Hi,

Hi,
here is a visualisation of the first 4 frames of what the program should do:



the x and y coordinates should be shifted everyframe. y+1, x+[i].
It's not a simple shift, because every frame all circles on display are being duplicated and another constraint would be that only the nonwhite pixels should be shifted.

 I tried using PImage and create a new image with all new pixels after every shift. But  more in pseudocode, because it seems a little complicated to me.

Hi,
I read some older thread about mapping midiinput to variables in the forums and decided to try it myself, since i have a "korg nanoKontrol".

I want to controll the RGB values of a stroke with 3 different controllers on the "nanoKontrol".
Here is what i got so far:

import themidibus.*;
MidiBus myBus;

void setup() {
  myBus = new MidiBus(this, 0, 2);
  size(200, 200);
}

void draw() {
}

void controllerChange(int channel, int number, int value) {
  int R = value*2;
  int G = value*2;
  int B = value*2;


  if (mousePressed==true) {
    stroke(R, G, B);
    line(mouseX, mouseY, pmouseX, pmouseY);
  }
}


 

I know the stroke() function belongs into the draw() function, because otherwise i can only draw while I change the controller.
I tried putting it in draw(), but then I can't access the value variable inside controllerChange().

How do I assign each RGB value a different channel number and its corresponding value? (So changing the first controller on the nanoKontrol will result in changing only the R value)

R= controllerChange(0, 2, int valueR)
G=controllerChange(0, 3, int valueG)
B=controllerChange(0, 4, int valueB)


Thanks!

rhklein

Hi,
I'm currently having a hard time understanding an array example from the book "Learning Procesing: A Beginner's Guide to Programming" by Daniel Shiffman.

The task is to make a programm so that the mouse will leave a trail of 50 circles behind. Here is the example code from the book:

1. // Daniel Shiffman
   // http://www.learningprocessing.com
   
   // Example 9-8: A snake following the mouse
   
   // Declare two arrays with 50 elements.
   int[] xpos = new int[50];
   int[] ypos = new int[50];
   
   void setup() {
     size(200,200);
     frameRate(1);
    
     smooth();
     // Initialize all elements of each array to zero.
     for (int i = 0; i < xpos.length; i ++ ) {
       xpos[i] = 0;
       ypos[i] = 0;
     }
   }
   
   void draw() {
     background(255);
    
     // Shift array values
     for (int i = 0; i < xpos.length-1; i ++ ) {
       // Shift all elements down one spot.
       // xpos[0] = xpos[1], xpos[1] = xpos = [2], and so on. Stop at the second to last element.
       xpos[i] = xpos[i+1];
       ypos[i] = ypos[i+1];
     }
   
    
     // New location
     xpos[xpos.length-1] = mouseX; // Update the last spot in the array with the mouse location.
     ypos[ypos.length-1] = mouseY;
    
    
     // Draw everything
     for (int i = 0; i < xpos.length; i ++ ) {
        // Draw an ellipse for each element in the arrays.
        // Color and size are tied to the loop's counter: i.
       noStroke();
       fill(255-i*5);
       ellipse(xpos[i],ypos[i],i,i);
      
     }
       println(xpos[48]);
    
   }

I'm trying to generate a random color transition with a few restrictions.

I want to change each HSB value like I can change the RGB values in Photoshop with a curve like this:

Of course processing needs the mathematical function to describe this gradient. (my first problem)

My second problem is generating random curves with a restriction that the curve never drops like this:


Here is what I got so far:

1. void setup(){
     size (300,300);
   }
   
    
   void draw() {
   
   colorMode(HSB);
   float h = 1.;
   float s = 1;
   float b = 1;
   for (float i = 0; i < 300; i++) {
    
      
       stroke(h, s, b);
       line(i, 0, i, 300);
       h += 0.5;
       s += 0.3;
       b +=0.8;
   }
   
   }
   

I'm a beginner, so bare with me.

Rheinhard