Creating a class of Crafty JS entity (class of a class?) - javascript

I am trying to create a class which creates a Crafty entity with specific properties. So far, the functions within the class do not run because 'this' refers to the window object
$(document).ready(function () {
Crafty.init(window.innerWidth, window.innerHeight);
var player = new controller(37,38,39,40);
player.d.color("red").attr({
w: 50,
h: 50,
x: 0,
y: 0
});
// Jump Height = velocity ^ 2 / gravity * 2
// Terminal Velocity = push * (1 / viscosity)
var gravity = 1;
var viscosity = 0.5;
var frame = (1 / 20);
var distanceMultiplier = 10; //pixels per meter
var timeMultiplier = 20; //relative to actual time
var keystart = [];
var keyboard = [];
function controller (controls) {
this.d = Crafty.e();
this.d.addComponent("2D, Canvas, Color, Collision");
this.d.collision();
this.d.mass = 1;
this.d.a = {
extradistance : 0,
velocity : 0,
acceleration : 0,
force : 0,
resistance : 0
};
this.d.a.push = 0;
this.d.v = {
extradistance : 0,
velocity : 0,
acceleration : 0,
force : 0
};
this.d.jumping = true;
this.d.onHit("Collision", function () {
var a = this.d.hit("Collision");
if (a) {
for (var b in a) {
this.d.x = this.d.x - a[b].normal.x * a[b].overlap;
this.d.y = this.d.y - a[b].normal.y * a[b].overlap;
if (a[b].normal.y < -0.5) {
this.d.jumping = false;
}
if (Math.abs(a[b].normal.x) < 0.2) {
this.d.v.velocity = this.d.v.velocity * a[b].normal.y * 0.2;
}
if (Math.abs(a[b].normal.y) < 0.2) {
this.d.a.velocity = this.d.a.velocity * a[b].normal.x * 0.2;
}
}
return;
}
});
this.d.physics = function () {
if (keyboard[arguments[1]] && !this.jumping) {
this.v.velocity = 5;
this.jumping = true;
}
if (keyboard[arguments[1]] && this.jumping) {
var now = new Date();
if (now.getTime() - keystart[arguments[1]].getTime() < 500) {
this.v.velocity = 5;
}
}
if (keyboard[arguments[0]] && keyboard[arguments[2]]) {
this.a.velocity = 0;
} else {
if (keyboard[arguments[0]]) {
this.a.velocity = -3;
}
if (keyboard[arguments[2]]) {
this.a.velocity = 3;
}
}
if (keyboard[arguments[3]]) {
this.v.velocity = -5;
}
this.a.force = this.a.push - this.a.resistance;
this.a.acceleration = this.a.force / this.mass;
this.a.velocity = this.a.velocity + (this.a.acceleration * frame);
this.a.extradistance = (this.a.velocity * frame);
this.a.resistance = this.a.velocity * viscosity;
this.attr({
x: (this.x + (this.a.extradistance * distanceMultiplier))
});
this.v.force = gravity * this.mass;
this.v.acceleration = this.v.force / this.mass;
this.v.velocity = this.v.velocity - (this.v.acceleration * frame);
this.v.extradistance = (this.v.velocity * frame);
this.attr({
y: (this.y - (this.v.extradistance * distanceMultiplier))
});
setTimeout(this.physics, (frame * 1000) / timeMultiplier);
};
this.d.listen = function(){ document.body.addEventListener("keydown", function (code) {
var then = new Date();
if (!keyboard[code.keyCode] && !this.jumping && code.keyCode == arguments[1]) { //only if not yet pressed it will ignore everything until keyup
keyboard[code.keyCode] = true; //start movement
keystart[code.keyCode] = then; //set time
}
if (!keyboard[code.keyCode] && code.keyCode != arguments[1]) { //only if not yet pressed it will ignore everything until keyup
keyboard[code.keyCode] = true; //start movement
keystart[code.keyCode] = then; //set time
}
});
};
}
player.d.physics();
player.d.listen();
document.body.addEventListener("keyup", function (code) {
keyboard[code.keyCode] = false;
});
});
In trying to put the functions as prototypes of the class, I run into a problem.
Crafty.init(500,500);
function block () {
block.d = Crafty.e("2D, Color, Canvas");
block.d.color("red");
block.d.attr({x:0,y:0,h:50,w:50});
}
block.d.prototype.green = function() {
this.color("green");
}
var block1 = new block();
block1.d.color();
If an object is defined in the constructor, I cannot use it to add a prototype to.

Generally in Crafty, we favor composition. That is, you extend an entity by adding more components to it. You can have kind of a hierarchy by having one component automatically add others during init.
