I've been trying to figure out how I can add a play again button to refresh the page after a player has lost. This is a classic snake game. I followed a tutorial on it and but they never said anything about a Play Again button. Any help would be appreciated. Nothing too complicated though please, I'm still learning.
const ctx = canvas.getContext("2d");
class SnakePart {
constructor(x, y) {
this.x = x;
this.y = y;
}
}
let speed = 7;
let tileCount = 20;
let tileSize = canvas.width / tileCount - 2;
let headX = 10;
let headY = 10;
const snakeParts = [];
let tailLength = 2;
let appleX = 5;
let appleY = 5;
let inputsXVelocity = 0;
let inputsYVelocity = 0;
let xVelocity = 0;
let yVelocity = 0;
let score = 0;
const gulpSound = new Audio("gulp.mp3");
//game loop
function drawGame() {
xVelocity = inputsXVelocity;
yVelocity = inputsYVelocity;
changeSnakePosition();
let result = isGameOver();
if (result) {
return;
}
clearScreen();
checkAppleCollision();
drawApple();
drawSnake();
drawScore();
if (score > 5) {
speed = 9;
}
if (score > 10) {
speed = 11;
}
setTimeout(drawGame, 1000 / speed);
}
function isGameOver() {
let gameOver = false;
if (yVelocity === 0 && xVelocity === 0) {
return false;
}
//walls
if (headX < 0) {
gameOver = true;
} else if (headX === tileCount) {
gameOver = true;
} else if (headY < 0) {
gameOver = true;
} else if (headY === tileCount) {
gameOver = true;
}
for (let i = 0; i < snakeParts.length; i++) {
let part = snakeParts[i];
if (part.x === headX && part.y === headY) {
gameOver = true;
break;
}
}
if (gameOver) {
ctx.fillStyle = "white";
ctx.font = "50px Verdana";
if (gameOver) {
ctx.fillStyle = "white";
ctx.font = "50px Verdana";
var gradient = ctx.createLinearGradient(0, 0, canvas.width, 0);
gradient.addColorStop("0", " magenta");
gradient.addColorStop("0.5", "blue");
gradient.addColorStop("1.0", "red");
// Fill with gradient
ctx.fillStyle = gradient;
ctx.fillText("Game Over!", canvas.width / 6.5, canvas.height / 2);
}
ctx.fillText("Game Over!", canvas.width / 6.5, canvas.height / 2);
}
return gameOver;
}
function drawScore() {
ctx.fillStyle = "white";
ctx.font = "10px Verdana";
ctx.fillText("Score " + score, canvas.width - 50, 10);
}
function clearScreen() {
ctx.fillStyle = "black";
ctx.fillRect(0, 0, canvas.width, canvas.height);
}
function drawSnake() {
ctx.fillStyle = "green";
for (let i = 0; i < snakeParts.length; i++) {
let part = snakeParts[i];
ctx.fillRect(part.x * tileCount, part.y * tileCount, tileSize, tileSize);
}
snakeParts.push(new SnakePart(headX, headY)); //put an item at the end of the list next to the head
while (snakeParts.length > tailLength) {
snakeParts.shift(); // remove the furthet item from the snake parts if have more than our tail size.
