1 files changed, 281 insertions, 0 deletions
diff --git a/public/assets/javascripts/rectangles/models/surface.js b/public/assets/javascripts/rectangles/models/surface.js
new file mode 100644
index 0000000..53977c8
--- /dev/null
+++ b/public/assets/javascripts/rectangles/models/surface.js
@@ -0,0 +1,281 @@
+(function(){
+
+	var vec2, Rect
+	if ('window' in this) {
+		vec2 = window.vec2
+		Rect = window.Rect
+	}
+	else {
+		vec2 = require('./vec2')
+		Rect = require('./rect')
+	}
+	
+	var Surface = function (face){
+		this.bounds = new Rect (new vec2(0, 0), new vec2(0, 0))
+		this.faces = []
+		if (face) {
+			this.add(face)
+		}
+	}
+	Surface.prototype.add = function(rect){
+		if (this.faces.length == 0) {
+			this.bounds.x.a = rect.x.a
+			this.bounds.x.b = rect.x.a
+			this.bounds.y.a = rect.y.a
+			this.bounds.y.b = rect.y.a
+		}
+		this.bounds.x.b += rect.width()
+		this.bounds.y.a = Math.min(this.bounds.y.a, rect.y.a)
+		this.bounds.y.b = Math.max(this.bounds.y.b, rect.y.b)
+		this.faces.push(rect)
+	}
+	Surface.prototype.fits_scale = function(v, scale){
+		v = v.clone().mul(scale)
+		return this.fits(v)
+	}
+	Surface.prototype.fits = function(v){
+		var faces = this.faces
+		var scratch
+		if (this.bounds.x.b < v.a || this.bounds.y.b < v.b) {
+			return null
+		}
+		for (var i = 0; i < faces.length; i++) {
+			if (faces[i].fits(v)) {
+				return faces[i]
+			}
+		}
+		scratch = new Rect (0,0,0,0)
+		for (var i = 0; i < faces.length; i++) {
+			if (faces[i].y.length() < v.b) {
+				continue
+			}
+			scratch.x.a = faces[i].x.a
+			scratch.x.b = faces[i].x.b
+			scratch.y.a = faces[i].y.a
+			scratch.y.b = faces[i].y.b
+			SEARCH: for (var j = i+1; j < faces.length; j++) {
+				if (faces[j].y.a > scratch.y.a) {
+					scratch.y.a = faces[j].y.a
+				}
+				if (faces[j].y.b < scratch.y.b) {
+					scratch.y.b = faces[j].y.b
+				}
+				if (scratch.y.b <= scratch.y.a || scratch.y.length() < v.b) {
+					break SEARCH
+				}
+				scratch.x.b = faces[j].x.b
+				if (scratch.fits(v)) {
+					return scratch
+				}
+			}
+		}
+		return null
+	}
+
+	function center_for (dimension, position, delta) {
+		var center = new vec2( position.a + dimension.a/2, position.b + dimension.b/2 )
+    if (delta) {
+      center.a += delta.a
+      center.b += delta.b
+    }
+    return center
+	}
+
+	Surface.prototype.clamp_delta = function (bounds, dimension, position, delta) {
+		var left_edge = position.a + delta.a - bounds.x.a
+		if (left_edge < 0) {
+			delta.a -= left_edge
+		}
+
+		var right_edge = position.a + dimension.a + delta.a - bounds.x.b
+		if (right_edge > 0) {
+			delta.a -= right_edge
+		}
+		var bottom_edge = position.b + delta.b - bounds.y.a
+		if (bottom_edge < 0) {
+			delta.b -= bottom_edge
+		}
+		
+		var top_edge = position.b + dimension.b + delta.b - bounds.y.b
+		if (top_edge > 0) {
+			delta.b -= top_edge
+		}
+		
+		return delta
+	}
+
+	Surface.prototype.translate = function (old_bounds, dimension, position, delta) {
+		this.clamp_delta( this.bounds, dimension, position, delta )
+
+		var new_delta = delta.clone()
+		if (this.clamp_delta(old_bounds, dimension, position, new_delta).eq(delta)) {
+			return old_bounds
+		}
+
+//     var left_index   = this.index_for_x( position.a + delta.a, 0 )
+//     var center_index = this.index_for_x( position.a + dimension.a/2 + delta.a, left_index )
+//     var right_index  = this.index_for_x( position.a + dimension.a   + delta.a, center_index )
+// 		var new_bounds = this.bounds_at_index_with_dimensions(center_index, dimension)
+// 		
+// 		this.clamp_delta(new_bounds, dimension, position, delta)
+// 		
+// 		return new_bounds
+
+    var left_side = this.index_for_x( position.a + delta.a, 0 )
+    var right_side = this.index_for_x( position.a + dimension.a + delta.a, left_side )
+
+    var bounds = this.faces[left_side].clone()
+    var intersection
+
+    for (var i = Math.min(left_side+1, right_side); i <= right_side; i++) {
