/// <summary>
/// Get collision data between two collliders. NOTE, this will not cause a physical collision, if you want to cause a collision use the function "collide()" in the object returned.
/// </summary>
/// <param name="a">Any circle collider.</param>
/// <param name="b">Any line collider.</param>
/// <returns>The collision data between the colliders, or null if no collision occured.</returns>
public static Collision getCollision(CircleCollider a, LineCollider b)
{
//precalculate gradient for efficiancy.
double gradient = b.globalGradient;
//squere distance between circle center to possible contact point
double sqrDistance = a.globalCenter.Y - b.globalCenter.Y + gradient * (b.globalCenter.X - a.globalCenter.X);
sqrDistance *= sqrDistance / (gradient * gradient + 1);
if (sqrDistance > a.radius * a.radius)
{
return(null);
}
if (a.globalCenter.sqrDistance(b.globalCenter) - sqrDistance > b.length * b.length / 4)
{
return(null);
}
Vector2d normal = b.globalNormalVector;
//look here for 1 directional colliders.
if ((a.globalCenter - b.globalCenter).cosineOfAngleBetween(normal) > 0)
{
normal *= -1;
}
return(new Collision(a,
b,
normal,
a.globalCenter + Sqrt(sqrDistance) * normal,
a.radius - Sqrt(sqrDistance)));
}
/// <summary>
/// Get collision data between two collliders. NOTE, this will not cause a physical collision, if you want to cause a collision use the function "collide()" in the object returned.
/// </summary>
/// <param name="a">Any circle collider.</param>
/// <param name="b">Any Circle collider.</param>
/// <returns>The collision data between the colliders, or null if no collision occured.</returns>
public static Collision getCollision(CircleCollider a, CircleCollider b)
{
if ((a.globalCenter - b.globalCenter).LengthSquared <= (a.radius + b.radius) * (a.radius + b.radius))
{
return(new Collision(a,
b,
-(a.globalCenter - b.globalCenter).Normalized(), //normal
(a.globalCenter * a.radius + b.globalCenter * b.radius) / (a.radius + b.radius), //point(weighted average)
a.radius + b.radius - a.globalCenter.distance(b.globalCenter)));
}
return(null);
}
/// <summary>
/// Get collision data between two collliders. NOTE, this will not cause a physical collision, if you want to cause a collision use the function "collide()" in the object returned.
/// </summary>
/// <param name="a">Any line collider.</param>
/// <param name="b">Any Circle collider.</param>
/// <returns>The collision data between the colliders, or null if no collision occured.</returns>
public static Collision getCollision(LineCollider a, CircleCollider b)
{
return(getCollision(b, a));
}