I haven't looked through all of your example code, because there's a lot! But consider the second block:
function block () {
block.d = Crafty.e("2D, Color, Canvas");
block.d.color("red");
block.d.attr({x:0,y:0,h:50,w:50});
}
block.d.prototype.green = function() {
this.color("green");
}
var block1 = new block();
block1.d.color();
You're trying to combine Crafty's way of doing things (an entity component system) with classes in a way that's not very idiomatic. Better to do this:
// Define a new component with Crafty.c(), rather than creating a class
Crafty.c("Block", {
// On init, add the correct components and setup the color and dimensions
init: function() {
this.requires("2D, Color, Canvas")
.color("red")
.attr({x:0,y:0,h:50,w:50});
},
// method for changing color
green: function() {
this.color("green");
}
});
// Create an entity with Crafty.e()
block1 = Crafty.e("Block");
// It's not easy being green!
block1.green();

Related

When spawning many iterations of a class object, how do I take an object out of the array using a if statement inside of the Class?

I'm a beginner using p5js and I'm trying to work with classes. I'm making a game where you have to find and click a 'wanted man', from a crowd.
So basically, a randomizer picks between 7 different types of 'civilians', and it's supposed to remove one of the types from the 'civilians' that have been spawned. After removing the 'wanted man', I want to add one wanted man so that there is only one 'wanted man'.
So the code spawns a bunch of random 'civilians', then it will delete all 'wanted man' types in the array, and add only one of them. I think there is a better way to do this though.
My basic desire is to have a crowd of 'civilians' that run around, - one of which is a 'wanted man' - and you would have to find and click that 'wanted man' (kind of like a hunting/assassination game).
This is the code for the sketch.js file:
var civilians = [];
var page = 0;
var man1img;
var man2img;
var man3img;
var man4img;
var man5img;
var man6img;
var aliemanimg;
var w;
var h;
var spawnCount = 14;
var wantedMan;
var randCiv;
function preload() {
man1img = loadImage("man1.png");
man2img = loadImage("man2.png");
man3img = loadImage("man3.png");
man4img = loadImage("man4.png");
man5img = loadImage("man5.png");
man6img = loadImage("man6.png");
aliemanimg = loadImage("alieman.png");
}
function windowResized() {
resizeCanvas(windowWidth, windowHeight);
}
function setup() {
createCanvas(windowWidth, windowHeight);
imageMode(CENTER);
// wantedMan = round(random(0, 6));
wantedMan = 0;
for (var i = 0; i < spawnCount; i++) {
randCiv = round(random(0, 6));
w = random(windowWidth);
h = random(windowHeight);
civilians.push(new Civilian(w, h, wantedMan, randCiv));
console.log(wantedMan);
if (civilians[i].isWantedMan()) {
//OVER HERE \/
civilians.splice(i, 1);
}
}
civilians.push(new Civilian(w, h, wantedMan, wantedMan));
}
// page setup
// page 1 : main screen (play, settings, and those stuff)
// page 2 : show chosen civilian
// page 3 : playing
// page 4 : lose
// page 5 : options
function draw() {
background(220, 80, 80);
for (var i = civilians.length - 1; i >= 0; i--) {
civilians[i].update();
civilians[i].show(mouseX, mouseY);
if (civilians[i].clickedOn(mouseX, mouseY)) {
// detect if is right person
console.log("clicked on boi");
if (civilians[i].isWantedMan()) {
console.log("HES WANTED");
} else {
console.log("HES NOT WANTED");
}
}
}
text(round(frameRate()), 20, 20);
//show wanted man
var tempImg = man1img;
if (wantedMan == 1) {
tempImg = man2img;
} else if (wantedMan == 2) {
tempImg = man3img;
} else if (wantedMan == 3) {
tempImg = man4img;
}
if (wantedMan == 4) {
tempImg = man5img;
} else if (wantedMan == 5) {
tempImg = man6img;
} else if (wantedMan == 6) {
tempImg = aliemanimg;
}
image(tempImg, 50, 70, 70, 90);
}
This is the code for the class:
class Civilian {
constructor(x, y, wantedMan, type) {
this.x = x;
this.y = y;
this.w = 47;
this.h = 60;
this.t = {
x: x,
y: y,
};
this.size = 47;
this.moveSpeed = 0.01;
this.moveDist = 20;
this.wantedMan = wantedMan;
this.civilian = type
this.civilianImg = man1img
this.wantedMan = wantedMan
}
update() {
//move target to random position
this.t.x = random(this.t.x - this.moveDist, this.t.x + this.moveDist);
this.t.y = random(this.t.y - this.moveDist, this.t.y + this.moveDist);
//edge detect
if (this.t.x < 0) {
this.t.x += 5;
}
if (this.t.x > width) {
this.t.x -= 5;
}
if (this.t.y < 0) {
this.t.y += 5;
}
if (this.t.y > height) {
this.t.y -= 5;
}
//images position follows target but with easing
this.x += (this.t.x - this.x) * this.moveSpeed;
this.y += (this.t.y - this.y) * this.moveSpeed;
}
show(ex, ey) {
var d = dist(ex, ey, this.x, this.y);
if (d > this.size / 2) {
tint(255, 255, 255);
} else {
tint(0, 255, 0);
}
if(this.civilian == 1) {
this.civilianImg = man2img
} else if(this.civilian == 2) {
this.civilianImg = man3img
} else if(this.civilian ==3) {
this.civilianImg = man4img
} if(this.civilian == 4) {
this.civilianImg = man5img
} else if(this.civilian == 5) {
this.civilianImg = man6img
} else if(this.civilian == 6) {
this.civilianImg = aliemanimg
}
image(this.civilianImg, this.x, this.y, 47, 60);
}
clickedOn(ex, ey) {
var d = dist(ex, ey, this.x, this.y);
return d < this.size / 2 && mouseIsPressed;
}
isWantedMan() {
return this.civilian == this.wantedMan;
}
}
However, whenever I add a .splice(i,1) under the 'for' loop in setup function - to remove the 'wanted man', it shows this error:
"TypeError: Cannot read properties of undefined (reading
'isWantedMan') at /sketch.js:41:22".
