shader_utils.h

#ifndef _SHADER_UTILS_H
#define _SHADER_UTILS_H

#include <optional>

namespace ShaderUtils
{

    enum Type
    {
        FRAGMENT_SHADER_TYPE,
        VERTEX_SHADER_TYPE,
    };

    struct Program
    {

    private:
        /**
         * @brief The vertex shader ID, as an optional
         */
        std::optional<unsigned int> vertexShader = std::nullopt;

        /**
         * @brief The fragment shader ID, as an optional
         */
        std::optional<unsigned int> fragmentShader = std::nullopt;

        /**
         * @brief The GPU program ID (or shader ID), as an optional
         */
        std::optional<unsigned int> program = std::nullopt;

        /**
         * @brief Stores if the shader has been registered or not
         */
        bool registered = false;

    public:
        /**
         * @brief Constructor
         */
        Program();

        /**
         * @brief Destructor
         */
        ~Program();

        /**
         * @brief Register a shader
         *
         * @param shader_type The type: fragment or vertex
         * @param shader_source The source code as a string
         * @return true The shader has been successfully registered
         * @return false The shader has not been registered - error is logged
         */
        bool registerShader(const Type shader_type, const char *shader_source);

        /**
         * @brief Register the GPU program (or shader), after compilation
         * of the fragment and vertex shaders.
         *
         * @param erase_if_registered Erase the current program if one is already registered
         * @return true The shader has been successfully registered
         * @return false The shader has not been successfully registered - error is logged
         */
        bool registerProgram(bool erase_if_registered);

        /**
         * @brief Returns the GPU program ID object, as optional
         *
         * @return std::optional<unsigned int>
         */
        std::optional<unsigned int> getProgram() const;

        /**
         * @brief Returns if the GPU program object has been registered or not
         */
        bool programIsRegistered() const;
    };

}

#endif /* SHADER_UTILS_H */