rework logging to be more optimised, and some minor improvements.

removed function definitions and opted for using macros instead.
It now does not have a set limit when it comes to printing (at least,
it's the stdc's limit again). However, it is now no longer possible to
use a character pointer to print information to the screen.

src/main.c

@@ -5,6 +5,7 @@
 #undef GLAD_GL_IMPLEMENTATION
 
 #include <GLFW/glfw3.h>
+#include <stdio.h>
 #include <stdlib.h>
 
 #include "error.h"
@@ -15,6 +16,11 @@
 #define WIN_DEFAULT_WIDTH  640
 #define WIN_DEFAULT_HEIGHT 480
 
+// callback for GLFW errors
+static void error_callback(int err, char const* const msg) {
+	fprintf(stderr, "\033[91mE: glfw returned (%i); \"%s\"\033[0m\n", err, msg);
+}
+
 static inline int init(void) {
 	glfwSetErrorCallback(error_callback);
 	glfwInitHint(GLFW_JOYSTICK_HAT_BUTTONS, GLFW_FALSE); // disable joystick buttons
@@ -31,7 +37,7 @@ static inline void quit(void) {
 
 int main(int argc, char** argv) {
 	(void)argc, (void)argv;
-
+	printf("debug: [DBG], info: [INF], warning: [WAR], error: [ERR], fatal: [FAT]\n");
 	if (init()) fatal("failed to initialize!");
 
 	window_loop();