}
ctx.fillStyle = "orange";
ctx.fillRect(headX * tileCount, headY * tileCount, tileSize, tileSize);
}
function changeSnakePosition() {
headX = headX + xVelocity;
headY = headY + yVelocity;
}
function drawApple() {
ctx.fillStyle = "red";
ctx.fillRect(appleX * tileCount, appleY * tileCount, tileSize, tileSize);
}
function checkAppleCollision() {
if (appleX === headX && appleY == headY) {
appleX = Math.floor(Math.random() * tileCount);
appleY = Math.floor(Math.random() * tileCount);
tailLength++;
score++;
gulpSound.play();
}
}
document.body.addEventListener("keydown", keyDown);
function keyDown(event) {
//up
if (event.keyCode == 38 || event.keyCode == 87) {
//87 is w
if (inputsYVelocity == 1) return;
inputsYVelocity = -1;
inputsXVelocity = 0;
}
//down
if (event.keyCode == 40 || event.keyCode == 83) {
// 83 is s
if (inputsYVelocity == -1) return;
inputsYVelocity = 1;
inputsXVelocity = 0;
}
//left
if (event.keyCode == 37 || event.keyCode == 65) {
// 65 is a
if (inputsXVelocity == 1) return;
inputsYVelocity = 0;
inputsXVelocity = -1;
}
//right
if (event.keyCode == 39 || event.keyCode == 68) {
//68 is d
if (inputsXVelocity == -1) return;
inputsYVelocity = 0;
inputsXVelocity = 1;
}
}
drawGame();```
The easiest way to refresh the page would be just:
window.location.reload(false)
Source:
https://www.freecodecamp.org/news/location-reload-method-how-to-reload-a-page-in-javascript/
I would suggest that simply reloading the page is not a great way to implement a play again feature but I appreciate the creativity of it.
I was making a snake game. I have a basic game but I wanted to move the snake more smoothly and specially I wanted to turn the direction of the snake more smoothly.
The problem until now is that I have been removing the tail of the snake and adding it to the head for the movement part.
Moving the snake smoothly is rather easy by reducing the interval for calling the draw function and incrementing the x and y values by small amounts but what I am having problem is with turning the snake smoothly,it is exactly where I am lost/confused as to how to do it like done here (only the turning of snake part and not the changing of head when snake gets blocked)
can anyone help out please? here is my code:
let cvs = "";
let ctx = "";
let size = [];
var direction = 'b';
var speed = 200;
//moving lines on arrow click
window.addEventListener("keydown", moveSomething, false);
function moveSomething(e) {
switch (e.keyCode) {
case 37:
//left
if (direction != 'r') {
direction = 'l';
}
break;
case 38:
//up
if (direction != 'b') {
direction = 't';
}
break;
case 39:
//right
if (direction != 'l') {
direction = 'r';
}
break;
case 40:
//bottom
if (direction != 't') {
direction = 'b';
}
break;
}
}
let food = {
x: Math.floor(Math.random() * 220),
y: Math.floor(Math.random() * 400),
s: 20,
draw: function() {
//this if block rounds off the x and y values
if ((this.x % 20) != 0 || (this.y % 20) != 0) {
if ((this.x % 20) != 0) {
let e = this.x % 20;
e = 20 - e;
this.x = this.x + e;
}
if ((this.y % 20) != 0) {
let e = this.y % 20;
e = 20 - e;
this.y = this.y + e;
}
};
ctx.fillStyle = "red";
ctx.fillRect(this.x, this.y, this.s, this.s);
},
newfood: function() {
this.x = Math.floor(Math.random() * 220);
this.y = Math.floor(Math.random() * 400);
this.draw();
}
}
const snake = {
s: 20,
draw: function(x, y) {
ctx.fillStyle = "green";
ctx.fillRect(this.s * x, this.s * y, this.s, this.s);
ctx.strokeStyle = "black";
ctx.strokeRect(this.s * x, this.s * y, this.s, this.s);
},
snakeInit: function() {
for (let i = 8; i >= 4; i--) {
size.push({
x: i,
y: 6
})
}
},
callDraw: function() {
for (let i = 0; i < size.length; i++) {
this.draw(size[i].x, size[i].y);
}
},
move: function() {
var snakeX = size[0].x;
var snakeY = size[0].y;
if (direction == 'r') {
snakeX++;
} else if (direction == 'l') {
snakeX--;
} else if (direction == 't') {
snakeY--;
} else if (direction == 'b') {
snakeY++;
}
//console.log("Inside move1", speed);
if (snakeX == -1 || snakeX == cvs.width / this.s || snakeY == -1 || snakeY == Math.floor(cvs.height / this.s) || this.checkSelfCollision(snakeX, snakeY, size)) {
ctx.clearRect(0, 0, cvs.width, cvs.height);
gameloop = clearInterval(gameloop);
return;
} else {
ctx.clearRect(0, 0, cvs.width, cvs.height);
food.draw();
}
if (snakeX * 20 == food.x && snakeY * 20 == food.y) {
var tail = {
x: snakeX,
