cocos-enhance-kit/cocos2d-x/cocos/renderer/gfx/Program.h

/****************************************************************************
 Copyright (c) 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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 all copies or substantial portions of the Software.
 
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 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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 THE SOFTWARE.
 ****************************************************************************/

#pragma once

#include "../Macro.h"
#include "../Types.h"

#include "GraphicsHandle.h"

#include <string>
#include <vector>

RENDERER_BEGIN

/**
 * @addtogroup gfx
 * @{
 */

class DeviceGraphics;

/**
 * Program class manages the internal GL shader program.
 */
class Program final: public GraphicsHandle
{
public:
    /**
     * Describes vertex attribute informations used in the program
     * @struct Attribute
     */
    struct Attribute
    {
        /**
         * Attribute name
         */
        std::string name;
        size_t hashName;
        /**
         * Number of components per attribute
         */
        GLsizei size;
        /**
         * Attribute location
         */
        GLuint location;
        /**
         * Attribute type
         */
        GLenum type;
    };

    /**
     * Describes uniform informations used in the program
     * @struct Uniform
     */
    struct Uniform
    {
        /**
         * Uniform name
         */
        std::string name;
        
        /**
         * Uniform hash name
         */
        size_t hashName;
        /**
         * The length of the array for uniforms declared as arrays, default value is 1
         */
        GLsizei size;
        /**
         * Uniform location
         */
        GLint location;
        /**
         * Uniform type
         */
        GLenum type;
        /**
         * Sets the uniform value
         */
        void setUniform(const void* value, UniformElementType elementType, size_t uniformCount) const;
        /**
         * Sets the callback which will be called when uniform updated
         */
        using SetUniformCallback = void (*)(GLint, GLsizei, const void*, UniformElementType); // location, count, value, elementType
    private:
        SetUniformCallback _callback;
        friend class Program;
    };

    /**
     * Creates a Program with device and shader sources
     */
    RENDERER_DEFINE_CREATE_METHOD_3(Program, init, DeviceGraphics*, const char*, const char*)
    Program();
    virtual ~Program();

    /**
     * Initializes a Program with device and program sources
     * @param[in] device DeviceGraphics pointer
     * @param[in] vertSource Vertex shader program
     * @param[in] fragSource Fragment shader program
     */
    bool init(DeviceGraphics* device, const char* vertSource, const char* fragSource);
    /**
     * Gets the id of program
     */
    inline uint32_t getID() const { return _id; }
    /**
     * Gets the attibutes used in the program
     */
    inline const std::vector<Attribute>& getAttributes() const { return _attributes; }
    /**
     * Gets the uniforms used in the program
     */
    inline const std::vector<Uniform>& getUniforms() const { return _uniforms; }
    /**
     * Indicates whether the program is successfully linked
     */
    inline bool isLinked() const { return _linked; }
    /**
     * Link the program with its shader sources
     */
    void link();
    
    inline size_t getHash() const { return _hash; }
    inline void setHash(size_t hash) { _hash = hash; }
private:
    DeviceGraphics* _device;
    std::vector<Attribute> _attributes;
    std::vector<Uniform> _uniforms;
    std::string _vertSource;
    std::string _fragSource;
    uint32_t _id;
    bool _linked;
    size_t _hash = 0;
};

// end of gfx group
/// @}

RENDERER_END