Split Item#hitTest() into separate private function that does need to do arguments reading, for improved performance also when iterating over children.

src/core/PaperScript.js

@@ -282,7 +282,7 @@ Base.exports.PaperScript = (function() {
 		// end of the code execution, so we can retrieve their values from the
 		// function call.
 		handlers = Base.each(handlers, function(key) {
-			// Check for each handler explicitely and only return them if they
+			// Check for each handler explicitly and only return them if they
 			// seem to exist.
 			if (new RegExp('\\s+' + key + '\\b').test(code)) {
 				params.push(key);

src/item/HitResult.js

@@ -106,9 +106,7 @@ var HitResult = Base.extend(/** @lends HitResult# */{
 		 * @private
 		 */
 		getOptions: function(options) {
-			// Use _merged property to not repeatetly merge using new Base in
-			// recursion.
-			return options && options._merged ? options : new Base({
+			return new Base({
 				// Type of item, for instanceof check: Group, Layer, Path,
 				// CompoundPath, Shape, Raster, PlacedSymbol, ...
 				type: null,
@@ -129,14 +127,12 @@ var HitResult = Base.extend(/** @lends HitResult# */{
 				ends: false,
 				// Hit test the center of the bounds
 				center: false,
-				// Hit test the corners and side-centers of the boudning box
+				// Hit test the corners and side-centers of the bounding box
 				bounds: false,
 				//  Hit items that are marked as guides
 				guides: false,
 				// Only hit selected objects
-				selected: false,
-				// Mark as merged
-				_merged: true
+				selected: false
 			}, options);
 		}
 	}

src/item/Item.js

@@ -1671,9 +1671,13 @@ var Item = Base.extend(Callback, /** @lends Item# */{
 	 * information about what exactly was hit or {@code null} if nothing was
 	 * hit
 	 */
-	hitTest: function(point, options) {
-		point = Point.read(arguments);
-		options = HitResult.getOptions(Base.read(arguments));
+	hitTest: function(/* point, options */) {
+		return this._hitTest(
+				Point.read(arguments),
+				HitResult.getOptions(Base.read(arguments)));
+	},
+
+	_hitTest: function(point, options) {
 		if (this._locked || !this._visible || this._guide && !options.guides
 				|| this.isEmpty())
 			return null;
@@ -1747,10 +1751,10 @@ var Item = Base.extend(Callback, /** @lends Item# */{
 			var opts = this._getChildHitTestOptions(options);
 			// Loop backwards, so items that get drawn last are tested first
 			for (var i = children.length - 1; i >= 0 && !res; i--)
-				res = children[i].hitTest(point, opts);
+				res = children[i]._hitTest(point, opts);
 		}
 		if (!res && checkSelf)
-			res = this._hitTest(point, options);
+			res = this._hitTestSelf(point, options);
 		// Transform the point back to the outer coordinate system.
 		if (res && res.point)
 			res.point = matrix.transform(res.point);
@@ -1764,7 +1768,7 @@ var Item = Base.extend(Callback, /** @lends Item# */{
 		return options;
 	},
 
-	_hitTest: function(point, options) {
+	_hitTestSelf: function(point, options) {
 		// The default implementation honly handles 'fill' through #_contains()
 		if (options.fill && this.hasFill() && this._contains(point))
 			return new HitResult('fill', this);

src/item/PlacedSymbol.js

@@ -115,8 +115,8 @@ var PlacedSymbol = Item.extend(/** @lends PlacedSymbol# */{
 				cacheItem);
 	},
 
-	_hitTest: function(point, options) {
-		var res = this._symbol._definition.hitTest(point, options);
+	_hitTestSelf: function(point, options) {
+		var res = this._symbol._definition._hitTest(point, options);
 		// TODO: When the symbol's definition is a path, should hitResult
 		// contain information like HitResult#curve?
 		if (res)

src/item/Raster.js

@@ -618,7 +618,7 @@ var Raster = Item.extend(/** @lends Raster# */{
 		return matrix ? matrix._transformBounds(rect) : rect;
 	},
 
-	_hitTest: function(point) {
+	_hitTestSelf: function(point) {
 		if (this._contains(point)) {
 			var that = this;
 			return new HitResult('pixel', that, {

src/item/Shape.js

@@ -250,7 +250,7 @@ var Shape = Item.extend(/** @lends Shape# */{
 		return matrix ? matrix._transformBounds(rect) : rect;
 	}
 },
-new function() { // Scope for _contains() and _hitTest() code.
+new function() { // Scope for _contains() and _hitTestSelf() code.
 
 	// Returns the center of the quarter corner ellipse for rounded rectangle,
 	// if the point lies within its bounding box.
@@ -296,7 +296,7 @@ new function() { // Scope for _contains() and _hitTest() code.
 			}
 		},
 
-		_hitTest: function _hitTest(point, options) {
+		_hitTestSelf: function _hitTestSelf(point, options) {
 			var hit = false;
 			if (this.hasStroke()) {
 				var type = this._type,
@@ -326,7 +326,7 @@ new function() { // Scope for _contains() and _hitTest() code.
 			}
 			return hit
 					? new HitResult('stroke', this)
-					: _hitTest.base.apply(this, arguments);
+					: _hitTestSelf.base.apply(this, arguments);
 		}
 	};
 }, {

src/path/Path.js

@@ -1409,7 +1409,7 @@ var Path = PathItem.extend(/** @lends Path# */{
 		return null;
 	},
 
-	_hitTest: function(point, options) {
+	_hitTestSelf: function(point, options) {
 		var that = this,
 			style = this.getStyle(),
 			segments = this._segments,

src/project/Project.js

@@ -307,7 +307,7 @@ var Project = PaperScopeItem.extend(/** @lends Project# */{
 			options = HitResult.getOptions(Base.read(arguments));
 		// Loop backwards, so layers that get drawn last are tested first
 		for (var i = this.layers.length - 1; i >= 0; i--) {
-			var res = this.layers[i].hitTest(point, options);
+			var res = this.layers[i]._hitTest(point, options);
 			if (res) return res;
 		}
 		return null;