public override void CheckForCollisions(List <LPhysicsObject2D> objs, float deltaTime)
{
base.CheckForCollisions(objs, deltaTime);
for (int i = objs.Count - 1; i >= 1; i--)
{
for (int j = i - 1; j >= 0; j--)
{
LPhysicsObject2D objA = objs[i];
LPhysicsObject2D objB = objs[j];
if (objA.collider != null &&
objB.collider != null &&
objA.collider.bounds.Intersects(objB.collider.bounds))
{
simplex.Clear();
direction = Vector2.one;
epa.Clear();
closestFace = null;
safety.Clear();
LContactConstraint2D constraint = CollisionDetect(objA, objB);
if (constraint != null)
{
contactConstraints.Add(constraint);
}
}
}
}
}
/// <summary>
/// 寻找距离原点最近的face
/// </summary>
/// <returns></returns>
public EPAFace2D FindClosestFace()
{
EPAFace2D minFace = null;
for (int i = faces.Count - 1; i >= 0; i--)
{
if (minFace == null ||
faces[i].sqrMagnitude < minFace.sqrMagnitude)
{
minFace = faces[i];
}
}
return(minFace);
}
/// <summary>
/// <para>EPA判断渗透方向和深度</para>
/// <para>1.找到list中离原点最近的face</para>
/// <para>2.如果与上一次找到的相同，直接返回</para>
/// <para>3.否则找face.normal的最远点A</para>
/// <para>4.移除使A看不到的原点的face，将(A, face.A)和(A, face.B)构建为新的face添加到list中，返回第一步</para>
/// </summary>
/// <returns></returns>
private void PenetrationDetect(LPhysicsObject2D objA, LPhysicsObject2D objB)
{
EPAFace2D face = epa.FindClosestFace();
if (closestFace == null ||
Mathf.Abs(closestFace.sqrMagnitude - face.sqrMagnitude) > EPAFace2D.Threshold)
{
closestFace = face;
safety.Add(closestFace);
Vector2 a = objA.collider.GetFurtherPointInDirection(closestFace.direction);
Vector2 b = objB.collider.GetFurtherPointInDirection(-closestFace.direction);
SimplexPoint2D sp = new SimplexPoint2D(a, b);
epa.ImportNewSupportPoint(sp);
PenetrationDetect(objA, objB);
}
}
public void Add(EPAFace2D face)
{
faces.Add(face);
}