isWantedMan() is a function in the Civilian Class, that returns true if the current 'civilian' is wanted. The .splice is supposed to remove a object from the array, when it is a 'wanted man'.
I don't know why this happens. When I replace the .splice code with a console.log() code, then there is no error.
Also there were probably a lot of things that I could have done better in the code.

Random movement of circles created by the script

I have a function that craeates divs with a circle.
Now they are all created and appear at the beginning of the page and go further in order.
Next, I need each circle to appear in a random place. I did this.
Now I need all of them to move randomly across the entire page, I have difficulties with this.
Here is an example of how everything works for one element that is already on the page.
https://jsfiddle.net/quej8wko/
But when I add this code, all my created circles don't move.
I get an error:
"message": "Uncaught TypeError: Cannot set properties of null (setting 'willChange')",
This is probably due to the fact that initially there are no circles on the page. How can I connect the code so that all created circles move?
//creating circles
var widthHeight = 40; // <-- circle width
var margin = 20; // <-- margin - is it necessary ?
var delta = widthHeight + margin;
function createDiv(id, color) {
let div = document.createElement('div');
var currentTop = 0;
var documentHeight = document.documentElement.clientHeight;
var documentWidth = document.documentElement.clientWidth;
div.setAttribute('class', id);
if (color === undefined) {
let colors = ['#35def2', '#35f242', '#b2f235', '#f2ad35', '#f24735', '#3554f2', '#8535f2', '#eb35f2', '#f2359b', '#f23547'];
div.style.backgroundColor = colors[Math.floor(Math.random() * colors.length)];
}
else {
div.style.backgroundColor = color;
}
div.classList.add("circle");
div.classList.add("animation");
// Get the random positions minus the delta
currentTop = Math.floor(Math.random() * documentHeight) - delta;
currentLeft = Math.floor(Math.random() * documentWidth) - delta;
// Keep the positions between -20px and the current positions
var limitedTop = Math.max(margin * -1, currentTop);
var limitedLeft = Math.max(margin * -1, currentLeft);
div.style.top = limitedTop + "px";
div.style.left = limitedLeft + "px";
document.body.appendChild(div);
}
let i = 0;
const oneSecond = 1000;
setInterval(() => {
i += 1;
createDiv(`circle${i}`)
}, oneSecond);
//move circles
function RandomObjectMover(obj, container) {
this.$object = obj;
this.$container = container;
this.container_is_window = container === window;
this.pixels_per_second = 250;
this.current_position = { x: 0, y: 0 };
this.is_running = false;
}
// Set the speed of movement in Pixels per Second.
RandomObjectMover.prototype.setSpeed = function(pxPerSec) {
this.pixels_per_second = pxPerSec;
}
RandomObjectMover.prototype._getContainerDimensions = function() {
if (this.$container === window) {
return { 'height' : this.$container.innerHeight, 'width' : this.$container.innerWidth };
} else {
return { 'height' : this.$container.clientHeight, 'width' : this.$container.clientWidth };
}
}
RandomObjectMover.prototype._generateNewPosition = function() {
// Get container dimensions minus div size
var containerSize = this._getContainerDimensions();
var availableHeight = containerSize.height - this.$object.clientHeight;
var availableWidth = containerSize.width - this.$object.clientHeight;
// Pick a random place in the space
var y = Math.floor(Math.random() * availableHeight);
var x = Math.floor(Math.random() * availableWidth);
return { x: x, y: y };
}
RandomObjectMover.prototype._calcDelta = function(a, b) {
var dx = a.x - b.x;
var dy = a.y - b.y;
var dist = Math.sqrt( dx*dx + dy*dy );
return dist;
}
RandomObjectMover.prototype._moveOnce = function() {
// Pick a new spot on the page
var next = this._generateNewPosition();
// How far do we have to move?
var delta = this._calcDelta(this.current_position, next);
// Speed of this transition, rounded to 2DP
var speed = Math.round((delta / this.pixels_per_second) * 100) / 100;
//console.log(this.current_position, next, delta, speed);
this.$object.style.transition='transform '+speed+'s linear';
this.$object.style.transform='translate3d('+next.x+'px, '+next.y+'px, 0)';
// Save this new position ready for the next call.
