X-Git-Url: http://nitlanguage.org

diff --git a/lib/geometry/quadtree.nit b/lib/geometry/quadtree.nit
index 97c0783..7c3f2d4 100644
--- a/lib/geometry/quadtree.nit
+++ b/lib/geometry/quadtree.nit
@@ -29,7 +29,7 @@ import pipeline
 abstract class QuadTree[E: Boxed[Numeric]]
 	super BoxedCollection[E]
 
-	protected var center: nullable Point[Numeric]
+	protected var center: nullable Point[Numeric] = null
 	var data: Array[E] = new Array[E]
 
 	#  ________________
@@ -39,20 +39,14 @@ abstract class QuadTree[E: Boxed[Numeric]]
 	#  |   0   |   3   |
 	#  |_______|_______|
 
-	protected var child0: nullable QuadTree[E]
-	protected var child1: nullable QuadTree[E]
-	protected var child2: nullable QuadTree[E]
-	protected var child3: nullable QuadTree[E]
+	protected var child0: nullable QuadTree[E] = null
+	protected var child1: nullable QuadTree[E] = null
+	protected var child2: nullable QuadTree[E] = null
+	protected var child3: nullable QuadTree[E] = null
 
 	# represent the threshold before subdividing the node
-	protected var item_limit = 4
-	protected var parent_node: nullable QuadTree[E]
-
-	# create the quadtree and set the item limit for each node
-	init(limit: Int)
-	do
-		self.item_limit = limit
-	end
+	protected var item_limit: Int
+	protected var parent_node: nullable QuadTree[E] = null
 
 	# create a node, giving him self as a parent. Used to create children nodes
 	init with_parent(limit: Int, parent: QuadTree[E])
@@ -61,14 +55,14 @@ abstract class QuadTree[E: Boxed[Numeric]]
 		self.parent_node = parent
 	end
 
-	redef fun items_overlapping(region :Boxed[Numeric]): SimpleCollection[E] do
-        var res = new Array[E]
-        items_overlapping_in(region,res)
-        return res
-     end  
+	redef fun items_overlapping(region): SimpleCollection[E] do
+		var res = new Array[E]
+		items_overlapping_in(region,res)
+		return res
+	end
 
 	# add the item to the tree, create children if the limit is reached
-	redef fun add(item: E) do if self.is_leaf then self.data.add(item) else add_to_children(item)
+	redef fun add(item) do if self.is_leaf then self.data.add(item) else add_to_children(item)
 
 	private fun add_to_children(item: Boxed[Numeric])
 	do
@@ -92,14 +86,14 @@ abstract class QuadTree[E: Boxed[Numeric]]
 			else if self.center.y > item.top then
 				self.data.add(item)
 			else if self.center.y < item.bottom then
-					self.data.add(item)
+				self.data.add(item)
 			else
 				self.data.add(item)
 			end
 		end
 	end
 
-	redef fun is_empty: Bool do return data.is_empty and (self.is_leaf or (child0.is_empty and child1.is_empty and child2.is_empty and child3.is_empty))
+	redef fun is_empty do return data.is_empty and (self.is_leaf or (child0.is_empty and child1.is_empty and child2.is_empty and child3.is_empty))
 
 	# Return whether or not the Node is a leaf of the tree
 	fun is_leaf: Bool do return child0 == null
@@ -215,33 +209,42 @@ end
 # the center of the parent node
 class SQuadTree[E: Boxed[Numeric]]
 	super QuadTree[E]
-	
+
 	# the width of the current node of the QuadTree
 	var width: Numeric
 	# the height of the current node of the QuadTree
 	var height: Numeric
 
-	init(l: Int, c: Point[Numeric], w: Numeric, h: Numeric)
+	init
 	do
-		self.item_limit = l
-		self.center = c
-		self.width = w
-		self.height = h
+		center = new Point[Numeric](width.div(2), height.div(2))
 	end
 
 	init with_parent(l: Int, c: Point[Numeric], w: Numeric, h: Numeric, p: QuadTree[E])
 	do
-		init(l, c, w, h)
+		init(l, w, h)
+		center = c
 		self.parent_node = p
 	end
 
 	redef fun subdivide
 	do
-		var two = self.center.x.value_of(2)
-		var tree = self.center.x.value_of(3)
-		child0 = new SQuadTree[E].with_parent(self.item_limit, new Point[Numeric](self.center.x/two, self.center.y/two), self.width/two, self.height/two, self)
-		child1 = new SQuadTree[E].with_parent(self.item_limit, new Point[Numeric](self.center.x/two, (self.center.y*tree)/two), self.width/two, self.height/two, self)
-		child2 = new SQuadTree[E].with_parent(self.item_limit, new Point[Numeric]((self.center.x*tree)/two, (self.center.y*tree)/two), self.width/two, self.height/two, self)
-		child3 = new SQuadTree[E].with_parent(self.item_limit, new Point[Numeric]((self.center.x*tree)/two, self.center.y/two), self.width/two, self.height/two, self)
+		child0 = new SQuadTree[E].with_parent(self.item_limit, new Point[Numeric](self.center.x.div(2), self.center.y.div(2)), self.width.div(2), self.height.div(2), self)
+		child1 = new SQuadTree[E].with_parent(self.item_limit, new Point[Numeric](self.center.x.div(2), (self.center.y.mul(3)).div(2)), self.width.div(2), self.height.div(2), self)
+		child2 = new SQuadTree[E].with_parent(self.item_limit, new Point[Numeric]((self.center.x.mul(3)).div(2), (self.center.y.mul(3)).div(2)), self.width.div(2), self.height.div(2), self)
+		child3 = new SQuadTree[E].with_parent(self.item_limit, new Point[Numeric]((self.center.x.mul(3)).div(2), self.center.y.div(2)), self.width.div(2), self.height.div(2), self)
+	end
+
+	redef fun to_s
+	do
+		var s = "center : {center.to_s}\n"
+		for d in data do s += d.to_s
+		if child0 != null then
+			s += "\nchild0: {child0.to_s}\n"
+			s += "   child1: {child1.to_s}\n"
+			s += "   child2: {child2.to_s}\n"
+			s += "   child3: {child3.to_s}\n"
+		end
+		return s
 	end
 end