refactor: use GLFW time

This removes the requirement for std::chrono

src/hello.cpp

@@ -42,19 +42,9 @@
 #include <iostream>
 #include <string>
 
-#include <chrono>
-
 #include "gfx.hpp"
 #include "triangle.hpp"
 
-std::chrono::steady_clock::time_point startTime = std::chrono::steady_clock::now();
-float getTime()
-{
-    std::chrono::steady_clock::time_point now = std::chrono::steady_clock::now();
-    std::chrono::duration<float> timeSpan = std::chrono::duration_cast<std::chrono::duration<float>>(now - startTime);
-    return timeSpan.count();
-}
-
 #include <cmath>
 #include "astro/twoBodyMethods.hpp"
 
@@ -114,7 +104,7 @@ int main()
         glClearColor(0.2, 0.3, 0.3, 1.0);
         glClear(GL_COLOR_BUFFER_BIT);
 
-        triangle.render(getTime());
+        triangle.render(glfwGetTime());
 
         glfwSwapBuffers(window);
         glfwPollEvents();