Thread: SDL_Timer

I'm trying to use SDL_AddTimer or SDL_SetTimer, it's the same... My problem is that I don't know what I'm doing wrong with the callback function... I have this method:

Code:

Uint32 showNextFrame(Uint32 interval,void*param){

.........

return interval
}

And then on another method within the same class I have:

Code:

SDL_AddTimer(30,showNextFrame, NULL);

I'm getting this error:

error C2664: 'SDL_AddTimer' : cannot convert parameter 2 from 'unsigned __int32 (unsigned __int32,void *)' to 'unsigned __int32 (__cdecl *)(unsigned __int32,void *)'

You have to declare the showNextFrame() function as "__cdecl Uint32"

Doesn't seem to be working... The first error it shows me now is:

error C2146: syntax error : missing ';' before identifier 'showNextFrame'

Originally Posted by manugarciac

Doesn't seem to be working... The first error it shows me now is:

error C2146: syntax error : missing ';' before identifier 'showNextFrame'

I need to see the line of code.

Code:

__cdecl Uint32 showNextFrame(Uint32 interval,void*param){
....
}

I noticed that if I take it out of the class and use it as a global function, it works... Do you have any idea how to make it work without having to do that?

Originally Posted by manugarciac

I noticed that if I take it out of the class and use it as a global function, it works... Do you have any idea how to make it work without having to do that?

I don't think an SDL callback can be an object method. It would have no way of knowing what the "this" pointer is, since C++ doesn't have such a concept as a bound method pointer.

I guess you are right... And I can't take the function out, it'd completely mess my encapsulation... What do you recommend? I have a set of bmps, that act like different frames in a video... Suppose I have to show them at 20fps, that would mean I need to show the next frame every 50ms. That's why I was trying to use those functions... Do you have any ideas?