this.current_position = next;
};
RandomObjectMover.prototype.start = function() {
if (this.is_running) {
return;
}
// Make sure our object has the right css set
this.$object.willChange = 'transform';
this.$object.pointerEvents = 'auto';
this.boundEvent = this._moveOnce.bind(this)
// Bind callback to keep things moving
this.$object.addEventListener('transitionend', this.boundEvent);
// Start it moving
this._moveOnce();
this.is_running = true;
}
RandomObjectMover.prototype.stop = function() {
if (!this.is_running) {
return;
}
this.$object.removeEventListener('transitionend', this.boundEvent);
this.is_running = false;
}
// Init it
var x = new RandomObjectMover(document.querySelector(".circle"), window);
// Start it off
x.start();
.circle {
clip-path: circle(50%);
height: 40px;
width: 40px;
margin: 20px;
position: absolute;
}
I have modified the snippet which works as you expected.
There was a mistake where you were initializing and creating the object instance only once and none of the div elements that you created inside the setInterval function never got Instantiated.
I think you are just starting out with JavaScript with this sample project.
Below are few suggestions:
Learn to debug the code. You should be using dev tools by making use of debugger statement where it takes you to the source code to analyze the variable scope and stack during the runtime. console.log also helps in few situations.
I could see a lot of confusing naming convention (You have named the create div parameter as id but creating a div class using that id)
Try using ES6 features (class syntax is really good when writing OOP in JS although it's just a syntactic sugar for prototype)
//creating circles
var widthHeight = 40; // <-- circle width
var margin = 20; // <-- margin - is it necessary ?
var delta = widthHeight + margin;
function createAndInitializeDivObject(id, color) {
let div = document.createElement('div');
var currentTop = 0;
var documentHeight = document.documentElement.clientHeight;
var documentWidth = document.documentElement.clientWidth;
div.setAttribute('class', id);
if (color === undefined) {
let colors = ['#35def2', '#35f242', '#b2f235', '#f2ad35', '#f24735', '#3554f2', '#8535f2', '#eb35f2', '#f2359b', '#f23547'];
div.style.backgroundColor = colors[Math.floor(Math.random() * colors.length)];
}
else {
div.style.backgroundColor = color;
}
div.classList.add("circle");
div.classList.add("animation");
// Get the random positions minus the delta
currentTop = Math.floor(Math.random() * documentHeight) - delta;
currentLeft = Math.floor(Math.random() * documentWidth) - delta;
// Keep the positions between -20px and the current positions
var limitedTop = Math.max(margin * -1, currentTop);
var limitedLeft = Math.max(margin * -1, currentLeft);
div.style.top = limitedTop + "px";
div.style.left = limitedLeft + "px";
document.body.appendChild(div);
var x = new RandomObjectMover(document.querySelector(`.${id}`), window);
x.start();
}
let i = 0;
const oneSecond = 1000;
setInterval(() => {
i += 1;
createAndInitializeDivObject(`circle${i}`)
}, oneSecond);
//move circles
function RandomObjectMover(obj, container) {
this.$object = obj;
this.$container = container;
this.container_is_window = container === window;
this.pixels_per_second = 250;
this.current_position = { x: 0, y: 0 };
this.is_running = false;
}
// Set the speed of movement in Pixels per Second.
RandomObjectMover.prototype.setSpeed = function(pxPerSec) {
this.pixels_per_second = pxPerSec;
}
RandomObjectMover.prototype._getContainerDimensions = function() {
if (this.$container === window) {
return { 'height' : this.$container.innerHeight, 'width' : this.$container.innerWidth };
} else {
return { 'height' : this.$container.clientHeight, 'width' : this.$container.clientWidth };
}
}
RandomObjectMover.prototype._generateNewPosition = function() {
// Get container dimensions minus div size
var containerSize = this._getContainerDimensions();
var availableHeight = containerSize.height - this.$object.clientHeight;
var availableWidth = containerSize.width - this.$object.clientHeight;
// Pick a random place in the space
var y = Math.floor(Math.random() * availableHeight);
var x = Math.floor(Math.random() * availableWidth);
return { x: x, y: y };
}
RandomObjectMover.prototype._calcDelta = function(a, b) {
var dx = a.x - b.x;
var dy = a.y - b.y;
var dist = Math.sqrt( dx*dx + dy*dy );
return dist;
}
RandomObjectMover.prototype._moveOnce = function() {
// Pick a new spot on the page
var next = this._generateNewPosition();
// How far do we have to move?
var delta = this._calcDelta(this.current_position, next);
// Speed of this transition, rounded to 2DP
var speed = Math.round((delta / this.pixels_per_second) * 100) / 100;
//console.log(this.current_position, next, delta, speed);
this.$object.style.transition='transform '+speed+'s linear';
this.$object.style.transform='translate3d('+next.x+'px, '+next.y+'px, 0)';
// Save this new position ready for the next call.
