Shader.h

#pragma once

#include <glad/glad.h>

#include <glm/glm.hpp>
#include <glm/gtc/type_ptr.hpp>
#include <glm/gtc/matrix_transform.hpp>

#include <string>
#include <fstream>
#include <sstream>
#include <iostream>

class Shader
{
public:
    unsigned int ID = 0;
    
    Shader(const char* vertexPath, const char* fragmentPath)
    {
        std::string vertexCode;
        std::string fragmentCode;
        std::ifstream vShaderFile;
        std::ifstream fShaderFile;
        
        vShaderFile.exceptions(std::ifstream::failbit | std::ifstream::badbit);
        fShaderFile.exceptions(std::ifstream::failbit | std::ifstream::badbit);
        try
        {
            vShaderFile.open(vertexPath);
            fShaderFile.open(fragmentPath);
            std::stringstream vShaderStream, fShaderStream;

            vShaderStream << vShaderFile.rdbuf();
            fShaderStream << fShaderFile.rdbuf();

            vShaderFile.close();
            fShaderFile.close();

            vertexCode = vShaderStream.str();
            fragmentCode = fShaderStream.str();
        }
        catch (std::ifstream::failure& e)
        {
            std::cout << "ERROR::SHADER::FILE_NOT_SUCCESFULLY_READ: " << e.what() << std::endl;
        }


        const char* vShaderCode = vertexCode.c_str();
        const char* fShaderCode = fragmentCode.c_str();

        unsigned int vertex, fragment;  ////Insert a compute shader in the future

        vertex = glCreateShader(GL_VERTEX_SHADER);
        glShaderSource(vertex, 1, &vShaderCode, NULL);
        glCompileShader(vertex);
        checkCompileErrors(vertex, "VERTEX");

        fragment = glCreateShader(GL_FRAGMENT_SHADER);
        glShaderSource(fragment, 1, &fShaderCode, NULL);
        glCompileShader(fragment);
        checkCompileErrors(fragment, "FRAGMENT");

        ID = glCreateProgram();
        glAttachShader(ID, vertex);
        glAttachShader(ID, fragment);
        glLinkProgram(ID);
        checkCompileErrors(ID, "PROGRAM");
        // delete the shaders as they're linked into our program now and no longer necessary
        glDeleteShader(vertex);
        glDeleteShader(fragment);
    }
    
    void use()
    {
        glUseProgram(ID);
    }
   
    void setBool(const std::string& name, bool value) const
    {
        glUniform1i(glGetUniformLocation(ID, name.c_str()), (int)value);
    }

    void setInt(const std::string& name, int value) const
    {
        glUniform1i(glGetUniformLocation(ID, name.c_str()), value);
    }
    
    void setFloat(const std::string& name, float value) const
    {
        glUniform1f(glGetUniformLocation(ID, name.c_str()), value);
    }

    void setVec3(const std::string& name, const glm::vec3& value) const
    {
        glUniform3fv(glGetUniformLocation(ID, name.c_str()), 1, &value[0]);
    }

    void setMat3(const std::string& name, glm::mat3& mat) const
    {
        glUniformMatrix3fv(glGetUniformLocation(ID, name.c_str()), 1, GL_FALSE, &mat[0][0]);
    }

    void setMat4(const std::string& name, glm::mat4 &mat) const
    {
        glUniformMatrix4fv(glGetUniformLocation(ID, name.c_str()), 1, GL_FALSE, &mat[0][0]);
    }

    void destroy()
    {
        glDeleteShader(ID);
    }

private:
    void checkCompileErrors(unsigned int shader, std::string type)
    {
        int success;
        char infoLog[1024];
        if (type != "PROGRAM")
        {
            glGetShaderiv(shader, GL_COMPILE_STATUS, &success);
            if (!success)
            {
                glGetShaderInfoLog(shader, 1024, NULL, infoLog);
                std::cout << "ERROR::SHADER_COMPILATION_ERROR of type: " << type << "\n" << infoLog << "\n -- --------------------------------------------------- -- " << std::endl;
            }
        }
        else
        {
            glGetProgramiv(shader, GL_LINK_STATUS, &success);
            if (!success)
            {
                glGetProgramInfoLog(shader, 1024, NULL, infoLog);
                std::cout << "ERROR::PROGRAM_LINKING_ERROR of type: " << type << "\n" << infoLog << "\n -- --------------------------------------------------- -- " << std::endl;
            }
        }
    }

};