CCRenderTexture.h

/****************************************************************************
Copyright (c) 2009      Jason Booth
Copyright (c) 2010-2012 cocos2d-x.org
Copyright (c) 2013-2016 Chukong Technologies Inc.
Copyright (c) 2017-2018 Xiamen Yaji Software Co., Ltd.

http://www.cocos2d-x.org

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****************************************************************************/
#pragma once

#include "2d/CCNode.h"
#include "2d/CCSprite.h"
#include "platform/CCImage.h"
#include "renderer/CCGroupCommand.h"
#include "renderer/CCCustomCommand.h"
#include "renderer/CCCallbackCommand.h"
#include "renderer/backend/Types.h"

NS_CC_BEGIN

namespace backend
{
    class TextureBackend;
}

class EventCustom;

/**
 * @addtogroup _2d
 * @{
 */

/**
 * @brief RenderTexture is a generic rendering target. To render things into it,
 * simply construct a render target, call begin on it, call visit on any cocos
 * scenes or objects to render them, and call end. For convenience, render texture
 * adds a sprite as it's display child with the results, so you can simply add
 * the render texture to your scene and treat it like any other CocosNode.
 * There are also functions for saving the render texture to disk in PNG or JPG format.
 * @since v0.8.1
 */
class CC_DLL RenderTexture : public Node 
{
public:
    /** Initializes a RenderTexture object with width and height in Points and a pixel format( only RGB and RGBA formats are valid ) and depthStencil format. 
     *
     * @param w The RenderTexture object width.
     * @param h The RenderTexture object height.
     * @param format In Points and a pixel format( only RGB and RGBA formats are valid ).
     * @param depthStencilFormat The depthStencil format.
     */
    static RenderTexture * create(int w ,int h, backend::PixelFormat format, backend::PixelFormat depthStencilFormat);

    /** Creates a RenderTexture object with width and height in Points and a pixel format, only RGB and RGBA formats are valid. 
     *
     * @param w The RenderTexture object width.
     * @param h The RenderTexture object height.
     * @param format In Points and a pixel format( only RGB and RGBA formats are valid ).
     */
    static RenderTexture * create(int w, int h, backend::PixelFormat format);

    /** Creates a RenderTexture object with width and height in Points, pixel format is RGBA8888. 
     *
     * @param w The RenderTexture object width.
     * @param h The RenderTexture object height.
     */
    static RenderTexture * create(int w, int h);

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

    /** Starts grabbing. */
    virtual void begin();

    /** Starts rendering to the texture while clearing the texture first.
     * This is more efficient then calling -clear first and then -begin.
     *
     * @param r Red.
     * @param g Green.
     * @param b Blue.
     * @param a Alpha.
     */
    virtual void beginWithClear(float r, float g, float b, float a);

    /** Starts rendering to the texture while clearing the texture first.
     * This is more efficient then calling -clear first and then -begin.
     *
     * @param r Red.
     * @param g Green.
     * @param b Blue.
     * @param a Alpha.
     * @param depthValue The depth Value.
     */
    virtual void beginWithClear(float r, float g, float b, float a, float depthValue);

    /** Starts rendering to the texture while clearing the texture first.
     * This is more efficient then calling -clear first and then -begin. 
     *
     * @param r Red.
     * @param g Green.
     * @param b Blue.
     * @param a Alpha.
     * @param depthValue A specified depth value.
     * @param stencilValue A specified stencil value.
     */
    virtual void beginWithClear(float r, float g, float b, float a, float depthValue, int stencilValue);

    /** Ends grabbing.
     * @lua endToLua
     */
    virtual void end();

    /** Clears the texture with a color. 
     *
     * @param r Red.
     * @param g Green.
     * @param b Blue.
     * @param a Alpha.
     */
    void clear(float r, float g, float b, float a);

    /** Clears the texture with a specified depth value. 
     *
     * @param depthValue A specified depth value.
     */
    virtual void clearDepth(float depthValue);

    /** Clears the texture with a specified stencil value.
     *
     * @param stencilValue A specified stencil value.
     */
    virtual void clearStencil(int stencilValue);
    
    /* Creates a new Image from with the texture's data.
     * Caller is responsible for releasing it by calling delete.
     *
     * @param flipImage Whether or not to flip image.
     * @return An image.
     * @js NA
     */
    void newImage(std::function<void(Image*)> imageCallback, bool flipImage = true);

    /**
     * New Version Of Create a new Image from with the texture's data.
     * FIX: Null Image Data In RenderTexture::newImage Callback Issue (#20776)
     * 
     * @param imageCallback 
     * @param flipImage 
     */
    void createNewImage(std::function<void(Image*)> imageCallback, bool flipImage = true);
    