this.current_position = next;
};
RandomObjectMover.prototype.start = function() {
if (this.is_running) {
return;
}
// Make sure our object has the right css set
this.$object.willChange = 'transform';
this.$object.pointerEvents = 'auto';
this.boundEvent = this._moveOnce.bind(this)
// Bind callback to keep things moving
this.$object.addEventListener('transitionend', this.boundEvent);
// Start it moving
this._moveOnce();
this.is_running = true;
}
RandomObjectMover.prototype.stop = function() {
if (!this.is_running) {
return;
}
this.$object.removeEventListener('transitionend', this.boundEvent);
this.is_running = false;
}
// Init it
var x = new RandomObjectMover(document.querySelector(".circle"), window);
// Start it off
x.start();
.circle {
width: 35px;
height: 35px;
border-radius: 35px;
background-color: #ffffff;
border: 3px solid purple;
position: absolute;
}
<!DOCTYPE html>
<html>
<head>
<link rel="stylesheet" href="style.css">
</head>
<body>
<div class="circle"></div>
<script src="app.js"></script>
</body>
</html>

Paper.js - convert `paperscript` to `javascript`

I am trying to change this paperscript:
<script type="text/paperscript" canvas="canvas-1">
tool.minDistance = 10;
tool.maxDistance = 45;
var path;
function onMouseDown(event) {
path = new Path();
path.fillColor = new Color({ hue: Math.random() * 360, saturation: 1, brightness: 1 });
path.add(event.point);
}
function onMouseDrag(event) {
var step = event.delta / 2;
step.angle += 90;
var top = event.middlePoint + step;
var bottom = event.middlePoint - step;
path.add(top);
path.insert(0, bottom);
path.smooth();
}
function onMouseUp(event) {
path.add(event.point);
path.closed = true;
path.smooth();
}
</script>
to a stand alone javascript like:
paper.install(window);
window.onload = function() {
paper.setup('myCanvas');
tool.minDistance = 10;
tool.maxDistance = 45;
var path;
function onMouseDown(event) {
path = new Path();
path.fillColor = {
hue: Math.random() * 360,
saturation: 1,
brightness: 1
};
path.add(event.point);
}
function onMouseDrag(event) {
var step = event.delta / 2;
step.angle += 90;
var top = event.middlePoint + step;
var bottom = event.middlePoint - step;
path.add(top);
path.insert(0, bottom);
path.smooth();
}
function onMouseUp(event) {
path.add(event.point);
path.closed = true;
path.smooth();
}
}
it give me an error:
TypeError: undefined is not an object (evaluating 'tool.minDistance =
10')
What is tool here? I understand that I might need to declare it before I can use it. Any idea how to resolve this?
You need to make the global scope as outlined in the documentation :
paper.install(window);
Then get on with global defs. :
window.onload = function() {
// Get a reference to the canvas object
paper.setup('myCanvas');
// In your case create tools
var tool = new Tool();
tool.minDistance = 10;
tool.maxDistance = 45;
Then continue as usual, this will set up your tools.. More can be found here.
Incidentally you've actually already done this correctly for Path(), so the same applies to Tool()
When I use Paper.js directly in javascript I prefer to create paper object this way:
var canvas = document.getElementById('canvas-line');
paper.setup(canvas);
// and then if you want to create some Paper.js object prefix it's name with paper
var myPath = new paper.Path();
If you want to use tool you need to decelerate it with new paper.Tool();
For example if you want to check whether path was clicked:
var tool1 = new paper.Tool();
var handle;
var myPath;
myPath.fullySelected = true;
tool1.onMouseDown = function(event) {
handle = null;
// Do a hit test on path for handles:
var hitResult = myPath.hitTest(event.point, {
handles: true,
fill: true,
stroke: true,
segments: true,
tolerance: 2
});
if (hitResult) {
if (hitResult.type == 'handle-in') {
handle = hitResult.segment.handleIn;
} else if (hitResult.type == 'segment') {
handle = hitResult.segment.point;
} else if (hitResult.type == 'handle-out') {
handle = hitResult.segment.handleOut;
}
}
}
You can find more informations about tools in here http://paperjs.org/reference/tool/

0x800a01bd - JavaScript runtime error: Object doesn't support this action

I am reading and trying to do this tutorial:
http://www.sitepoint.com/creating-a-simple-windows-8-game-with-javascript-input-and-sound/
Yesterday, I wrote in this forum with one error, and solved it, but today, I'm in the final one and getting another error.
