New to Processing - Help making rainbow drawer!?

Programming Questions

dexteredw..

New to Processing - Help making rainbow drawer!?

in Programming Questions • 8 months ago

Hi, I am trying to make a rainbow drawer so that a line drawn continuously cycles through colours of the rainbow. At the moment I have a program that draws the line as a rainbow, but it doesn't cycle through the colours. I am new to Programming so I'm not sure of the best way to do this but I was thinking of using the color mode 'HSB' to constantly change the hue, is there a way to apply this to the 'whole display' if you get what I mean?

Here is the code I have so far:

float colourdegrees = 0;
void setup(){
size(400,400);
colorMode(HSB, 360, 100, 100);
background(360);
}
void line() {
stroke(colourdegrees, 97, 100);
strokeWeight(16);
smooth();
if(mousePressed){
line(mouseX, mouseY, pmouseX, pmouseY);
colourdegrees=colourdegrees+1.5;
if(colourdegrees > 359) {
colourdegrees = 0;
}
}
}
void draw() {
line();
}

Thanks in advance!

Replies(4)

tfguy44

Re: New to Processing - Help making rainbow drawer!?

8 months ago

Pretty! Give me 15 minutes and I'll be back with a working version of what you want.

tfguy44

Re: New to Processing - Help making rainbow drawer!?

8 months ago

float colourdegrees = 0;
class RainbowLine {
int x, y, px, py;
float off;
RainbowLine() {
x=mouseX;
y=mouseY;
px=pmouseX;
py=pmouseY;
off=colourdegrees;
}
void draw() {
stroke( (colourdegrees+off)%360, 97, 100);
line(x, y, px, py);
}
}
ArrayList RainbowLines;
void setup() {
size(400, 400);
strokeWeight(16);
smooth();
colorMode(HSB, 360, 100, 100);
background(360);
RainbowLines = new ArrayList();
}
void draw() {
background(360);
// Add new line?
if (mousePressed){
RainbowLines.add( new RainbowLine() );
}
// Cycle colors.
colourdegrees+=1.5;
colourdegrees%=360;
// Render all lines
for( int i = 0; i < RainbowLines.size(); i++ ){
RainbowLine t = (RainbowLine) RainbowLines.get(i);
t.draw();
}
// Limit ArrayList size (optional)!
while( RainbowLines.size() > 400 ){
RainbowLines.remove(0);
}
}
void keyPressed(){
if( key == ' ' ){
RainbowLines = new ArrayList();
}
}

dexteredw..

Re: New to Processing - Help making rainbow drawer!?

8 months ago

wow great! thanks for your help!

GoToLoop

Re: New to Processing - Help making rainbow drawer!?

8 months ago

I was really thinking that you wanted a literal drawer w/ rainbows!

Anyways, it's a rly nicey Nyan effect!

So nice that I've decided to make an "enhanced" version of it.
But this time, replacing ArrayList w/ ArrayDeque.

That is so b/c an ArrayList is extremely slow to remove its 1st element -> remove(0);
It needs to shift each element to left afterwards. A daunting heavy task indeed!

However, an ArrayDeque can remove an item from the beginning (or from its tail too),
w/o any need of shifting!!!

Other mods I did was to use callback function mouseDragged() and method clear() to remove all rainbows!

Check it out for yourselves:

/**
 * Rainbow Drawing (v3.0)
 * by:  DexteredWards (2013/Feb)
 * mod: tfguy44
 * enh: GoToLoop
 * 
 * http://forum.processing.org/topic/help-making-rainbow-drawer
 */

//import java.util.*;

final static short maxRainbows = 02000;
final static Queue
               
                <Rainbow> rainbows = 
                new ArrayDeque(maxRainbows);


                boolean isFull;

                short numRainbows;

                color shades;


                void 
                setup() {
  
                size(800, 600);
  
                colorMode(
                HSB, 360, 100, 100);
  
                frameRate(50);
  
                smooth();
  
                strokeWeight(16);
}


                void 
                draw() {
  
                background(360);
  shades = (shades+1) % 360;
  
                for (Rainbow bow: rainbows)   bow.display();
}


                void 
                keyPressed() {
  rainbows.clear();
  isFull = 
                false;
  numRainbows = 0;
}


                void 
                mouseDragged() {
  
                if (isFull)                              rainbows.remove();
  
                else 
                if (++numRainbows == maxRainbows)   isFull = 
                true;

  rainbows.
                add( 
                new Rainbow() );

  
                print(rainbows.
                size() + 
                "\t");
}


                final 
                class Rainbow {
  
                final 
                int x, y, px, py;
  
                final 
                color colour;

  Rainbow() {
    x  = 
                mouseX;
    y  = 
                mouseY;

    px = 
                pmouseX;
    py = 
                pmouseY;

    colour = shades;
  }

  
                void display() {
    
                stroke( (shades+colour) % 360, 95, 100 );
    
                line(x, y, px, py);
  }
}

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