Workshop › OutRun-style Racer › Step 27 of 44

Which segment am I on?

What we are doing

To feel a curve, the car must know which segment it is on. segmentAt(z) gives the segment at a distance z along the track. Our car is PLAYER_Z in front of the camera, so it is on segmentAt(position + PLAYER_Z).

```js
const PLAYER_Z = CAMERA_HEIGHT * DEPTH // how far in front of the camera the player's car is

const segmentAt = (z) => segments[Math.floor(z / SEG) % segments.length]
```

What it means

• PLAYER_Z is how far in front of the camera the bottom of the screen is: about 839 units.
• Math.floor(z / SEG) is the segment number, % segments.length wraps past the end of the track, and segments[...] takes that element (numbers start at 0).

Your turn

1. Under the DEPTH line write PLAYER_Z.
2. Above function update() { write segmentAt, followed by an empty line.

Skills: Arrays and objects

← No jumps in the curve Curves pull you outwards →

All steps

1. Sky and ground
2. Draw again and again
3. Perspective
4. One piece of road
5. A road made of segments
6. Where we are on the track
7. The road ahead
8. Stripes
9. Paint from far to near
10. Kerbs and a center line
11. Striped grass
12. Moving is one number
13. Which keys are down?
14. The gas pedal
15. Brake, coast and a top speed
16. Your car
17. Speedometer
18. A pedal for phones
19. Move the camera sideways
20. Steering
21. No turning on the spot
22. The grass is slow
23. Steering by touch
24. A track with curves
25. Bend the road
26. No jumps in the curve
27. Which segment am I on?
28. Curves pull you outwards
29. Other cars
30. Distance on a loop
31. Cars that shrink with distance
32. Traffic moves
33. Rear-end crash
34. Counting laps
35. Show the lap
36. A lap timer
37. Show the time
38. Best lap
39. Show the best lap
40. Racing or finished
41. The finish line
42. Finished!
43. Race again
44. Build it yourself: beat the clock