y: snakeY
};
food.eaten();
speed += 200;
food.newfood();
} else {
var tail = size.pop();
tail.x = snakeX;
tail.y = snakeY;
}
size.unshift(tail);
for (let i = 0; i < size.length; i++) {
this.draw(size[i].x, size[i].y);
}
},
checkSelfCollision: function(x, y, arr) {
for (let i = 0; i < arr.length; i++) {
if (arr[i].x == x && arr[i].y == y) {
return true;
}
}
return false;
}
}
function loop() {
const cvsL = document.getElementById("snakes");
const ctxL = cvsL.getContext('2d');
cvs = cvsL;
ctx = ctxL;
snake.snakeInit();
snake.callDraw();
food.draw();
gameloop = setInterval(function() {
snake.move();
}, speed);
}
<body onload="loop();">
<canvas id="snakes" width=240px height=420px style="border: 1px solid black;display: block;"></canvas>
</body>
This snake style game is opened in a popup when you click a button on a page, then you are given a start screen and instructions, you click start to begin the game, and when you lose it displays your score and some text, if you close the popup and reopen it, it still shows the score rather than the start screen.
How do I make it reset when the popup is closed?
jQuery(document).ready(function($) {
$("#canvas").addClass("displayNone");
$("#lose").addClass("displayNone");
$("#post").removeClass("displayNone");
$("#controls").removeClass("displayNone");
$('#play').on('click', function() {
$('#playdiv').addClass('show-game');
})
var canvas = $("#canvas")[0];;
var ctx = canvas.getContext("2d");
var w = $("#canvas").width();
var h = $("#canvas").height();
var cw = 10;
var d;
var food;
var score;
var snake_array;
$("#score").addClass("displayNone");
$("#start").click(function() {
$("#start").addClass("displayNone");
$("#lose").addClass("displayNone");
$("#post").addClass("displayNone");
$("#canvas").removeClass("displayNone");
init();
})
var keys = [];
window.addEventListener("keydown",
function(e) {
keys[e.keyCode] = true;
switch (e.keyCode) {
case 37:
case 39:
case 38:
case 40:
case 32:
e.preventDefault();
break;
default:
break;
}
},
false);
window.addEventListener('keyup',
function(e) {
keys[e.keyCode] = false;
},
false);
// was here
function init() {
d = "right";
create_snake();
create_food();
score = 0;
if (typeof game_loop != "undefined") clearInterval(game_loop);
game_loop = setInterval(paint, 90);
}
// init();
function create_snake() {
var length = 5;
snake_array = [];
for (var i = length - 1; i >= 0; i--) {
snake_array.push({
x: i,
y: 0
});
}
}
function create_food() {
food = {
x: Math.round(Math.random() * (w - cw) / cw),
y: Math.round(Math.random() * (h - cw) / cw),
};
}
function paint() {
ctx.fillStyle = "white";
ctx.fillRect(0, 0, w, h);
ctx.strokeStyle = "black";
ctx.strokeRect(0, 0, w, h);
var nx = snake_array[0].x;
var ny = snake_array[0].y;
if (d == "right") nx++;
else if (d == "left") nx--;
else if (d == "up") ny--;
else if (d == "down") ny++;
if (nx == -1 || nx == w / cw || ny == -1 || ny == h / cw || check_collision(nx, ny, snake_array)) {
document.querySelector('#score').innerText = 'Your score: ' + score;
$("#score").removeClass("displayNone");
$("#lose").removeClass("displayNone");
$("#start").removeClass("displayNone");
$("#canvas").addClass("displayNone");
//init();
return;
}
if (nx == food.x && ny == food.y) {
var tail = {
x: nx,
y: ny
};
score++;
create_food();
} else {
var tail = snake_array.pop();
tail.x = nx;
tail.y = ny;
}
snake_array.unshift(tail);
for (var i = 0; i < snake_array.length; i++) {
var c = snake_array[i];
paint_cell(c.x, c.y);
}
paint_cell(food.x, food.y);
var score_text = "Score: " + score;
ctx.fillText(score_text, 5, h - 5);
}
function paint_cell(x, y) {
ctx.fillStyle = "pink";
ctx.fillRect(x * cw, y * cw, cw, cw);
ctx.strokeStyle = "red";
ctx.strokeRect(x * cw, y * cw, cw, cw);
}
function check_collision(x, y, array) {
for (var i = 0; i < array.length; i++) {
if (array[i].x == x && array[i].y == y) return true;
}
return false;
}
$(document).keydown(function(e) {
var key = e.which;
if (key == "37" && d != "right") d = "left";
else if (key == "38" && d != "down") d = "up";
else if (key == "39" && d != "left") d = "right";
else if (key == "40" && d != "up") d = "down";
})
})
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div> unknown HTML please post it here</div>
Seems like you never clean setInterval on exit. Please try to clearInterval. Attach to the window, not local valriable.
