BPM Counter / step sequencer

I've just cobbled together a very basic BPM-based sound trigger / sequencer.

Attach the script to an object with an audiosource (preferably a drum sound - kick, snare, hat) and in the inspector you can set the BPM, the notes on/off pattern, and the step size.

I've tried a few 4/4 combos around 120 bpm and it seems ok, though I suspect the timing is not as tight as it could be.

Is there a better method for solid timing than calling InvokeRepeating?

Code (csharp):

1. #pragma strict
2. #pragma implicit
3. #pragma downcast
4.  
5. var BPM : float = 120.0;
6. private var t : float = 0.0;
7. var beatgrid : int[]; // in inspector assign 0/1 for beat on/off on individual step
8. private var beatmarker : int=0;
9. var steps : int = 4;
10.  
11. function Start(){
12.    
13.     t = BPM/60.0; // how many beats per second 
14.     t=(1.0/t)/steps; // divide by steps
15.     beatmarker=0;
16.     InvokeRepeating("Trigger",0,t);
17. }
18.  
19.  
20. function Trigger () {
21.    
22.     if (beatgrid[beatmarker]==1)audio.Play();
23.     beatmarker+=1;
24.     if (beatmarker>beatgrid.length-1)beatmarker=0;
25. }

Feel free to use / modify

 

Try Fixed Update