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I would like to stop drawing new particles after 5 seconds and restart drawing on click anywhere.
Here is the code https://codepen.io/Jeremboo/pen/ENVaMY for the animation.
Right now it keeps on drawing until you click on the screen to restart it again.
What I want is to stop drawing after 5 seconds and then on click anywhere restart it from zero particles. I tried the following to stop but I am not able to start it again.
this is the js code
/**/ const canvas = document.createElement('canvas');
/**/ const context = canvas.getContext('2d');
/**/ let windowWidth = canvas.width = window.innerWidth;
/**/ let windowHeight = canvas.height = window.innerHeight;
/**/ canvas.id = 'canvas';
/**/ document.body.insertBefore(canvas, document.body.firstChild);
/**/ /* ---- CORE END ---- */
/* ---- CREATING ZONE ---- */
/* ---- SETTINGS ---- */
const numberParticlesStart = 1000;
const particleSpeed = 0.3;
const velocity = 0.9;
const circleWidth = 50;
/* ---- INIT ---- */
let particles = [];
const getRandomFloat = (min, max) => (Math.random() * (max - min) + min);
/* ---- Particle ---- */
function Particle (x, y) {
this.x = x;
this.y = y;
this.vel = {
x : getRandomFloat(-20, 20)/100,
y : getRandomFloat(-20, 20)/100,
min : getRandomFloat(2, 10),
max : getRandomFloat(10, 100)/10
}
this.color = 'rgba(255, 255, 255, 0.05)';
}
Particle.prototype.render = function() {
context.beginPath();
context.fillStyle = this.color;
context.arc(this.x, this.y, 1, 0, Math.PI * 2);
context.fill();
};
Particle.prototype.update = function() {
const forceDirection = {
x: getRandomFloat(-1, 1),
y: getRandomFloat(-1, 1),
};
if (Math.abs(this.vel.x + forceDirection.x) < this.vel.max) {
this.vel.x += forceDirection.x;
}
if (Math.abs(this.vel.y + forceDirection.y) < this.vel.max) {
this.vel.y += forceDirection.y;
}
this.x += this.vel.x * particleSpeed;
this.y += this.vel.y * particleSpeed;
if (Math.abs(this.vel.x) > this.vel.min) {
this.vel.x *= velocity;
}
if (Math.abs(this.vel.y) > this.vel.min) {
this.vel.y *= velocity;
}
this.testBorder();
};
Particle.prototype.testBorder = function() {
if (this.x > windowWidth) {
this.setPosition(this.x, 'x');
} else if (this.x < 0) {
this.setPosition(windowWidth, 'x');
}
if (this.y > windowHeight) {
this.setPosition(this.y, 'y');
} else if (this.y < 0) {
this.setPosition(windowHeight, 'y');
}
};
Particle.prototype.setPosition = function(pos, coor) {
if (coor === 'x') {
this.x = pos;
} else if (coor === 'y') {
this.y = pos;
}
};
/* ---- Functions ----*/
function loop() {
let i;
const length = particles.length;
for (i = 0; i < length; i++) {
particles[i].update();
particles[i].render();
}
requestAnimationFrame(loop);
}
/* ---- START ---- */
function init() {
let i;
for (i = 0; i < numberParticlesStart; i++) {
const angle = Math.random() * 360;
particles.push(new Particle(
windowWidth * 0.5 + (Math.cos(angle) * circleWidth),
windowHeight * 0.5 - (Math.sin(angle) * circleWidth),
));
}
}
init();
window.onresize = () => {
windowWidth = canvas.width = window.innerWidth;
windowHeight = canvas.height = window.innerHeight;
particles = [];
context.clearRect(0,0, windowWidth, windowHeight);
init();
}
window.addEventListener('click', () => {
particles = [];
context.clearRect(0,0, windowWidth, windowHeight);
init();
});
loop();
i replaced the function loop() with this to stop it after 5 seconds -
function loop(stp) {
let i;
const length = particles.length;
for (i = 0; i < length; i++) {
particles[i].update();
particles[i].render();
}
if (stp > 5000) return;
requestAnimationFrame(loop);
}
Try to rely on system clock, as setTimeout and setInterval are not accurate
let start;
function loop(startTime) {
let i;
if(startTime){
// Set the current time in milliseconds from 1st of jenuary 1970
start = new Date().getTime();
}
const length = particles.length;
for (i = 0; i < length; i++) {
particles[i].update();
particles[i].render();
}
// Comparison from current dateTime with the stored one
// as setInterval and setTimeout are not accurate
if (start - (new Date().getTime() >= 5000) return;
requestAnimationFrame(loop);
}
loop(true);
I am working on a college project that requires me to build a 2D game in javascript. A problem that I'm having at the moment is that it cannot read the 'addEventListener'. This error has caused my game to not work completely.
document.getElementById('restart').addEventListener('click', startGame);
Here is the full code that I have used. The error is down the very bottom.
