Spritesheet not animating HTML5 Canvas - html

I have been trying to get my player to animate for some time now and i've read multiple tutorials but i cant seem to achieve this. The tutorial i am following is at : https://www.simplifiedcoding.net/javascript-sprite-animation-tutorial-html5-canvas/
I create the player of a component class:
mySprite = new component(168, 33, "Images/Run/character.png", 0, 0, "sprite");
Then i create the component class with an update function:
function component(width, height, color, x, y,type)
{
this.width = width;
this.height = height;
this.type = type;
if (type == "image" || type == "background" || type == "sprite" ) {
this.image = new Image();
this.image.src = color;
}
this.x = x;
this.y = y;
this.update = function()
{
ctx = myGameArea.context;
if (this.type == "sprite")
{
var curFrame = 0;
curFrame = ++curFrame % 8;
var srcX =0;
srcX = curFrame * this.width /8;
ctx.drawImage(this.image,srcX,y,this.width/8,this.height,x,y,this.width/8,this.height);
}
}
this.newPos = function()
{
this.gravitySpeed += this.gravity;
this.x += this.speedX;
this.y += this.speedY + this.gravitySpeed;
this.hitBottom();
this.jumpGravity();
if (this.type == "background") {
if (this.x == -(this.width)) {
this.x = 0;
}
}
}
}
Then i call both update and newPos functions in the game loop:
mySprite.newPos();
mySprite.update();
I am hoping someone could advise what i am doing wrong.

I noticed when debugging the curFrame variable that it was not incrementing. I solved this by making curframe a variable of the component class and incrementing it directly with this.curFrame +=1; in the game loop.

Related

Where am I going wrong? When I have tested it, for example if I type abc it would output to the canvas aaaaaaaabbbbbbccccccc

function TextTool(){
//set an icon and a name for the object
this.icon = "assets/icons/texttool.jpg";
this.name = "texttool";
var x = 0;
var y = 0;
var startingX = 0;
this.event = function() {
if(mouseX > 0 &&
mouseX < canvas.width &&
mouseY > 0 &&
mouseY < canvas.height
) {
x = mouseX;
y = mouseY;
startingX = x;
return true;
}
return false;
};
this.draw = function() {
if(c.mouseClicked(this.event)) {
if(keyIsPressed) {
if(keyCode === ENTER) {
// Enter key is pressed
console.log("enter");
x = startingX;
y += 15;
}
else {
text(key, x, y);
console.log('called');
x += 20;
}
}
}
else {
if(keyIsPressed) {
if(keyCode === ENTER) {
// Enter key is pressed
console.log("enter");
x = startingX;
y += 15;
}
else {
text(key, x, y);
console.log('called');
x += 20;
}
}
}
};
}
I am trying to create a text tool for my app.
How do I make it so (enter and called) is only called once. Only the this.draw function gets called in the draw function in the sketch file.
I have to use p5.js library for this, can someone help tell me why am I outputting aaaabbbbcccc when i pressed abc.
I used https://p5js.org/reference/#/p5/mouseClicked as a guide for the mouseClicked function.
This is my first time using this type of function as usually for the other tool I created I just had to use mousePressed methode which now seem way easier.

html5 game object movement not working

I am trying to improve my html5 game that I am creating, I am trying to put player object movement into the game like so :
var canvas = document.getElementById('myCanvas');
var context = canvas.getContext('2d');
theplayer = function(width, height, color, x, y)
{
this.width = width;
this.height = height;
this.color = color;
this.speedx = 0;
this.speedy = 0;
this.x = x;
this.y = y;
this.update=function()
{
context.fillStyle = color;
context.fillRect(this.x,this.y,this.width,this.height);
}
this.newpos=function()
{
this.x += this.speedx;
this.y += this.speedy;
}
}
var theplayer = new theplayer(30, 30, "red", 10, 120);
function clearboard()
{
context.clearRect(0,0,canvas.width,canvas.height);
}
function movement()
{
document.addEventListener("keydown",keyPressed, false);
document.addEventListener("keyup",keyLifted, false);
}
function keyPressed(event)
{
var keyPressed = String.fromCharCode(event.keyCode);
if (keyPressed == "W")
{
theplayer.speedx += 1;
}
else if (keyPressed == "D")
{
theplayer.speedy += 1;
}
else if (keyPressed == "S")
{
theplayer.speedx -= 1;
}
else if (keyPressed == "A")
{
theplayer.speedy -= 1;
}
}
var rungame = setInterval(function()
{
clearboard();
theplayer.newpos();
theplayer.update();
}, 20);
The program should make the player control the player object with the WASD keys but I am unable to make the change of X and Y coordinates apply to 'theplayer' object into the 'newpos' function. How can I solve the problem and is there anyway to put multiple key stroke presses of the WASD keys ?

