apologies if this has been asked before.

I've got a sketch where I want to be able to "chord" keypresses - you hold down one key, then another, and both key presses can be detected.

Here's the code...

1. void keyPressed() {
2.   if (key=='p') lambda0+=.025;
3.   if (key=='o') lambda0-=.025;
4.   if (key=='q') theta1+=.025;
5.   if (key=='a') theta1-=.025;
6.   if (key==' ') {
7.     lambda0=0;
8.     theta1=0;
9.   }
10. }
    

If I hold down 'p', the value of key is 'p' - until I press 'a', then it's 'a' all the way. I want to be able to trigger lines 2 and 5 if the user holds down the keys 'p' and 'a' at the same time.

Is there any way to detect when the user has held down multiple keys?

thanks,

Steve