My default.html file
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>CatapultGame</title>
<!-- WinJS references -->
<link href="//Microsoft.WinJS.1.0/css/ui-light.css" rel="stylesheet" />
<script src="//Microsoft.WinJS.1.0/js/base.js"></script>
<script src="//Microsoft.WinJS.1.0/js/ui.js"></script>
<!-- CatapultGame references -->
<link href="/css/default.css" rel="stylesheet" />
<script src="/js/default.js"></script>
<script src="js/CreateJS/easeljs-0.6.0.min.js"></script>
<script src="js/CreateJS/preloadjs-0.2.0.min.js"></script>
</head>
<body>
<canvas id="gameCanvas"></canvas>
</body>
</html>
and default.js file :
// For an introduction to the Blank template, see the following documentation:
// http://go.microsoft.com/fwlink/?LinkId=232509
(function () {
"use strict";
var app = WinJS.Application;
var activation = Windows.ApplicationModel.Activation;
WinJS.strictProcessing();
var canvas, context, stage;
var bgImage, p1Image, p2Image, ammoImage, p1Lives, p2Lives, title, endGameImage;
var bgBitmap, p1Bitmap, p2Bitmap, ammoBitmap;
var preload;
// calculate display scale factor - original game assets assume 800x480
var SCALE_X = window.innerWidth / 800;
var SCALE_Y = window.innerHeight / 480;
var MARGIN = 25;
var GROUND_Y = 390 * SCALE_Y;
var LIVES_PER_PLAYER = 3;
var player1Lives = LIVES_PER_PLAYER;
var player2Lives = LIVES_PER_PLAYER;
var isShotFlying = false;
var playerTurn = 1;
var playerFire = false;
var shotVelocity;
var MAX_SHOT_POWER = 10;
var GRAVITY = 0.07;
var isAiming = false;
var aimPower = 1;
var aimStart, aimVector;
var FIRE_SOUND_FILE = "/sounds/CatapultFire.wav";
var HIT_SOUND_FILE = "/sounds/BoulderHit.wav";
var EXPLODE_SOUND_FILE = "/sounds/CatapultExplosion.wav";
var LOSE_SOUND_FILE = "/sounds/Lose.wav";
var AIM_SOUND_FILE = "/sounds/RopeStretch.wav";
var WIN_SOUND_FILE = "/sounds/Win.wav";
app.onactivated = function (args) {
if (args.detail.kind === activation.ActivationKind.launch) {
if (args.detail.previousExecutionState !== activation.ApplicationExecutionState.terminated) {
// TODO: This application has been newly launched. Initialize
// your application here.
} else {
// TODO: This application has been reactivated from suspension.
// Restore application state here.
}
args.setPromise(WinJS.UI.processAll());
}
};
function initialize() {
canvas = document.getElementById("gameCanvas");
canvas.width = window.innerWidth;
canvas.height = window.innerHeight;
context = canvas.getContext("2d");
canvas.addEventListener("MSPointerUp", endAim, false);
canvas.addEventListener("MSPointerMove", adjustAim, false);
canvas.addEventListener("MSPointerDown", beginAim, false)
**var stage = new createjs.Stage(canvas);** <<========== HERE IS THE ERROR LINE !!!!
// use preloadJS to get sounds and images loaded before starting
preload = new createjs.PreloadJS();
preload.onComplete = prepareGame;
var manifest = [
{ id: "screenImage", src: "images/Backgrounds/gameplay_screen.png" },
{ id: "redImage", src: "images/Catapults/Red/redIdle/redIdle.png" },
{ id: "blueImage", src: "images/Catapults/Blue/blueIdle/blueIdle.png" },
{ id: "ammoImage", src: "images/Ammo/rock_ammo.png" },
{ id: "winImage", src: "images/Backgrounds/victory.png" },
{ id: "loseImage", src: "images/Backgrounds/defeat.png" },
{ id: "blueFire", src: "images/Catapults/Blue/blueFire/blueCatapultFire.png" },
{ id: "redFire", src: "images/Catapults/Red/redFire/redCatapultFire.png" },
{ id: "hitSound", src: HIT_SOUND_FILE },
{ id: "explodeSound", src: EXPLODE_SOUND_FILE },
{ id: "fireSound", src: FIRE_SOUND_FILE },
{ id: "loseSound", src: LOSE_SOUND_FILE },
{ id: "aimSound", src: AIM_SOUND_FILE },
{ id: "winSound", src: WIN_SOUND_FILE }
];
preload.loadManifest(manifest);
}
function prepareGame()
{
// draw Bg first, others appear on top
bgImage = preload.getResult("screenImage").result;
bgBitmap = new createjs.Bitmap(bgImage);
bgBitmap.scaleX = SCALE_X;
bgBitmap.scaleY = SCALE_Y;
stage.addChild(bgBitmap);
// draw p1 catapult
p1Image = preload.getResult("redImage").result;
p1Bitmap = new createjs.Bitmap(p1Image);
p1Bitmap.scaleX = SCALE_X;
p1Bitmap.scaleY = SCALE_Y;
p1Bitmap.x = MARGIN;
p1Bitmap.y = GROUND_Y - p1Image.height * SCALE_Y;
