From af825cefe94eb8a677d61bc6721451af63105988 Mon Sep 17 00:00:00 2001
From: Jules Laplace <jules@okfoc.us>
Date: Tue, 15 Apr 2014 14:47:56 -0400
Subject: rect clipping works properly

---
 rect.js         | 92 ++++++++++++++++++++++++++++++++++++++++++---------------
 rectangles.html | 42 +++++++++++++++++++++++---
 tree.js         |  6 ++--
 vec2.js         | 14 +++++++--
 4 files changed, 122 insertions(+), 32 deletions(-)

diff --git a/rect.js b/rect.js
index f1f19e1..ed94689 100644
--- a/rect.js
+++ b/rect.js
@@ -1,3 +1,5 @@
+var FRONT = 0x1, BACK = 0x2, LEFT = 0x4, RIGHT = 0x8
+
 function rect (x0,y0,x1,y1){
 	if (x0 instanceof vec2) {
 		this.x = x0
@@ -12,6 +14,9 @@ function rect (x0,y0,x1,y1){
 		this.y = new vec2(y0,y1)
 	}
 	this.translation = new vec2(0,0)
+	this.sides = FRONT | BACK | LEFT | RIGHT
+	this.focused = false
+	this.id = 0
 }
 rect.prototype.clone = function(){
 	return new rect( this.x.clone(), this.y.clone() )
@@ -37,13 +42,30 @@ rect.prototype.intersects = function(r){
 rect.prototype.width = function(){ return this.x.length() }
 rect.prototype.height = function(){ return this.y.length() }
 rect.prototype.fill = function(){
+// 	if (! this.sides) return this
 	ctx.fillRect(this.x.a + this.translation.a, this.y.a + this.translation.b, this.x.length(), this.y.length())
+	return this
+}
+rect.prototype.stroke_sides = function(){
+	if (this.sides & FRONT) line(this.x.a, this.y.a, this.x.b, this.y.a)
+	if (this.sides &  BACK) line(this.x.a, this.y.b, this.x.b, this.y.b)
+	if (this.sides &  LEFT) line(this.x.a, this.y.a, this.x.a, this.y.b)
+	if (this.sides & RIGHT) line(this.x.b, this.y.a, this.x.b, this.y.b)
+
+	function line(a,b,c,d){
+		ctx.beginPath()
+		ctx.moveTo(a,b)
+		ctx.lineTo(c,d)
+		ctx.stroke()
+	}
+	return this
 }
 rect.prototype.stroke = function(){
 	ctx.beginPath()
 	ctx.moveTo(this.x.a, this.y.a)
 	ctx.lineTo(this.x.b, this.y.b)
 	ctx.stroke()
+	return this
 }
 rect.prototype.perimeter = function(){
 	line( this.x.a, this.y.a, this.x.b, this.y.a, this.translation )
@@ -52,7 +74,14 @@ rect.prototype.perimeter = function(){
 	line( this.x.b, this.y.a, this.x.b, this.y.b, this.translation )
 }
 rect.prototype.toString = function(){
-	return "[" + this.x.toString() + " " + this.y.toString() + "]"
+	var sides = ""
+	if (this.sides & FRONT) sides += "front "
+	if (this.sides & BACK)  sides += "back "
+	if (this.sides & LEFT)  sides += "left "
+	if (this.sides & RIGHT) sides += "right "
+	var s = this.id + " " + "[" + this.x.toString() + " " + this.y.toString() + "] " + sides
+	if (this.focused) return "<b>" + s + "</b>"
+	return s
 }
 rect.prototype.quantize = function(n){
 	this.x.quantize(n)
@@ -60,13 +89,16 @@ rect.prototype.quantize = function(n){
 }
 rect.prototype.reset = function(){
 	var copy = this.clone()
-	copy.sides = 0xf
+	copy.sides = FRONT | BACK | LEFT | RIGHT
+	copy.focused = this.focused
+	copy.id = this.id
 	this.regions = [ copy ]
 }
 rect.prototype.clipTo = function(r){
 	// for each of this rect's regions split the region if necessary
 	var regions = this.regions
 	var splits
+
 	for (var i = 0, len = regions.length; i < len; i++) {
 		if (regions[i] && regions[i].intersects(r)) {
 			splits = regions[i].split(r)
@@ -77,59 +109,73 @@ rect.prototype.clipTo = function(r){
 	this.regions = regions
 }
 rect.prototype.split = function(r){
+	var rz = this
 	var splits = []
+	var split_contains = 0
 	var x_intervals = [], y_intervals = []
+	var sides = this.sides
 
