内置的常用层：LayerColor、LayerGradient

颜色布景层类LayerColor

颜色布景层类LayerColor是Layer的子类，包含Layer类的特性，并且有两个拓展功能：为布景层增添颜色以及设置不透明度。

分析其源码:

class CC_DLL LayerColor : public Layer, public BlendProtocol
{
public:
    /** Creates a fullscreen black layer.
     *
     * @return An autoreleased LayerColor object.
     */
    static LayerColor* create();
    /** Creates a Layer with color, width and height in Points.
     *
     * @param color The color of layer.
     * @param width The width of layer.
     * @param height The height of layer.
     * @return An autoreleased LayerColor object.
     */
    static LayerColor * create(const Color4B& color, GLfloat width, GLfloat height);
    /** Creates a Layer with color. Width and height are the window size.
     *
     * @param color The color of layer.
     * @return An autoreleased LayerColor object.
     */
    static LayerColor * create(const Color4B& color);

    /** Change width in Points.
     * 
     * @param w The width of layer.
     */
    void changeWidth(GLfloat w);
    /** Change height in Points.
     *
     * @param h The height of layer.
     */
    void changeHeight(GLfloat h);
    /** Change width and height in Points.
     * 
     * @param w The width of layer.
     * @param h The Height of layer.
    @since v0.8
    */
    void changeWidthAndHeight(GLfloat w ,GLfloat h);

    //
    // Overrides
    //
    virtual void draw(Renderer *renderer, const Mat4 &transform, uint32_t flags) override;

    virtual void setContentSize(const Size & var) override;
    /** BlendFunction. Conforms to BlendProtocol protocol */
    /**
    * @lua NA
    */
    virtual const BlendFunc& getBlendFunc() const override;
    /**
    *@code
    *When this function bound into js or lua,the parameter will be changed
    *In js: var setBlendFunc(var src, var dst)
    *In lua: local setBlendFunc(local src, local dst)
    *@endcode
    */
    virtual void setBlendFunc(const BlendFunc& blendFunc) override;

    virtual std::string getDescription() const override;
    
CC_CONSTRUCTOR_ACCESS:
    LayerColor();
    virtual ~LayerColor();
    
    bool init() override;
    bool initWithColor(const Color4B& color, GLfloat width, GLfloat height);
    bool initWithColor(const Color4B& color);

protected:
    void onDraw(const Mat4& transform, uint32_t flags);

    virtual void updateColor() override;

    BlendFunc _blendFunc;
    Vec2 _squareVertices[4];
    Color4F  _squareColors[4];
    CustomCommand _customCommand;
    Vec3 _noMVPVertices[4];
private:
    CC_DISALLOW_COPY_AND_ASSIGN(LayerColor);

};

主要用法举例如下：

	auto colorBack = LayerColor::create
		( Color4B(170,170,170,255),
		64*4+4*5, 64*4+4*5
		);
	colorBack->ignoreAnchorPointForPosition(false);
	colorBack->setAnchorPoint(Point(0.5,0.5));

	colorBack->setPosition(Point(visiblesize.width/2, visiblesize.height/2));
	this->addChild(colorBack);

重点说明这句：colorBack->ignoreAnchorPointForPosition(false);

使用ignoreAnchorPointForPosition将是否忽略锚点置为false，由于是否忽略锚点的默认值是true，也就是忽略锚点，而以左下角为锚点。可以让布景层考虑锚点的影响

展示效果：

带有颜色渐变布景层类LayerGradient

class CC_DLL LayerGradient : public LayerColor
{
public:
    /** Creates a fullscreen black layer.
     *
     * @return An autoreleased LayerGradient object.
     */
    static LayerGradient* create();

    /** Creates a full-screen Layer with a gradient between start and end.
     *
     * @param start The start color.
     * @param end The end color.
     * @return An autoreleased LayerGradient object.
     */
    static LayerGradient* create(const Color4B& start, const Color4B& end);

    /** Creates a full-screen Layer with a gradient between start and end in the direction of v.
     *
     * @param start The start color.
     * @param end The end color.
     * @param v The direction of gradient color.
     * @return An autoreleased LayerGradient object.
     */
    static LayerGradient* create(const Color4B& start, const Color4B& end, const Vec2& v);
    Vec2（1,0）从左往右渐变
    Vec2（-1,0）从右往左渐变
    Vec2（0,1） 从下往上渐变
    Vec2（0，-1）从上往下渐变
    Vec2（1,1）从左下往右上渐变
    Vec2（-1,1）从右下往左上渐变
    Vec2（1,-1） 从左上往右下渐变
    Vec2（-1，-1）从右上往左下渐变
    /** Whether or not the interpolation will be compressed in order to display all the colors of the gradient both in canonical and non canonical vectors.
     Default: true.
     *
     * @param compressedInterpolation The interpolation will be compressed if true.
     */
    void setCompressedInterpolation(bool compressedInterpolation);
    /** Get the compressedInterpolation
     *
     * @return The interpolation will be compressed if true.
     */
    bool isCompressedInterpolation() const;

    /** Sets the start color of the gradient.
     * 
     * @param startColor The start color.
     */
    void setStartColor( const Color3B& startColor );
    /** Returns the start color of the gradient.
     *
     * @return The start color.
     */
    const Color3B& getStartColor() const;

    /** Sets the end color of the gradient.
     *
     * @param endColor The end color.
     */
    void setEndColor( const Color3B& endColor );
    /** Returns the end color of the gradient.
     *
     * @return The end color.
     */
    const Color3B& getEndColor() const;

    /** Returns the start opacity of the gradient.
     *
     * @param startOpacity The start opacity, from 0 to 255.
     */
    void setStartOpacity( GLubyte startOpacity );
    /** Returns the start opacity of the gradient.
     *
     * @return The start opacity.
     */
    GLubyte getStartOpacity() const;

    /** Returns the end opacity of the gradient.
     *
     * @param endOpacity The end opacity, from 0 to 255.
     */
    void setEndOpacity( GLubyte endOpacity );
    /** Returns the end opacity of the gradient.
     *
     * @return The end opacity.
     */
    GLubyte getEndOpacity() const;

    /** Sets the directional vector that will be used for the gradient.
    The default value is vertical direction (0,-1). 
     *
     * @param alongVector The direction of gradient.
     */
    void setVector(const Vec2& alongVector);
    /** Returns the directional vector used for the gradient.
     *
     * @return The direction of gradient.
     */
    const Vec2& getVector() const;

    virtual std::string getDescription() const override;
    
CC_CONSTRUCTOR_ACCESS:
    LayerGradient();
    virtual ~LayerGradient();
    
    virtual bool init() override;
    /** Initializes the Layer with a gradient between start and end.
     * @js init
     * @lua init
     */
    bool initWithColor(const Color4B& start, const Color4B& end);
    
    /** Initializes the Layer with a gradient between start and end in the direction of v.
     * @js init
     * @lua init
     */
    bool initWithColor(const Color4B& start, const Color4B& end, const Vec2& v);

protected:
    virtual void updateColor() override;

    Color3B _startColor;
    Color3B _endColor;
    GLubyte _startOpacity;
    GLubyte _endOpacity;
    Vec2   _alongVector;
    bool    _compressedInterpolation;
};

具体实例：

LayerGradient* layergradient = LayerGradient::create
		(Color4B(0,255,0,0),Color4B(0,0,255,255));
	addChild(layergradient);