(function()
{
//Define variables
var canvas = document.getElementById('canvas');
var ctx = canvas.getContext('2d');
var player, score, stop, ticker;
var ground = [], water = [], enemies = [], environment = [];
//Platform variables
var platformHeight, platformLength, gapLength;
var platformWidth = 32;
var platformBase = canvas.height - platformWidth;
var platformSpacer = 64;
//Randomly generates a number
function random(low, high)
{
return Math.floor(Math.random() * (high - low + 1) + low);
}
//Bounds a number
function bound(num, low, high)
{
return Math.max(Math.min(num, high), low);
}
//Loads all of the assets
var assetLoader = (function()
{
this.imgs = {
'bg' : 'Images/bg.png',
'sky' : 'Images/sky.png',
'backdrop' : 'Images/backdrop.png',
'backdrop2' : 'Images/backdrop_ground.png',
'grass' : 'Images/grass.png',
'avatar_normal' : 'Images/normal_walk.png',
'water' : 'imgs/water.png',
'grass1' : 'imgs/grassMid1.png',
'grass2' : 'imgs/grassMid2.png',
'bridge' : 'imgs/bridge.png',
'plant' : 'imgs/plant.png',
'bush1' : 'imgs/bush1.png',
'bush2' : 'imgs/bush2.png',
'cliff' : 'imgs/grassCliffRight.png',
'spikes' : 'imgs/spikes.png',
'box' : 'imgs/boxCoin.png',
'slime' : 'imgs/slime.png'
};
var assetsLoaded = 0; //How many assets have been loaded
var numImgs = Object.keys(this.imgs).length; //Total number of image assets
this.totalAssest = numImgs; //Total number of assets
function assetLoaded(dic, name)
{
if(this[dic][name].status !== 'loading')
{
return;
}
this[dic][name].status = 'loaded';
assetsLoaded++;
if(assetsLoaded === this.totalAssest && typeof this.finished === 'function')
{
this.finished();
}
}
this.downloadAll = function()
{
var _this = this;
var src;
for (var img in this.imgs)
{
if (this.imgs.hasOwnProperty(img))
{
src = this.imgs[img];
(function(_this, img)
{
_this.imgs[img] = new Image();
_this.imgs[img].status = 'loading';
_this.imgs[img].name = img;
_this.imgs[img].onload = function() {assetLoaded.call(_this, 'imgs', img)};
_this.imgs[img].src = src;
})(_this, img);
}
}
}
return{
imgs: this.imgs,
totalAssest: this.totalAssest,
downloadAll: this.downloadAll
};
})();
assetLoader.finished = function()
{
startGame();
}
function SpriteSheet(path, frameWidth, frameHeight)
{
this.image = new Image();
this.frameWidth = frameWidth;
this.frameHeight = frameHeight;
var self = this;
this.image.onload = function()
{
self.framesPerRow = Math.floor(self.image.width / self.frameWidth);
};
this.image.src = path;
}
function Animation(spritesheet, frameSpeed, startFrame, endFrame)
{
var animationSequence = [];
var currentFrame = 0;
var counter = 0;
for (var frameNumber = startFrame; frameNumber <= endFrame; frameNumber++)
{
animationSequence.push(frameNumber);
}
this.update = function()
{
if (counter == (frameSpeed - 1))
{
currentFrame = (currentFrame + 1) % animationSequence.length;
}
counter = (counter + 1) % frameSpeed;
};
this.draw = function(x, y)
{
var row = Math.floor(animationSequence[currentFrame] / spritesheet.framesPerRow);
var col = Math.floor(animationSequence[currentFrame] % spritesheet.framesPerRow);
ctx.drawImage
(
spritesheet.image,
col * spritesheet.frameWidth, row * spritesheet.frameHeight,
spritesheet.frameWidth, spritesheet.frameHeight,
x, y,
spritesheet.frameWidth, spritesheet.frameHeight);
};
}
var background = (function()
{
var sky = {};
var backdrop = {};
var backdrop2 = {};
this.draw = function()
{
ctx.drawImage(assetLoader.imgs.bg, 0, 0);
sky.x -= sky.speed;
backdrop.x -= backdrop.speed;
backdrop2.x -= backdrop2.speed;
ctx.drawImage(assetLoader.imgs.sky, sky.x, sky.y);
ctx.drawImage(assetLoader.imgs.sky, sky.x + canvas.width, sky.y);
ctx.drawImage(assetLoader.imgs.backdrop, backdrop.x, backdrop.y);
ctx.drawImage(assetLoader.imgs.backdrop, backdrop.x + canvas.width, backdrop.y);
ctx.drawImage(assetLoader.imgs.backdrop2, backdrop2.x, backdrop2.y);
ctx.drawImage(assetLoader.imgs.backdrop2, backdrop2.x + canvas.width, backdrop2.y);
if (sky.x + assetLoader.imgs.sky.width <= 0)
{
sky.x = 0;
}
if (backdrop.x + assetLoader.imgs.backdrop.width <= 0)
{
backdrop.x = 0;
}
if (backdrop2.x + assetLoader.imgs.backdrop2.width <= 0)
{
backdrop2.x = 0;
}
};
this.reset = function()
{
sky.x = 0;
sky.y = 0;
sky.speed = 0.2;
backdrop.x = 0;
backdrop.y = 0;
backdrop.speed = 0.4;
backdrop2.x = 0;
backdrop2.y = 0;
backdrop2.speed = 0.6;
}
return{
draw: this.draw,
reset: this.reset
};
})();
//A vector for 2D space
function Vector(x, y, dx, dy)
{
// position
this.x = x || 0;
this.y = y || 0;
// direction
this.dx = dx || 0;
this.dy = dy || 0;
}
//Advances the vector's position
Vector.prototype.advance = function()
{
this.x += this.dx;
this.y += this.dy;
};
//Gets the minimum distance between two vectors
Vector.prototype.minDist = function(vec)
{
var minDist = Infinity;
var max = Math.max(Math.abs(this.dx), Math.abs(this.dy),Math.abs(vec.dx), Math.abs(vec.dy));
var slice = 1 / max;
var x, y, distSquared;
// get the middle of each vector
var vec1 = {}, vec2 = {};
vec1.x = this.x + this.width/2;
