Fixed #1152: fixed a cc.ParticleSystem's bug that it doesn't work in position type cc.PARTICLE_TYPE_RELATIVE

Author: dingpinglv

cocos2d/particle_nodes/CCParticleSystem.js

@@ -1830,8 +1830,10 @@ cc.ParticleSystem = cc.Node.extend(/** @lends cc.ParticleSystem# */{
         // position
         if (this._positionType == cc.PARTICLE_TYPE_FREE)
             particle.startPos = this.convertToWorldSpace(this._pointZeroForParticle);
-        else if (this._positionType == cc.PARTICLE_TYPE_RELATIVE)
-            particle.startPos = this._position;
+        else if (this._positionType == cc.PARTICLE_TYPE_RELATIVE){
+            particle.startPos.x = this._position.x;
+            particle.startPos.y = this._position.y;
+        }
 
         // direction
         var a = cc.DEGREES_TO_RADIANS(this._angle + this._angleVar * locRandomMinus11());
@@ -2056,7 +2058,6 @@ cc.ParticleSystem = cc.Node.extend(/** @lends cc.ParticleSystem# */{
         var currentPosition = cc.Particle.TemporaryPoints[0];
         if (this._positionType == cc.PARTICLE_TYPE_FREE) {
             cc.pIn(currentPosition, this.convertToWorldSpace(this._pointZeroForParticle));
-
         } else if (this._positionType == cc.PARTICLE_TYPE_RELATIVE) {
             currentPosition.x = this._position.x;
             currentPosition.y = this._position.y;