Actionscript 3 error 1009: Cannot access a property or method of a null object reference

I'm trying to make a simple game on Animate CC. Everything seems to work fine except when I look in the output, I get the following error:
TypeError: Error #1009: Cannot access a property or method of a null
object reference.
at _2D_CW2_Game_v10_8_fla::MainTimeline/move()
at _2D_CW2_Game_v10_8_fla::MainTimeline/updateOb()
So I know where the issue might be, and I've been trying tweaking the code for days, googling possible solutions, but to no avail...
My entire source code is as below. Any feedback/suggestions will be greatly appreciated.
import flash.ui.Keyboard;
import flash.events.KeyboardEvent;
import flash.events.MouseEvent;
import flash.events.Event;
import flash.display.MovieClip;
import flash.net.URLRequest;
import flash.media.Sound;
import flash.media.SoundMixer;
//==================================================
// Variable declaration
//==================================================
// defines the variables for boundaries
var left:Number = 0;
var top:Number = 0;
var right:Number = stage.stageWidth;
var bottom:Number = stage.stageHeight;
var velX:Number = 0;
var velY:Number = 0;
var gravity:Number = 1;
var friction:Number = 0.8;
var bounce:Number = -0.5;
var score:Number = 2;
var cv:Number = 0;
var curCount:Number = 30; // countdown 30s
var rightKeyDown:Boolean = false;
var leftKeyDown:Boolean = false;
var upKeyDown:Boolean = false;
var touchGround:Boolean = false;
// create and place player object on stage
var player:Player = new Player();
player.x = 110;
player.y = 460;
addChild(player);
// create obstacle array
var obstacles:Array = new Array();
var numOb:Number = 3;
// create and place enemies on stage
for (var i:Number = 0; i < numOb; i++) {
var ob:Npc = new Npc();
ob.x = 800;
ob.y = 470;
ob.scaleX = -1;
ob.vx = Math.random() * 20 + 1;
addChild(ob);
obstacles.push(ob);
}
//==================================================
// Event handlers
//==================================================
stage.addEventListener(Event.ENTER_FRAME, EntFrame);
addEventListener(Event.ENTER_FRAME, updateOb);
stage.addEventListener(KeyboardEvent.KEY_DOWN, keyDown);
stage.addEventListener(KeyboardEvent.KEY_UP, keyUp);
//==================================================
// Functions
//==================================================
function keyDown(e:KeyboardEvent):void {
if (e.keyCode == Keyboard.RIGHT) {
rightKeyDown = true;
}
if (e.keyCode == Keyboard.LEFT) {
leftKeyDown = true;
}
if (e.keyCode == Keyboard.UP) {
// if player isn't already jumping and is on the ground
if (!upKeyDown && touchGround) {
// then start jumping
isJumping();
}
upKeyDown = true;
}
}
function keyUp(e:KeyboardEvent):void {
if (e.keyCode == Keyboard.RIGHT) {
rightKeyDown = false;
}
if (e.keyCode == Keyboard.LEFT) {
leftKeyDown = false;
}
if (e.keyCode == Keyboard.UP) {
upKeyDown = false;
}
}
function EntFrame(e:Event):void {
player.x += velX;
player.y += velY;
velX *= friction;
velY += gravity;
if (player.y >= 450) {
touchGround = true;
player.y = 450;
}
// boundary checks
if (player.x + player.width/2 > right) {
player.x = right - player.width/2;
player.velX *= bounce;
} else if (player.x - player.width/2 < left) {
player.x = left + player.width/2;
player.velX *= bounce;
}
// make player move left or right
controls();
if (curCount > 0) {
cv++;
if (cv >= 30) {
curCount--;
cv = 0;
timertext.text = String(curCount);
if (curCount == 0) {
restart();
gotoAndStop("gameOverWon");
}
}
}
}
function updateOb(e:Event):void {
// make obstacles move
for (var i:Number = 0; i < numOb; i++) {
var ob:Npc = obstacles[i];
move(ob);
if (player.hitTestObject(obstacles[i])) {
/*if (obstacles[i].hitTestPoint(player.x + player.width/2, player.y + player.height/2, true)
