axmol/core/renderer/backend/metal/ShaderModuleMTL.h

/****************************************************************************
 Copyright (c) 2018-2019 Xiamen Yaji Software Co., Ltd.

 https://axmolengine.github.io/

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 THE SOFTWARE.
 ****************************************************************************/

#pragma once

#include "../ShaderModule.h"
#include "../Types.h"
#include <stdint.h>
#include <string>
#include <vector>
#include <memory>
#include <unordered_map>
#import <Metal/Metal.h>

NS_AX_BACKEND_BEGIN
/**
 * @addtogroup _metal
 * @{
 */

struct SLCReflectContext;

/**
 * To Create a vertex or fragment shader.
 */
class ShaderModuleMTL : public ShaderModule
{
public:
    /**
     * @param mtlDevice The device for which MTLFunction object was created.
     * @param stage Specify what kinds of shader to be created.
     * @param source Specify the shader source.
     */
    ShaderModuleMTL(id<MTLDevice> mtlDevice, ShaderStage stage, std::string_view source);
    ~ShaderModuleMTL();

    /**
     * Get MTLFunction object.
     * @return A MTLFunction object.
     */
    inline id<MTLFunction> getMTLFunction() const { return _mtlFunction; }

    /**
     * Get all uniformInfos.
     * @return The uniformInfos.
     */
    inline const hlookup::string_map<UniformInfo>& getAllActiveUniformInfo() const { return _activeUniformInfos; }

    /**
     * Get maximum uniform location.
     * @return Maximum uniform location.
     */
    inline const int getMaxLocation() const { return _maxLocation; }

    /**
     * Get active attribute informations.
     * @return Active attribute informations. key is attribute name and Value is corresponding attribute info.
     */
    inline const hlookup::string_map<AttributeBindInfo>& getAttributeInfo() const { return _attributeInfo; }

    /**
     * Get uniform location by engine built-in uniform enum name.
     * @param name Specifies the engine built-in uniform enum name.
     * @return The uniform location.
     */
    UniformLocation getUniformLocation(Uniform name) const;

    /**
     * Get uniform location by name.
     * @param uniform Specifies the uniform name.
     * @return The uniform location.
     */
    UniformLocation getUniformLocation(std::string_view name) const;

    /**
     * Get attribute location by engine built-in attribute enum name.
     * @param name Specifies the engine built-in attribute enum name.
     * @return The attribute location.
     */
    int getAttributeLocation(Attribute name) const;

    /**
     * Get attribute location by attribute name.
     * @param name Specifies the attribute name.
     * @return The attribute location.
     */
    int getAttributeLocation(std::string_view name);

    /**
     * Get uniform buffer size in bytes that holds all the uniforms.
     * @return The uniform buffer size.
     */
    inline std::size_t getUniformBufferSize() const { return _uniformBufferSize; }

private:
    void parseAttibute(SLCReflectContext* context);
    void parseUniform(SLCReflectContext* context);
    void parseTexture(SLCReflectContext* context);
    void setBuiltinLocations();

    id<MTLFunction> _mtlFunction = nil;

    hlookup::string_map<UniformInfo> _activeUniformInfos;
    hlookup::string_map<AttributeBindInfo> _attributeInfo;
    
    int _attributeLocation[ATTRIBUTE_MAX];
    
    int _maxLocation = -1;
    UniformLocation _uniformLocation[UNIFORM_MAX]; // the builtin uniform locations
    
    std::size_t _uniformBufferSize = 0;
};

// end of _metal group
/// @}
NS_AX_BACKEND_END