 	// Split vertically
 	if (this.x.contains(r.x.a) && r.x.contains(this.x.b)) {
-		x_intervals.push( new vec2( this.x.a,    r.x.a ))
-		x_intervals.push( new vec2(    r.x.a, this.x.b ))
+		x_intervals.push([ new vec2( this.x.a,    r.x.a ), LEFT  ])
+		x_intervals.push([ new vec2(    r.x.a, this.x.b ), RIGHT ])
+		split_contains |= RIGHT
 	}
 
 	else if (r.x.contains(this.x.a) && this.x.contains(r.x.b)) {
-		x_intervals.push( new vec2( this.x.a,    r.x.b ))
-		x_intervals.push( new vec2(    r.x.b, this.x.b ))
+		x_intervals.push([ new vec2( this.x.a,    r.x.b ), LEFT  ])
+		x_intervals.push([ new vec2(    r.x.b, this.x.b ), RIGHT ])
+		split_contains |= LEFT
 	}
 	
 	else if (this.x.contains(r.x.a) && this.x.contains(r.x.b)) {
-		x_intervals.push( new vec2( this.x.a,    r.x.a ))
-		x_intervals.push( new vec2(    r.x.a, 	 r.x.b ))
-		x_intervals.push( new vec2(    r.x.b, this.x.b ))
+		x_intervals.push([ new vec2( this.x.a,    r.x.a ), LEFT  ])
+		x_intervals.push([ new vec2(    r.x.a, 	  r.x.b ), 0     ])
+		x_intervals.push([ new vec2(    r.x.b, this.x.b ), RIGHT ])
+		split_contains |= LEFT | RIGHT
 	}
 
 	else { // if (r.x.contains(this.x.a) && r.x.contains(r.x.b)) {
-		x_intervals.push( new vec2( this.x.a, this.x.b ))
+		x_intervals.push([ new vec2( this.x.a, this.x.b ), LEFT | RIGHT ])
+		split_contains |= LEFT | RIGHT
 	}
 
-
 	// Split horizontally
 	if (this.y.contains(r.y.a) && r.y.contains(this.y.b)) {
-		y_intervals.push( new vec2( this.y.a,    r.y.a ))
-		y_intervals.push( new vec2(    r.y.a, this.y.b ))
+		y_intervals.push([ new vec2( this.y.a,    r.y.a ), FRONT ])
+		y_intervals.push([ new vec2(    r.y.a, this.y.b ), BACK  ])
+		split_contains |= BACK
 	}
 
 	else if (r.y.contains(this.y.a) && this.y.contains(r.y.b)) {
-		y_intervals.push( new vec2( this.y.a,    r.y.b ))
-		y_intervals.push( new vec2(    r.y.b, this.y.b ))
+		y_intervals.push([ new vec2( this.y.a,    r.y.b ), FRONT ])
+		y_intervals.push([ new vec2(    r.y.b, this.y.b ), BACK  ])
+		split_contains |= FRONT
 	}
 	
 	else if (this.y.contains(r.y.a) && this.y.contains(r.y.b)) {
-		y_intervals.push( new vec2( this.y.a,    r.y.a ))
-		y_intervals.push( new vec2(    r.y.a, 	 r.y.b ))
-		y_intervals.push( new vec2(    r.y.b, this.y.b ))
+		y_intervals.push([ new vec2( this.y.a,    r.y.a ), FRONT ])
+		y_intervals.push([ new vec2(    r.y.a, 	  r.y.b ), 0     ])
+		y_intervals.push([ new vec2(    r.y.b, this.y.b ), BACK  ])
+		split_contains |= FRONT | BACK
 	}
 
 	else { // if (r.y.contains(this.y.a) && this.y.contains(r.y.b)) {
-		y_intervals.push( new vec2( this.y.a, this.y.b ))
+		y_intervals.push([ new vec2( this.y.a, this.y.b ), FRONT | BACK ])
+		split_contains |= FRONT | BACK
 	}
 
 	x_intervals.forEach(function(x){
 		y_intervals.forEach(function(y){
-			splits.push(new rect(x,y))
+			var rn = new rect(x[0], y[0])
+			rn.id = rz.id
+			rn.sides = ((x[1] | y[1]) & sides)
+			if (r.intersects(rn)) {
+				rn.sides = 0
+			}
+			rn.focused = rz.focused
+			splits.push(rn)
 		})
 	})
-
 	return splits
 }
-zz = false
-document.body.addEventListener("click", function(){ zz = true })
\ No newline at end of file
diff --git a/rectangles.html b/rectangles.html
index 71f83c6..c8b3c82 100644
--- a/rectangles.html
+++ b/rectangles.html
@@ -31,6 +31,8 @@ body > div {
 <script type="text/javascript" src="vec2.js"></script>
 <script type="text/javascript">
 
