title: What's the most efficient way to simulate a car's ECU logic?
body: <p>I've been thinking a lot lately when driving my car - inside the ECU there is a memory module with pre-calculated values for almost anything. For example, the ECU can calculate how much fuel to inject based on several readings such as throttle position, current RPM's, etc. When people remap their cars they change the predefined values which in turn changes the output calculated in realtime by the ECU. Let's keep it simple and imagine we have 2 parameters we constantly juggle around on a predefined 2D graph. We have 4 reference points: A1(2000 RPM - 200 foo units), A2(3000 RPM - 270 foo units), A3(4000 RPM - 350 foo units), A4(5000 RPM - 400 foo units). So the question I'm struggling with is how can you calculate the exact amount of foo units on let's say 3650 RPM in realtime on "slow" hardware without any errors or delays. I'd love to see some C style pseudo code on how it could be implemented logic-wise to run efficiently. The first thing that comes to my mind are 2 arrays (a matrix), but things get messy when you account for multiple variables making a difference on the final outcome. I'd like to experiment with this and try to write a small program to do this kind of math, but I'm stuck on choosing the clean, sane way of representing and manipulating values...</p>
  
  <p>Sorry for no formatting, wrote this post on my phone!</p>