hyt-Project-11: Turtle Abstract Drawing

hyt-project-11

// helen tsui
// 15-104 section d
// hyt@andrew.cmu.edu
// project-11-turtles-freestyle


var img; 
var px = 0; // set one variable as x position 
var py = 0; // set one variable as y position
    
// preload image onto canvas
function preload() {
    img = loadImage("https://i.imgur.com/BRPnejy.jpg");    
}

// basic setup, load pixels and display image
function setup() {
    createCanvas(480, 480);
    background(0);
    img.loadPixels();
    image(img, 0, 0);
}

function draw() {

    // retrieve brightness value
    var rgb = img.get(px, py);
    var brightnessVal = brightness(rgb);

    // create new turtle pixel + other properties
    var pixel = makeTurtle(px, py);
    pixel.setWeight(5);
    print(brightnessVal)

    // restrain px position within canvas
    if (px <= width) { 

        // draw in the lighter zones
        if (brightnessVal >= 92 & brightnessVal < 100) { 
            pixel.setColor(color(200, 191, 201, 150));
            pixel.forward(1);

        } 
        // draw in dark zones
        if (brightnessVal < 92) {
            pixel.setColor(color(128, 122, 128, 150));
            pixel.forward(1);
        }

        // draw in gray-ish zones
        if (brightnessVal >= 100) {
            pixel.setColor(color(251, 244, 238, 150));
            pixel.forward(1);
        }
    }

    // if out of canvas then reset
    if (px > width) {
        px = 0;
        py += 8;
    }

    // make the turtles move! 
    px += 2;
}










// turtle function
function turtleLeft(d){this.angle-=d;}function turtleRight(d){this.angle+=d;}
function turtleForward(p){var rad=radians(this.angle);var newx=this.x+cos(rad)*p;
var newy=this.y+sin(rad)*p;this.goto(newx,newy);}function turtleBack(p){
this.forward(-p);}function turtlePenDown(){this.penIsDown=true;}
function turtlePenUp(){this.penIsDown = false;}function turtleGoTo(x,y){
if(this.penIsDown){stroke(this.color);strokeWeight(this.weight);
line(this.x,this.y,x,y);}this.x = x;this.y = y;}function turtleDistTo(x,y){
return sqrt(sq(this.x-x)+sq(this.y-y));}function turtleAngleTo(x,y){
var absAngle=degrees(atan2(y-this.y,x-this.x));
var angle=((absAngle-this.angle)+360)%360.0;return angle;}
function turtleTurnToward(x,y,d){var angle = this.angleTo(x,y);if(angle< 180){
this.angle+=d;}else{this.angle-=d;}}function turtleSetColor(c){this.color=c;}
function turtleSetWeight(w){this.weight=w;}function turtleFace(angle){
this.angle = angle;}function makeTurtle(tx,ty){var turtle={x:tx,y:ty,
angle:0.0,penIsDown:true,color:color(128),weight:1,left:turtleLeft,
right:turtleRight,forward:turtleForward, back:turtleBack,penDown:turtlePenDown,
penUp:turtlePenUp,goto:turtleGoTo, angleto:turtleAngleTo,
turnToward:turtleTurnToward,distanceTo:turtleDistTo, angleTo:turtleAngleTo,
setColor:turtleSetColor, setWeight:turtleSetWeight,face:turtleFace};
return turtle;}

For this project, I wanted to create an abstract landscape work that’s based off of a found minimalist photo, and the turtle drawing process would imitate a machine printing out the pixelated drawing. I didn’t really have a sketch, since the found image itself is my inspiration. I think the most challenging part was to incorporate the brightness() function into turtles, which took me a long time to figure out (for quite a while the brightness value was not calling the right (px, py) position) however I am quite satisfied with the foggy, pastel painting that generated.

* i’m using a grace day for this week!

The first image is an iteration without the original image, and the second image incorporates both the original + iterated turtles. Enjoy!