Project -11

var mtnDetail = 0.005; // detail in tall mountain 
var mtnSpeed = 0.0001; // speed of mountains
var mtnDetail2 = 0.007; //detail of short mountain
var birds = []

function setup() {
    createCanvas(480, 400);
    for (var i = 0; i < 5; i ++){
        var rx = random(width);
        var ry = random(10, 50)
        birds[i] = makeBird(rx, ry);
    }
    frameRate(15);
}

function draw() {
	background(153, 153, 204);
    sun();
	makeMtns();
    field();
    updateBird();
    removeBird();
    addBird();	
}

function makeMtns() {
    fill(138, 118, 139);
    stroke(133, 114, 137);
    strokeWeight(1);
    beginShape();
    vertex(0, height);
    for (var x = 0; x < width; x++) {
        var t = (x * mtnDetail) + (millis() * mtnSpeed);
        var y = map(noise(t), 0, 1, height / 8 * 2, height / 8 * 4);
        vertex(x, y);
    }
    vertex(width, height);
    endShape();
    //second mountain
    beginShape();
    fill(175, 143, 178);
    vertex(0, height);
    for (var x = 0; x < width; x++) {
        var t2 = (x * mtnDetail2) + (millis() * mtnSpeed);
        var y = map(noise(t2), 0, 1, 100, 300);
        vertex(x, y);
    }
    vertex(width, height);
    endShape();
}

function field(){
    stroke(118, 139, 121);
    fill(122, 145, 132);
    rect(0, 300, width, 100);
}

function sun(){
    // sun ray inner
    noStroke();
    fill(229, 187, 161, 60);
    ellipse(240, 150, 225, 225);
    //sun ray outer
    fill(229, 187, 161, 60);
    ellipse(240, 150, 300, 300);
    // sun
    stroke(198, 115, 76);
    strokeWeight(1);
    fill(184, 106, 70 );
    ellipse(240, 150, 175, 175);
}
//bird object

function updateBird(){
    for (var i = 0; i < birds.length; i ++){
        birds[i].move();
        birds[i].display();
    }
}

function removeBird(){
    var keepBirds=[];
    for (var i = 0; i < birds.length; i++) {
        if (birds[i].x < width) {
            keepBirds.push(birds[i]);
        }
    }
    birds = keepBirds;
}

function addBird(){
    //little probability
    var newBirdLikelihood = 0.007; 
    if (random(0,1) < newBirdLikelihood) {
        birds.push(makeBird(15, 15));
    }
}

function moveBird(){
    this.x += this.speed;
}

function displayBird(){
    fill(0);
    stroke(0);
    push();
    translate(this.x, height-300);
    //top wing
    triangle(0, 0, 5, 0, -2, -7);
    //bottom wing
    triangle(0, 0, 5, 0, 2, 7);
    pop();
}

function makeBird(birthLocationX, birthLocationY){
    var bird = {x: birthLocationX,
                y:birthLocationY,
                speed:random(3, 7),
                move: moveBird,
                display: displayBird};
    return bird;
}