Implemented logging utilities

source/app/src/App.cpp

@@ -1,24 +1,31 @@
 #include "App.hpp"
 
-#include <cstdlib>
 #include <iostream>
 
 #include <GL/glew.h>
 #include <GLFW/glfw3.h>
 
+#include "LogUtils.hpp"
 #include "ShaderProgramBuilder.hpp"
+#include "TimestampLog.hpp"
+
 
 int App::main(std::vector<std::string> &args) {
+    auto cerrLog = ugly::TimestampLog{std::cerr, "ugly::log"};
+    ugly::log = ugly::LogAlias{&cerrLog};
+    ugly::log("hello, world! app started.");
+
     auto app = App{};
     app.game_loop();
-    return EXIT_SUCCESS;
+
+    ugly::log("app quitting.");
+    return 0;
 }
 
 
 void App::error_callback_s(int error, const char *description)
 {
-    std::cerr << "[GLFW error]: " << description << '\n';
-    exit(EXIT_FAILURE);
+    ugly::log("(glfw error): {}", description);
 }
 
 
@@ -45,7 +52,7 @@ App::App():
     glfwMakeContextCurrent(mpWindow);
     glewExperimental = GL_TRUE;
     if(glewInit() != GLEW_OK) {
-        error_callback_s(GLFW_NO_ERROR, "glewInit() failed");
+        ugly::log("glewInit() failed!");
     }
 
     float vertices[] = {