vec1.y = this.y + this.height/2;
vec2.x = vec.x + vec.width/2;
vec2.y = vec.y + vec.height/2;
for(var percent = 0; percent < 1; percent += slice)
{
x = (vec1.x + this.dx * percent) - (vec2.x + vec.dx * percent);
y = (vec1.y + this.dy * percent) - (vec2.y + vec.dy * percent);
distSquared = x * x + y * y;
minDist = Math.min(minDist, distSquared);
}
return Math.sqrt(minDist);
};
//The player object
var player = (function(player)
{
//Player properties
player.width = 60;
player.height = 96;
player.speed = 6;
//Jumping
player.gravity = 1;
player.dy = 0;
player.jumpDy = -10;
player.isFalling = false;
player.isJumping = false;
//Spritesheets
player.sheet = new SpriteSheet('Images/normal_walk.png', player.width, player.height);
player.walkAnim = new Animation(player.sheet, 4, 0, 15);
player.jumpAnim = new Animation(player.sheet, 4, 15, 15);
player.fallAnim = new Animation(player.sheet, 4, 11, 11);
player.anim = player.walkAnim;
Vector.call(player, 0, 0, 0, player.dy);
var jumpCounter = 0;
player.update = function()
{
//Jump if not currently jumping or falling
if(KEY_STATUS.space && player.dy === 0 && !player.isJumping)
{
player.isJumping = true;
player.dy = player.jumpDy;
jumpCounter = 12;
}
//Jump higher if the spacebar is continually pressed
if(KEY_STATUS.space && jumpCounter)
{
player.dy = player.jumpDy;
}
jumpCounter = Math.max(jumpCounter - 1, 0);
this.advance();
//Gravity
if(player.isFalling || player.isJumping)
{
player.dy += player.gravity;
}
//Falling Animation
if(player.dy > 0)
{
player.anim = player.fallAnim;
}
// change animation is jumping
else if(player.dy < 0)
{
player.anim = player.jumpAnim;
}
else
{
player.anim = player.walkAnim;
}
player.anim.update();
};
//Draw the player's current position
player.draw = function()
{
player.anim.draw(player.x, player.y);
};
//Resets the player's position
player.reset = function()
{
player.x = 64;
player.y = 250;
};
return player;
})(Object.create(Vector.prototype));
//Sprites
function Sprite(x, y, type)
{
this.x = x;
this.y = y;
this.width = platformWidth;
this.height = platformWidth;
this.type = type;
Vector.call(this, x, y, 0, 0);
//Updating the sprites
this.update = function()
{
this.dx = -player.speed;
this.advancer();
}
//Drawing the sprites
this.draw = function()
{
ctx.save();
ctx.translate(0.5, 0.5);
ctx.drawImage(assetLoader.imgs[this.type], this.x, this.y);
ctx.restore();
}
}
Sprite.prototype = Object.create(Vector.prototype);
//Platforms
function getType()
{
var type;
switch(platformHeight)
{
case 0:
case 1:
type = Math.random() > 0.5 ? 'grass1' : 'grass2';
break;
case 2:
type = 'grass';
break;
case 3:
type = 'bridge';
break;
case 4:
type = 'box';
break;
}
if (platformLength === 1 && platformHeight < 3 && rand(0, 3) === 0)
{
type = 'cliff';
}
return type;
}
//Update and draw all ground positions
function updateGround()
{
//Animate ground
player.isFalling = true;
for(var i = 0; i < ground.length; i++)
{
ground[i].update();
ground[i].draw();
//Stop the player going through the platforms when landing
var angle;
if(player.minDist(ground[i]) <= player.height/2 + platformWidth/2 && (angle = Math.atan2(player.y - ground[i].y, player.x - ground[i].x) * 180/Math.PI) > -130 &&angle < -50)
{
player.isJumping = false;
player.isFalling = false;
player.y = ground[i].y - player.height + 5;
player.dy = 0;
}
}
//Remove the ground that has gone off screen
if(ground[0] && ground[0].x < -platformWidth)
{
ground.splice(0, 1);
}
}
//Update and draw all water positions
function updateWater()
{
//Animate water
for(var i = 0; i < water.length; i++)
{
water[i].update();
water[i].draw();
}
//Remove water that has gone off screen
if (water[0] && water[0].x < -platformWidth)
{
var w = water.splice(0, 1)[0];
w.x = water[water.length-1].x + platformWidth;
water.push(w);
}
}
//Update and draw all environment positions
function updateEnvironment()
{
//Animate environment
for(var i = 0; i < environment.length; i++)
{
environment[i].update();
environment[i].draw();
}
//R emove environment that have gone off screen
if(environment[0] && environment[0].x < -platformWidth)
{
environment.splice(0, 1);
}
}
//Update and draw all enemies position. Also check for collision against the player.
function updateEnemies()
{
//Animate enemies
for(var i = 0; i < enemies.length; i++)
{
enemies[i].update();
enemies[i].draw();
//Player ran into enemy
if(player.minDist(enemies[i]) <= player.width - platformWidth/2)
{
gameOver();
}
}
//Remove enemies that have gone off screen
if(enemies[0] && enemies[0].x < -platformWidth)
{
enemies.splice(0, 1);
}
}
//Update and draw the players position
function updatePlayer()
{
player.update();
player.draw();
//Game over
if(player.y + player.height >= canvas.height)
{
gameOver();
}
}
//Spawn new sprites off screen
function spawnSprites()
{
//Increase score
score++;
//First create a gap
if(gapLength > 0)
{
gapLength--;
}
//Then create the ground
else if(platformLength > 0)
{
var type = getType();
ground.push(new Sprite(
canvas.width + platformWidth % player.speed,
