private static Projection ProjectOn(this RectangleCollider rectCollider, Vector2 vector)
{
Requires.NotNull(rectCollider, nameof(rectCollider));
float min = Vector2.Dot(rectCollider.GetPoints2D()[0], vector);
float max = min;
for (int i = 1; i < rectCollider.GetPoints2D().Length; ++i)
{
float dot = Vector2.Dot(rectCollider.GetPoints2D()[i], vector);
min = Math.Min(dot, min);
max = Math.Max(dot, max);
}
return(new Projection(min, max));
}
/// <summary>
/// Since a rectangle is a type of parallelogram, I only need to get two axes - two adjacent ones. In the
/// more general case, I would get the normals of all the edges in the convex polygon.
/// This function assumes the "GetPoints2D()" method is ordered (first and second points are an edge,
/// second and third are an edge, etc)
/// </summary>
/// <param name="rectCollider">The <see cref="RectangleCollider"/> to get all testing axes</param>
/// <returns>An <see cref="IEnumerable{T}"/> that needs to be tested.</returns>
private static IEnumerable <Vector2> GetTestingAxes(RectangleCollider rectCollider)
{
Requires.NotNull(rectCollider, nameof(rectCollider));
Vector2 edge1 = rectCollider.GetPoints2D()[1] - rectCollider.GetPoints2D()[0];
Vector2 axis1 = edge1.Normal();
axis1.Normalize();
yield return(axis1);
Vector2 edge2 = rectCollider.GetPoints2D()[0] - rectCollider.GetPoints2D()[3];
Vector2 axis2 = edge2.Normal();
axis2.Normalize();
yield return(axis2);
}
/// <summary>
/// Since a rectangle is a type of parallelogram, I only need to get two axes - two adjacent ones. In the
/// more general case, I would get the normals of all the edges in the convex polygon.
/// This function assumes the "GetPoints2D()" method is ordered (first and second points are an edge,
/// second and third are an edge, etc)
/// </summary>
/// <param name="rectCollider">The <see cref="RectangleCollider"/> to get all testing axes</param>
/// <returns>An <see cref="IEnumerable{T}"/> that needs to be tested.</returns>
private static IEnumerable<Vector2> GetTestingAxes(RectangleCollider rectCollider)
{
Requires.NotNull(rectCollider, nameof(rectCollider));
Vector2 edge1 = rectCollider.GetPoints2D()[1] - rectCollider.GetPoints2D()[0];
Vector2 axis1 = edge1.Normal();
axis1.Normalize();
yield return axis1;
Vector2 edge2 = rectCollider.GetPoints2D()[0] - rectCollider.GetPoints2D()[3];
Vector2 axis2 = edge2.Normal();
axis2.Normalize();
yield return axis2;
}