const window.timerId = setInterval(init, 9000)
// On init
if (window.game_loop != "undefined") clearInterval(game_loop);
window.game_loop = setInterval(paint, 90);
My raycaster's sprites keep blinking, and I think it has to do with ZBuffer.
Using this for reference: https://lodev.org/cgtutor/index.html
I have done plenty of research and can't find any JS raycasters that answer my problem. By sprites, I mean billboarded images, and when you move they blink like an atari game that is being pushed to its limits.
Here is the project on JSFiddle: https://jsfiddle.net/Vakore/bsvx1m26/
Here is where I am using ZBuffer:
for (var stripe = drawStartX; stripe < drawEndX; stripe++) {
var texX =
floor((256 * (stripe - (-spriteWidth / 2 + spriteScreenX)) * texWidth) / spriteWidth) / 256;
// the conditions in the if are:
// 1) it's in front of camera plane so you don't see things behind you
// 2) it's on the screen (left)
// 3) it's on the screen (right)
// 4) ZBuffer, with perpendicular distance
var ruffer = 0;
if (sprite[i][2] == "barrel") {
ruffer = 576 - 64;
}
if (sprite[i][2] == "pillar") {
ruffer = 576;
}
if (sprite[i][2] == "greenlight") {
ruffer = 576 + 64;
}
if (
transformY > 0 &&
stripe > 0 &&
stripe < w &&
transformY < ZBuffer[stripe]
) {
can.drawImage(
document.getElementById(sprite[i][2]),
texX + ruffer, 0, 1, texHeight, stripe, drawStartY, 1, drawEndY - drawStartY
);
}
}
ZBuffer was declared and assigned an array value earlier in the code.
var keys = {
"a": false,
"s": false,
"d": false,
"A": false,
"S": false,
"D": false,
"W": false,
"Z": false,
"X": false,
"C": false,
"ENTER": false
};
document.addEventListener("keydown", function(e) {
e.preventDefault();
if (e.keyCode === 16)
keys["SHIFT"] = true;
if (e.keyCode === 37)
keys["a"] = true;
if (e.keyCode === 39)
keys["d"] = true;
if (e.keyCode === 65)
keys["A"] = true;
if (e.keyCode === 68)
keys["D"] = true;
if (e.keyCode === 83)
keys["S"] = true;
if (e.keyCode === 87)
keys["W"] = true;
if (e.keyCode === 40)
keys["S"] = true;
if (e.keyCode === 38)
keys["W"] = true;
if (e.keyCode === 67)
keys["C"] = true;
if (e.keyCode === 88)
keys["X"] = true;
if (e.keyCode === 90)
keys["Z"] = true;
if (e.keyCode === 13)
keys["ENTER"] = true;
})
document.addEventListener("keyup", function(e) {
e.preventDefault();
if (e.keyCode === 16)
keys["SHIFT"] = false;
if (e.keyCode === 37)
keys["a"] = false;
if (e.keyCode === 39)
keys["d"] = false;
if (e.keyCode === 65)
keys["A"] = false;
if (e.keyCode === 68)
keys["D"] = false;
if (e.keyCode === 83)
keys["S"] = false;
if (e.keyCode === 87)
keys["W"] = false;
if (e.keyCode === 40)
keys["S"] = false;
if (e.keyCode === 38)
keys["W"] = false;
if (e.keyCode === 67)
keys["C"] = false;
if (e.keyCode === 88)
keys["X"] = false;
if (e.keyCode === 90)
keys["Z"] = false;
})
/*
Basic functions(ease of access)
*/
var canvas = document.getElementById("canva");
var can = canvas.getContext("2d");
canvas.requestPointerLock = canvas.requestPointerLock || canvas.mozRequestPointerLock;
