public void Remove(Rib rib)
{
if (times.ContainsKey(rib))
{
rib.Collision.times.Remove(self);
times.Remove(rib);
}
}
public Rib(Rib other)
{
speed = other.speed;
pos0 = other.pos0;
pos1 = other.pos1;
time0 = other.time0;
time1 = other.time1;
sprite = other.sprite;
}
public double GetTime(Rib rib)
{
double res;
if (!times.TryGetValue(rib, out res))
{
throw new KeyNotFoundException(string.Format("the rib {0} is not found", rib.Sprite.Id));
}
return(res);
}
public void Clip(List <Rib> ribs)
{
var radius = sprite.Radius;
bool hit = false;
double poshit = 0.0;
if (speed.X < 0)
{
if (pos1.X < radius)
{
hit = true;
poshit = radius;
}
}
else if (pos1.X > U.WX - radius)
{
hit = true;
poshit = U.WX - radius;
}
if (hit)
{
// clipped by X
double thit = (poshit - pos0.X) / speed.X;
Rib next = Split(thit);
next.setSpeed(new Vec(-speed.X, speed.Y));
next.Clip(ribs);
ribs.Add(next);
hit = false;
}
if (speed.Y < 0)
{
if (pos1.Y < radius)
{
hit = true;
poshit = radius;
}
}
else if (pos1.Y > U.WY - radius)
{
hit = true;
poshit = U.WY - radius;
}
if (hit)
{
double thit = (poshit - pos0.Y) / speed.Y;
Rib next = Split(thit);
next.setSpeed(new Vec(speed.X, -speed.Y));
next.Clip(ribs);
ribs.Add(next);
hit = false;
}
}
public Rib Split(double deltat)
{
Rib next = new Rib(this);
next.pos0 = pos0.Add(speed.Scale(deltat));
next.pos1 = pos1;
pos1 = next.pos0;
next.time0 = time0 + deltat;
next.time1 = time1;
time1 = next.time0;
return(next);
}
public Rib GetFirstHit(out double time)
{
Rib rib = null;
time = 0.0;
foreach (KeyValuePair <Rib, double> kv in times)
{
if (rib == null || kv.Value < time)
{
rib = kv.Key;
time = kv.Value;
}
}
return(rib);
}
public RibRect(Rib r)
{
var radius = r.Sprite.Radius;
min = r.StartPos;
max = r.EndPos;
if (max.X < min.X)
{
var t = max.X;
max.X = min.X;
min.X = t;
}
if (max.Y < min.Y)
{
var t = max.Y;
max.Y = min.Y;
min.Y = t;
}
min.X -= radius;
min.Y -= radius;
max.X += radius;
max.Y += radius;
}
public bool CollidesWith(Rib rib, out double hittime)
{
// we are working in the reference frame of this.pos0, moving with the speed this.speed
Vec ribpos = rib.pos0.Subtract(pos0);
Vec ribspd = rib.speed.Subtract(speed);
double time = time0;
if (time0 < rib.time0)
{
// correct the position
time = rib.time0;
ribpos = ribpos.Subtract(speed.Scale(time - time0));
}
else if (time0 > rib.time0)
{
ribpos = ribpos.Add(rib.speed.Scale(time - rib.time0));
}
var spd2 = ribspd.Length2;
if (spd2 <= 0.00001)
{
hittime = 0;
return(false);
}
// Let's only find the closest position
// Xclose = X - (X*V)*V / (V*V)
// Tclose = -(X*V) / (V*V)
hittime = -ribpos.Scalar(ribspd) / spd2;
if (hittime < time ||
hittime > time1 ||
hittime > rib.time1)
{
return(false);
}
return(true);
}
public static int CompareByTime(Rib a, Rib b)
{
return(a.time0.CompareTo(b.time0));
}
public int CompareTo(Rib r)
{
return(pos0.X < r.pos0.X ? -1 : (pos0.X > r.pos0.X ? 1 : 0));
}
private static bool matchRibNull(Rib rib)
{
return(rib == null || rib.Sprite == null);
}
public void Run(double dt)
{
List <Collision> collisions = new List <Collision>();
foreach (Rib rib in ribs)
{
if (rib.Collision.Fill(ribs))
{
collisions.Add(rib.Collision);
}
}
while (collisions.Count > 0)
{
U.show(string.Format("Total {0} collisions", collisions.Count));
// run through all collisions
Collision first = null;
double firsttime = 0.0;
Rib firstrib = null;
foreach (var coll in collisions)
{
if (coll == null || coll.IsEmpty || coll.SelfRib == null)
{
continue;
}
double time;
Rib rib = coll.GetFirstHit(out time);
if (rib == null)
{
throw new Exception("the collection must have a hit");
}
if (first == null || time < firsttime)
{
first = coll;
firsttime = time;
firstrib = rib;
}
}
if (first == null)
{
break;
}
U.show(string.Format("first collision time found: {0}", firsttime));
List <Rib> moreribs = applyCollision(first, firstrib, dt);
if (moreribs != null)
{
// we have more ribs
foreach (Rib rib in moreribs)
{
if (rib.Collision.Fill(ribs))
{
collisions.Add(rib.Collision);
}
}
ribs.AddRange(moreribs);
}
}
// finally, cleanup ribs
ribs.RemoveAll(rib => rib == null || rib.Sprite == null);
ribs.Sort(compareRibsByEndTime);
}
/*
* private static int compareRibRectsByX(RibRect a, RibRect b) {
* return a.min.X.CompareTo(b.min.X);
* }
*/
private static int compareRibsByEndTime(Rib a, Rib b)
{
return(a.EndTime.CompareTo(b.EndTime));
}
public Collision(Rib rib)
{
self = rib;
rect = new RibRect(rib);
times = new Dictionary <Rib, double>();
}
public void Update(Rib rib)
{
Position = rib.EndPos;
Speed = rib.Speed;
alpha += omega * rib.DeltaTime;
}