From 97a29e6adaeee0cc2623405f9d7137337906a823 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=BCrg=20Lehni?= <juerg@scratchdisk.com>
Date: Sat, 2 Nov 2013 09:30:40 +0100
Subject: [PATCH] Improve SVG path data parser.

---
 src/path/PathItem.js | 44 +++++++++++++-------------------------------
 1 file changed, 13 insertions(+), 31 deletions(-)

diff --git a/src/path/PathItem.js b/src/path/PathItem.js
index a46876b7..5aefa674 100644
--- a/src/path/PathItem.js
+++ b/src/path/PathItem.js
@@ -85,25 +85,16 @@ var PathItem = Item.extend(/** @lends PathItem# */{
 		// This is a very compact SVG Path Data parser that works both for Path
 		// and CompoundPath.
 
-		var parts = data.match(/[a-z][^a-z]*/ig),
+		// First split the path data into parts of command-coordinates pairs
+		// Commands are any of these characters: mzlhvcsqta
+		var parts = data.match(/[mzlhvcsqta][^mzlhvcsqta]*/ig),
 			coords,
-			coordsLength,
 			relative = false,
 			control,
 			current = new Point(); // the current position
 
 		function getCoord(index, coord, update) {
-			var val = coords[index];
-			// Before parsing the value, we might actually have to further split
-			// it, in case it contains two '.':
-			var match = val.match(/^([+-]?\d*\.\d+)(\.\d*)$/);
-			if (match) {
-				// Insert the 2nd half as the next value.
-				coords.splice(index + 1, 0, match[2]);
-				coordsLength++;
-				val = match[1];
-			}
-			val = parseFloat(val);
+			var val = parseFloat(coords[index]);
 			if (relative)
 				val += current[coord];
 			if (update)
@@ -125,36 +116,27 @@ var PathItem = Item.extend(/** @lends PathItem# */{
 			var part = parts[i],
 				cmd = part[0],
 				lower = cmd.toLowerCase();
-			// Split at white-space, commas but also before signs.
-			// Use positive lookahead to include signs.
-			// Note that we should also check for coordinate values that contain
-			// two decimal periods, as these should be plit into two separate
-			// values. With positive lookbehind, this would look like this:
-			// |(?<=\d*\.\d+)(?=\.\d+)
-			// Unfortunately, JavaScript does not have lookbehind in RegExps, so
-			// instead we leave these values that way and parse them further in
-			// getCoord() above. Note that coordsLength may increase as we're 
-			// reading values.
-			coords = part.slice(1).trim().split(/[\s,]+|(?=[+-])/);
-			coordsLength = coords.length;
+			// Match all coordinate values
+			coords = part.match(/([+-]?(?:\d*\.\d+|\d+\.?)(?:[eE][+-]?\d+)?)/g);
+			var length = coords && coords.length;
 			relative = cmd === lower;
 			switch (lower) {
 			case 'm':
 			case 'l':
-				for (var j = 0; j < coordsLength; j += 2)
+				for (var j = 0; j < length; j += 2)
 					this[j === 0 && lower === 'm' ? 'moveTo' : 'lineTo'](
 							getPoint(j, true));
 				break;
 			case 'h':
 			case 'v':
 				var coord = lower == 'h' ? 'x' : 'y';
-				for (var j = 0; j < coordsLength; j++) {
+				for (var j = 0; j < length; j++) {
 					getCoord(j, coord, true);
 					this.lineTo(current);
 				}
 				break;
 			case 'c':
-				for (var j = 0; j < coordsLength; j += 6) {
+				for (var j = 0; j < length; j += 6) {
 					this.cubicCurveTo(
 							getPoint(j),
 							control = getPoint(j + 2),
@@ -163,7 +145,7 @@ var PathItem = Item.extend(/** @lends PathItem# */{
 				break;
 			case 's':
 				// Shorthand cubic bezierCurveTo, absolute
-				for (var j = 0; j < coordsLength; j += 4) {
+				for (var j = 0; j < length; j += 4) {
 					this.cubicCurveTo(
 							// Calculate reflection of previous control points
 							current.multiply(2).subtract(control),
@@ -172,14 +154,14 @@ var PathItem = Item.extend(/** @lends PathItem# */{
 				}
 				break;
 			case 'q':
-				for (var j = 0; j < coordsLength; j += 4) {
+				for (var j = 0; j < length; j += 4) {
 					this.quadraticCurveTo(
 							control = getPoint(j),
 							getPoint(j + 2, true));
 				}
 				break;
 			case 't':
-				for (var j = 0; j < coordsLength; j += 2) {
+				for (var j = 0; j < length; j += 2) {
 					this.quadraticCurveTo(
 							// Calculate reflection of previous control points
 							control = current.multiply(2).subtract(control),