|| obstacles[i].hitTestPoint(player.x + player.width/2, player.y - player.height/2, true)
|| obstacles[i].hitTestPoint(player.x - player.width/2, player.y + player.height/2, true)
|| obstacles[i].hitTestPoint(player.x - player.width/2, player.y - player.height/2, true))*/
bumpOb(obstacles[i]);
}
}
scoretext.text = String(score);
if (score == 0) {
restart();
gotoAndStop("gameOverLost");
}
}
// applies basic velocity to enemies
function move(moveOb) {
moveOb.x -= moveOb.vx;
if (moveOb.x + moveOb.width/2 > right) {
moveOb.x = right - moveOb.width/2;
moveOb.vx *= bounce;
moveOb.scaleX = -1;
}
if (moveOb.x - moveOb.width/2 < left) {
moveOb.x = left + moveOb.width/2;
moveOb.vx *= bounce;
moveOb.scaleX = 1;
}
}
function bumpOb(p) {
if (p) {
p.removeEventListener(Event.ENTER_FRAME, updateOb);
if (p.parent) {
removeChild(p);
score--;
}
}
}
function restart() {
if(contains(player)) {
removeChild(player);
}
for (var i:int = 0; i < numOb; i++) {
if (contains(obstacles[i]) && obstacles[i] != null) {
removeChild(obstacles[i]);
obstacles[i] = null;
}
}
// returns a new array that consists of a range of elements from the original array,
// without modifying the original array
obstacles.slice(0);
}
function controls() {
if (rightKeyDown) {
velX += 3;
player.scaleX = 1;
}
if (leftKeyDown) {
velX -= 3;
player.scaleX = -1;
}
}
function isJumping() {
touchGround = false;
velY = -15;
}
//==================================================
// Sound control for background music
//==================================================
btnMute.addEventListener(MouseEvent.CLICK, mute);
function mute(e:MouseEvent):void {
SoundMixer.soundTransform = new SoundTransform(0);
btnMute.removeEventListener(MouseEvent.CLICK, mute);
btnMute.addEventListener(MouseEvent.CLICK, unmute);
}
function unmute(e:MouseEvent):void {
SoundMixer.soundTransform = new SoundTransform(1);
btnMute.removeEventListener(MouseEvent.CLICK, unmute);
btnMute.addEventListener(MouseEvent.CLICK, mute);
}
I had the same problem when I created interactive elements for animation. Check which layer the interactive object is on. A similar error occurred when the object overlapped something that was located on the layer above.
You can try...
1) Your Npc is a class/library object, right?
Give the source MC/Sprite, the instance name of moveOb or p.
2) or else try... Use function parameters (this is a better coding style):
(2a) Since you say..
var ob:Npc = obstacles[i];
move(ob);
ps: why not simplify (without var) as : move( obstacles[i] ); ...?
(2b) Your move function should specify a data type together with your parameter name...
//# applies basic velocity to enemies
//# Wrong...
//function move(moveOb) {
//# Better...
function move( moveOb : Npc ) {
//# Aso fix as...
function bumpOb(p : Npc ) {
By using function parameters, you can now give unique names to the (function's) input parameters but stay referencing the same (or compatible) data type.
Let me know how it goes.
The obstacles array may have null elements in the middle. What if you add a condition to continue if it's null?
function updateOb(e:Event):void {
// make obstacles move
for (var i:Number = 0; i < obstacles.length; i++) {
var ob:Npc = obstacles[i];
if(!ob) continue;
move(ob);
if (player.hitTestObject(ob)) {
/*if (obstacles[i].hitTestPoint(player.x + player.width/2, player.y +
player.height/2, true)
|| obstacles[i].hitTestPoint(player.x + player.width/2, player.y -
player.height/2, true)
|| obstacles[i].hitTestPoint(player.x - player.width/2, player.y +
player.height/2, true)
|| obstacles[i].hitTestPoint(player.x - player.width/2, player.y -
player.height/2, true))*/
bumpOb(obstacles[i]);
}
}
scoretext.text = String(score);
if (score == 0) {
restart();
gotoAndStop("gameOverLost");
}
}

