add loadIdentityMatrix in Director

cocos/2d/CCDirector.cpp

@@ -461,6 +461,26 @@ void Director::popMatrix(MATRIX_STACK_TYPE type)
     }
 }
 
+void Director::loadIdentityMatrix(MATRIX_STACK_TYPE type)
+{
+    if(MATRIX_STACK_TYPE::MATRIX_STACK_MODELVIEW == type)
+    {
+        kmMat4Identity(&_modelViewMatrixStack.top());
+    }
+    else if(MATRIX_STACK_TYPE::MATRIX_STACK_PROJECTION == type)
+    {
+        kmMat4Identity(&_projectionMatrixStack.top());
+    }
+    else if(MATRIX_STACK_TYPE::MATRIX_STACK_TEXTURE == type)
+    {
+        kmMat4Identity(&_textureMatrixStack.top());
+    }
+    else
+    {
+        CCASSERT(false, "unknow matrix stack type");
+    }
+}
+
 void Director::loadMatrix(MATRIX_STACK_TYPE type, const kmMat4& mat)
 {
     if(MATRIX_STACK_TYPE::MATRIX_STACK_MODELVIEW == type)

cocos/2d/CCDirector.h

@@ -84,15 +84,15 @@ and when to execute the Scenes.
   - GL_COLOR_ARRAY is enabled
   - GL_TEXTURE_COORD_ARRAY is enabled
 */
+enum class MATRIX_STACK_TYPE
+{
+    MATRIX_STACK_MODELVIEW,
+    MATRIX_STACK_PROJECTION,
+    MATRIX_STACK_TEXTURE
+};
+
 class CC_DLL Director : public Ref
 {
-public:
-    enum class MATRIX_STACK_TYPE
-    {
-        MATRIX_STACK_MODELVIEW,
-        MATRIX_STACK_PROJECTION,
-        MATRIX_STACK_TEXTURE
-    };
 private:
     std::stack<kmMat4> _modelViewMatrixStack;
     std::stack<kmMat4> _projectionMatrixStack;
@@ -102,6 +102,7 @@ protected:
 public:
     void pushMatrix(MATRIX_STACK_TYPE type);
     void popMatrix(MATRIX_STACK_TYPE type);
+    void loadIdentityMatrix(MATRIX_STACK_TYPE type);
     void loadMatrix(MATRIX_STACK_TYPE type, const kmMat4& mat);
     void multiplyMatrix(MATRIX_STACK_TYPE type, const kmMat4& mat);
     kmMat4 getMatrix(MATRIX_STACK_TYPE type);