bonk-docs/content/api/IShape2D.md

title	date	weight
IShape2D	2019-09-15T11:06:50-07:00	5

An IShape2D is an interface that, when implemented, allows for spatial hashing and the computation of Minkowski Differences.

Your IShape2D types should be structs for memory efficiency purposes.

Methods

Vector2 Support(Vector2 direction, Transform2D transform)

A method which implements a support function for use with a Minkowski Difference.

The support function must, given a directional vector and a Transform2D, return the farthest possible vertex of the transformed shape in the given direction.

For example, the support function for Bonk's Circle implementation:

public Vector2 Support(Vector2 direction, Transform2D transform)
{
    return Vector2.Transform(Vector2.Normalize(direction) * Radius, transform.TransformMatrix);
}

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AABB AABB(Transform2D transform)

A method which returns the axis-aligned bounding box for the transformed shape.

For example, the AABB method for Bonk's Circle implementation:

public AABB AABB(Transform2D Transform2D)
{
    return new AABB(
        Transform2D.Position.X - Radius,
        Transform2D.Position.Y - Radius,
        Transform2D.Position.X + Radius,
        Transform2D.Position.Y + Radius
    );
}