simulate onmouseup event to canvas

i have a simple HTML5 with a canvas object, i just need to add replicate the same events on the button below the code-
As you can see pushing the button, the canvas calls accelerate() and onmouseUp event calls the function again with different argument, and the canvas stops going up and starts with the gravity
I would like to use in a touch screen, the only problem is the event OnmuseUp that i do not know how to manage
this is the code:
var myGamePiece;
var myObstacles = [];
var myScore;
function startGame() {
myGamePiece = new component(30, 30, "red", 10, 120);
myGamePiece.gravity = 0.05;
myScore = new component("30px", "Consolas", "black", 280, 40, "text");
myGameArea.start();
}
var myGameArea = {
canvas : document.createElement("canvas"),
start : function() {
this.canvas.width = 480;
this.canvas.height = 270;
this.context = this.canvas.getContext("2d");
document.body.insertBefore(this.canvas, document.body.childNodes[0]);
this.frameNo = 0;
this.canvas.addEventListener('click', function() {accelerate(-0.2);}, false);
updateGameArea();
},
clear : function() {
this.context.clearRect(0, 0, this.canvas.width, this.canvas.height);
}
}
function component(width, height, color, x, y, type) {
this.type = type;
this.score = 0;
this.width = width;
this.height = height;
this.speedX = 0;
this.speedY = 0;
this.x = x;
this.y = y;
this.gravity = 0;
this.gravitySpeed = 0;
this.update = function() {
ctx = myGameArea.context;
if (this.type == "text") {
ctx.font = this.width + " " + this.height;
ctx.fillStyle = color;
ctx.fillText(this.text, this.x, this.y);
} else {
ctx.fillStyle = color;
ctx.fillRect(this.x, this.y, this.width, this.height);
}
}
this.newPos = function() {
this.gravitySpeed += this.gravity;
this.x += this.speedX;
this.y += this.speedY + this.gravitySpeed;
this.hitBottom();
}
this.hitBottom = function() {
var rockbottom = myGameArea.canvas.height - this.height;
if (this.y > rockbottom) {
this.y = rockbottom;
this.gravitySpeed = 0;
}
}
this.crashWith = function(otherobj) {
var myleft = this.x;
var myright = this.x + (this.width);
var mytop = this.y;
var mybottom = this.y + (this.height);
var otherleft = otherobj.x;
var otherright = otherobj.x + (otherobj.width);
var othertop = otherobj.y;
var otherbottom = otherobj.y + (otherobj.height);
var crash = true;
if ((mybottom < othertop) || (mytop > otherbottom) || (myright < otherleft) || (myleft > otherright)) {
crash = false;
}
return crash;
}
}
function updateGameArea() {
var x, height, gap, minHeight, maxHeight, minGap, maxGap;
for (i = 0; i < myObstacles.length; i += 1) {
if (myGamePiece.crashWith(myObstacles[i])) {
return;
}
}
myGameArea.clear();
myGameArea.frameNo += 1;
if (myGameArea.frameNo == 1 || everyinterval(150)) {
x = myGameArea.canvas.width;
minHeight = 20;
maxHeight = 200;
height = Math.floor(Math.random()*(maxHeight-minHeight+1)+minHeight);
minGap = 50;
maxGap = 200;
gap = Math.floor(Math.random()*(maxGap-minGap+1)+minGap);
myObstacles.push(new component(10, height, "green", x, 0));
myObstacles.push(new component(10, x - height - gap, "green", x, height + gap));
}
for (i = 0; i < myObstacles.length; i += 1) {
myObstacles[i].x += -1;
myObstacles[i].update();
}
myScore.text="SCORE: " + myGameArea.frameNo;
myScore.update();
myGamePiece.newPos();
myGamePiece.update();
}
function everyinterval(n) {
if ((myGameArea.frameNo / n) % 1 == 0) {return true;}
return false;
}
function accelerate(n) {
if (!myGameArea.interval) {myGameArea.interval = setInterval(updateGameArea, 20);}
myGamePiece.gravity = n;
}
<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1.0"/>
<style>
canvas {
border:1px solid #d3d3d3;
background-color: #f1f1f1;
}
</style>
</head>
<body onload="startGame()">
<br>
<button onmousedown="accelerate(-0.2)" onmouseup="accelerate(0.05)">ACCELERATE</button>
<p>Click the ACCELERATE button to start the game</p>
<p>How long can you stay alive? Use the ACCELERATE button to stay in the air..</p>
</body>
</html>
Rather than use the event listener to drive the game, use the event listener just to track the input state.
Eg
canvas.addEventListener("mousedown",inputEvent);
canvas.addEventListener("touchstart",inputEvent);
const input = {
active : false;
}
function inputEvent(){
input.active = true;
}
Then rather than use setInterval (which you should never use for animation) create a main loop function
function mainLoop(){
// see answer below
requestAnimationFrame(mainLoop); // get the next frame
}
requestAnimationFrame(mainLoop); // starts the first frame
This will start being called every 1/60th second. In this you monitor the input and do what is needed depending on the game state.
const thrust = -0.4;
const gravity = 0.1;
var inplay = false; // when true game is playing.
function mainLoop(){
if(input.active && !inplay){
inplay = true;
input.active = false; // clear the input
}
if(inplay){
if(input.active){ // input
myGamePiece.speedY += thrust;