    /** Saves the texture into a file using JPEG format. The file will be saved in the Documents folder.
     * Returns true if the operation is successful.
     *
     * @param filename The file name.
     * @param isRGBA The file is RGBA or not.
     * @param callback When the file is save finished,it will callback this function.
     * @return Returns true if the operation is successful.
     */
    bool saveToFileAsNonPMA(const std::string& filename, bool isRGBA = true, std::function<void(RenderTexture*, const std::string&)> callback = nullptr);

    /** Saves the texture into a file using JPEG format. The file will be saved in the Documents folder.
     * Returns true if the operation is successful.
     *
     * @param filename The file name.
     * @param isRGBA The file is RGBA or not.
     * @param callback When the file is save finished,it will callback this function.
     * @return Returns true if the operation is successful.
     */
    bool saveToFile(const std::string& filename, bool isRGBA = true, std::function<void (RenderTexture*, const std::string&)> callback = nullptr);

   /** saves the texture into a file in non-PMA. The format could be JPG or PNG. The file will be saved in the Documents folder.
        Returns true if the operation is successful.
     * Notes: since v3.x, saveToFile will generate a custom command, which will be called in the following render->render().
     * So if this function is called in a event handler, the actual save file will be called in the next frame. If we switch to a different scene, the game will crash.
     * To solve this, add Director::getInstance()->getRenderer()->render(); after this function.
     *
     * @param filename The file name.
     * @param format The image format.
     * @param isRGBA The file is RGBA or not.
     * @param callback When the file is save finished,it will callback this function.
     * @return Returns true if the operation is successful.
     */
    bool saveToFileAsNonPMA(const std::string& fileName, Image::Format format, bool isRGBA, std::function<void(RenderTexture*, const std::string&)> callback);

    /** saves the texture into a file. The format could be JPG or PNG. The file will be saved in the Documents folder.
        Returns true if the operation is successful.
     * Notes: since v3.x, saveToFile will generate a custom command, which will be called in the following render->render().
     * So if this function is called in a event handler, the actual save file will be called in the next frame. If we switch to a different scene, the game will crash.
     * To solve this, add Director::getInstance()->getRenderer()->render(); after this function.
     *
     * @param filename The file name.
     * @param format The image format.
     * @param isRGBA The file is RGBA or not.
     * @param callback When the file is save finished,it will callback this function.
     * @return Returns true if the operation is successful.
     */
    bool saveToFile(const std::string& filename, Image::Format format, bool isRGBA = true, std::function<void (RenderTexture*, const std::string&)> callback = nullptr);
    
    /** Listen "come to background" message, and save render texture.
     * It only has effect on Android.
     * 
     * @param event Event Custom.
     */
    void listenToBackground(EventCustom *event);
    
    /** Listen "come to foreground" message and restore the frame buffer object.
     * It only has effect on Android.
     *
     * @param event Event Custom.
     */
    void listenToForeground(EventCustom *event);

    /** Valid when "autoDraw" is true.
     *
     * @return Clear flags.
     */
    inline ClearFlag getClearFlags() const { return _clearFlags; }

    /** Set flags.
     *
     * @param clearFlags set clear flags.
     */
    void setClearFlags(ClearFlag clearFlags);
    
    /** Clear color value. Valid only when "autoDraw" is true. 
     *
     * @return Color value.
     */
    inline const Color4F& getClearColor() const { return _clearColor; }
    
    /** Set color value. 
     *
     * @param clearColor Color value.
     */
    inline void setClearColor(const Color4F &clearColor) { _clearColor = clearColor; }
    
    /** Value for clearDepth. Valid only when "autoDraw" is true. 
     *
     * @return Value for clearDepth.
     */
    inline float getClearDepth() const { return _clearDepth; }
    
    /** Set Value for clearDepth.
     *
     * @param clearDepth Value for clearDepth.
     */
    inline void setClearDepth(float clearDepth) { _clearDepth = clearDepth; }
    
    /** Value for clear Stencil. Valid only when "autoDraw" is true.
     *
     * @return Value for clear Stencil.
     */
    inline int getClearStencil() const { return _clearStencil; }
    
    /** Set Value for clear Stencil.
     *
     * @param clearStencil Value for clear Stencil.
     */
    inline void setClearStencil(int clearStencil) { _clearStencil = clearStencil; }
    
    /** When enabled, it will render its children into the texture automatically. Disabled by default for compatibility reasons.
     * Will be enabled in the future.
     *
     * @return Return the autoDraw value.
     */
    inline bool isAutoDraw() const { return _autoDraw; }
    
    /** Set a valve to control whether or not render its children into the texture automatically. 
     *
     * @param isAutoDraw Whether or not render its children into the texture automatically.
     */
    inline void setAutoDraw(bool isAutoDraw) { _autoDraw = isAutoDraw; }

