manipulate vectors in 2d
npm install vec2
A generic library useful when you need to work with points/vectors in 2d space.
``javascript
var a = new Vec2(10, 10), // new keyword
b = Vec2(100, 10); // call the constructor directly
console.log(a.distance(b)); // 90
`
Stuff to Note: most of the Vec2's methods take a returnNew as the last parameter. If passed a truthy value, a new vector will be returned to you. Otherwise the operation will be applied to this and this will be returned.
Also, since Infinityand NaN are so insidious, this library will throw as soon as it detects either of these so you can take action to fix your data/algorithm.
__change__([fn])
Add an observer fn that will be called whenever this vector changes. Calling this method without a function causes it to notify observers.
fn signature: function(vec, prev) {} - where prev is a clone of the vector before the last operation.
this function returns the passed fn
_returns_: Vec2
__ignore__([fn])
Pass a fn to remove it from the observers list. Calling this function without a fn will remove all observers.
_returns_: Vec2
__set__(x, y [, notify]) or __set__(vec2 [, notify])
Sets the x and y coordinates of this vector. If false is passed for notify, none of the observers will be called.
_returns_: Vec2
__zero__()
Sets the x and y of this vector to 0
_returns_: Vec2
__clone__()
Returns a clone of this vector.
_Note_: this does not clone observers
_returns_: Vec2
__negate__([returnNew])
Negate the x and y coords of this vector. If returnNew is truthy, a new vector with the negated coordinates will be returned.
_returns_: Vec2
__add__(x, y [, returnNew]) or __add__(array, [, returnNew]) or __add__(vec2 [, returnNew])
Add the x and y to this vector's coordinates.
If returnNew is truthy, return a new vector containing the resulting coordinates. Otherwise apply them to this vector and return it.
_returns_: Vec2
__subtract__(x, y [, returnNew]) or __subtract__(array, [, returnNew]) or __subtract__(vec2 [, returnNew])
_returns_: Vec2
__multiply__(scalar [, returnNew]) or __multiply__(x, y [, returnNew]) or __multiply__(array, [, returnNew]) or __multiply__(vec2 [, returnNew])
Multiply this vectors components with the incoming, returning a clone if returnNew is truthy.
_returns_: Vec2
__divide__(scalar [, returnNew]) or __divide__(x, y [, returnNew]) or __divide__(array, [, returnNew]) or __divide__(vec2 [, returnNew])
Divide this vectors components by the incoming, returning a clone if returnNew is truthy.
_note_: this method will throw if you attempt to divide by zero or pass values that cause NaNs
_returns_: Vec2
__rotate__(radians [, inverse [, returnNew]])
Rotate this vector's cordinates around (0,0). If returnNew is specified, a new Vec2 will be created and populated with the result and returned. Otherwise the result is applied to this vector and this is returned.
inverse - inverts the direction of the rotation
returnNew - causes the result to be applied to a new Vec2, otherwise the result is applied to this
_returns_: Vec2
__length__()
Returns the length of this vector from (0,0)
_returns_: double
__lengthSquared__()
Returns the length of this vector prior to the Math.sqrt call.
This is usefull when you don't need to know the actual distance, but need a normalized value to compare with another Vec2#lengthSquared or similar.
_returns_: double
__distance__(vec2)
_returns_: the distance between this vector and the incoming
__nearest__(array)
_returns_: closest vector in array to this vector.
__normalize__([returnNew])
Normalizes this vector. If returnNew is truthy, a new vector populated with the normalized coordinates will be returned.
_returns_: Vec2
__equal__(vec2) or __equal__(x, y) or __equal__(array)
returns true if the incoming coordinates are the same as this vector's
_returns_: boolean
__abs__([returnNew])
Return a Vec2 that contains the absolute value of each of this vector's parts.
If returnNew is truthy, create a new Vec2 and return it. Otherwise apply the absolute values to to this.
_returns_: Vec2
__min__(vec)
Return a Vec2 consisting of the smallest values from this vector and the incoming
When returnNew is truthy, a new Vec2 will be returned otherwise the minimum values in either this or vec will be applied to this vector.
_returns_: Vec2
__max__(vec)
Return a Vec2 consisting of the largest values from this vector and the incoming
When returnNew is truthy, a new Vec2 will be returned otherwise the maximum values in either this or vec will be applied to this vector.
_returns_: Vec2
__clamp__(low, high [, returnNew])
Clamp the coordinates of this vector to the high/low of the incoming vec2s. If returnNew apply the result to the new vector and return. Otherwise apply to this vector.
_returns_: Vec2
__lerp__(vec, amount [, returnNew])
Perform linear interpolation between this vector and the incoming.
amount - the percentage along the path to place the vector
returnNew - if truthy, apply the result to a new vector and return it, otherwise return this
_returns_: Vec2
__skew__([returnNew])
Returns a vector set with the (-y,x) coordinates of this vector. If returnNew a new vector is created and the operation is applied to the new vector.
_returns_: Vec2
__dot__()
_returns_: double
__perpDot__()
_returns_: double
__angleTo__(vec)
returns the angle from this vector to the incoming.
_returns_: double
__isPointOnLine__(start, end)
where start and end are vec2-like (e.g. start.x and start.y)
_returns_: boolean
__toArray__()
_returns_: [x, y]
__fromArray__(array)
Applies the [0] to this.x and [1] to this.y
_returns_: Vec2
__toJSON__()
_returns_: { x: ..., y: ...}
__toString__()
_returns_: '(x, y)'
`html``
install with npm
npm install vec2
and then require it!
var Vec2 = require('vec2');
MIT (see LICENSE.txt)