.
if (MathF.Random() < 0.5) // swap order of contact handling randomly
{
foreach (var ce in Contacts)
{
ce.Obj.Contact(ce, hitTime, this);
}
}
else
{
for (var i = Contacts.Count - 1; i != -1; --i)
{
Contacts[i].Obj.Contact(Contacts[i], hitTime, this);
}
}
Contacts.Clear();
// TODO C_BALL_SPIN_HACK
// new delta .. i.e. time remaining
dTime -= hitTime;
// swap order of ball-ball collisions
SwapBallCollisionHandling = !SwapBallCollisionHandling;
}
}
