How to properly set up GLFW for a c project?

July 29, 2023

I am working on an OpenGL project which makes use of GLFW and OpenGL, however I cannot manage to successfully include GLFW in my project.

I am on Linux Mint, and am using C code compiled via terminal with clang version 10.0.0-4ubuntu1. IDE is Visual Studio Code.

Code:

#include "gui/window.h"

void key_callback(GLFWwindow* window, int key, int scancode, int action, int mods) {
    if (key == GLFW_KEY_ESCAPE && action == GLFW_PRESS) {
        glfwSetWindowShouldClose(window, GLFW_TRUE);
    }
}

int windowMain() {
    // Initialize GLFW
    if (!glfwInit()) {
        fprintf(stderr, "Failed to initialize GLFW\n");
        return -1;
    }

    // Create a window and OpenGL context
    GLFWwindow* window = glfwCreateWindow(800, 600, "Basic OpenGL Window", NULL, NULL);
    if (!window) {
        fprintf(stderr, "Failed to create GLFW window\n");
        glfwTerminate();
        return -1;
    }

    // Set the window as the current context
    glfwMakeContextCurrent(window);

    // Set the key callback function
    glfwSetKeyCallback(window, key_callback);

    // Main loop
    while (!glfwWindowShouldClose(window)) {
        // Render here

        // Swap front and back buffers
        glfwSwapBuffers(window);

        // Poll for and process events
        glfwPollEvents();
    }

    // Terminate GLFW
    glfwTerminate();
    return 0;
}

Header file (gui/window.h):

#ifndef WINDOW_H
#define WINDOW_H

#include <stdio.h>
#include <GLFW/glfw3.h>

int windowMain();

#endif // WINDOW_H

IntelliSense fails to find GLFW/glfw3.h, and ld says the following:

    /usr/bin/ld: build/gui/window.o: in function `key_callback':
    /home/stv/work/c/crss/src/gui/window.c:5: undefined reference to `glfwSetWindowShouldClose'
    /usr/bin/ld: build/gui/window.o: in function `windowMain':
    /home/stv/work/c/crss/src/gui/window.c:12: undefined reference to `glfwInit'
    /usr/bin/ld: /home/stv/work/c/crss/src/gui/window.c:18: undefined reference to `glfwCreateWindow'
    /usr/bin/ld: /home/stv/work/c/crss/src/gui/window.c:21: undefined reference to `glfwTerminate'
    /usr/bin/ld: /home/stv/work/c/crss/src/gui/window.c:26: undefined reference to `glfwMakeContextCurrent'
    /usr/bin/ld: /home/stv/work/c/crss/src/gui/window.c:29: undefined reference to `glfwSetKeyCallback'
    /usr/bin/ld: /home/stv/work/c/crss/src/gui/window.c:32: undefined reference to `glfwWindowShouldClose'
    /usr/bin/ld: /home/stv/work/c/crss/src/gui/window.c:36: undefined reference to `glfwSwapBuffers'
    /usr/bin/ld: /home/stv/work/c/crss/src/gui/window.c:39: undefined reference to `glfwPollEvents'
    /usr/bin/ld: /home/stv/work/c/crss/src/gui/window.c:43: undefined reference to `glfwTerminate'

As far as I can tell, the linker cannot find the correct files to include, but I am pretty bad at configuring projects like this and have no idea how to fix this.

I installed glfw using the following commands:

sudo apt-get update
sudo apt-get install libglfw3 libglfw3-dev

and also tried messing around with different flags, the flags in my makefile (I use make to compile and run everything) are: -lGL -lglfw3 -lm -lX11 -lXxf86vm -lXrandr -lpthread -lXi -ldl however clang also complains that these linker inputs are ‘unused’. I’m not quite sure how to correctly set up this kind of project, and since most online tutorials are c++, I’ve been having a hard time finding tutorials for OpenGL using generic C.

Thank you for your time.