added framerate control

src/engine/Engine.java

@@ -151,11 +151,14 @@ public class Engine {
         smiley2.translate(new Vector3f(0.0f,0.0f,10.0f));
 
         long timer = System.currentTimeMillis();
+        long lastFrame = System.currentTimeMillis();
         int frame = 0;
+        boolean nextFrame = false;
 
         while(engine.isRunning()){
             // Game logic should fit here
             double time = glfwGetTime();
+            lastFrame = System.currentTimeMillis();
 
             smiley.translate(new Vector3f( (float) Math.sin(time), (float) Math.cos(time), 0.0f));
 
@@ -173,6 +176,11 @@ public class Engine {
                 frame = 0;
             }
 
+            while(!nextFrame){
+                nextFrame = System.currentTimeMillis() - lastFrame >= 16.66f;
+            }
+
+            nextFrame = false;
             if(engine.shouldClose()) engine.setRunning(false);
         }
     }