JSM: Convert TypedArrayUtils.

examples/jsm/utils/TypedArrayUtils.js

@@ -0,0 +1,604 @@
+
+var TypedArrayUtils = {};
+
+/**
+ * In-place quicksort for typed arrays (e.g. for Float32Array)
+ * provides fast sorting
+ * useful e.g. for a custom shader and/or BufferGeometry
+ *
+ * @author Roman Bolzern <[email protected]>, 2013
+ * @author I4DS http://www.fhnw.ch/i4ds, 2013
+ * @license MIT License <http://www.opensource.org/licenses/mit-license.php>
+ *
+ * Complexity: http://bigocheatsheet.com/ see Quicksort
+ *
+ * Example: 
+ * points: [x, y, z, x, y, z, x, y, z, ...]
+ * eleSize: 3 //because of (x, y, z)
+ * orderElement: 0 //order according to x
+ */
+
+TypedArrayUtils.quicksortIP = function ( arr, eleSize, orderElement ) {
+
+	var stack = [];
+	var sp = - 1;
+	var left = 0;
+	var right = arr.length / eleSize - 1;
+	var tmp = 0.0, x = 0, y = 0;
+
+	var swapF = function ( a, b ) {
+
+		a *= eleSize; b *= eleSize;
+
+		for ( y = 0; y < eleSize; y ++ ) {
+
+			tmp = arr[ a + y ];
+			arr[ a + y ] = arr[ b + y ];
+			arr[ b + y ] = tmp;
+
+		}
+
+	};
+	
+	var i, j, swap = new Float32Array( eleSize ), temp = new Float32Array( eleSize );
+
+	while ( true ) {
+
+		if ( right - left <= 25 ) {
+
+			for ( j = left + 1; j <= right; j ++ ) {
+
+				for ( x = 0; x < eleSize; x ++ ) {
+			
+					swap[ x ] = arr[ j * eleSize + x ];
+
+				}
+				
+				i = j - 1;
+				
+				while ( i >= left && arr[ i * eleSize + orderElement ] > swap[ orderElement ] ) {
+
+					for ( x = 0; x < eleSize; x ++ ) {
+
+						arr[ ( i + 1 ) * eleSize + x ] = arr[ i * eleSize + x ];
+
+					}
+
+					i --;
+
+				}
+
+				for ( x = 0; x < eleSize; x ++ ) {
+
+					arr[ ( i + 1 ) * eleSize + x ] = swap[ x ];
+
+				}
+
+			}
+			
+			if ( sp == - 1 ) break;
+
+			right = stack[ sp -- ]; //?
+			left = stack[ sp -- ];
+
+		} else {
+
+			var median = ( left + right ) >> 1;
+
+			i = left + 1;
+			j = right;
+	
+			swapF( median, i );
+
+			if ( arr[ left * eleSize + orderElement ] > arr[ right * eleSize + orderElement ] ) {
+		
+				swapF( left, right );
+				
+			}
+
+			if ( arr[ i * eleSize + orderElement ] > arr[ right * eleSize + orderElement ] ) {
+		
+				swapF( i, right );
+		
+			}
+
+			if ( arr[ left * eleSize + orderElement ] > arr[ i * eleSize + orderElement ] ) {
+		
+				swapF( left, i );
+			
+			}
+
+			for ( x = 0; x < eleSize; x ++ ) {
+
+				temp[ x ] = arr[ i * eleSize + x ];
+
+			}
+			
+			while ( true ) {
+				
+				do i ++; while ( arr[ i * eleSize + orderElement ] < temp[ orderElement ] );
+				do j --; while ( arr[ j * eleSize + orderElement ] > temp[ orderElement ] );
+				
+				if ( j < i ) break;
+		
+				swapF( i, j );
+			
+			}
+
+			for ( x = 0; x < eleSize; x ++ ) {
+
+				arr[ ( left + 1 ) * eleSize + x ] = arr[ j * eleSize + x ];
+				arr[ j * eleSize + x ] = temp[ x ];
+
+			}
+
+			if ( right - i + 1 >= j - left ) {
+
+				stack[ ++ sp ] = i;
+				stack[ ++ sp ] = right;
+				right = j - 1;
+
+			} else {
+
+				stack[ ++ sp ] = left;
+				stack[ ++ sp ] = j - 1;
+				left = i;
+
+			}
+
+		}
+
+	}
+
+	return arr;
+
+};
+
+
+
+/**
+ * k-d Tree for typed arrays (e.g. for Float32Array), in-place
+ * provides fast nearest neighbour search
+ * useful e.g. for a custom shader and/or BufferGeometry, saves tons of memory
+ * has no insert and remove, only buildup and neares neighbour search
+ *
+ * Based on https://github.com/ubilabs/kd-tree-javascript by Ubilabs
+ *
+ * @author Roman Bolzern <[email protected]>, 2013
+ * @author I4DS http://www.fhnw.ch/i4ds, 2013
+ * @license MIT License <http://www.opensource.org/licenses/mit-license.php>
+ *
+ * Requires typed array quicksort
+ *
+ * Example: 
+ * points: [x, y, z, x, y, z, x, y, z, ...]