document.exitPointerLock = document.exitPointerLock || document.mozExitPointerLock;
canvas.onclick = function() {
canvas.requestPointerLock();
clicked = true;
};
var mouseX = 0;
var mouseMove = function(e) {
mouseX += e.movementX;
};
var rect = function(x, y, w, h) {
can.fillRect(x, y, w, h);
};
var arc = function(x, y, r, start, stop) {
can.beginPath();
can.arc(x, y, r, start, stop);
can.fill();
};
var circle = function(x, y, r) {
arc(x, y, r, 0, 360);
};
var fill = function(r, g, b, a) {
if (a === undefined) {
a = 1;
}
can.fillStyle = "rgb(" + r + "," + g + "," + b + "," + a + ")";
};
var font = function(siz) {
can.font = siz;
};
var textAlign = function(ali) {
can.textAlign = ali;
};
var text = function(txt, x, y, w, h) {
can.fillText(txt, x, y, w, h);
};
var quad = function(x1, y1, x2, y2, x3, y3, x4, y4) {
can.beginPath();
can.moveTo(x1, y1);
can.lineTo(x2, y2);
can.lineTo(x3, y3);
can.lineTo(x4, y4);
can.closePath();
can.fill();
};
var random = function(min, max) {
return round(Math.random() * (max - min)) + min;
};
var translate = function(x, y) {
can.save();
can.translate(x, y);
};
var scale = function(w, h) {
can.scale(w, h);
}
var trestore = function() {
can.restore();
};
var floor = function(num) {
return Math.floor(num);
};
var sqrt = function(num) {
return Math.sqrt(num);
};
var abs = function(num) {
return Math.abs(num);
};
var color = function(r, g, b, a) {
return [r, g, b, a];
};
var dist = function() {
return true;
};
var cos = function(num) {
return Math.cos(num);
}
var sin = function(num) {
return Math.sin(num);
}
var dist = function(x1, y1, x2, y2) {
dx = x1 - x2;
dy = y1 - y2;
return Math.sqrt(dx * dx + dy * dy);
};
//Begin the raycaster
var scaler = 3; //This reduces the resolution so that it can display large rooms without lagging
var w = 640 / scaler;
var h = 480 / scaler;
var texWidth = 64;
var texHeight = 64;
var rotSpeed = 0.1;
var moveSpeed = 0.1;
var worldMap = [
"1111111111111111111111111111111111111111",
"1001000001234567800000000000000000000001",
"1001000000000000000000000000000000000001",
"1000000000000000000000000000000000000001",
"1001000000000000000000000000000000000001",
"1001000000000000000000000000222200000001",
"1001000000000000000000000000200200000001",
"1111000000000000000000000000200200000001",
"1000000000000000000000000033300333000001",
"8008000000000000000000000000000000000001",
"8000800000000000000000000033300333000001",
"8000080000000000000000000000300300000001",
"8000008000000000000000000000333300000001",
"8888888000000000000000000000000000000001",
"1000000000000000000000000000000000000001",
"1000000000000000000000000000000000000001",
"1000000000000000000000000000000000000001",
"1000000000000000000000000000000000000001",
"1000000000000000000000000000000000000001",
"1666006660000000000000000000000000000001",
"1000000060000000000000000000000000000001",
"1000000060000000000000000000000000000001",
"1000000060000000000000000000000000000001",
"1000000060000000000000000000000000000001",
"1666666660000000000000000000000000000001",
"1000000000000000000000000000000000000001",
