Point2D

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Vector.png

Point2D represents a 2-D point with (x,y) coordinates. It can also be used to represent a 2-D vector from (0,0) to (x,y).

Hand-point.png Point2D Javadoc

Vector Math

The Point2D class provides several methods related to linear algebra, e.g.:

Method Meaning
plus A + B
minus A - B
times f * A
scalar times vector, i.e. (f * x, f * y)
div A / f
vector divided by scalar, i.e. (x/f, y/f)
getLength |A|
i.e. sqrt(x*x + y*y)
getAngle angle between the positive X-axis and this vector
unit Â
a.k.a. normalized version of A
same direction as A with length 1
rotate(alpha) rotates the vector alpha radians counter clockwise
perpendicular A' ⊥ A
returns vector A' perpendicular to A
(basically rotates A by 90 degrees counter clockwise)

None of the above methods modify the Point2D object that the method is invoked on.

To modify a Point2D object in place (in situ) use one of these methods: plusInSitu, minusInSitu, timesInSitu, divInSitu, unitInSitu, rotateInSitu.

Hand-point.png See also Transform

Point2DArray

Point2DArray represents an array of Point2D objects. It's a thin wrapper around a Javascript array.

Hand-point.png Point2DArray Javadoc

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