Shader.h

#ifndef SLIMEMOLDSIMULATION_SHADER_H
#define SLIMEMOLDSIMULATION_SHADER_H

#include <glm/glm.hpp>
#include <string>
#include <fstream>
#include <sstream>
#include <iostream>

class Shader {
    const std::string enumValues[3] = {"VERTEX", "FRAGMENT", "PROGRAM"};
    enum ShaderErrorType {
        VERTEX, FRAGMENT, PROGRAM
    };

public:
    unsigned int ID;

    Shader(const char *vertexPath, const char *fragmentPath) {
        std::string vertexShader;
        std::string fragmentShader;
        std::ifstream vertexShaderFile;
        std::ifstream fragmentShaderFile;

        vertexShaderFile.exceptions(std::ifstream::failbit | std::ifstream::badbit);
        fragmentShaderFile.exceptions(std::ifstream::failbit | std::ifstream::badbit);
        try {
            vertexShaderFile.open(vertexPath);
            fragmentShaderFile.open(fragmentPath);
            std::stringstream vertexStream, fragmentStream;

            vertexStream << vertexShaderFile.rdbuf();
            fragmentStream << fragmentShaderFile.rdbuf();

            vertexShaderFile.close();
            fragmentShaderFile.close();

            vertexShader = vertexStream.str();
            fragmentShader = fragmentStream.str();
        } catch (std::ifstream::failure &e) {
            std::cout << "ERROR: Could not read shader file" << std::endl;
        }
        const char *vShader = vertexShader.c_str();
        const char *fShader = fragmentShader.c_str();

        uint32_t vertex, fragment;

        // Vertex Shader
        vertex = glCreateShader(GL_VERTEX_SHADER);
        glShaderSource(vertex, 1, &vShader, NULL);
        glCompileShader(vertex);
        checkCompileErrors(vertex, ShaderErrorType::VERTEX);

        // Fragment Shader
        fragment = glCreateShader(GL_FRAGMENT_SHADER);
        glShaderSource(fragment, 1, &fShader, NULL);
        glCompileShader(fragment);
        checkCompileErrors(fragment, ShaderErrorType::FRAGMENT);

        // Shader Program
        ID = glCreateProgram();
        glAttachShader(ID, vertex);
        glAttachShader(ID, fragment);
        glLinkProgram(ID);
        checkCompileErrors(ID, ShaderErrorType::PROGRAM);

        glDeleteShader(vertex);
        glDeleteShader(fragment);
    }

    void use() const {
        glUseProgram(ID);
    }

    // utility uniform functions
    // ------------------------------------------------------------------------
    [[maybe_unused]]
    void setBool(const std::string &name, bool value) const {
        glUniform1i(glGetUniformLocation(ID, name.c_str()), (int) value);
    }

    // ------------------------------------------------------------------------
    [[maybe_unused]]
    void setInt(const std::string &name, int value) const {
        glUniform1i(glGetUniformLocation(ID, name.c_str()), value);
    }

    // ------------------------------------------------------------------------
    [[maybe_unused]]
    void setFloat(const std::string &name, float value) const {
        glUniform1f(glGetUniformLocation(ID, name.c_str()), value);
    }

    // ------------------------------------------------------------------------
    [[maybe_unused]]
    void setVec2(const std::string &name, const glm::vec2 &value) const {
        glUniform2fv(glGetUniformLocation(ID, name.c_str()), 1, &value[0]);
    }

    [[maybe_unused]]
    void setVec2(const std::string &name, float x, float y) const {
        glUniform2f(glGetUniformLocation(ID, name.c_str()), x, y);
    }

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

    [[maybe_unused]]
    void setVec3(const std::string &name, float x, float y, float z) const {
        glUniform3f(glGetUniformLocation(ID, name.c_str()), x, y, z);
    }

    // ------------------------------------------------------------------------
    [[maybe_unused]]
    void setVec4(const std::string &name, const glm::vec4 &value) const {
        glUniform4fv(glGetUniformLocation(ID, name.c_str()), 1, &value[0]);
    }

    [[maybe_unused]]
    void setVec4(const std::string &name, float x, float y, float z, float w) const {
        glUniform4f(glGetUniformLocation(ID, name.c_str()), x, y, z, w);
    }

    // ------------------------------------------------------------------------
    [[maybe_unused]]
    void setMat2(const std::string &name, const glm::mat2 &mat) const {
        glUniformMatrix2fv(glGetUniformLocation(ID, name.c_str()), 1, GL_FALSE, &mat[0][0]);
    }

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

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

private:
    // utility function for checking shader compilation/linking errors.
    // ------------------------------------------------------------------------
    void checkCompileErrors(GLuint shader, ShaderErrorType type) {
        GLint success;
        unsigned int logSize = 1024;
        GLchar infoLog[logSize];
        if (type != ShaderErrorType::PROGRAM) {
            glGetShaderiv(shader, GL_COMPILE_STATUS, &success);
            if (!success) {
                glGetShaderInfoLog(shader, 1024, NULL, infoLog);
                std::cout << "ERROR::SHADER_COMPILATION_ERROR of type: " << enumValues[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: " << enumValues[type] << "\n"
                          << infoLog << "\n -- --------------------------------------------------- -- " << std::endl;
            }
        }
    }
};

#endif