platformBase - platformHeight * platformSpacer,
type
));
platformLength--;
//Add random environment sprites
spawnEnvironmentSprites();
//Add random enemies
spawnEnemySprites();
}
//Start over
else
{
//Increase gap length every speed increase of 4
gapLength = rand(player.speed - 2, player.speed);
// only allow a ground to increase by 1
platformHeight = bound(rand(0, platformHeight + rand(0, 2)), 0, 4);
platformLength = rand(Math.floor(player.speed/2), player.speed * 4);
}
}
//Spawn new environment sprites off screen
function spawnEnvironmentSprites()
{
if(score > 40 && rand(0, 20) === 0 && platformHeight < 3)
{
if (Math.random() > 0.5)
{
environment.push(new Sprite(canvas.width + platformWidth % player.speed, platformBase - platformHeight * platformSpacer - platformWidth, 'plant'));
}
else if(platformLength > 2)
{
environment.push(new Sprite(canvas.width + platformWidth % player.speed, platformBase - platformHeight * platformSpacer - platformWidth, 'bush1'));
environment.push(new Sprite(canvas.width + platformWidth % player.speed + platformWidth, platformBase - platformHeight * platformSpacer - platformWidth, 'bush2'));
}
}
}
//Spawn new enemy sprites off screen
function spawnEnemySprites()
{
if(score > 100 && Math.random() > 0.96 && enemies.length < 3 && platformLength > 5 && (enemies.length ? canvas.width - enemies[enemies.length-1].x >= platformWidth * 3 || canvas.width - enemies[enemies.length-1].x < platformWidth : true))
{
enemies.push(new Sprite(canvas.width + platformWidth % player.speed, platformBase - platformHeight * platformSpacer - platformWidth, Math.random() > 0.5 ? 'spikes' : 'slime'));
}
}
//Game Loop
function animate()
{
if(!stop)
{
requestAnimFrame(animate);
ctx.clearRect(0, 0, canvas.width, canvas.height);
background.draw();
//Update entities
updateWater();
updateEnvironment();
updatePlayer();
updateGround();
updateEnemies();
//Draw the score
ctx.fillText('Score: ' + score + 'm', canvas.width - 140, 30);
//Spawn a new Sprite
if(ticker % Math.floor(platformWidth / player.speed) === 0)
{
spawnSprites();
}
//Increase player's speed only when player is jumping
if(ticker > (Math.floor(platformWidth / player.speed) * player.speed * 20) && player.dy !== 0)
{
player.speed = bound(++player.speed, 0, 15);
player.walkAnim.frameSpeed = Math.floor(platformWidth / player.speed) - 1;
//Reset ticker
ticker = 0;
//Spawn a platform to fill in gap created by increasing player speed
if(gapLength === 0)
{
var type = getType();
ground.push(new Sprite(canvas.width + platformWidth % player.speed, platformBase - platformHeight * platformSpacer, type));
platformLength--;
}
}
ticker++;
}
}
//Spacebar events
var KEY_CODES = {
32: 'space'
};
var KEY_STATUS = {};
for(var code in KEY_CODES)
{
if(KEY_CODES.hasOwnProperty(code))
{
KEY_STATUS[KEY_CODES[code]] = false;
}
}
document.onkeydown - function(e)
{
var keyCode = (e.keyCode) ? e.keyCode : e.charCode;
if(KEY_CODES[keyCode])
{
e.preventDefault();
KEY_STATUS[KEY_CODES[keyCode]] = true;
}
};
document.onkeydown - function(e)
{
var keyCode = (e.keyCode) ? e.keyCode : e.charCode;
if(KEY_CODES[keyCode])
{
e.preventDefault();
KEY_STATUS[KEY_CODES[keyCode]] = false;
}
};
//Request Animation Polyfill
var requestAnimFrame = (function()
{
return window.requestAnimationFrame || window.webkitRequestAnimationFrame || window.mozRequestAnimationFrame || window.oRequestAnimationFrame || window.msRequestAnimationFrame || function(callback, element)
{
window.setTimeout(callback, 1000 / 60);
};
})();
//Start the game and resets all variables and entities, spawn ground and water.
function startGame()
{
document.getElementById('game-over').style.display = 'none';
ground = [];
water = [];
environment = [];
enemies = [];
player.reset();
ticker = 0;
stop = false;
score = 0;
platformHeight = 2;
platformLength = 15;
gapLength = 0;
ctx.font = '16px arial, sans-serif';
for (var i = 0; i < 30; i++)
{
ground.push(new Sprite(i * (platformWidth-3), platformBase - platformHeight * platformSpacer, 'grass'));
}
for (i = 0; i < canvas.width / 32 + 2; i++)
{
water.push(new Sprite(i * platformWidth, platformBase, 'water'));
}
background.reset();
animate();
}
//End the game and restart
function gameOver()
{
stop = true;
document.getElementById('game-over').style.display = 'block';
}
document.getElementById('restart').addEventListener('click', startGame);
assetLoader.downloadAll();
})();
Currently I am creating a Javascript game. I have successfully created all the game pieces and how my game's basic functions should work. However, I am having 2 issues that I can't seem to solve, and I've looked for a few weeks now trying to figure out how to do it. I can't figure out how to get the game to result in a gameover if my player gets pushed of falls off screen. Also, I am unsure on how I can get the score to continously increase for as long as the player is still "alive". If anyone can either demonstrate how to do these things or point me in the direction of a tutorial or article on how to do it it would be very helpful.