+ * metric: function(a, b){	return Math.pow(a[0] - b[0], 2) +  Math.pow(a[1] - b[1], 2) +  Math.pow(a[2] - b[2], 2); }  //Manhatten distance
+ * eleSize: 3 //because of (x, y, z)
+ *
+ * Further information (including mathematical properties)
+ * http://en.wikipedia.org/wiki/Binary_tree
+ * http://en.wikipedia.org/wiki/K-d_tree
+ *
+ * If you want to further minimize memory usage, remove Node.depth and replace in search algorithm with a traversal to root node (see comments at TypedArrayUtils.Kdtree.prototype.Node)
+ */
+
+ TypedArrayUtils.Kdtree = function ( points, metric, eleSize ) {
+
+	var self = this;
+	
+	var maxDepth = 0;
+	
+	var getPointSet = function ( points, pos ) {
+
+		return points.subarray( pos * eleSize, pos * eleSize + eleSize );
+
+	};
+		
+	function buildTree( points, depth, parent, pos ) {
+
+		var dim = depth % eleSize,
+			median,
+			node,
+			plength = points.length / eleSize;
+
+		if ( depth > maxDepth ) maxDepth = depth;
+		
+		if ( plength === 0 ) return null;
+		if ( plength === 1 ) {
+
+			return new self.Node( getPointSet( points, 0 ), depth, parent, pos );
+
+		}
+
+		TypedArrayUtils.quicksortIP( points, eleSize, dim );
+		
+		median = Math.floor( plength / 2 );
+		
+		node = new self.Node( getPointSet( points, median ), depth, parent, median + pos );
+		node.left = buildTree( points.subarray( 0, median * eleSize ), depth + 1, node, pos );
+		node.right = buildTree( points.subarray( ( median + 1 ) * eleSize, points.length ), depth + 1, node, pos + median + 1 );
+
+		return node;
+	
+	}
+
+	this.root = buildTree( points, 0, null, 0 );
+		
+	this.getMaxDepth = function () {
+
+		return maxDepth;
+
+	};
+	
+	this.nearest = function ( point, maxNodes, maxDistance ) {
+	
+		 /* point: array of size eleSize 
+			maxNodes: max amount of nodes to return 
+			maxDistance: maximum distance to point result nodes should have
+			condition (not implemented): function to test node before it's added to the result list, e.g. test for view frustum
+		*/
+
+		var i,
+			result,
+			bestNodes;
+
+		bestNodes = new TypedArrayUtils.Kdtree.BinaryHeap(
+
+			function ( e ) {
+
+				return - e[ 1 ];
+
+			}
+
+					);
+
+		function nearestSearch( node ) {
+
+			var bestChild,
+				dimension = node.depth % eleSize,
+				ownDistance = metric( point, node.obj ),
+				linearDistance = 0,
+				otherChild,
+				i,
+				linearPoint = [];
+
+			function saveNode( node, distance ) {
+
+				bestNodes.push( [ node, distance ] );
+
+				if ( bestNodes.size() > maxNodes ) {
+
+					bestNodes.pop();
+
+				}
+
+			}
+
+			for ( i = 0; i < eleSize; i += 1 ) {
+
+				if ( i === node.depth % eleSize ) {
+
+					linearPoint[ i ] = point[ i ];
+
+				} else {
+
+					linearPoint[ i ] = node.obj[ i ];
+
+				}
+
+			}
+
+			linearDistance = metric( linearPoint, node.obj );
+
+			// if it's a leaf
+
+			if ( node.right === null && node.left === null ) {
+
+				if ( bestNodes.size() < maxNodes || ownDistance < bestNodes.peek()[ 1 ] ) {
+
+					saveNode( node, ownDistance );
+
+				}
+
+				return;
+
+			}
+
+			if ( node.right === null ) {
+
+				bestChild = node.left;
