void ResolveCircleVsCircle(OurCollider circle1, OurCollider circle2, ref float pushAmt, ref Vector3 pushDir)
{
Vector2 relation = circle2.center - circle1.center;
float distance = relation.magnitude;
float desiredDistance = circle1.boundingRadius + circle2.boundingRadius;
pushAmt = desiredDistance - distance;
pushDir = -(Vector3)relation.normalized;
}
void ResolveCircleVsBox(OurCollider circle, OurCollider box, ref float pushAmt, ref Vector3 pushDir)
{
Vector3 relation = box.bounds.ClosestPoint(circle.center) - circle.center;
pushDir = relation.normalized;
pushAmt = circle.boundingRadius - relation.magnitude;
}
bool IsCollidingWith(OurCollider other)
{
float r1 = boundingRadius, r2 = other.boundingRadius;
Vector2 relation = other.center - center;
float distance = relation.magnitude;
float desiredDistance = r1 + r2;
// bounding radius intersects && bounding box intersects = collision
return distance < desiredDistance && bounds.Intersects(other.bounds);
}
void ResolveBoxVsBox(OurCollider box, OurCollider box2, ref float pushAmt, ref Vector3 pushDir)
{
Bounds b1 = box.bounds;
Bounds b2 = box2.bounds;
Vector2 relation = b2.center - b1.center;
Vector2 desired = b1.extents + b2.extents;
float overlapHorizontal = Mathf.Abs(relation.x) - desired.x;
float overlapVertical = Mathf.Abs(relation.y) - desired.y;
if(overlapHorizontal < overlapVertical){
// vertical collision
pushAmt = overlapVertical;
if(relation.y < 0)
pushDir = new Vector3(0, -1, 0);
else
pushDir = new Vector3(0, 1, 0);
} else {
// horizontal collision
pushAmt = overlapHorizontal;
if(relation.x < 0)
pushDir = new Vector3(-1, 0, 0);
else
pushDir = new Vector3(1, 0, 0);
}
}
public bool ResolveCollision(OurCollider other)
{
if(IsCollidingWith(other)){
// amount to push objects apart
float pushAmt = 0;
Vector3 pushDir = new Vector3();
// figure out the collision type and check it
if(boxCollider != null){ // we are a box
if(other.boxCollider != null){ // both boxes
ResolveBoxVsBox(this, other, ref pushAmt, ref pushDir);
} else { // we are a box, they are a circle
ResolveCircleVsBox(other, this, ref pushAmt, ref pushDir);
}
} else {
if(other.boxCollider != null){ // we are a circle, they are a box
ResolveCircleVsBox(this, other, ref pushAmt, ref pushDir);
pushAmt *= -1; // since we're the second object, we have to reverse the push
} else { // both circles
ResolveCircleVsCircle(this, other, ref pushAmt, ref pushDir);
}
}
// figure out how much to push each object
// object with less mass will get pushed harder
float ourAmt = other.mass / (mass + other.mass);
float otherAmt = 1 - ourAmt;
// check for immoveable objects
if(immoveable){
ourAmt = 0;
otherAmt = 1;
if(other.immoveable){ // both immoveable?
otherAmt = 0;
}
} else if (other.immoveable){
otherAmt = 0;
ourAmt = 1;
}
// push both objects
pushAmt += EXTRA_PUSH;
transform.position += pushDir * pushAmt * ourAmt;
other.transform.position -= pushDir * pushAmt * otherAmt;
return true;
}
return false; // did not collide
}