(function() {
var requestAnimationFrame = window.requestAnimationFrame || window.mozRequestAnimationFrame || window.webkitRequestAnimationFrame || window.msRequestAnimationFrame;
window.requestAnimationFrame = requestAnimationFrame;
})();
const seeded = (() => {
var seed = 1;
return {
max: 2576436549074795,
reseed(s) {
seed = s
},
random() {
return seed = ((8765432352450986 * seed) + 8507698654323524) % this.max
},
}
})();
const randSeed = (seed) => seeded.reseed(seed);
const randSI = (min, max = min + (min = 0)) => (seeded.random() % (max - min)) + min;
const randS = (min, max = min + (min = 0)) => (seeded.random() / seeded.max) * (max - min) + min;
randSeed(100); // seed the random generators
function Player(color, keymap, x) {
this.x = (typeof x === 'undefined') ? 1 : x;
this.y = 7;
this.width = 15;
this.height = 15;
this.speed = 10;
this.velX = 0;
this.velY = 0;
this.jumping = false;
this.keymap = {}
for (let key in keymap) {
switch (keymap[key]) {
case 'jump':
this.keymap[key] = this.jump
break;
case 'left':
this.keymap[key] = this.moveLeft
break;
case 'right':
this.keymap[key] = this.moveRight
break;
}
}
this.color = color;
} // Player()
Player.prototype.jump = function() {
if (!this.jumping) {
this.jumping = true;
this.velY = -this.speed * 1.5;
}
}
Player.prototype.moveRight = function() {
if (this.velX < this.speed) {
this.velX++;
}
}
Player.prototype.moveLeft = function() {
if (this.velX > -this.speed) {
this.velX--;
}
}
// Globals
var canvas = document.getElementById("canvas"),
ctx = canvas.getContext("2d"),
width = 700,
height = 600,
keys = [],
friction = .9,
gravity = .9;
canvas.width = width;
canvas.height = height;
// Set up players
var players = [];
players.push(new Player('purple', {
32: 'jump',
37: 'left',
38: 'jump',
39: 'right'
}))
/*players.push(new Player('yellow', {
56: 'jump',
52: 'left',
54: 'right'
}, width-25))*/
players.push(new Player('blue', {
87: 'jump',
65: 'left',
68: 'right'
}, (width-25)/2))
function update() {
ctx.clearRect(0, 0, width, height);
addPlatformsToBottom(); // will add platforms if needed
drawPlatforms();
players.forEach(player => {
// check player-specific keys
for (let i in player.keymap) {
if (keys[i] && typeof player.keymap[i] === 'function')
player.keymap[i].bind(player)();
}
player.velX *= friction;
player.velY += gravity;
player.x += player.velX;
player.y += player.velY;
if (player.x >= width - player.width) {
player.x = width - player.width;
} else if (player.x <= 0) {
player.x = 0;
}
if (player.y >= height - player.height) {
player.y = height - player.height;
player.jumping = false;
player.velY = 0;
}
testPlayerForPlatforms(player);
ctx.fillStyle = player.color;
ctx.fillRect(player.x, player.y, player.width, player.height);
}) // player.forEach
requestAnimationFrame(update);
}
document.body.addEventListener("keydown", function(e) {
// console.log(e.keyCode);
keys[e.keyCode] = true;
});
document.body.addEventListener("keyup", function(e) {
keys[e.keyCode] = false;
});
window.addEventListener("load", function() {
update();
});
function testPlayerForPlatforms(player) {
player.hitPlatform = false; // reset platform hit flag
for (var i = 0; i < platforms.length; i++) {
var p = platforms[i];
if (p.active) {
testPlayer(player, p);
if (player.hitPlatform) {
break; // stop search as player has hit a platform
}
}
}
}
function drawPlatforms() { // draws all platforms and move up
platformInfo.lastPlatformY += platformInfo.speed;
for (var i = 0; i < platforms.length; i++) {
var p = platforms[i];
if (p.active) {
p.yPos += platformInfo.speed;
if (p.yPos + p.height < 0) { // platform above top
p.active = false; // turn it off
} else {
p.draw();
}
}
}
}
function addPlatformsToBottom() {
while (platformInfo.lastPlatformY < ctx.canvas.height) {
generateLevel();
}
}
// some constants and vars to control random generation of platforms
const platformInfo = {
speed: -2.5,
height: 8, // platform height
minLength: 100, // in pixels
maxLength: 300,
vertSpacing: 100, // distance between platforms
minHorSpacing: 50, // should be larger than player
maxHorSpacing: 80,
lastPlatformY: 100, // y position of last platform created
maxHoleCount: 3,
color: "#FFF",
}
// array object holds platforms
const platforms = [];
// a platform template object that will be used to create platforms from
const platform = {
left: 0,
right: 0,
yPos: 0,
height: 0, // thickness
active: false, // true if platform in use
color: "#F84",
draw() { // function to draw the platform
ctx.fillStyle = this.color;
ctx.fillRect(this.left, this.yPos, this.right - this.left, this.height);
},
init(left, right, yPos) { // function to initialize
// alias to save typing.
const pI = platformInfo
this.yPos = yPos;
this.left = left;
this.right = right;
this.height = pI.height;
this.color = pI.color;
this.active = true;
},
}
// function adds platforms to array. If no inactive platforms a
// new one is created
function addPlatform() {
var platform;
for (var i = 0; i < platforms.length; i++) {
if (!platforms[i].active) { // is the platform inactive
platform = platforms[i];
break; // stop searching
}
}
if (!platform) { // if no inactive platform then create a new one
platform = createPlatform();
platforms.push(platform);
}
return platform;
}
// a function to create a platform object
function createPlatform(customProps = {}) { // custom props can be used to modify the
// platform in future. For now it just defaults to empty
return Object.assign({}, platform, customProps);
}
// creates a set of platforms for a single level
function generateLevel() {
var numHoles = randSI(1, platformInfo.maxHoleCount);
var spacing = ctx.canvas.width / (numHoles); // get spacing
var ypos = platformInfo.lastPlatformY;
platformInfo.lastPlatformY += platformInfo.vertSpacing;
var left = 0; // the starting left edge
for (var i = 1; i <= numHoles; i++) { // create numHoles
var platform = addPlatform();
var holeOffset = randSI(-spacing, 0);
platform.init(left, spacing * i + holeOffset, ypos);
left = spacing * i + holeOffset + randSI(platformInfo.minHorSpacing, platformInfo.maxHorSpacing);
}
// add the last platform
platform = addPlatform();
platform.init(left, ctx.canvas.width, ypos);
}
function testPlayer(player, platform) {
var p, pl; // p for player, pl for platform
p = player;
pl = platform;
// is the player above or below platform
if (!(p.x + p.width < pl.left || p.x > pl.right)) { // yes
if (p.velY > 0 && p.y < pl.yPos) { // is player moving down and above platform
if (p.y + p.height > pl.yPos) { //is bottom of player below top of platform
// must have hit platform
p.jumping = false;
p.y = pl.yPos - p.height; // move player so that it is on the platform
p.velY = 0;
p.hitPlatform = true; // flag a platform has been hit
}
} else if (p.y + p.height > pl.yPos + pl.height) { // player must be moving up so check if below platform
if (p.y < pl.yPos + pl.height) { // is top of player above bottom of platform
// must have hit head on platform
p.velY = 0;
p.y = pl.yPos + pl.height;
p.jumping = false;
p.hitPlatform = true; // flag a platform has been hit
}
}
}
}
#score {
color:white;
font-size:35px;
}
0<html>
<head>
<title>Square Stairs™</title>
</head>
<body bgcolor="#000">
<div id="score">SCORE:</div>
<br><br><br> <!-- line breaks to move canvas away from SO title bar that gets in the way when switching to full page mode -->
<canvas id="canvas" style="border:3px solid #fff"></canvas>
</body>
</html>
This is my code as it stands currently. I made on the websiteCodePenand this is my original code. I have nothing to do with Unity or any other coding platform so if you have any information on how to solve this it has to be able to run on the CodePen website. Thank you for your assistance.