"1000000000000000000000000000000000000001",
"1000000000000000000000000000000000000001",
"1000000040444444444444400000000000000001",
"1000000040000000000000400000000000000001",
"1000000040000000000000400000000000000001",
"1000000040000000000000400000000000000001",
"1000000044444444444444400000000000000001",
"1000000000000000000000000000000000000001",
"1000000000000007775777000000000000000001",
"1000000000000007000007000000000000000001",
"1000000000000005000005000000000000000001",
"1000000000000007000007000000000000000001",
"1000000000000000000007000000000000000001",
"1111111111111117775777111111111111111111",
];
try {
var ZBuffer = [];
var sprite = [
[5, 5, "barrel", 0], //Y and X are reversed
[6.5, 2.5, "pillar", 1],
[6.5, 1.5, "pillar", 1.5],
[8, 6, "greenlight", 2],
];
var posX = 2,
posY = 2,
dirX = -1,
dirY = 0,
planeX = 0,
planeY = 0.66; //The 2d raycaster version of the camera plane
} catch (e) {
alert(e);
}
var castRays = function() {
for (var x = 0; x < w; x++) {
var cameraX = 2 * x / (w) - 1; //x-coordinate in camera space
var rayDirX = dirX + planeX * cameraX;
var rayDirY = dirY + planeY * cameraX;
//which box of the map we're in
var mapX = floor(posX);
var mapY = floor(posY);
//length of ray from current position to next x or y-side
var sideDistX;
var sideDistY;
//length of ray from one x or y-side to next x or y-side
var deltaDistX = sqrt(1 + (rayDirY * rayDirY) / (rayDirX * rayDirX));
var deltaDistY = sqrt(1 + (rayDirX * rayDirX) / (rayDirY * rayDirY));
var perpWallDist = 0;
//what direction to step in x or y-direction (either +1 or -1)
var stepX = 0;
var stepY = 0;
var hit = 0; //was there a wall hit?
var side = 0; //was a NS or a EW wall hit?
//calculate step and initial sideDist
if (rayDirX < 0) {
stepX = -1;
sideDistX = (posX - mapX) * deltaDistX;
} else {
stepX = 1;
sideDistX = (mapX + 1.0 - posX) * deltaDistX;
}
if (rayDirY < 0) {
stepY = -1;
sideDistY = (posY - mapY) * deltaDistY;
} else {
stepY = 1;
sideDistY = (mapY + 1.0 - posY) * deltaDistY;
}
while (hit == 0) {
//jump to next map square, OR in x-direction, OR in y-direction
if (sideDistX < sideDistY) {
sideDistX += deltaDistX;
mapX += stepX;
side = 0;
} else {
sideDistY += deltaDistY;
mapY += stepY;
side = 1;
}
//Check if ray has hit a wall
if (worldMap[mapX][mapY] == 0) {}
if (worldMap[mapX][mapY] != 0) {
hit = 1;
}
} //end of while loop
//Calculate distance of perpendicular ray (Euclidean distance will give fisheye effect!)
if (side == 0) {
perpWallDist = (mapX - posX + (1 - stepX) / 2) / rayDirX;
} else {
perpWallDist = (mapY - posY + (1 - stepY) / 2) / rayDirY;
}
//Calculate height of line to draw on screen
var lineHeight = abs(floor(h / perpWallDist));
//calculate lowest and highest pixel to fill in current stripe
var drawStart = -lineHeight / 2 + h / 2;
//if(drawStart < 0) {drawStart = 0;}
var drawEnd = lineHeight / 2 + h / 2;
//if(drawEnd >= h) {drawEnd = h - 1;}
//texturing calculations
//var texNum = worldMap[mapX][mapY] - 1; //1 subtracted from it so that texture 0 can be used!
