47 lines
1.3 KiB
Markdown
47 lines
1.3 KiB
Markdown
---
|
|
title: "IShape2D"
|
|
date: 2019-09-15T11:06:50-07:00
|
|
weight: 5
|
|
---
|
|
|
|
An *IShape2D* is an interface that, when implemented, allows for spatial hashing and the computation of Minkowski Differences.
|
|
|
|
Your *IShape2D* implementations 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:
|
|
|
|
```cs
|
|
public Vector2 Support(Vector2 direction, Transform2D transform)
|
|
{
|
|
return Vector2.Transform(Vector2.Normalize(direction) * Radius, transform.TransformMatrix);
|
|
}
|
|
```
|
|
|
|
---
|
|
|
|
##### **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:
|
|
|
|
```cs
|
|
public AABB AABB(Transform2D Transform2D)
|
|
{
|
|
return new AABB(
|
|
Transform2D.Position.X - Radius,
|
|
Transform2D.Position.Y - Radius,
|
|
Transform2D.Position.X + Radius,
|
|
Transform2D.Position.Y + Radius
|
|
);
|
|
}
|
|
```
|