/* built with Studio Sketchpad: 
 *   https://sketchpad.cc
 * 
 * observe the evolution of this sketch: 
 *   https://studio.sketchpad.cc/sp/pad/view/ro.zYD2H29ebny/rev.491
 * 
 * authors: 
 *   Stuart Allen

 * license (unless otherwise specified): 
 *   creative commons attribution-share alike 3.0 license.
 *   https://creativecommons.org/licenses/by-sa/3.0/ 
 */ 



// Pressing Control-R will render this sketch.

int i = 0; 
int range = 100;
void setup() {  // this is run once.   
    
    // set the background color
    background(255);
    
    // canvas size (Variable aren't evaluated. Integers only, please.)
    size(400, 400); 
      
    // smooth edges
    smooth();
    
    // limit the number of frames per second
    frameRate(30);
    
    // set the width of the line. 
    strokeWeight(12);
} 

void draw() {  // this is run repeatedly. 
    stroke(random(50),random(50),random(255),100);
    line(width/2 + range*cos(2*Math.PI*i/200),
        height/2 + range*sin(2*Math.PI*i/50),
        50,
        50);
    line(width/2 + -range*cos(2*Math.PI*-i/200),
        height/2 + -range*sin(2*Math.PI*-i/50),
        width - 50,
        50);
    stroke(0,0,random(255),255);
    line(width/2 + range*cos(2*Math.PI*i/200),
        height/2 + range*sin(2*Math.PI*i/50),
        width/2 + range*cos(2*Math.PI*i/200),
        height/2 + range*sin(2*Math.PI*i/50));
    line(width/2 + -range*cos(2*Math.PI*-i/200),
        height/2 + -range*sin(2*Math.PI*-i/50),
        width/2 + -range*cos(2*Math.PI*-i/200),
        height/2 + -range*sin(2*Math.PI*-i/50));
    fill(255,255,255,10);
    rect(0,
         0,
         width,
         height);
    // move over a pixel
    if (i < width) {
        i++;
    } else {
        i = 0; 
    }
}