//calculate value of wallX
var wallX = 0; //where exactly the wall was hit
if (side == 0) {
wallX = posY + perpWallDist * rayDirY;
} else {
wallX = posX + perpWallDist * rayDirX;
}
wallX -= floor((wallX));
//x coordinate on the texture
var texX = floor(wallX * (texWidth));
if (side == 0 && rayDirX > 0) {
texX = texWidth - texX - 1;
}
if (side == 1 && rayDirY < 0) {
texX = texWidth - texX - 1;
}
//Untextured variant
/*var currentColor = color(255, 255, 255);
if (worldMap[mapX][mapY] == "1") {currentColor = color(150, 150, 150);}
if (worldMap[mapX][mapY] == "2") {currentColor = color(255, 255, 255);}
if (worldMap[mapX][mapY] == "3") {currentColor = color(255,0,0);}
if (worldMap[mapX][mapY] == "4") {currentColor = color(0,0,255);}
if (worldMap[mapX][mapY] == "5") {currentColor = color(0,255,0);}
if (worldMap[mapX][mapY] == "6") {currentColor = color(255,0,255);}
if (worldMap[mapX][mapY]=="7") {currentColor = color(0,255,255);}
if (side === 1) {currentColor = [currentColor[0] - 40, currentColor[1] - 40, currentColor[2] - 40];}
//if (dist(mapX, mapY, px, pz) > 10) {continue;}
fill(currentColor[0],currentColor[1],currentColor[2]);
rect(x, drawStart, 1, drawEnd - drawStart);*/
var currentImg = "bluestone";
if (worldMap[mapX][mapY] == "1") {
currentImg = "bluestone";
}
if (worldMap[mapX][mapY] == "2") {
currentImg = "greystone";
}
if (worldMap[mapX][mapY] == "3") {
currentImg = "wood";
}
if (worldMap[mapX][mapY] == "4") {
currentImg = "colorstone";
}
if (worldMap[mapX][mapY] == "5") {
currentImg = "eagle";
}
if (worldMap[mapX][mapY] == "6") {
currentImg = "mossy";
}
if (worldMap[mapX][mapY] == "7") {
currentImg = "redbrick";
}
if (worldMap[mapX][mapY] == "8") {
currentImg = "purplestone";
}
//if (worldMap[mapX][mapY] =="a") {currentImg = "barrel";}
//if (dist(mapX, mapY, posX, posY) > 20) {continue;}
can.drawImage(document.getElementById(currentImg), texX + ((worldMap[mapX][mapY] - 1) * 64), 0, 1, texHeight, x, drawStart, 1, drawEnd - drawStart);
//fill(255, 0, 0);rect(x, drawStart, 1, drawEnd - drawStart);
if (side === 1) {
fill(0, 0, 0, 0.3);
rect(x, drawStart, 1, drawEnd - drawStart);
}
//Set the ZBuffer
ZBuffer[x] = perpWallDist;
//FLOOR CASTING(not using till figure out how to do without lag)
var floorXWall = 0,
floorYWall = 0;
if (side == 0 && rayDirX > 0) {
floorXWall = mapX;
floorYWall = mapY + wallX;
} else if (side == 0 && rayDirX < 0) {
floorXWall = mapX + 1.0;
floorYWall = mapY + wallX;
} else if (side == 1 && rayDirY > 0) {
floorXWall = mapX + wallX;
floorYWall = mapY;
} else {
floorXWall = mapX + wallX;
floorYWall = mapY + 1.0;
}
var distWall, distPlayer, currentDist;
distWall = perpWallDist;
distPlayer = 0.0;
for (var y = drawEnd + 1; y < h; y++) {
//if (dist(mapX, mapY, posX, posY) > 5) {continue;}
currentDist = h / (2.0 * y - h); //you could make a small lookup table for this instead
var weight = (currentDist - distPlayer) / (distWall - distPlayer);
var currentFloorX = weight * floorXWall + (1.0 - weight) * posX;
var currentFloorY = weight * floorYWall + (1.0 - weight) * posY;
var floorTexX, floorTexY;
floorTexX = floor(currentFloorX * texWidth) % texWidth;
floorTexY = floor(currentFloorY * texHeight) % texHeight;
//OPTIMIZE FOR LESS LAG!!!!!!!!!! (search
//FLOOR
//can.drawImage(document.getElementById("greystone"), floorTexX, floorTexY, texWidth, texHeight, x, y, texWidth, texHeight);
//CEILING
//can.drawImage(document.getElementById("wood"), floorTexX, floorTexY, texWidth, 1, x, h - y, texWidth, 1);
} //End of the 'y' loop
} //end the loop
//SPRITE CASTING
//Sort sprites
sprite.sort(function(a, b) {
return b[3] - a[3];
}); //Sort the depth of each sprite
//Draw sprites
for (var i = 0; i < sprite.length; i++) {
var spriteX = sprite[i][0] - posX;
var spriteY = sprite[i][1] - posY;
sprite[i][3] = abs((posX - sprite[i][0]) - (posY - sprite[i][1]));
var invDet = 1.0 / (planeX * dirY - dirX * planeY);
var transformX = invDet * (dirY * spriteX - dirX * spriteY);
var transformY = invDet * (-planeY * spriteX + planeX * spriteY); //this is actually the depth inside the screen, that what Z is in 3D(Thanks lodev.org for explanation!)
