SimpleEngine/include/simpleengine/gfx/shader.h

#pragma once

#include <chrono>

#ifdef __linux__
#include <GL/glew.h>
#include <GL/gl.h>
#else
#include <gl/glew.h>
#include <gl/gl.h>
#endif

#include <GLFW/glfw3.h>

#include <glm/fwd.hpp>
#include <glm/glm.hpp>

#include "../event/event.h"

#include <exception>
#include <fstream>
#include <memory>
#include <stdexcept>
#include <string>
#include <iostream>
#include <sstream>

namespace simpleengine::gfx {
    class ShaderException : public std::runtime_error {
    public:
        explicit ShaderException(char const* const msg) : std::runtime_error(msg) {

        }
    };

    enum ShaderType {
        ST_Vertex = GL_VERTEX_SHADER,
        ST_Fragment = GL_FRAGMENT_SHADER,
    };

    class Shader {
    private:
        static GLuint inuse_program;
        //static GLuint inuse_shader;
    public:
        GLuint program;
        GLuint shader;

        Shader() = default;
        Shader(GLuint program);
        Shader(GLuint program, GLuint shader);

        static Shader from_source(const ShaderType& type, std::string& shader_source);

        static Shader from_source(GLuint program, const ShaderType& type, std::string& shader_source);

        /**
         * @brief Load a shader from a filepath.
         * 
         * @param type The type of the shader.
         * @param shader_path The path of the shader source.
         */
        static Shader from_filepath(const ShaderType& type, const std::string& shader_path);

        /**
         * @brief Load a shader from a filepath.
         * 
         * @param program The shader program that this shader will be attached to.
         * @param type The type of the shader.
         * @param shader_path The path of shader source.
         */
        static Shader from_filepath(GLuint program, const ShaderType& type, const std::string& shader_path);

        virtual ~Shader();

        /**
         * @brief Link the shader program and checks for errors.
         * 
         */
        void link();
        
        /**
         * @brief Delete the shader with glDeleteShader. Only do this after we've linked.
         * 
         */
        void delete_shader();

        /**
         * @brief Use the shader program.
         * 
         */
        void use() const;

        /**
         * @brief Un-use the shader program by using the id of "0".
         * 
         */
        void unuse();

        /**
         * @brief Attach the shader to a program. No need to call this if its already attached once.
         * 
         * @param program The program to attach the shader to.
         */
        void attach(GLuint program);

        /**
         * @brief Get the location of the uniform variable in the shader.
         * 
         * @param uniform_name The name of the uniform variable.
         * @return int The location of the uniform in the shader.
         */
        int get_uniform_location(const std::string& uniform_name) const;

        /**
         * @brief Get the location of the uniform variable in the shader.
         * 
         * @param uniform_name The name of the uniform variable.
         * @return int The location of the uniform in the shader.
         */
        int get_uniform_location(const char* uniform_name) const;

        /**
         * @brief Get a Uniform Float from the shader using a `location`.
         * 
         * @param location The location of the uniform float.
         * @return GLfloat The value of the uniform float from the shader.
         */
        GLfloat get_uniform_float(GLint location) const;

        /**
         * @brief Get a Uniform Float from the shader finding the location of the uniform using `uniform_name`.
         * 
         * @param uniform_name The name of the uniform inside of the shader.
         * @return GLfloat The value of the uniform float from the shader.
         */
        GLfloat get_uniform_float(const char* uniform_name) const;

        /**
         * @brief Get a Uniform integer from the shader using a `location`.
         * 
         * @param location The location of the uniform integer.
         * @return GLint The value of the uniform integer from the shader.
         */
        GLint get_uniform_int(GLint location) const;

        /**
         * @brief Get a Uniform integer from the shader finding the location of the uniform using `uniform_name`.
         * 
         * @param uniform_name The name of the uniform inside of the shader.
         * @return GLint The value of the uniform integer from the shader.
         */
        GLint get_uniform_int(const char* uniform_name) const;

        /**
         * @brief Get a Uniform unsigned integer from the shader using a `location`.
         * 
         * @param location The location of the uniform unsigned integer.
         * @return GLuint The value of the uniform unsigned integer from the shader.
         */
        GLuint get_uniform_uint(GLint location) const;

        /**
         * @brief Get a Uniform unsigned integer from the shader finding the location of the uniform using `uniform_name`.
         * 
         * @param uniform_name The name of the uniform inside of the shader.
         * @return GLuint The value of the uniform unsigned integer from the shader.
         */
        GLuint get_uniform_uint(const char* uniform_name) const;

        /**
         * @brief Get a Uniform double from the shader using a `location`.
         * 
         * @param location The location of the uniform double.
         * @return GLdouble The value of the uniform double from the shader.
         */
        GLdouble get_uniform_double(GLint location) const;

