Game Dev From Zero · Episode 4

Delta race

Three ghosts, three pretend computers, each running at its own frame rate. Same code in every lane. Race them without delta time, then with it, and see who wins.

The race each lane only moves on its own frames

Lag! freezes that computer for half a second, like a real hiccup.

The update line every lane runs this


      

        
lanedeltamovedx

        
      

    


    

      
Things to try

      
    
        
  1. Press Race! with delta time off. Who wins? Is that fair?
    2. 
        
  2. Switch use delta time on and race again. (The times can still differ by a hair: each lane can
            only cross the line on one of its own frames.)
    3. 
        
  3. Set a lane to 10 FPS. With delta on it's choppy... but is it slower?
    4. 
        
  4. Mid-race, press Lag! on a lane, once with delta off and once with it on.
    5. 
        
  5. Look at the 60 FPS lane: it's the same with or without delta. Why? (Hint: 60 × 1/60 = 1.)
    6.