Corrected Kinetic.Path.getPointOnLine() to work in negative x direction. Including Unit test.

dist/kinetic-core.js

@@ -3,7 +3,7 @@
  * http://www.kineticjs.com/
  * Copyright 2012, Eric Rowell
  * Licensed under the MIT or GPL Version 2 licenses.
- * Date: Sep 24 2012
+ * Date: Sep 25 2012
  *
  * Copyright (C) 2011 - 2012 by Eric Rowell
  *
@@ -5780,6 +5780,7 @@ Kinetic.Path.getPointOnLine = function(dist, P1x, P1y, P2x, P2y, fromX, fromY) {
 
     var m = (P2y - P1y) / ((P2x - P1x) + 0.00000001);
     var run = Math.sqrt(dist * dist / (1 + m * m));
+    if(P2x < P1x) run *= -1;
     var rise = m * run;
     var pt;
 
@@ -5804,6 +5805,7 @@ Kinetic.Path.getPointOnLine = function(dist, P1x, P1y, P2x, P2y, fromX, fromY) {
         var pRise = this.getLineLength(fromX, fromY, ix, iy);
         var pRun = Math.sqrt(dist * dist - pRise * pRise);
         run = Math.sqrt(pRun * pRun / (1 + m * m));
+        if(P2x < P1x) run *= -1;
         rise = m * run;
         pt = {
             x: ix + run,

src/shapes/Path.js

@@ -90,6 +90,7 @@ Kinetic.Path.getPointOnLine = function(dist, P1x, P1y, P2x, P2y, fromX, fromY) {
 
     var m = (P2y - P1y) / ((P2x - P1x) + 0.00000001);
     var run = Math.sqrt(dist * dist / (1 + m * m));
+    if(P2x < P1x) run *= -1;
     var rise = m * run;
     var pt;
 
@@ -114,6 +115,7 @@ Kinetic.Path.getPointOnLine = function(dist, P1x, P1y, P2x, P2y, fromX, fromY) {
         var pRise = this.getLineLength(fromX, fromY, ix, iy);
         var pRun = Math.sqrt(dist * dist - pRise * pRise);
         run = Math.sqrt(pRun * pRun / (1 + m * m));
+        if(P2x < P1x) run *= -1;
         rise = m * run;
         pt = {
             x: ix + run,

tests/js/unitTests.js

@@ -5794,6 +5794,51 @@ Test.prototype.tests = {
         layer.add(textpath);
         stage.add(layer);
     },
+    '*PATH - getPointOnLine for different directions': function() {
+        var origo = {x: 0, y: 0};
+        
+        var p, point;
+        
+        //point up left
+        p = {x:-10, y: -10};
+        point = Kinetic.Path.getPointOnLine(10, origo.x, origo.y, p.x, p.y);
+        test(point.x < 0 && point.y < 0, 'The new point should be up left');
+              
+        //point up right
+        p = {x:10, y: -10};
+        point = Kinetic.Path.getPointOnLine(10, origo.x, origo.y, p.x, p.y);
+        test(point.x > 0 && point.y < 0, 'The new point should be up right');
+
+        //point down right
+        p = {x:10, y: 10};
+        point = Kinetic.Path.getPointOnLine(10, origo.x, origo.y, p.x, p.y);
+        test(point.x > 0 && point.y > 0, 'The new point should be down right');
+
+        //point down left
+        p = {x:-10, y: 10};
+        point = Kinetic.Path.getPointOnLine(10, origo.x, origo.y, p.x, p.y);
+        test(point.x < 0 && point.y > 0, 'The new point should be down left');
+
+        //point left
+        p = {x:-10, y: 0};
+        point = Kinetic.Path.getPointOnLine(10, origo.x, origo.y, p.x, p.y);
+        test(point.x == -10 && point.y == 0, 'The new point should be left');
+
+        //point up
+        p = {x:0, y: -10};
+        point = Kinetic.Path.getPointOnLine(10, origo.x, origo.y, p.x, p.y);
+        test(Math.abs(point.x) < 0.0000001 && point.y == -10, 'The new point should be up');
+
+        //point right
+        p = {x:10, y: 0};
+        point = Kinetic.Path.getPointOnLine(10, origo.x, origo.y, p.x, p.y);
+        test(point.x == 10 && point.y == 0, 'The new point should be right');
+
+        //point down
+        p = {x:0, y: 10};
+        point = Kinetic.Path.getPointOnLine(10, origo.x, origo.y, p.x, p.y);
+        test(Math.abs(point.x) < 0.0000001 && point.y == 10, 'The new point should be down');
+    },
     'PATH - Borneo Map (has scientific notation: -10e-4)': function(containerId) {
 
         var stage = new Kinetic.Stage({