I've added code to your code, look for ////////////////////
I added the following to your source code:
Added the functions checkPlayerBounds(player) and addToScore(x)
checkPlayerBounds(player) checks if player has been pushed/fell off the screen.
Note: You need to add more functionality here to have the Game Over do what you want.
addToScore(x) increases the score variable and the Score HTML element if scoreShouldUpdate is true.
Added global variables updates, score, and scoreShouldUpdate.
updates keeps track of how many times the update() function has been called.
score keeps track of the games score.
Added code inside your update() function.
The first bit keeps adding to the score, but only after the game has been updated a specified amount of times.
The next bit calls the checkPlayerBounds function on every player.
This all works, the only problem is that the player starts off/right on the edge of the screen, so the score won't update until that is changed in your project.
(function() {
var requestAnimationFrame = window.requestAnimationFrame || window.mozRequestAnimationFrame || window.webkitRequestAnimationFrame || window.msRequestAnimationFrame;
window.requestAnimationFrame = requestAnimationFrame;
})();
const seeded = (() => {
var seed = 1;
return {
max: 2576436549074795,
reseed(s) {
seed = s
},
random() {
return seed = ((8765432352450986 * seed) + 8507698654323524) % this.max
},
}
})();
const randSeed = (seed) => seeded.reseed(seed);
const randSI = (min, max = min + (min = 0)) => (seeded.random() % (max - min)) + min;
const randS = (min, max = min + (min = 0)) => (seeded.random() / seeded.max) * (max - min) + min;
randSeed(100); // seed the random generators
///////////////////////////
// This function increases the score by 'x' amount.
///////////////////////////
function addToScore(x){
if(scoreShouldUpdate){
score += x;
var scoreElement = document.getElementById("score");
scoreElement.innerHTML = "Score: " + score;
}
}
function checkPlayerBounds(player){
if(player.y >= 0){
scoreShouldUpdate = false;
// Insert game over stuff here.
}
}
function Player(color, keymap, x) {
this.x = (typeof x === 'undefined') ? 1 : x;
this.y = 7;
this.width = 15;
this.height = 15;
this.speed = 10;
this.velX = 0;
this.velY = 0;
this.jumping = false;
this.keymap = {}
for (let key in keymap) {
switch (keymap[key]) {
case 'jump':
this.keymap[key] = this.jump
break;
case 'left':
this.keymap[key] = this.moveLeft
break;
case 'right':
this.keymap[key] = this.moveRight
break;
}
}
this.color = color;
} // Player()
Player.prototype.jump = function() {
if (!this.jumping) {
this.jumping = true;
this.velY = -this.speed * 1.5;
}
}
Player.prototype.moveRight = function() {
if (this.velX < this.speed) {
this.velX++;
}
}
Player.prototype.moveLeft = function() {
if (this.velX > -this.speed) {
this.velX--;
}
}
// Globals
var canvas = document.getElementById("canvas"),
ctx = canvas.getContext("2d"),
width = 700,
height = 600,
keys = [],
friction = .9,
gravity = .9;
//////////////////////////////
//New variables for score increase
//////////////////////////////
var updates = 0;
var score = 0;
var scoreShouldUpdate = true;
canvas.width = width;
canvas.height = height;
// Set up players
var players = [];
players.push(new Player('purple', {
32: 'jump',
37: 'left',
38: 'jump',
39: 'right'
}))
/*players.push(new Player('yellow', {
56: 'jump',
52: 'left',
54: 'right'
}, width-25))*/
players.push(new Player('blue', {
87: 'jump',
65: 'left',
68: 'right'
}, (width-25)/2))
function update() {
/////////////////////////////////////
// You can change the '5' to something else to change the rate of which score is increased.
/////////////////////////////////////
if(updates == 5){
updates = 0;
addToScore(1);
}
updates++;
ctx.clearRect(0, 0, width, height);
addPlatformsToBottom(); // will add platforms if needed
drawPlatforms();
players.forEach(player => {
// check player-specific keys
for (let i in player.keymap) {
if (keys[i] && typeof player.keymap[i] === 'function')
player.keymap[i].bind(player)();
}
player.velX *= friction;
player.velY += gravity;
player.x += player.velX;
player.y += player.velY;
if (player.x >= width - player.width) {
player.x = width - player.width;
} else if (player.x <= 0) {
player.x = 0;
}
if (player.y >= height - player.height) {
player.y = height - player.height;
player.jumping = false;
player.velY = 0;
}
testPlayerForPlatforms(player);
ctx.fillStyle = player.color;
ctx.fillRect(player.x, player.y, player.width, player.height);
//My code
checkPlayerBounds(player);
}) // player.forEach
requestAnimationFrame(update);
}
document.body.addEventListener("keydown", function(e) {
// console.log(e.keyCode);
keys[e.keyCode] = true;
});
document.body.addEventListener("keyup", function(e) {
keys[e.keyCode] = false;
});
window.addEventListener("load", function() {
update();
});
function testPlayerForPlatforms(player) {
player.hitPlatform = false; // reset platform hit flag
for (var i = 0; i < platforms.length; i++) {
var p = platforms[i];
if (p.active) {
testPlayer(player, p);
if (player.hitPlatform) {
break; // stop search as player has hit a platform
}
}
}
}
function drawPlatforms() { // draws all platforms and move up
platformInfo.lastPlatformY += platformInfo.speed;
for (var i = 0; i < platforms.length; i++) {
var p = platforms[i];
if (p.active) {
p.yPos += platformInfo.speed;
if (p.yPos + p.height < 0) { // platform above top
p.active = false; // turn it off
} else {
p.draw();
}
}
}
}
function addPlatformsToBottom() {
while (platformInfo.lastPlatformY < ctx.canvas.height) {
generateLevel();
}
}
// some constants and vars to control random generation of platforms
const platformInfo = {
speed: -2.5,
height: 8, // platform height
minLength: 100, // in pixels
maxLength: 300,
vertSpacing: 100, // distance between platforms
minHorSpacing: 50, // should be larger than player
maxHorSpacing: 80,
lastPlatformY: 100, // y position of last platform created
maxHoleCount: 3,
color: "#FFF",
}
// array object holds platforms
const platforms = [];
// a platform template object that will be used to create platforms from
const platform = {
left: 0,
right: 0,
yPos: 0,
height: 0, // thickness
active: false, // true if platform in use
color: "#F84",
draw() { // function to draw the platform
ctx.fillStyle = this.color;
ctx.fillRect(this.left, this.yPos, this.right - this.left, this.height);
},
init(left, right, yPos) { // function to initialize
// alias to save typing.
