Add ability to clear emission shapes.

core/2d/CCParticleSystem.cpp

@@ -1119,6 +1119,11 @@ void ParticleSystem::setAnimationDescriptor(unsigned short indexOfDescriptor,
     desc.reverseIndices         = reverse;
 }
 
+void ParticleSystem::resetEmissionShapes()
+{
+    _emissionShapes.clear();
+}
+
 void ParticleSystem::addEmissionShapePoint(Vec2 pos)
 {
     EmissionShape shape{};

core/2d/CCParticleSystem.h

@@ -1133,6 +1133,9 @@ public:
     void setEmissionShapes(bool enabled) { _isEmissionShapes = enabled; }
     bool isEmissionShapes() { return _isEmissionShapes; }
 
+    /** Resets the count of emission shapes to 0 and empties the emission shapes array */
+    void resetEmissionShapes();
+
     /** Adds an emission shape of type point to the system. */
     void addEmissionShapePoint(Vec2 pos);