Limit a parameter to max-min depending to the width ? and Midi assignment ?

Programming Questions

GiorgioMa..

Limit a parameter to max-min depending to the width ? and Midi assignment ?

in Programming Questions • 1 years ago

Hi,

I want to set the mouseX to control the value of something.

But,if my window is 400px width, i dont want the values to be from 0 to 400, instead i want it to send from 0 to and 1

0 being 0 and 1 being 400px.

How do i do this ?

And also how do i map this parameter o my midi controler ?

Thanx !

Replies(6)

jun.jk

Re: Limit a parameter to max-min depending to the width ? and Midi assignment ?

1 years ago

With your first question, let's think about it mathematically. You have a value between 0 and 400. You want it to be between 0 and 1. Halfway from 0 to 400 is 200. Halfway from 0 to 1 is 0.5. What mathematical operation could you perform on 0 such that it equals 0, on 200 such that it equals 0.5, and on 400 such that it equals 1?

As to your second question, have a look here for starters.

GiorgioMa..

Re: Re: Limit a parameter to max-min depending to the width ? and Midi assignment ?

1 years ago

Thanx , i tried to divide mouseX between 400, as i want that at 0 in the x axis of the window the valuebe 0,

and i want the maximum value(width ) to be 1.

But now, it jumps from 0 to 1, and it bypasses all the numbers in between like 0,1 0,25 , 0,6 etc..

float time =0;

void setup () {

size ( 800, 400);

smooth();

background(255);

frameRate (25);

}

void draw () {

float x =0 ;

float m1 ;

fill ( #1D2124,10);

noStroke ();

rect (0, 0, width, height);

while ( x<width ) {

strokeWeight (3);

stroke ( 255);

point (x, height* noise(x/100, time));

x=x+10;

}

m1 = mouseX/400;

time = time+m1;

println ( m1 );

what is wrong ?

Thanx !

and about the midi link you send me.... mm what ? i just see a self paying midi piano..

i just want to assign a midi knob to a variable... any ideas on how to do this the easy way ?

thanx !

jun.jk

Re: Limit a parameter to max-min depending to the width ? and Midi assignment ?

1 years ago

You need to cast mouseX to a float like this:

m1 = float(mouseX) / 400;

The link I gave you gives a simple example of how to use Java's MIDI package in Processing. It is documented in full here.

GiorgioMa..

Re: Re: Limit a parameter to max-min depending to the width ? and Midi assignment ?

1 years ago

Awesome ! Thanx !

Now i want to do the same thing for the mouseY controlling the spacing between points...

but i get a white scree :( can u help me ?

thanx !

float time =0;

void setup () {

size ( 800, 400);

smooth();

background(255);

frameRate (25);

}

void draw () {

float x =0 ;

float m1=0 ;

float m2=0;



fill ( #1D2124, 50);

noStroke ();

rect (0, 0, width, height);

while ( x<width ) {

strokeWeight (3);

stroke ( 255);

point (x, height* noise(x/100, time));

x=x+m2;

}

m1 = float(mouseX) / 400;

time = time+m1;



m2 = mouseY/20;





}

jun.jk

Re: Limit a parameter to max-min depending to the width ? and Midi assignment ?

1 years ago

There are a number of problems here. One is that you are not using a do while statement correctly. You probably mean to be using an if statement. Please take a look at the documentation. Also, like mouseX, you need to cast mouseY to a float. There's another problem but you may see it once you correct these.

GiorgioMa..

Re: Re: Limit a parameter to max-min depending to the width ? and Midi assignment ?

1 years ago

Hi, thanx !

I finally did it with 2 for loops.

But , 2 problems :

Sometimes it just draws half the screen 8?

and if sometimes the mouse goes out of the screen , the sketch hangs 8?

Any ideas on whats the problem ? Thanx !

also, how to make the effect not just in the upper left corner but that is uses a larger range so that the changes arent so fast?