axmol/cocos/renderer/CCCustomCommand.h

/****************************************************************************
 Copyright (c) 2013-2016 Chukong Technologies Inc.
 Copyright (c) 2017-2018 Xiamen Yaji Software Co., Ltd.

 http://www.cocos2d-x.org

 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
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 The above copyright notice and this permission notice shall be included in
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 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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 ****************************************************************************/
#pragma once

#include "renderer/CCRenderCommand.h"

/**
 * @addtogroup renderer
 * @{
 */

NS_CC_BEGIN

namespace backend
{
    class Buffer;
}

/**
Custom command is used to draw all things except triangle commands. You can use
this command to draw things, just provide vertex/index data and set corret flags.
*/
class CC_DLL CustomCommand : public RenderCommand
{
public:
    enum class DrawType
    {
        ARRAY,
        ELEMENT
    };

    using PrimitiveType = backend::PrimitiveType;
    /**
    Buffer usage of vertex/index buffer. If the contents is not updated every frame,
    then use STATIC, other use DYNAMIC.
    */
    using BufferUsage = backend::BufferUsage;
    /**
    The index format determine the size for index data. U_SHORT is enough for most
    cases.
    */
    using IndexFormat = backend::IndexFormat;


    typedef std::function<void()> CallBackFunc;

	/**Constructor.*/
    CustomCommand();
    /**Destructor.*/
    ~CustomCommand();
    

public:
	/**
    TODO: should remove it.
	Init function.
	@param globalZOrder GlobalZOrder of the render command.
	@param modelViewTransform When in 3D mode, depth sorting needs modelViewTransform.
	@param flags Use to identify that the render command is 3D mode or not.
	*/
    void init(float globalZOrder, const Mat4& modelViewTransform, unsigned int flags);
    
    /**
    Init function. The render command will be in 2D mode.
    @param globalZOrder GlobalZOrder of the render command.
    */
    void init(float globalZOrder);
    /**
    Init function. The render command will be in 2D mode.
    @param globalZOrder GlobalZOrder of the render command.
    @param blendFunc blend function of the render command.
    */
    void init(float globalZOrder, const BlendFunc& blendFunc);

    /**
    Create a vertex buffer of the custom command. The buffer size is (vertexSize * capacity).
    If the buffer already exists, then it will delete the old buffer and create a new one.
    @param vertexSize the size of every vertex data.
    @param capacity how many vertices of the buffer
    @param usage the usage of the vertex buffer. Use Static of the vertex data are not updated
                 every frame, otherwise use DYNAMIC.
    */
    void createVertexBuffer(std::size_t vertexSize, std::size_t capacity, BufferUsage usage);
    /**
    Create an index buffer of the custom command. The buffer size is (indexSize * capacity).
    Index size is determined by format. If the buffer already exists, then it will delete the
    old buffer and create a new one.
    @param format index fomrat, if format is U_SHORT, then the index data type should be
                  unsigned short, otherwise should be unsigned int.
    @param capacity how many indices of the buffer
    @param usage the usage of the vertex buffer. Use Static of the index data are not updated
                 every frame, otherwise use DYNAMIC.
    */
    void createIndexBuffer(IndexFormat format, std::size_t capacity, BufferUsage usage);

    /**
    Update vertex buffer contents.
    @param data Specifies a pointer to the new data that will be copied into the data store.
    @param length Specifies the length in bytes of the data store region being replaced.
    */
    void updateVertexBuffer(void* data, std::size_t length);
    /**
    Update index buffer contents.
    @param data Specifies a pointer to the new data that will be copied into the data store.
    @param length Specifies the size in bytes of the data store region being replaced.
    */
    void updateIndexBuffer(void* data, std::size_t length);
    /**
    Update some or all contents of vertex buffer.
    @param data Specifies a pointer to the new data that will be copied into the data store.
    @param offset Specifies the offset into the buffer object's data store where data replacement will begin, measured in bytes.
    @param length Specifies the size in bytes of the data store region being replaced.
    */
    void updateVertexBuffer(void* data, std::size_t offset, std::size_t length);
    /**
    Update some or call contents of index buffer
    @param data Specifies a pointer to the new data that will be copied into the data store.
    @param offset specifies the offset into the buffer object's data store where data replacement will begin, measured in bytes.
    @param length Specifies the size in bytes of the data store region being replaced.
    */
    void updateIndexBuffer(void* data, std::size_t offset, std::size_t length);