+window.z = true;
+
 (function(){
 	var color_palettes = {
 		alpha: [
@@ -88,8 +90,8 @@ canvas.addEventListener("mousedown", function(e){
 		mouse.quantize(10)
 	}
 
-	var intersects = rects.filter(function(r){ return r.contains(x,y) })
-	console.log(intersects)
+	var intersects = rects.filter(function(r){ return r.focused = r.contains(x,y) })
+	// console.log(intersects)
 	
 	if (intersects.length){
 		dragging = intersects[0]
@@ -180,6 +182,7 @@ function solve_rects(){
 	rects = sort_rects()
 
 	for (var i = 0; i < rects.length; i++) {
+		rects[i].id = i
 		rects[i].reset()
 	}
 	regions = []
@@ -206,17 +209,46 @@ function solve_rects(){
 	// generate walls from surviving regions
 	// generate ceiling-walls where ceiling has discontinuity
 
+	// regions = shuffle( regions.filter(function(r){ return !!r }) )
 	regions = regions.filter(function(r){ return !!r })
+
+// 	var ty = new tree (regions[0].y.a, [regions[0]])
+// 	var tx = new tree (regions[0].x.a, ty)
+// 	var ttx, tty
+// 	
+// 	for (var i = 1; i < regions.length; i++) {
+// 		ttx = tx.add (regions[i].x.a, null)
+// 		if (ttx.data) {
+// 			tty = ttx.data.add (regions[i].y.a, null)
+// 			// duplicate polygon?
+// 			if (tty.data) {
+// 				tty.data.forEach(function(yy){
+// 					if (yy.x.eq(regions[i].x) && yy.y.eq(regions[i].y) ) {
+// 						yy.sides = 0
+// 						regions[i].sides = 0
+// 					}
+// 				})
+// 			}
+// 			else {
+// 				tty.data = [regions[i]]
+// 			}
+// 		}
+// 		else {
+// 			ttx.data = new tree (regions[i].y.a, [regions[i]])
+// 		}
+// 	}
+	z = false
 	for (var i = 0; i < regions.length; i++) {
 		ctx.fillStyle = colors[i % colors.length]
-		regions[i] && regions[i].fill()
+		regions[i].fill().stroke_sides()
 	}
 
 	document.getElementById("intersects").innerHTML = regions.join("<br>")
 }
+
 function sort_rects(){
 	return rects.sort(function(a,b){
-		if (a.x.a <= b.x.a) {
+		if (a.x.a < b.x.a) {
 			return -1
 		}
 		if (a.x.a > b.x.a) {
@@ -263,5 +295,7 @@ function draw_mouse(){
 	}
 }
 
+document.body.addEventListener("mousedown", function(){ z = true })
+
 </script>
 </html>
diff --git a/tree.js b/tree.js
index 8229cae..07b90c6 100644
--- a/tree.js
+++ b/tree.js
@@ -11,9 +11,9 @@ tree.prototype.find = function(n){
 }
 tree.prototype.add = function(n, data){
 	var closest = this.find(n)
-	if (n == closest.value) return
-	if (n < closest.value) closest.lo = new tree(n, data)
-	if (n > closest.value) closest.hi = new tree(n, data)
+	if (n == closest.value) return closest
+	if (n < closest.value) return closest.lo = new tree(n, data)
+	if (n > closest.value) return closest.hi = new tree(n, data)
 }
 tree.prototype.toString = function(){
 	var s = "";
diff --git a/vec2.js b/vec2.js
index 973613f..f4d6a84 100644
--- a/vec2.js
+++ b/vec2.js
@@ -22,6 +22,9 @@ vec2.prototype.abs = function(){
 vec2.prototype.midpoint = function(){
 	return lerp(0.5, this.a, this.b)
 }
+vec2.prototype.eq = function(v){
+	return this.a == v.a && this.b == v.b
+}
 vec2.prototype.add = function(n){
 	this.a += n
 	this.b += n
@@ -41,9 +44,16 @@ vec2.prototype.div = function(n){
 vec2.prototype.contains = function(n){
 	return this.a <= n && n <= this.b
 }
-// assumes (vec2)v falls to the right of (vec2)this
 vec2.prototype.intersects = function(v){
-  return (this.b > v.a && this.b < v.b) || (v.b > this.a && v.b < this.b)
+	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 true
+	}
+	else if (this.a > v.a) {
+		return (this.a < v.b && v.b <= this.b) || (v.a < this.b && this.b <= v.b)
+	}
 }
 vec2.prototype.union = function(v){
 	if (this.intersects(v)) {
-- 
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