    /** Gets the Sprite being used. 
     *
     * @return A Sprite.
     */
    inline Sprite* getSprite() const { return _sprite; }
    
    /** Sets the Sprite being used. 
     *
     * @param sprite A Sprite.
     */
    void setSprite(Sprite* sprite);

    /** Flag: Use stack matrix computed from scene hierarchy or generate new modelView and projection matrix.
     *
     * @param keepMatrix Whether or not use stack matrix computed from scene hierarchy or generate new modelView and projection matrix.
     * @js NA
     */
    inline void setKeepMatrix(bool keepMatrix) { _keepMatrix = keepMatrix; }
    /**Used for grab part of screen to a texture. 
     * @param rtBegin The position of renderTexture on the fullRect.
     * @param fullRect The total size of screen.
     * @param fullViewport The total viewportSize.
     */
    void setVirtualViewport(const Vec2& rtBegin, const Rect& fullRect, const Rect& fullViewport);

public:
    /** FIXME: should be protected.
     * but due to a bug in PowerVR + Android,
     * the constructor is public again.
     * @js ctor
     */
    RenderTexture();

    /**
     * @js NA
	 * @lua NA
     */
    virtual ~RenderTexture();
    /** Initializes a RenderTexture object with width and height in Points and a pixel format, only RGB and RGBA formats are valid.
     *
     * @param w The RenderTexture object width.
     * @param h The RenderTexture object height.
     * @param format In Points and a pixel format( only RGB and RGBA formats are valid ).
     * @return If succeed, it will return true.
     */
    bool initWithWidthAndHeight(int w, int h, backend::PixelFormat format);
    /** Initializes a RenderTexture object with width and height in Points and a pixel format( only RGB and RGBA formats are valid ) and depthStencil format. 
     *
     * @param w The RenderTexture object width.
     * @param h The RenderTexture object height.
     * @param format In Points and a pixel format( only RGB and RGBA formats are valid ).
     * @param depthStencilFormat The depthStencil format.
     * @return If succeed, it will return true.
     */
    bool initWithWidthAndHeight(int w, int h, backend::PixelFormat format, backend::PixelFormat depthStencilFormat);

protected:
    virtual void beginWithClear(float r, float g, float b, float a, float depthValue, int stencilValue, ClearFlag flags);
    //renderer caches and callbacks
    void onBegin();
    void onEnd();
    void clearColorAttachment();

    void onSaveToFile(const std::string& fileName, bool isRGBA = true, bool forceNonPMA = false);

    bool         _keepMatrix = false;
    Rect         _rtTextureRect;
    Rect         _fullRect;
    Rect         _fullviewPort;

    Viewport     _oldViewport;
    
    Texture2D* _texture2D = nullptr;
    Texture2D* _depthStencilTexture = nullptr;
    Texture2D* _texture2DCopy = nullptr;    // a copy of _texture
    Texture2D* _oldColorAttachment = nullptr;
    Texture2D* _oldDepthAttachment = nullptr;
    Texture2D* _oldStencilAttachment = nullptr;
    RenderTargetFlag _renderTargetFlags;
    RenderTargetFlag _oldRenderTargetFlag;
    Image*     _UITextureImage = nullptr;
    backend::PixelFormat _pixelFormat = backend::PixelFormat::RGBA8888;
    
    Color4F _clearColor;
    float _clearDepth = 1.f;
    int _clearStencil = 0;
    bool _autoDraw = false;
    ClearFlag _clearFlags = ClearFlag::NONE;

    /** The Sprite being used.
     The sprite, by default, will use the following blending function: BlendFactor::ONE, BlendFactor::ONE_MINUS_SRC_ALPHA.
     The blending function can be changed in runtime by calling:
     - renderTexture->getSprite()->setBlendFunc((BlendFunc){BlendFactor::ONE, BlendFactor::ONE_MINUS_SRC_ALPHA});
     */
    Sprite* _sprite = nullptr;
    
    GroupCommand _groupCommand;
    CallbackCommand _beginCommand;
    CallbackCommand _endCommand;

    CallbackCommand _beforeClearAttachmentCommand;
    CallbackCommand _afterClearAttachmentCommand;
    /*this command is used to encapsulate saveToFile,
     call saveToFile twice will overwrite this command and callback
     and the command and callback will be executed twice.
    */
    CallbackCommand _saveToFileCommand;

    /**
     * This Command Use to Fix Null Image Data In RenderTexture::newImage(#20776)
     */
    CallbackCommand _newImageCommand;

    std::function<void (RenderTexture*, const std::string&)> _saveFileCallback = nullptr;
    
    Mat4 _oldTransMatrix, _oldProjMatrix;
    Mat4 _transformMatrix, _projectionMatrix;

private:
    CC_DISALLOW_COPY_AND_ASSIGN(RenderTexture);
};

// end of textures group
/// @}

NS_CC_END