48 lines
1.3 KiB
Markdown
48 lines
1.3 KiB
Markdown
---
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title: "IShape2D"
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date: 2019-09-15T11:06:50-07:00
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weight: 5
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---
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An *IShape2D* is an interface that, when implemented, allows for spatial hashing and the computation of Minkowski Differences.
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Your *IShape2D* implementations should be structs for memory efficiency purposes.
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## Properties
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##### **public AABB { get; }**
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An axis-aligned bounding box for the shape. This is stored so we can efficiently transform the AABB when necessary.
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## Methods
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##### **Vector2 Support(Vector2 direction, Transform2D transform)**
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A method which implements a support function for use with a Minkowski Difference.
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The support function must, given a directional vector and a Transform2D, return the farthest possible vertex of the transformed shape in the given direction.
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For example, the support function for Bonk's *Circle* implementation:
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```cs
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public Vector2 Support(Vector2 direction, Transform2D transform)
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{
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return Vector2.Transform(Vector2.Normalize(direction) * Radius, transform.TransformMatrix);
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}
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```
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---
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##### **AABB AABB(Transform2D transform)**
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A method which returns the axis-aligned bounding box for the transformed shape.
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For example, the AABB method for Bonk's *Circle* implementation:
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```cs
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public AABB TransformedAABB(Transform2D Transform2D)
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{
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return AABB.Transformed(AABB, transform2D);
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}
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```
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