stage.addChild(p1Bitmap);
// draw p2 catapult and flip
p2Image = preload.getResult("blueImage").result;
p2Bitmap = new createjs.Bitmap(p2Image);
p2Bitmap.regX = p2Image.width;
p2Bitmap.scaleX = -SCALE_X; // flip from right edge
p2Bitmap.scaleY = SCALE_Y;
p2Bitmap.x = canvas.width - MARGIN - (p2Image.width * SCALE_X);
p2Bitmap.y = GROUND_Y - (p2Image.height * SCALE_Y);
stage.addChild(p2Bitmap);
// draw the boulder, and hide for the moment
ammoImage = preload.getResult("ammoImage").result;
ammoBitmap = new createjs.Bitmap(ammoImage);
ammoBitmap.scaleX = SCALE_X;
ammoBitmap.scaleY = SCALE_Y;
ammoBitmap.visible = false; // hide until fired
stage.addChild(ammoBitmap);
// player 1 lives
p1Lives = new createjs.Text("Lives Left : " + player1Lives, "20px sans-serif", "red");
p1Lives.scaleX = SCALE_X;
p1Lives.scaleY = SCALE_Y;
p1Lives.x = MARGIN;
p1Lives.y = MARGIN * SCALE_Y;
stage.addChild(p1Lives);
//player 2 lives
p2Lives = new createjs.Text("Lives Left : " + player2Lives, "20px sans-serif", "red");
p2Lives.scaleX = SCALE_X;
p2Lives.scaleY = SCALE_Y;
p2Lives.x = canvas.width - p2Lives.getMeasuredWidth() * SCALE_X - MARGIN;
p2Lives.y = MARGIN * SCALE_Y;
stage.addChild(p2Lives);
// game title
title = new createjs.Text("Catapult Wars", "30px sans-serif", "black");
title.scaleX = SCALE_X;
title.scaleY = SCALE_Y;
title.x = canvas.width / 2 - (title.getMeasuredWidth() * SCALE_X) / 2
title.y = 30 * SCALE_Y;
stage.addChild(title);
stage.update();
startGame();
}
function startGame()
{
Ticker.setInterval(window.requestAnimationFrame);
Ticker.addListener(gameLoop);
}
function gameLoop()
{
update();
draw();
}
function update() {
if (isShotFlying)
{
// shot in the air
ammoBitmap.x += shotVelocity.x;
ammoBitmap.y += shotVelocity.y;
shotVelocity.y += GRAVITY; //apply gravity to the y(height) values only, obviously
if (ammoBitmap.y + ammoBitmap.image.height >= GROUND_Y ||
ammoBitmap.x <= 0 ||
ammoBitmap.x + ammoBitmap.image.width >= canvas.width)
{
// missed
isShotFlying = false; //stop shot
ammoBitmap.visible = false;
playerTurn = playerTurn % 2 + 1; // invert player ( switch between 1 and 2)
}
else if (playerTurn == 1)
{
if (checkHit(p2Bitmap)) {
// Hit
p2Lives.text = "Lives Left : " + --player2Lives;
processHit();
}
}
else if (playerTurn == 2)
{
if (checkHit(p1Bitmap))
{
// Hit
p1Lives.text = "Lives Left : " + --player1Lives;
processHit();
}
}
}
// No current shot, should either player fire ?
else if (playerTurn == 1)
{
// does the player want to fire ?
if (playerFire)
{
playerFire = false;
ammoBitmap.x = p1Bitmap.x + (p1Bitmap.image.width * SCALE_X / 2);
ammoBitmap.y = p1Bitmap.y;
shotVelocity = aimVector;
fireShot();
}
}
else if (playerTurn == 2)
{
// AI automatically fires (randomly on it's turn)
ammoBitmap.x = p2Bitmap.x + (p2Bitmap.image.width * SCALE_X / 2);
ammoBitmap.y = p2Bitmap.y;
shotVelocity = new createjs.Point(
Math.random() * (-4 * SCALE_X) - 3,
Math.random() * (-3 * SCALE_Y) - 1);
fireShot();
}
}
// triggered by MSPointerDown event
function beginAim(event)
{
if (playerTurn == 1)
{
if (!isAiming)
{
aimStart = new createjs.Point(event.x, event.y);
isAiming = true;
}
}
}
// triggered by MSPointerMove event
function adjustAim(event)
{
if (isAiming)
{
var aimCurrent = new createjs.Point(event.x, event.y);
aimVector = calculateAim(aimStart, aimCurrent);
// TODO write text and/or show aiming arrow on screen
Debug.writeln("Aiming..." + aimVector.x + "/" + aimVector.y);
}
}
// triggered by MSPointerUp event
function endAim(event)
{
if (isAiming) {
isAiming = false;
var aimCurrent = new createjs.Point(event.x, event.y);
aimVector = calculateAim(aimStart, aimCurrent);
playerFire = true;
}
}
function calculateAim(start, end)
{
// this only works for player 1
var aim = new createjs.Point(
(end.x - start.x) / 80,
(end.y - start.y) / 80);
aim.x = Math.min(MAX_SHOT_POWER, aim.x); // cap velocity
aim.x = Math.max(0, aim.x); // fire forward only
aim.y = Math.max(-MAX_SHOT_POWER, aim.y);/// cap velocity
aim.y = Math.min(0, aim.y); // fire up only
return aim;
}
function checkHit(target)
{
// EaselJS hit test doesn't factor in scaling
// so use simple bounding box vs center of rock
// get centre of rock
var shotX = ammoBitmap.x + ammoBitmap.image.width / 2;