+
+			} else if ( node.left === null ) {
+
+				bestChild = node.right;
+
+			} else {
+
+				if ( point[ dimension ] < node.obj[ dimension ] ) {
+
+					bestChild = node.left;
+
+				} else {
+
+					bestChild = node.right;
+
+				}
+
+			}
+
+			// recursive search
+
+			nearestSearch( bestChild );
+
+			if ( bestNodes.size() < maxNodes || ownDistance < bestNodes.peek()[ 1 ] ) {
+
+				saveNode( node, ownDistance );
+
+			}
+
+			// if there's still room or the current distance is nearer than the best distance
+
+			if ( bestNodes.size() < maxNodes || Math.abs( linearDistance ) < bestNodes.peek()[ 1 ] ) {
+
+				if ( bestChild === node.left ) {
+
+					otherChild = node.right;
+
+				} else {
+
+					otherChild = node.left;
+
+				}
+
+				if ( otherChild !== null ) {
+
+					nearestSearch( otherChild );
+
+				}
+
+			}
+
+		}
+
+		if ( maxDistance ) {
+
+			for ( i = 0; i < maxNodes; i += 1 ) {
+
+				bestNodes.push( [ null, maxDistance ] );
+
+			}
+
+		}
+
+		nearestSearch( self.root );
+
+		result = [];
+
+		for ( i = 0; i < maxNodes; i += 1 ) {
+
+			if ( bestNodes.content[ i ][ 0 ] ) {
+
+				result.push( [ bestNodes.content[ i ][ 0 ], bestNodes.content[ i ][ 1 ] ] );
+
+			}
+
+		}
+		
+		return result;
+	
+	};
+	
+};
+
+/**
+ * If you need to free up additional memory and agree with an additional O( log n ) traversal time you can get rid of "depth" and "pos" in Node:
+ * Depth can be easily done by adding 1 for every parent (care: root node has depth 0, not 1)
+ * Pos is a bit tricky: Assuming the tree is balanced (which is the case when after we built it up), perform the following steps:
+ *   By traversing to the root store the path e.g. in a bit pattern (01001011, 0 is left, 1 is right)
+ *   From buildTree we know that "median = Math.floor( plength / 2 );", therefore for each bit...
+ *     0: amountOfNodesRelevantForUs = Math.floor( (pamountOfNodesRelevantForUs - 1) / 2 );
+ *     1: amountOfNodesRelevantForUs = Math.ceil( (pamountOfNodesRelevantForUs - 1) / 2 );
+ *        pos += Math.floor( (pamountOfNodesRelevantForUs - 1) / 2 );
+ *     when recursion done, we still need to add all left children of target node:
+ *        pos += Math.floor( (pamountOfNodesRelevantForUs - 1) / 2 );
+ *        and I think you need to +1 for the current position, not sure.. depends, try it out ^^
+ *
+ * I experienced that for 200'000 nodes you can get rid of 4 MB memory each, leading to 8 MB memory saved.
+ */
+TypedArrayUtils.Kdtree.prototype.Node = function ( obj, depth, parent, pos ) {
+
+	this.obj = obj;
+	this.left = null;
+	this.right = null;
+	this.parent = parent;
+	this.depth = depth;
+	this.pos = pos;
+
+}; 
+
+/**
+ * Binary heap implementation
+ * @author http://eloquentjavascript.net/appendix2.htm
+ */
+
+TypedArrayUtils.Kdtree.BinaryHeap = function ( scoreFunction ) {
+
+	this.content = [];
+	this.scoreFunction = scoreFunction;
+
+};
+
+TypedArrayUtils.Kdtree.BinaryHeap.prototype = {
+
+	push: function ( element ) {
+
+		// Add the new element to the end of the array.
+		this.content.push( element );
+
+		// Allow it to bubble up.
