I tried to follow some guides but couldn't get their functions to work in my program. What i tried is commented out in my code(the for loop). I want a working function on space press create a bullet that goes right.
here is a fiddle: https://jsfiddle.net/tmanrocks999/7mLpo8uj/
code:
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1.0"/>
<style>
canvas {
border:4px solid #d3d3d3;
background-color: #f1f1f1;
}
</style>
</head>
<body onload="startGame()">
<script>
var myGamePiece;
var endGoalPiece;
var Enemy1;
var bullet;
function startGame() {
myGameArea.start();
myGamePiece = new component(30, 30, "red", 0, 240);
endGoalPiece = new component(30, 30, "black", 450, 240);
myEnemy1 = new component(30, 30, "green", 200, 240);
}
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.interval = setInterval(updateGameArea, 20);
window.addEventListener('keydown', function (e) {
myGameArea.key = e.keyCode;
})
window.addEventListener('keyup', function (e) {
myGameArea.key = false;
})
},
clear : function(){
this.context.clearRect(0, 0, this.canvas.width, this.canvas.height);
}
}
function component(width, height, color, x, y) {
this.gamearea = myGameArea;
this.width = width;
this.height = height;
this.speedX = 0;
this.speedY = 0;
//this.gravity = 0.05;
//this.gravitySpeed = 0;
this.x = x;
this.y = y;
this.color = color;
this.update = function() {
ctx = myGameArea.context;
ctx.fillStyle = this.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.hitTop();
this.hitRight();
this.hitLeft();
}
this.hitBottom = function() {
var rockbottom = myGameArea.canvas.height - this.height;
if (this.y > rockbottom) {
this.y = rockbottom;
}
}
this.hitTop = function() {
var rockTop = 0;
if (this.y < rockTop) {
this.y = rockTop;
}
}
this.hitRight = function() {
var rockRight = myGameArea.canvas.width - this.width;
if (this.x > rockRight) {
this.x = rockRight;
}
}
this.hitLeft = function() {
var rockLeft = 0;
if (this.x < rockLeft) {
this.x = rockLeft;
}
}
function jump() {
myGamePiece.gravitySpeed=-1;
}
}
function shootGun(){
//var b = new bullet();
//var bullets = []
//bullets.push(b)
//for (var i = 0; i < bullets.length; i++) {
bullet = new component(11, 5, "blue", myGamePiece.x+27 , myGamePiece.y+13 );
bullet.newPos();
bullet.speedX=1;
}
function updateGameArea() {
myGameArea.clear();
myGamePiece.speedX = 0;
myGamePiece.speedY = 0;
if (myGameArea.key && myGameArea.key == 37) {myGamePiece.speedX = -1; }//left
if (myGameArea.key && myGameArea.key == 39) {myGamePiece.speedX = 1; }//right
if (myGameArea.key && myGameArea.key == 38) {myGamePiece.gravitySpeed = -1; }//jump
if (myGameArea.key && myGameArea.key == 32) {shootGun()}//shoot gun
//if (myGameArea.key && myGameArea.key == 40) {myGamePiece.speedY = 1; }// down
myEnemy1.update();
endGoalPiece.update();
myGamePiece.newPos();
myGamePiece.update();
bullet.newPos();
bullet.update();
}
</script>
<p>use the arrow keys on you keyboard to move the red square.</p>
</body>
</html>
I expect on space press for a bullet to keep being created like shooting a gun. but at the moment only 2 bullet is made then if you press space again it resets the bullet. I get why this is happening but cant get my for loop to work. I will add something to happen if it hits a enemy later.
updateis usually expected to update the state of an entity, while a function which draws an entity would be called something likedraworrender. And acomponentis usually just one functionality of an entity and not the whole entity. The term is common in the Entity - Component - System pattern, but you don't seem to follow that pattern (which is OK, but using the term component outside of that pattern feels weird). \$\endgroup\$