    /**
    Get vertex buffer capacity.
    */
    inline std::size_t getVertexCapacity() const { return _vertexCapacity; }
    /**
    Get index buffer capacity.
    */
    inline std::size_t getIndexCapacity() const { return _indexCapacity; }

    inline void setDrawType(DrawType drawType) { _drawType = drawType; }
    inline DrawType getDrawType() const { return _drawType; }

    inline void setPrimitiveType(PrimitiveType primitiveType) { _primitiveType = primitiveType; }
    inline PrimitiveType getPrimitiveType() const { return _primitiveType; }

    /**
    Set the vertex buffer. The existing vertex buffer will be replaced if exist.
    */
    void setVertexBuffer(backend::Buffer* vertexBuffer);
    inline backend::Buffer* getVertexBuffer() const { return _vertexBuffer; }

    /**
    Set the index buffer. The existing index buffer will be replaced if exist.
    */
    void setIndexBuffer(backend::Buffer* indexBuffer, IndexFormat indexFormat);
    inline backend::Buffer* getIndexBuffer() const { return _indexBuffer; }

    /**
    Set the drawing information if the drawing type is ARRAY.
    @start specifices the starting index of vertex buffer
    @count specifices the number of vertices to be rendered
    */
    inline void setVertexDrawInfo(std::size_t start, std::size_t count) { _vertexDrawStart = start; _vertexDrawCount = count; }
    inline std::size_t getVertexDrawStart() const { return _vertexDrawStart; }
    inline std::size_t getVertexDrawCount() const { return _vertexDrawCount;}

    /**
    Set the drawing information if the drawing type is ELEMENT.
    @start specifices the starting index of index buffer
    @count specifices the number of indices to be rendered
    */
    inline void setIndexDrawInfo(std::size_t start, std::size_t count) { _indexDrawOffset = start * _indexSize; _indexDrawCount = count; }
    inline std::size_t getIndexDrawOffset() const { return _indexDrawOffset; }
    inline std::size_t getIndexDrawCount() const { return _indexDrawCount; }
    
    inline void setLineWidth(float lineWidth) { _lineWidth = lineWidth; }
    inline float getLineWidth() const { return _lineWidth; }

    inline IndexFormat getIndexFormat() const { return _indexFormat; }

    /**Callback function.*/
    //TODO:minggo: should remove it.
    std::function<void()> func;

    /**
    * set a callback which will be invoke before rendering
    */
    void setBeforeCallback(const CallBackFunc &before) { _beforeCallback = before; }

    /**
    * set a callback which will be invoke after rendering
    */
    void setAfterCallback(const CallBackFunc &after) { _afterCallback = after; }

    const CallBackFunc &getBeforeCallback() { return _beforeCallback; }

    const CallBackFunc &getAfterCallback() { return _afterCallback; }

protected:
    std::size_t computeIndexSize() const;

    backend::Buffer* _vertexBuffer = nullptr;
    backend::Buffer* _indexBuffer = nullptr;
    
    std::size_t _vertexDrawStart = 0;
    std::size_t _vertexDrawCount = 0;
    
    std::size_t _indexDrawOffset = 0;
    std::size_t _indexDrawCount = 0;
    
    DrawType _drawType = DrawType::ELEMENT;
    PrimitiveType _primitiveType = PrimitiveType::TRIANGLE;
    IndexFormat _indexFormat = IndexFormat::U_SHORT;
    
    float _lineWidth = 0.0;
    
    std::size_t _indexSize = 0;

    std::size_t _vertexCapacity = 0;
    std::size_t _indexCapacity = 0;


    CallBackFunc _beforeCallback = nullptr;
    CallBackFunc _afterCallback = nullptr;
};

NS_CC_END
/**
 end of support group
 @}
 */