+		this.bubbleUp( this.content.length - 1 );
+
+	},
+
+	pop: function () {
+
+		// Store the first element so we can return it later.
+		var result = this.content[ 0 ];
+
+		// Get the element at the end of the array.
+		var end = this.content.pop();
+
+		// If there are any elements left, put the end element at the
+		// start, and let it sink down.
+		if ( this.content.length > 0 ) {
+
+			this.content[ 0 ] = end;
+			this.sinkDown( 0 );
+
+		}
+
+		return result;
+
+	},
+
+	peek: function () {
+
+		return this.content[ 0 ];
+
+	},
+
+	remove: function ( node ) {
+
+		var len = this.content.length;
+
+		// To remove a value, we must search through the array to find it.
+		for ( var i = 0; i < len; i ++ ) {
+
+			if ( this.content[ i ] == node ) {
+
+				// When it is found, the process seen in 'pop' is repeated
+				// to fill up the hole.
+				var end = this.content.pop();
+
+				if ( i != len - 1 ) {
+
+					this.content[ i ] = end;
+
+					if ( this.scoreFunction( end ) < this.scoreFunction( node ) ) {
+
+						this.bubbleUp( i );
+
+					} else {
+
+						this.sinkDown( i );
+
+					}
+
+				}
+
+				return;
+
+			}
+
+		}
+
+		throw new Error( "Node not found." );
+
+	},
+
+	size: function () {
+
+		return this.content.length;
+
+	},
+
+	bubbleUp: function ( n ) {
+
+		// Fetch the element that has to be moved.
+		var element = this.content[ n ];
+
+		// When at 0, an element can not go up any further.
+		while ( n > 0 ) {
+
+			// Compute the parent element's index, and fetch it.
+			var parentN = Math.floor( ( n + 1 ) / 2 ) - 1,
+				parent = this.content[ parentN ];
+
+			// Swap the elements if the parent is greater.
+			if ( this.scoreFunction( element ) < this.scoreFunction( parent ) ) {
+
+				this.content[ parentN ] = element;
+				this.content[ n ] = parent;
+
+				// Update 'n' to continue at the new position.
+				n = parentN;
+
+			} else {
+
+				// Found a parent that is less, no need to move it further.
+				break;
+
+			}
+
+		}
+
+	},
+
+	sinkDown: function ( n ) {
+
+		// Look up the target element and its score.
+		var length = this.content.length,
+			element = this.content[ n ],
+			elemScore = this.scoreFunction( element );
+
+		while ( true ) {
+
+			// Compute the indices of the child elements.
+			var child2N = ( n + 1 ) * 2, child1N = child2N - 1;
+
+			// This is used to store the new position of the element, if any.
+			var swap = null;
+
+			// If the first child exists (is inside the array)...
+			if ( child1N < length ) {
+
+				// Look it up and compute its score.
+				var child1 = this.content[ child1N ],
+					child1Score = this.scoreFunction( child1 );
+
+				// If the score is less than our element's, we need to swap.
+				if ( child1Score < elemScore ) swap = child1N;
+
+			}
+
+			// Do the same checks for the other child.
+			if ( child2N < length ) {
+
+				var child2 = this.content[ child2N ],
+					child2Score = this.scoreFunction( child2 );
+
+				if ( child2Score < ( swap === null ? elemScore : child1Score ) ) swap = child2N;
+
+			}
+
+			// If the element needs to be moved, swap it, and continue.
+			if ( swap !== null ) {
+
+				this.content[ n ] = this.content[ swap ];
+				this.content[ swap ] = element;
+				n = swap;
+
+			} else {
+
+				// Otherwise, we are done.
+				break;
+
+			}
+
+		}
+
+	}
+
+};
+
+export { TypedArrayUtils };

utils/modularize.js

@@ -30,6 +30,7 @@ var files = [
 	{ path: 'utils/SceneUtils.js', ignoreList: [] },
 	{ path: 'utils/ShadowMapViewer.js', ignoreList: [ 'DirectionalLight', 'SpotLight' ] },
 	{ path: 'utils/SkeletonUtils.js', ignoreList: [] },
+	{ path: 'utils/TypedArrayUtils.js', ignoreList: [] },
 	{ path: 'utils/UVsDebug.js', ignoreList: [ 'SphereBufferGeometry' ] },
 ];