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I have a recurring problem that when I'm controlling leds, I make several different functions for different fx and just want to trigger them randomly but having a hard time to formulate it in an intelligent way and end up hardcoding every function call.

ex: I have let's say 10 functions called anim1();, anim2();, anim3(); etc and would like to called them randomly in that fashion :

randNumber = random(1,11);
anim[randNumber]();

I know that it's not that type of brackets I need to use but I can't find the proper syntax and I'm wondering if it's possible to do that.. I'm sure there must be a way ;)

thanks for your help

share|improve this question
up vote 3 down vote

What you want is an array of function pointers.

void anim1() {
    // blah blah
}

void anim2() { 
    // blah blah
}
// ... etc ...

typedef void (*animptr)();

animptr anims[10] = {
    anim1,
    anim2,
    anim3,
    // ... etc ...
    anim10
};

Then you can use:

anims[animNumber]();
share|improve this answer
    
You mean typedef void (*animptr)();. – Edgar Bonet May 21 at 12:42
    
Yes, I do. Thanks for spotting that. – Majenko May 21 at 12:43
    
I didn't know this was possible. But I think I would feel dirty when using it. It just seems wrong to do this. – Gerben May 21 at 13:46
    
Why so? Function pointers are one of the most powerful facilities of C. Imagine trying to implement callbacks without being able to use function pointers - and an array of them is just an extension of that. A function is, after all, just a location in memory... – Majenko May 21 at 13:47
    
thanks so much Majenko! exactly what i was looking for! :D – robophil May 23 at 0:56
up vote 0 down vote

I end up using another way and just wanted to share it here for anybody that would want a bit less efficient but simpler way of doing that ;) it's cleaner with Majenko's solution for sure but this gets the job done and is pretty easy to understand and troubleshoot. cheers!

int randNumber;

void loop(){
randNumber = random(1,14);

if (button is pressed or something){
callAnim(randNumber);
}
}


void callAnim(int randNumber){
if (randNumber==1){
anim1();
}
if (randNumber==2){
anim2();
}
}
// ... etc ...

void anim1() {
// blah blah
}

void anim2() { 
// blah blah
}
// ... etc ...
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