axmol/cocos/renderer/backend/ShaderCache.h

/****************************************************************************
 Copyright (c) 2018 Xiamen Yaji Software Co., Ltd.

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#pragma once

#include "Macros.h"
#include "base/CCRef.h"
#include "platform/CCPlatformMacros.h"
#include "renderer/backend/ShaderModule.h"

#include <string>
#include <unordered_map>

CC_BACKEND_BEGIN
/**
 * @addtogroup _backend
 * @{
 */

/**
 * Create and reuse shader module.
 */
class CC_DLL ShaderCache : public Ref
{
public:
    /** returns the shared instance */
    static ShaderCache* getInstance();

    /** purges the cache. It releases the retained instance. */
    static void destroyInstance();

    /**
     * Create a vertex shader module and add it to cache.
     * If it is created before, then just return the cached shader module.
     * @param shaderSource The source code of the shader.
     */
    static backend::ShaderModule* newVertexShaderModule(const std::string& shaderSource);

    /**
     * Create a fragment shader module.
     * If it is created before, then just return the cached shader module.
     * @param shaderSource The source code of the shader.
     */
    static backend::ShaderModule* newFragmentShaderModule(const std::string& shaderSource);

    /**
     * Remove all unused shaders.
     */
    void removeUnusedShader();

protected:
    virtual ~ShaderCache();

    /**
     * Initial shader cache.
     * @return true if initial successful, otherwise false.
     */
    bool init();

    /**
     * New a shaderModule.
     * If it was created before, then just return the cached shader module.
     * Otherwise add it to cache and return the object.
     * @param stage Specifies whether is vertex shader or fragment shader.
     * @param source Specifies shader source.
     * @return A ShaderModule object.
     */
    static backend::ShaderModule* newShaderModule(backend::ShaderStage stage, const std::string& shaderSource);

    static std::unordered_map<std::size_t, backend::ShaderModule*> _cachedShaders;
    static ShaderCache* _sharedShaderCache;
};

// end of _backend group
/// @}
CC_BACKEND_END