Project 11 Generative Landscape

//tjchen 
// project landscape 

var stars=[]; // array for circles 
var streaks=[]; // array for streaks
var speed = 3; // change for how zoom
// color initialization 
var r; 
var g;
var b;
// rate of change fo color 
var dr;
var dg;
var db;

function setup() {
    createCanvas(480, 480);
    //initalize objects
    for(i=0; i<=500; i++ ){
        var s =makeStar();
        var st=makeStreak();
        stars.push(s); 
        streaks.push(st);
    }
    //background color setup
    r = (random(255));
    g = (random(255));
    b = (random(255));
    dr = (random(-5,5));
    db = (random(-5,5));
    dg = (random(-5,5));
    }


function draw() {
    background(r,g,b);
    //set it up from the middle 
    translate(width/2,height/2);
    //draw the stars and streaks 
    for(i=0; i<500; i++){
        var s = stars[i];
        s.drawstar();
        s.updatestar()

        var st = streaks[i];
        st.drawstreak();
        st.updatestreak();
}
// color update 
    if (r>255 || r<0){
        dr= -dr;
    }
    if (g>255 || g<0){
        dg= -dg;
    }
    if (b>255 || b<0){
        db= -db;
    }
    r+=dr;
    g+=dg;
    b+=db;

}

//star construction 

function makeStar(){
    var star={
        x:random(-width,width),
        y:random(-height,height),
        z:random(width), // constant ratio for zoom 
        c:color(random(255),random(255),random(255)),
        drawstar: stardraw,
        updatestar: starupdate,
    }
    return star; 
}

function stardraw(){
    noStroke();
    fill(this.c);
    // draw stars but mapped to z 
    var dx = map(this.x/this.z,0,1,0,width);
    var dy = map(this.y/this.z,0,1,0,width);
    // map it for sizze increase 
    var r = map(this.z,0,width,20,0);  
    ellipse(dx,dy,r);
}

function starupdate(){
    this.z-=speed;
    // reset
    if (this.z<1){
        this.z = width;
        this.x = (random(-width,width));
        this.y = (random(-height,height));
    }

}

// streak construction 
function makeStreak(){
    var streak={
        x:random(-width,width),
        y:random(-height,height),
        z:random(width),
        c:color(random(255),random(255),random(255),50),
        pz: this.z, // previous location of z 
        drawstreak: streakdraw,
        updatestreak: streakupdate,
    }
    return streak; 

}

function streakdraw(){
    strokeWeight(5);
    stroke(this.c);
    var dx = map(this.x/this.z,0,1,0,width);
    var dy = map(this.y/this.z,0,1,0,width);
    var px = map(this.x/this.pz,0,1,0,width);
    var py = map(this.y/this.pz,0,1,0,width); 
    //draw line 
    line(dx,dy,px,py);
}

function streakupdate(){
    this.z-=speed;
    // reset 
    if (this.z<1){
        this.z = width;
        this.x = (random(-width,width));
        this.y = (random(-height,height));
        this.pz = this.z;
    }

}