Interactive Generative Art Series – 06 – lineStyle

var ball:Sprite = new Sprite();
ball.graphics.beginFill(0x000000, 1);
ball.graphics.drawCircle(0, 0, 10);
ball.graphics.endFill();
addChild(ball);

var anchor:Sprite = new Sprite();

anchor.graphics.beginFill(0x333333, .6);
anchor.graphics.drawCircle(0, 0, 12);
anchor.graphics.endFill();
addChild(anchor);

var div:Number = .1;
var line_max_width:Number = 64;
var line_min_width:Number = 2;
var line_width:Number = randomRange(line_min_width, line_max_width);
var line_width_velocity:Number = 0;
var dampen:Number = 0.95;

var ballax:Number = 0;
var ballay:Number = 0;
var oldx:Number = ball.x;
var oldy:Number = ball.y;

var anchorvx:Number = 0;
var anchorvy:Number = 0;

anchor.x = stage.stageWidth/2;
anchor.y = stage.stageHeight/2;
var gradientBoxMatrix:Matrix = new Matrix();

var colors:Object = new Object();
colors.r = 255;
colors.g = 255;
colors.b = 255;
colors.rv = 0;
colors.gv = 0;
colors.bv = 0;
colors.rmin = 0;
colors.rmax = 150;
colors.gmin = 100;
colors.gmax = 200;
colors.bmin = 200;
colors.bmax = 250;
colors.rate_of_change = 12;
var color_first:Number = 0xFFFFFF;
var color_second:Number = rgb2hex(colors.r, colors.g, colors.b);


function loop () {
   
    oldx = ball.x;
    oldy = ball.y;
   
    anchorvx += randomRangeAxis(10);
    anchorvy += randomRangeAxis(10);

    anchor.x += anchorvx;
    anchor.y += anchorvy;
   
    anchorvx *= dampen;
    anchorvy *= dampen;
   
    if(anchor.x > stage.stageWidth) {
        anchor.x = 0 - anchor.width;
    }
    else if(anchor.x < 0 - anchor.width) {
        anchor.x = stage.stageWidth;
    }
    if(anchor.y > stage.stageHeight) {
        anchor.y = 0 - anchor.height;
    }
    else if(anchor.y < 0 - anchor.height) {
        anchor.y = stage.stageHeight;
    }
   
    ball.x -= ballax = (ballax + (ball.x - anchor.x) * div) * .9;
    ball.y -= ballay = (ballay + (ball.y - anchor.y) * div) * .9;
       
    line_width_velocity += randomRangeAxis(1);
    line_width += line_width_velocity;
    line_width_velocity *= dampen;
    if(line_width > line_max_width) {
        line_width = line_max_width;
        line_width_velocity = 0;
    }
    else if (line_width < line_min_width) {
        line_width = line_min_width;
        line_width_velocity = 0;
    }
   
    color_step();
    color_first = color_second;
    color_second = rgb2hex(colors.r, colors.g, colors.b);
   
    var dx:Number = ball.x - oldx;
    var dy:Number = ball.y - oldy;
    this.graphics.lineStyle(line_width, color_first, (line_width+100-line_max_width)/100, true, LineScaleMode.NONE, CapsStyle.NONE);
    gradientBoxMatrix.createGradientBox(Math.abs(dx), Math.abs(dy), Math.atan2(dy,dx), Math.min(oldx, ball.x), Math.min(oldy, ball.y));
    this.graphics.lineGradientStyle(GradientType.LINEAR, [color_first, color_second], [(line_width+100-line_max_width)/100,(line_width+100-line_max_width)/100], [0, 255], gradientBoxMatrix);
    this.graphics.lineTo(ball.x, ball.y);
}

setInterval(loop, 1000/30);

function rgb2hex(r:Number, g:Number, b:Number):Number {
    return(r<<16 | g<<8 | b);
}
function color_step(){
    colors.rv += randomRangeAxis(colors.rate_of_change);
    colors.r  += colors.rv;
    colors.rv *= dampen;
    if (colors.r > colors.rmax) {
        colors.r = colors.rmax;
    } else if (colors.r < colors.rmin){
        colors.r = colors.rmin;
    }
   
    colors.gv += randomRangeAxis(colors.rate_of_change);
    colors.g  += colors.gv;
    colors.gv *= dampen;
    if (colors.g > colors.gmax) {
        colors.g = colors.gmax;
    } else if (colors.g < colors.gmin){
        colors.g = colors.gmin;
    }
   
    colors.bv += randomRangeAxis(colors.rate_of_change);
    colors.b  += colors.bv;
    colors.bv *= dampen;
    if (colors.b > colors.bmax) {
        colors.b = colors.bmax;
    } else if (colors.b < colors.bmin){
        colors.b = colors.bmin;
    }
}
//random number between min and max
function randomRange(max:Number, min:Number = 0):Number {
    return Math.random() * (max - min) + min;
}
//random number range centered at 0 with the specified max, randomRange(-max, max)
function randomRangeAxis(max:Number, axis:Number = 0):Number {
    return Math.random() * (max * 2) - max + axis;
}