+			intersection = bounds.y.intersection(this.faces[i].y)
+			if (intersection.length() < dimension.b) {
+				bounds = null
+				break
+			}
+			bounds.y.assign(intersection)
+      bounds.x.b = this.faces[i].x.b
+    }
+    if (! bounds || bounds.width() < dimension.a || bounds.height() < dimension.b ||
+        bounds.y.a > position.b + delta.b || bounds.y.b < position.b + dimension.b + delta.b) {
+      bounds = old_bounds
+    }
+
+    this.clamp_delta(bounds, dimension, position, delta)
+    return bounds
+	}
+	
+	Surface.prototype.index_for_x = function(x, min_i){
+    min_i = min_i || 0
+		for (var i = min_i; i < this.faces.length; i++) {
+			if (this.faces[i].x.contains(x)) {
+				return i
+			}
+		}
+		return -1
+	}
+
+	Surface.prototype.bounds_at_index_with_dimensions = function(index, dimensions){
+    var faces = this.faces
+    if (index == -1) index = this.faces.length-1
+
+		var bounds, intersection
+		var width = dimensions.a
+    var height = dimensions.b
+
+		for (var i = index; i >= 0; i--) {
+			var face = faces[i]
+			if (face.y.length() < height) {
+        if (bounds) break
+        else continue
+			}
+      if (! bounds) {
+        bounds = face.clone()
+        bounds.last = i
+      }
+      else if (bounds.width() < width) {
+      	intersection = bounds.y.intersection(face.y)
+      	if (intersection.length() < height) {
+      		// not totally sure if we can clobber the bounds here since this would prevent
+      		// us from looking rightwise later
+      		break
+      	}
+      	else {
+      		bounds.y.a = intersection.a
+      		bounds.y.b = intersection.b
+					bounds.x.a = face.x.a
+					bounds.first = i
+					continue
+				}
+      }
+      else {
+				if (face.y.a > bounds.y.a) break
+				if (face.y.b < bounds.y.b) break
+			}
+			bounds.x.a = face.x.a
+			bounds.first = i
+		}
+
+		for (var i = bounds ? bounds.last+1 : index+1; i < faces.length; i++) {
+			var face = faces[i]
+			if (face.y.length() < height) {
+        if (bounds) break
+        else continue
+			}
+      if (! bounds) {
+        bounds = face.clone()
+        bounds.first = i
+      }
+      else if (bounds.width() < width) {
+      	intersection = bounds.y.intersection(face.y)
+      	if (intersection.length() < height) {
+      		// here, since the element is tall enough, we can clobber the bounds completely
+      		bounds.y.a = face.y.a
+      		bounds.y.b = face.y.b
+      		bounds.x.a = face.x.a
+      		bounds.x.b = face.x.b
+      		bounds.first = bounds.last = i
+					continue
+      	}
+      	else {
+      		bounds.y.a = intersection.a
+      		bounds.y.b = intersection.b
+      		bounds.x.b = face.x.b
+      		bounds.last = i
+      		continue
+      	}
+      }
+			if (face.y.a > bounds.y.a) break
+			if (face.y.b < bounds.y.b) break
+			bounds.x.b = face.x.b
+			bounds.last = i
+		}
+
+    if (! bounds) {
+    	// console.log('no bounds')
+      return false
+    }
+    else if (bounds.width() < width) {
+    	// console.log('too narrow')
+      return false
+    }
+		return bounds
+	}
+	
+	Surface.prototype.bounds_at_index = function(index){
+    var faces = this.faces
+    if (index == -1) index = this.faces.length-1
+
+		var bounds = faces[index].clone()
+		var height = faces[index].height()
+		bounds.first = bounds.last = index
+
+		for (var i = index-1; i >= 0; i--) {
+			var face = faces[i]
+			if (face.y.length() < height) break
+			if (face.y.a > bounds.y.a) break
+			if (face.y.b < bounds.y.b) break
+      
+			bounds.x.a = face.x.a
+			bounds.first = i
+		}
+		
+		for (var i = index+1; i < faces.length; i++) {
+			var face = faces[i]
+			if (face.y.length() < height) break
+			if (face.y.a > bounds.y.a) break
+			if (face.y.b < bounds.y.b) break
+			
+			bounds.x.b = face.x.b
+			bounds.last = i
+		}
+		return bounds
+	}
+	
+	if ('window' in this) {
+		window.Surface = Surface
+	}
+	else {
+		module.exports = Surface
+	}
+})()