const pI = platformInfo
this.yPos = yPos;
this.left = left;
this.right = right;
this.height = pI.height;
this.color = pI.color;
this.active = true;
},
}
// function adds platforms to array. If no inactive platforms a
// new one is created
function addPlatform() {
var platform;
for (var i = 0; i < platforms.length; i++) {
if (!platforms[i].active) { // is the platform inactive
platform = platforms[i];
break; // stop searching
}
}
if (!platform) { // if no inactive platform then create a new one
platform = createPlatform();
platforms.push(platform);
}
return platform;
}
// a function to create a platform object
function createPlatform(customProps = {}) { // custom props can be used to modify the
// platform in future. For now it just defaults to empty
return Object.assign({}, platform, customProps);
}
// creates a set of platforms for a single level
function generateLevel() {
var numHoles = randSI(1, platformInfo.maxHoleCount);
var spacing = ctx.canvas.width / (numHoles); // get spacing
var ypos = platformInfo.lastPlatformY;
platformInfo.lastPlatformY += platformInfo.vertSpacing;
var left = 0; // the starting left edge
for (var i = 1; i <= numHoles; i++) { // create numHoles
var platform = addPlatform();
var holeOffset = randSI(-spacing, 0);
platform.init(left, spacing * i + holeOffset, ypos);
left = spacing * i + holeOffset + randSI(platformInfo.minHorSpacing, platformInfo.maxHorSpacing);
}
// add the last platform
platform = addPlatform();
platform.init(left, ctx.canvas.width, ypos);
}
function testPlayer(player, platform) {
var p, pl; // p for player, pl for platform
p = player;
pl = platform;
// is the player above or below platform
if (!(p.x + p.width < pl.left || p.x > pl.right)) { // yes
if (p.velY > 0 && p.y < pl.yPos) { // is player moving down and above platform
if (p.y + p.height > pl.yPos) { //is bottom of player below top of platform
// must have hit platform
p.jumping = false;
p.y = pl.yPos - p.height; // move player so that it is on the platform
p.velY = 0;
p.hitPlatform = true; // flag a platform has been hit
}
} else if (p.y + p.height > pl.yPos + pl.height) { // player must be moving up so check if below platform
if (p.y < pl.yPos + pl.height) { // is top of player above bottom of platform
// must have hit head on platform
p.velY = 0;
p.y = pl.yPos + pl.height;
p.jumping = false;
p.hitPlatform = true; // flag a platform has been hit
}
}
}
}
#score {
color:white;
font-size:35px;
}
<html>
<head>
<title>Square Stairs™</title>
</head>
<body bgcolor="#000">
<div id="score">SCORE:</div>
<br><br><br> <!-- line breaks to move canvas away from SO title bar that gets in the way when switching to full page mode -->
<canvas id="canvas" style="border:3px solid #fff"></canvas>
</body>
</html>
The Problem
I am creating a game where you have to move away from or dodge projectiles coming towards you, I have enabled the user to move the image they are controlling but at the moment the user can place the image anywhere on the canvas.
The Question
How can I only allow the user to move along designated part of the canvas and only along the X axis? for example:
Here is my game, "working progress":
The user is in control of the ship, they should only be able to move left or right like this for example:
The Code
<script>
var game = create_game();
game.init();
//music
var snd = new Audio("menu.mp3");
snd.play();
document.getElementById('mute').addEventListener('click', function (evt) {
if ( snd.muted ) {
snd.muted = false
evt.target.innerHTML = 'mute'
}
else {
snd.muted = true
evt.target.innerHTML = 'unmute'
}
})
function create_game() {
debugger;
var level = 1;
var projectiles_per_level = 1;
var min_speed_per_level = 1;
var max_speed_per_level = 2;
var last_projectile_time = 0;
var next_projectile_time = 0;
var width = 600;
var height = 500;
var delay = 1000;
var item_width = 30;
var item_height = 30;
var total_projectiles = 0;
var projectile_img = new Image();
var projectile_w = 30;
var projectile_h = 30;
var player_img = new Image();
var c, ctx;
var projectiles = [];
var player = {
x: 200,
y: 400,
score: 0
};
function init() {
projectile_img.src = "apple.png";
player_img.src = "basket.png";
level = 1;
total_projectiles = 0;
projectiles = [];
c = document.getElementById("c");
ctx = c.getContext("2d");
ctx.fillStyle = "#ff6600";
ctx.fillRect(0, 0, 500, 600);
c.addEventListener("mousemove", function (e) {
//moving over the canvas.
