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simple color mixer with controller (Read 674 times)

milc

simple color mixer with controller
Feb 17^th, 2009, 3:30am

hi,

I try to make a very simple RGB color mixer with MIDI controller faders to set RGB values.
I use proMIDI lib to connect my fader box, and to assign each fader RGB values, I use this lines of code.

void controllerIn(Controller controller, int device, int channel){
int num = controller.getNumber();
int val = controller.getValue();

//println(num + "and" + val);
//every fader has controller number of 7
int r = 0;
int g = 0;
int b = 0;
if (channel == 0){

val = r;

}
if (channel == 1){

val = g;

}
if (channel == 2){

val = b;

}
colorMode(RGB, 127, 127, 127);
background(r, g, b);
}

but it doesn't work.
for me, it's quite obvious to store incoming data to variables then use it in a function.

can you guys see where's the problem?

thank you.

PhiLho YaBB Moderator Offline Posts: 4190 Near Paris (France)	Re: simple color mixer with controller Reply #1 - Feb 17^th, 2009, 9:55am Might work better if you write: `r = val;` and similar instead of the reverse... Note that with this code, you don't mix, you will have only one primary color set at a time. You might want to keep the r g b variables outside of the function.

milc Junior Member Offline Posts: 52	Re: simple color mixer with controller Reply #2 - Feb 17^th, 2009, 12:14pm thanks, it works in that way. but as you said, it does not mix color at all. I have honestly no idea at all where to start to make a working color mixer. any kind of little help will be appriciated. an example, a website, a reference...whaetver. thanks a lot.

PhiLho

Re: simple color mixer with controller
Reply #3 - Feb 17^th, 2009, 5:06pm

Perhaps try:
Code:

int r = 0;
int g = 0;
int b = 0;
void controllerIn(Controller controller, int device, int channel) {
  //every fader has controller number of 7
  int num = controller.getNumber(); 
  int val = controller.getValue();
  if (channel == 0) {
    r = val;
  } else if (channel == 1) {
    g = val;
  } else if (channel == 2) {
    b = val;
  }
  colorMode(RGB, 127, 127, 127);
  background(r, g, b);
}

I no longer have Midi devices, so I can't try.

milc

Re: simple color mixer with controller
Reply #4 - Feb 17^th, 2009, 5:36pm

thank you infinitely, it works very very fine.
though I don't really get the idea how "else if" can change all...

I'm really sorry to bother you again, but there's one other small problem, that is the alpha value in background function not working at all. I've just added

int a = 0;
...
else if (channel == 3){
a = val;
}
...
colorMode(RGB, 127,127,127,127);
background(r,g,b,a);

for me, it has to work as other values, can you see what's going on here?

PhiLho

Re: simple color mixer with controller
Reply #5 - Feb 17^th, 2009, 6:16pm

The else changes nothing...

That's only a pet peeve of mine, I think once you have found one value, there is no need to test the next values.
Here, it is just a question of style, as performance is unchanged, of course.

I think you got the alpha right, but by definition, background is below everything, so you won't see anything by transparency: the alpha value cannot be seen (it alone doesn't change luminosity/brightness or something like that).

milc

Re: simple color mixer with controller
Reply #6 - Feb 17^th, 2009, 6:32pm

I finally understood and confirmed my understanding of alpha by successfully placing a rect under another rect that I control the alpha value.

I'll develop further my color mixer by layering rects and use different color schemes. if it'll go well, I'll post here later.

it has been a good lesson to have thread with you.

thank you very much.

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