1 files changed, 227 insertions, 0 deletions
diff --git a/assets/javascripts/math/point.js b/assets/javascripts/math/point.js
new file mode 100644
index 0000000..354be00
--- /dev/null
+++ b/assets/javascripts/math/point.js
@@ -0,0 +1,227 @@
+(function(){
+	function clamp(n,a,b){ return n<a?a:n<b?n:b }
+
+	var point = function (a,b){
+		this.a = a
+		this.b = b
+	}
+	point.prototype.magnitude = function(){
+		return this.b-this.a
+	}
+	point.prototype.length = function(){
+		return Math.abs(this.b-this.a)
+	}
+	point.prototype.dist = function(){
+		return dist(0,this.a,0,this.b)
+	}
+	point.prototype.clone = function(){
+		return new point(this.a, this.b)
+	}
+	point.prototype.assign = function(v){
+		this.a = v.a
+		this.b = v.b
+		return this
+	}
+	point.prototype.abs = function(){
+		if (this.b < this.a) {
+			this.invert()
+		}
+		return this
+	}
+	point.prototype.invert = function(){
+		this.a = this.a ^ this.b
+		this.b = this.a ^ this.b
+		this.a = this.a ^ this.b
+		return this
+	}
+	point.prototype.midpoint = function(){
+		return lerp(0.5, this.a, this.b)
+	}
+	point.prototype.lerp = function(n){
+	  return lerp(n, this.a, this.b)
+	}
+	point.prototype.eq = function(v){
+		return this.a == v.a && this.b == v.b
+	}
+	point.prototype.add = function(n){
+		this.a += n
+		this.b += n
+		return this
+	}
+	point.prototype.sub = function(n){
+		this.a -= n
+		this.b -= n
+		return this
+	}
+	point.prototype.mul = function(n){
+		this.a *= n
+		this.b *= n
+		return this
+	}
+	point.prototype.div = function(n){
+		this.a /= n
+		this.b /= n
+		return this
+	}
+	point.prototype.addVec = function(v){
+	  this.a += v.a
+	  this.b += v.b
+	  return this
+	}
+  point.prototype.subVec = function(v){
+	  this.a -= v.a
+	  this.b -= v.b
+	  return this
+	}
+	point.prototype.zero = function(){
+		this.a = this.b = 0
+	}
+	point.prototype.round = function(){
+	  this.a = Math.round(this.a)
+	  this.b = Math.round(this.b)
+	}
+	point.prototype.setPosition = function(n){
+		var len = this.length()
+		this.a = n
+		this.b = n + len
+	}
+	point.prototype.setLength = function(n){
+		this.b = this.a + n
+	}
+	point.prototype.normalize = function(){
+		var dim = max(this.a, this.b)
+		this.a = this.a/dim
+		this.b = this.b/dim
+		return this
+	}
+	point.prototype.contains = function(n){
+		return this.a <= n && n <= this.b
+	}
+	point.prototype.containsCenter = function(n){
+		return this.a < n && n < this.b
+	}
+	point.prototype.containsDisc = function(n,r){
+		return this.a <= n-r && n+r <= this.b
+	}
+	point.prototype.clamp = function(n){
+		return clamp(n, this.a, this.b)
+	}
+	point.prototype.clampDisc = function(n,r){
+		return clamp(n, this.a+r, this.b-r)
+	}
+	point.prototype.intersects = function(v){
+		if (this.a == v.a || this.b == v.b || this.a == v.b || this.b == v.a) {
+			return true
+		}
+		else if (this.a < v.a) {
+			return (v.a < this.b && this.b <= v.b) || (this.a < v.b && v.b <= this.b)
+		}
+		else if (this.a > v.a) {
+			return (this.a < v.b && v.b <= this.b) || (v.a < this.b && this.b <= v.b)
+		}
+	}
+	point.prototype.overlaps = function(v){
+		if (this.a == v.a || this.b == v.b) {
+			return true
+		}
+		if (this.a < v.a) {
+			return (v.a < this.b && this.b < v.b) || (this.a < v.b && v.b < this.b)
+		}
+		else if (v.a < this.a) {
+			return (this.a < v.b && v.b < this.b) || (v.a < this.b && this.b < v.b)
+		}
+	}
+
+
+	point.prototype.adjacent = function(v){
+		if (this.a == v.a || this.b == v.b || this.a == v.b || this.b == v.a) {
+			return true
+		}
+		return false
+	}
+	point.prototype.union = function(v){
+		if (this.intersects(v)) {
+			return new point( Math.min(this.a,v.a), Math.max(this.b, v.b) )
+		}
+	}
+	point.prototype.intersection = function(v){
+		if (this.intersects(v)) {
+			return new point( Math.max(this.a,v.a), Math.min(this.b, v.b) )
+		}
+	}
+
+	// given two vectors, test how they overlap
+	// return the set of overlapping segments in the initial vector, labelled with sides
+	point.prototype.split = function(v, left, right){
+		var intervals = [], _len
+
+		if (this.eq(v)) {
+			intervals.push([ new point( this.a, this.b ), left | right ])
+		}
+		
+		// a---A===b---B  (rightways overlap)
+		else if (this.contains(v.a) && v.contains(this.b)) {
+			intervals.push([ new point( this.a,    v.a ), left  ])
+			intervals.push([ new point(    v.a, this.b ), right ])
+		}
+
+    // A---a===B---b  (leftways overlap)
+		else if (v.contains(this.a) && this.contains(v.b)) {
+			intervals.push([ new point( this.a,    v.b ), left  ])
+			intervals.push([ new point(    v.b, this.b ), right ])
+		}
+	
+		// a---A===B---b  (contains v)
+		else if (this.contains(v.a) && this.contains(v.b)) {
+			intervals.push([ new point( this.a,    v.a ), left  ])
+			intervals.push([ new point(    v.a, 	  v.b ), 0     ])
+			intervals.push([ new point(    v.b, this.b ), right ])
+		}
+		
+		// A---a===b---B  (contained in v)
+		else { // if (v.contains(this.a) && v.contains(v.b)) {
+			intervals.push([ new point( this.a, this.b ), left | right ])
+		}
+		
+		// cull empty vectors
+		_len = intervals.length
+		if (_len > 1) {
+			if (intervals[0][0].magnitude() == 0) {
+				intervals[1][1] |= intervals[0][1]
+				intervals.shift()
+			}
+			else if (intervals[_len-1][0].magnitude() == 0) {
+				intervals[_len-2][1] |= intervals[_len-1][1]
+				intervals.pop()
+			}
+		}
+		
+		return intervals
+	}
+
+	point.prototype.toString = function(){
+		return "[" + round(this.a) + " " + round(this.b) + "]"
+	}
+	point.prototype.exactString = function(){
+		return "[" + this.a + " " + this.b + "]"
+	}
+	point.prototype.serialize = function(){
+		return [ round(this.a), round(this.b) ]
+	}
+	point.prototype.deserialize = function(data){
+		this.a = data[0]
+		this.b = data[1]
+	}
+	point.prototype.quantize = function(n){
+		n = n || 10
+		this.a = quantize(this.a, n)
+		this.b = quantize(this.b, n)
+	}
+	
+	if ('window' in this) {
+		window.point = point
+	}
+	else {
+		module.exports = point
+	}
+})()