var bounding_box = c.getBoundingClientRect();
player.x = (e.clientX - bounding_box.left) * (c.width / bounding_box.width) - player_img.width / 2;
player.y = (e.clientY - bounding_box.top) * (c.height / bounding_box.height) - player_img.height / 2;
}, false);
setupProjectiles();
requestAnimationFrame(tick);
}
function setupProjectiles() {
var max_projectiles = level * projectiles_per_level;
while (projectiles.length < max_projectiles) {
initProjectile(projectiles.length);
}
}
function initProjectile(index) {
var max_speed = max_speed_per_level * level;
var min_speed = min_speed_per_level * level;
projectiles[index] = {
x: Math.round(Math.random() * (width - 2 * projectile_w)) + projectile_w,
y: -projectile_h,
v: Math.round(Math.random() * (max_speed - min_speed)) + min_speed,
delay: Date.now() + Math.random() * delay
}
total_projectiles++;
}
function collision(projectile) {
if (projectile.y + projectile_img.height < player.y + 74) {
return false;
}
if (projectile.y > player.y + 74) {
return false;
}
if (projectile.x + projectile_img.width < player.x + 177) {
return false;
}
if (projectile.x > player.x + 177) {
return false;
}
return true;
}
function maybeIncreaseDifficulty() {
level = Math.max(1, Math.ceil(player.score / 10));
setupProjectiles();
}
function tick() {
var i;
var projectile;
var dateNow = Date.now();
c.width = c.width;
for (i = 0; i < projectiles.length; i++) {
projectile = projectiles[i];
if (dateNow > projectile.delay) {
projectile.y += projectile.v;
if (collision(projectile)) {
initProjectile(i);
player.score++;
} else if (projectile.y > height) {
initProjectile(i);
} else {
ctx.drawImage(projectile_img, projectile.x, projectile.y);
}
}
}
ctx.font = "bold 24px sans-serif";
ctx.fillStyle = "#ff6600";
ctx.fillText(player.score, c.width - 50, 50);
ctx.fillText("Level: " + level, 20, 50);
ctx.drawImage(player_img, player.x, player.y);
maybeIncreaseDifficulty();
requestAnimationFrame(tick);
}
return {
init: init
};
}
</script>
JSFiddle (Broken)
https://jsfiddle.net/3oc4jsf6/10/
If your ship is tied to mouse movement, and you want to only allow movement across the X-axis you can simply avoid changing its .y property in your mousemove listener.
Remove this line:
player.y = (e.clientY - bounding_box.top) * (c.height / bounding_box.height) - player_img.height / 2;
This is a game I am making. I cant figure out why it is not working. I have the JS fiddle here http://jsfiddle.net/aa68u/4/
// Create the canvas
var canvas = document.createElement("canvas");
var ctx = canvas.getContext("2d");
canvas.width = 512;
canvas.height = 480;
document.body.appendChild(canvas);
// Background image
var bgReady = false;
var bgImage = new Image();
bgImage.onload = function () {
bgReady = true;
};
bgImage.src = "http://6269-9001.zippykid.netdna-cdn.com/wp-content/uploads/2013/11/Woods-Wallpaper.jpg";
// Ship image
var shipReady = false;
var shipImage = new Image();
shipImage.onload = function () {
shipImage = true;
};
shipImage.src = "http://s29.postimg.org/3widtojzn/hero.png";
// Astroid image
var astroidReady = false;
var astroidImage = new Image();
astroidImage.onload = function () {
astroidReady = true;
};
astroidImage.src = "http://s29.postimg.org/4r4xfprub/monster.png";
// Game objects
var ship = {
speed: 256;
};
var astroid = {};
var health = 100;
window.keyStates = {};
addEventListener('keydown', function (e) {
keyStates[e.keyCode || e.key] = true;
e.preventDefault();
e.stopPropagation();
}, true);
addEventListener('keyup', function (e) {
keyStates[e.keyCode || e.key] = false;
e.preventDefault();
e.stopPropagation();
}, true);
var reset = function () {
astroid.width = 10;
astroid.height = 10;
astroid.x = 32 + (Math.random() * (canvas.width - 64));
astroid.y = 32 + (Math.random() * (canvas.height - 64));
ship.speed = 256;
for (var p in keyStates) keyStates[p]= false;
};
// Update game objects
function update (modifier) {
if (keyStates[38] ==true) { // Player holding up
astroid.x -= ship.speed * modifier;
}
if (keyStates[40]==true) { // Player holding down
astroid.x += ship.speed * modifier;
}
if (keyStates[37]==true) { // Player holding left
astroid.y -= ship.speed * modifier;
}
if (keyStates[39]==true) { // Player holding right
astroid.y += ship.speed * modifier;
}
if (astroid.width) < 200{
astroid.width +=10;
astroid.height += 10;
}
if (astroid.width) > 200{
reset();
}
// Are they touching?
if (keyStates[32] == true && ship.x <= (astroid.x + 32) && astroid.x <= (ship.x + 32) && ship.y <= (astroid.y + 32) && astroid.y <= (ship.y + 32)) {
monstersCaught += 1;
reset();
}
};
// Draw everything
var render = function () {
if (bgReady) {
ctx.drawImage(bgImage, 0, 0);
}
if (shipReady) {
ctx.drawImage(heroImage, hero.x, hero.y);
}
if (astroidReady) {
ctx.drawImage(monsterImage, monster.x, monster.y);
}
// Score
ctx.fillStyle = "rgb(250, 250, 250)";
ctx.font = "24px Helvetica";
ctx.textAlign = "left";
ctx.textBaseline = "top";
ctx.fillText("Your Health: " + health, 32, 32);
};
// The main game loop
var main = function () {
var now = Date.now();
var delta = now - then;
if (delta > 20) delta = 20;
update(delta / 1000);
render();
then = now;
};
// Let's play this game!
reset();
var then = Date.now();
setInterval(main, 1); // Execute as fast as possible
The game is supposed to be a ship(shoe image) that is avoiding astroids that get bigger(ants) but when you move your ship(shoe) stays in the same place and the astroids(ants) move. The ants/astroids also get bigger like you are going close to them.
var ship = {
speed: 256;
};
Remove the ; after the value.
if astroid.width < 200{
and
if astroid.width > 200{
Need parentheses around the if conditions.
The error console is helpful! But now it's just stuck in an infinite loop of monsterImage is not defined. Just... go back, write your code more carefully, and use the error console! It's there for a reason!