        /**
         * @brief Get a Uniform double from the shader finding the location of the uniform using `uniform_name`.
         * 
         * @param uniform_name The name of the uniform inside of the shader.
         * @return GLdouble The value of the uniform double from the shader.
         */
        GLdouble get_uniform_double(const char* uniform_name) const;

        void set_uniform_float(GLint location, GLfloat fl);
        void set_uniform_float(const char* uniform_name, GLfloat fl);

        void set_uniform_float_array(GLint location, int count, GLfloat* arr);
        void set_uniform_float_array(const char* uniform_name, int count, GLfloat* arr);
 
        void set_uniform_float_vec2(GLint location, glm::vec2 vec);
        void set_uniform_float_vec2(const char* uniform_name, glm::vec2 vec);

        void set_uniform_float_vec3(GLint location, glm::vec3 vec);
        void set_uniform_float_vec3(const char* uniform_name, glm::vec3 vec);
        
        void set_uniform_float_vec4(GLint location, glm::vec4 vec);
        void set_uniform_float_vec4(const char* uniform_name, glm::vec4 vec);
        
        void set_uniform_int(GLint location, GLint i);
        void set_uniform_int(const char* uniform_name, GLint i);

        void set_uniform_int_array(GLint location, int count, GLint* arr);
        void set_uniform_int_array(const char* uniform_name, int count, GLint* arr);
        
        void set_uniform_int_vec2(GLint location, glm::ivec2 vec);
        void set_uniform_int_vec2(const char* uniform_name, glm::ivec2 vec);
        
        void set_uniform_int_vec3(GLint location, glm::ivec3 vec);
        void set_uniform_int_vec3(const char* uniform_name, glm::ivec3 vec);
        
        void set_uniform_int_vec4(GLint location, glm::ivec4 vec);
        void set_uniform_int_vec4(const char* uniform_name, glm::ivec4 vec);
        
        void set_uniform_uint(GLint location, GLuint ui);
        void set_uniform_uint(const char* uniform_name, GLuint ui);
        
        void set_uniform_uint_vec2(GLint location, glm::uvec2 vec);
        void set_uniform_uint_vec2(const char* uniform_name, glm::uvec2 vec);
        
        void set_uniform_uint_vec3(GLint location, glm::uvec3 vec);
        void set_uniform_uint_vec3(const char* uniform_name, glm::uvec3 vec);
        
        void set_uniform_uint_vec4(GLint location, glm::uvec4 vec);
        void set_uniform_uint_vec4(const char* uniform_name, glm::uvec4 vec);

        void set_uniform_matrix_2f(GLint location, glm::mat2 mat, bool transpose = false);
        void set_uniform_matrix_2f(const char* uniform_name, glm::mat2 mat, bool transpose = false);
 
        void set_uniform_matrix_3f(GLint location, glm::mat3 mat, bool transpose = false);
        void set_uniform_matrix_3f(const char* uniform_name, glm::mat3 mat, bool transpose = false);
        
        void set_uniform_matrix_4f(GLint location, glm::mat4 mat, bool transpose = false);
        void set_uniform_matrix_4f(const char* uniform_name, glm::mat4 mat, bool transpose = false);
        
        void set_uniform_matrix_2x3f(GLint location, glm::mat2x3 mat, bool transpose = false);
        void set_uniform_matrix_2x3f(const char* uniform_name, glm::mat2x3 mat, bool transpose = false);
        
        void set_uniform_matrix_3x2f(GLint location, glm::mat3x2 mat, bool transpose = false);
        void set_uniform_matrix_3x2f(const char* uniform_name, glm::mat3x2 mat, bool transpose = false);
        
        void set_uniform_matrix_2x4f(GLint location, glm::mat2x4 mat, bool transpose = false);
        void set_uniform_matrix_2x4f(const char* uniform_name, glm::mat2x4 mat, bool transpose = false);
        
        void set_uniform_matrix_4x2f(GLint location, glm::mat4x2 mat, bool transpose = false);
        void set_uniform_matrix_4x2f(const char* uniform_name, glm::mat4x2 mat, bool transpose = false);
        
        void set_uniform_matrix_3x4f(GLint location, glm::mat2x4 mat, bool transpose = false);
        void set_uniform_matrix_3x4f(const char* uniform_name, glm::mat3x4 mat, bool transpose = false);
        
        void set_uniform_matrix_4x3f(GLint location, glm::mat4x3 mat, bool transpose = false);
        void set_uniform_matrix_4x3f(const char* uniform_name, glm::mat4x3 mat, bool transpose = false);
    };
}