var shotY = ammoBitmap.y + ammoBitmap.image.height / 2;
// return wether center of rock is in rectangle bounding target player
return (((shotX > target.x) &&
(shotX <= target.x + (target.image.width * SCALE_X)))
&&
((shotY >= target.y) &&
(shotY <= target.y + (target.image.height * SCALE_Y))));
}
function fireShot()
{
playSound(FIRE_SOUND_FILE);
ammoBitmap.visible = true;
isShotFlying = true;
}
function processHit()
{
playSound(EXPLODE_SOUND_FILE);
isShotFlying = false; // stop shot
ammoBitmap.visible = false; // hide shot
playerTurn = playerTurn % 2 + 1; // change player
if ((player1Lives <= 0) || (player2Lives <= 0)) {
endGame();
}
}
function endGame()
{
Ticker.setPaused(true); // stop game loop
// show win/lose graphic
var endGameImage;
if (player1Lives <= 0)
{
playSound(LOSE_SOUND_FILE);
endGameImage = preload.getResult("loseImage").result;
}
else if (player2Lives <= 0)
{
endGameImage = preload.getResult("winImage").result;
playSound(WIN_SOUND_FILE);
}
var endGameBitmap = new createjs.Bitmap(endGameImage);
stage.addChild(endGameBitmap);
endGameBitmap.x = (canvas.width / 2) - (endGameImage.width * SCALE_X / 2);
endGameBitmap.y = (canvas.height / 2) - (endGameImage.height * SCALE_Y / 2);
endGameBitmap.scaleX = SCALE_X;
endGameBitmap.scaleY = SCALE_Y;
stage.update();
}
function draw() {
// EaselJS allows for easy updates
stage.update();
}
function playSound(path)
{
var sound = document.createElement("audio");
sound.src = path;
sound.autoplay = true;
}
app.oncheckpoint = function (args) {
// TODO: This application is about to be suspended. Save any state
// that needs to persist across suspensions here. You might use the
// WinJS.Application.sessionState object, which is automatically
// saved and restored across suspension. If you need to complete an
// asynchronous operation before your application is suspended, call
// args.setPromise().
};
document.addEventListener("DOMContentLoaded", initialize, false);
app.start();
})();
And there is the problem: when I'm trying to build this game, I'm getting error like this:
0x800a01bd - JavaScript runtime error: Object doesn't support this action
in the marked place in my code
Thanks for any help :)
Three problems, I report them from previous comments:
easeljs not present in the correct folder
mages/Catapults/Red/redFire/redC‌​atapultFire.png missing
change var stage = new createjs.Stage(canvas); to stage = new createjs.Stage(canvas); you don't have to instantiate that variable as reported in the tutorial (http://www.sitepoint.com/creating-a-simple-windows-8-game-with-javascript-game-basics-createjseaseljs/)
And close this other related question (https://stackoverflow.com/a/16101960/975520), I think is solved by posting your solution as answer.

JavaScript: Why do I keep getting this error with a literal object custom method?

ctx is predefined along with other canvas properties. I didn't want to bombard the page with a huge chunk of code.
I'm building an array of literal objects and they have one method. When I try to call the method it says that It's undefined, like this:
var enemiesArray = [];
function createEnemy(ene) {
for (e = 0; e <= ene; e++) {
var t = Math.floor(Math.random() * 291)
var p = Math.floor(Math.random() * 101)
var enemies = {
x: t,
y: p,
hp: 20,
dir: 0,
damageImage: function () {
return "bomber4.png";
}
}
enemiesArray.push(enemies);
}
}
//an interval is set to call the following function:
function drawEnemey() {
for (zdp in enemiesArray) {
img = new Image();
img.src = "Images/" + enemiesArray[zdp].damageImage(); //this is where I get the error.
img.style.width = "20px";
ctx.drawImage(img, enemiesArray[zdp].x, enemiesArray[zdp].y);
//move from side to side
if (enemiesArray[zdp].dir == 0) {
//move left
enemiesArray[zdp].x -= 1;
if (enemiesArray[zdp].x <= 0) enemiesArray[zdp].dir = 1;
} else {
//move right
enemiesArray[zdp].x += 1;
if (enemiesArray[zdp].x >= 290) enemiesArray[zdp].dir = 0;
}
//check if they are hit
}
}
What I don't understand is when I run the code as is,enemiesArray[zdp].x through enemiesArray[zdp].dir are defined, but enemiesArray[zdp].damageImage() isn't.

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