/**
* Check if agent intersect with shape
*
* Agent will automatically detect which shape is used to calculate collision
**/
public virtual CollisionResult IntersectWithShape(ConvexShape shape)
{
switch (shape.ShapeId)
{
case ConvexShapeID.Rectangle:
ConvexRect rectShape = shape as ConvexRect;
if (rectShape == null)
{
#if DEBUG
Debug.LogError("Unable to down cast ConvexShape to ConvexRect");
#endif
}
return(ContactWithRectangle(rectShape));
case ConvexShapeID.Circle:
ConvexCircle circleShape = shape as ConvexCircle;
if (circleShape == null)
{
#if DEBUG
Debug.LogError("Unable to down cast ConvexShape to ConvexCircle");
#endif
}
return(ContactWIthCircle(circleShape));
case ConvexShapeID.Unknow:
#if DEBUG
Debug.LogError("Unknow convex shape");
#endif
break;
}
return(CollisionResult.None);
}
protected override CollisionResult ContactWIthCircle(ConvexCircle otherCircle)
{
bool collision = true;
Vector2 p = otherCircle.Center - _center;
//This circle projection
float circleProj = Vector2.Dot(p.normalized, _center);
float circleProjMin = circleProj - _radius;
float circleProjMax = circleProj + _radius;
//Another circle projection
float otherCircleProj = Vector2.Dot(p.normalized, otherCircle.Center);
float otherCircleProjMin = otherCircleProj - otherCircle.Radius;
float otherCircleProjMax = otherCircleProj + otherCircle.Radius;
if (circleProjMin > otherCircleProjMax || otherCircleProjMin > circleProjMax)
{
collision = false;
}
//Check if circle fit inside another circle
if (collision == true)
{
if (circleProjMin > otherCircleProjMin && circleProjMax < otherCircleProjMax)
{
return(CollisionResult.Fit);
}
return(CollisionResult.Overlap);
}
return(CollisionResult.None);
}
protected override CollisionResult ContactWithCircle(ConvexCircle otherCircle)
{
//We use circle collide rect to chcek
//reduce duplicate code because code is all most the same only
//rectangle inside circle need to be checked
CollisionResult result = otherCircle.IntersectWithShape(this);
//Check rectangle is inside circle when overlap
if (result == CollisionResult.Overlap)
{
/**
* For each corner of recntangle
* we check if corner inside circle
*
* Return fit if all corner insdie circle
**/
Vector2[] corners = AllCorners;
IEnumerator ie = corners.GetEnumerator();
while (ie.MoveNext())
{
//projection axis from corner to circle center
Vector2 p = otherCircle.Center - (Vector2)ie.Current;
//corner projection
float cornerP = Vector2.Dot(p.normalized, (Vector2)ie.Current);
//circle center projection
float circleP = Vector2.Dot(p.normalized, otherCircle.Center);
//if corner projection is outside of circle return overlap
if ((circleP - otherCircle.Radius) > cornerP || (circleP + otherCircle.Radius) < cornerP)
{
return(result);
}
}
return(CollisionResult.Fit);
}
//If circle fit in this rectangle return overlap
//as from rectangle poit of view rectangle overlap circle
if (result == CollisionResult.Fit)
{
return(CollisionResult.Overlap);
}
return(result);
}
/** * Subclass must override **/ protected abstract CollisionResult ContactWIthCircle(ConvexCircle otherCircle);
protected override CollisionResult ContactWithCircle(ConvexCircle otherCircle)
{
return(otherCircle.IntersectWithShape(this));
}