input.active = false; // clear input
}
updateGameArea(); // call the render game function.
}
requestAnimationFrame(mainLoop); // get the next frame
}
requestAnimationFrame(mainLoop); // starts the first frame
You will need to change the move function
You had
this.newPos = function() {
this.gravitySpeed += this.gravity;
this.x += this.speedX;
this.y += this.speedY + this.gravitySpeed;
this.hitBottom();
}
Change to
this.newPos = function() {
this.speedY += gravity;
this.x += this.speedX;
this.y += this.speedY;
this.hitBottom();
}
Or you can change the input to have a thrust over some frames
const input = {
active : 0;
}
const thrustFrameCount = 4;
function inputEvent(){
input.active = thrustFrameCount;
}
and change the main loop to
const thrust = -0.1;
const gravity = 0.1;
var inplay = false; // when true game is playing.
function mainLoop(){
if(input.active > 0 && !inplay){
inplay = true;
input.active = 0; // clear the input
}
if(inplay){
if(input.active > 0){ // input
myGamePiece.speedY += thrust * input.active;
input.active -= 1; // count down input on.
}
updateGameArea(); // call the render game function.
}
requestAnimationFrame(mainLoop); // get the next frame
}
requestAnimationFrame(mainLoop); // starts the first frame
Well everything is sort of like that, your game code is a little bit overly complex so I have hacked a quick mod to give you an example of what I meant in the above answer.
var myGamePiece;
var myObstacles = [];
var myScore;
function startGame() {
myGamePiece = new component(30, 30, "red", 10, 120);
myScore = new component("30px", "Consolas", "black", 280, 40, "text");
myGameArea.start();
}
var myGameArea = {
canvas : canvas,
start : function() {
this.canvas.width = 480;
this.canvas.height = 270;
this.context = this.canvas.getContext("2d");
this.frameNo = 0;
updateGameArea();
},
clear : function() {
this.context.clearRect(0, 0, this.canvas.width, this.canvas.height);
}
}
function component(width, height, color, x, y, type) {
this.type = type;
this.score = 0;
this.width = width;
this.height = height;
this.speedX = 0;
this.speedY = 0;
this.x = x;
this.y = y;
this.gravity = 0;
this.gravitySpeed = 0;
this.update = function() {
ctx = myGameArea.context;
if (this.type == "text") {
ctx.font = this.width + " " + this.height;
ctx.fillStyle = color;
ctx.fillText(this.text, this.x, this.y);
} else {
ctx.fillStyle = color;
ctx.fillRect(this.x, this.y, this.width, this.height);
}
}
this.newPos = function() {
this.speedY += gravity;
this.x += this.speedX;
this.y += this.speedY;
this.hitBottom();
}
this.hitBottom = function() {
var rockbottom = myGameArea.canvas.height - this.height;
if (this.y > rockbottom) {
this.y = rockbottom;
if(this.speedY > 0){
this.speedY = 0;
}
}
}
this.crashWith = function(otherobj) {
var myleft = this.x;
var myright = this.x + (this.width);
var mytop = this.y;
var mybottom = this.y + (this.height);
var otherleft = otherobj.x;
var otherright = otherobj.x + (otherobj.width);
var othertop = otherobj.y;
var otherbottom = otherobj.y + (otherobj.height);
var crash = true;
if ((mybottom < othertop) || (mytop > otherbottom) || (myright < otherleft) || (myleft > otherright)) {
crash = false;
}
return crash;
}
}
function updateGameArea() {
var x, height, gap, minHeight, maxHeight, minGap, maxGap;
for (i = 0; i < myObstacles.length; i += 1) {
if (myGamePiece.crashWith(myObstacles[i])) {
return;
}
}
myGameArea.clear();
if (myGameArea.frameNo % wallFrameCount === 0 ) {
x = myGameArea.canvas.width;
minHeight = 20;
maxHeight = 200;
height = Math.floor(Math.random()*(maxHeight-minHeight+1)+minHeight);
minGap = 50;
maxGap = 200;
gap = Math.floor(Math.random()*(maxGap-minGap+1)+minGap);
myObstacles.push(new component(10, height, "green", x, 0));
myObstacles.push(new component(10, x - height - gap, "green", x, height + gap));
}
for (i = 0; i < myObstacles.length; i += 1) {
myObstacles[i].x += -1;
myObstacles[i].update();
}
myScore.text="SCORE: " + myGameArea.frameNo;
myScore.update();
myGamePiece.newPos();
myGamePiece.update();
myGameArea.frameNo += 1;
}
canvas.addEventListener("mousedown",inputEvent);
canvas.addEventListener("touchstart",inputEvent);
const input = {active : 0 };
const thrustFrameCount = 4;
function inputEvent(){
input.active = thrustFrameCount;
}
const wallFrameCount = 200;
const thrust = -0.4;
const gravity = 0.2;
var inplay = false; // when true game is playing.
function mainLoop(){
if(input.active > 0 && !inplay){
startGame();
inplay = true;
input.active = 0; // clear the input
}
if(inplay){
if(input.active > 0){ // input
myGamePiece.speedY += thrust * input.active;
input.active -= 1; // count down input on.
}
updateGameArea(); // call the render game function.
}
requestAnimationFrame(mainLoop); // get the next frame
}
requestAnimationFrame(mainLoop); // starts the first frame
canvas {
border:1px solid #d3d3d3;
background-color: #f1f1f1;
}
<canvas id="canvas" width="480" height="270"></canvas><br>
Click touch canvas to start.

Making an HTML Jigsaw Puzzle in Flash CC [duplicate]

I am am doing this for a interactive assignment for a media arts class and I have no idea how to code in action script 3. I took the orignal code from a tutorial and it didn't work so I came here and attempted to learn how to modify it.
AS3 Code
//*********************
// Initialize:
flash.events.MouseEvent
var numPieces = 16;
for (var i = 0; i < numPieces; i++)
{
var pieceName = "p" + (i + 1);
var piece = this[pieceName];
if( piece ){
piece.name = pieceName;
piece.addEventListener(MouseEvent.MOUSE_DOWN, function)(evt)
{
this.scaleX = 1;
this.scaleY = 1;
this.shadow = null;
this.parent.addChild(this);// Bump to top
this.offset = {x:this.x - evt.stageX, y:this.y - evt.stageY};
});
piece.addEventListener(MouseEvent.MOUSE_MOVE, function)
{
this.x = evt.stageX + this.offset.x;
this.y = evt.stageY + this.offset.y;
});
piece.addEventListener(MouseEvent.MOUSE_UP, function)(evt)
{
var target = this.parent["t"+this.name.substr(1)];
if( target && hitTestInRange( target, 30) ){
this.x = target.x;
this.y = target.y;
}
});
}
}
function hitTestInRange( target, range )
{
if( target.x > stage.mouseX - range &&
target.x < stage.mouseX + range &&
target.y > stage.mouseY - range &&
target.y < stage.mouseY + range )
{
return true;
}
return false;
}
Please help me fix this code so I can run my puzzle and move the pieces.
I can upload the flash file if needed