var spriteScreenX = floor((w / 2) * (1 + transformX / transformY));
//calculate height of the sprite on screen
var spriteHeight = abs(floor(h / (transformY))); //using "transformY" instead of the real distance prevents fisheye
//calculate lowest and highest pixel to fill in current stripe
var drawStartY = -spriteHeight / 2 + h / 2;
//if (drawStartY < 0) {drawStartY = 0;} Don't need THIS
var drawEndY = spriteHeight / 2 + h / 2;
//if (drawEndY >= h) {drawEndY = h - 1;} Or THIS
//calculate width of the sprite
var spriteWidth = abs(floor(h / (transformY)));
var drawStartX = -spriteWidth / 2 + spriteScreenX;
//if (drawStartX < 0) {drawStartX = 0;} Nor this
var drawEndX = spriteWidth / 2 + spriteScreenX;
//if (drawEndX >= w) {drawEndX = w - 1;} Nor dis
//loop through every vertical stripe of the sprite on screen
for (var stripe = drawStartX; stripe < drawEndX; stripe++) {
var texX = floor(256 * (stripe - (-spriteWidth / 2 + spriteScreenX)) * texWidth / spriteWidth) / 256;
//the conditions in the if are:
//1) it's in front of camera plane so you don't see things behind you
//2) it's on the screen (left)
//3) it's on the screen (right)
//4) ZBuffer, with perpendicular distance
var ruffer = 0;
if (sprite[i][2] == "barrel") {
ruffer = 576 - 64;
}
if (sprite[i][2] == "pillar") {
ruffer = 576;
}
if (sprite[i][2] == "greenlight") {
ruffer = 576 + 64;
}
if (transformY > 0 && stripe > 0 && stripe < w && transformY < ZBuffer[stripe]) {
can.drawImage(document.getElementById(sprite[i][2]), texX + ruffer, 0, 1, texHeight, stripe, drawStartY, 1, drawEndY - drawStartY);
}
}
} //End of 'i' loop
//Bottom of dat
if (keys["W"]) {
if (worldMap[floor(posX + dirX * moveSpeed)][floor(posY)] == false) {
posX += dirX * moveSpeed
};
if (worldMap[floor(posX)][floor(posY + dirY * moveSpeed)] == false) {
posY += dirY * moveSpeed
};
}
//move backwards if no wall behind you
if (keys["S"]) {
if (worldMap[floor(posX - dirX * moveSpeed)][floor(posY)] == false) {
posX -= dirX * moveSpeed;
}
if (worldMap[floor(posX)][floor(posY - dirY * moveSpeed)] == false) {
posY -= dirY * moveSpeed;
}
}
if (keys["D"]) {
if (worldMap[floor(posX + planeX * moveSpeed)][floor(posY)] == false) {
posX += planeX * moveSpeed
};
if (worldMap[floor(posX)][floor(posY + planeY * moveSpeed)] == false) {
posY += planeY * moveSpeed
};
}
if (keys["A"]) {
if (worldMap[floor(posX - planeX * moveSpeed)][floor(posY)] == false) {
posX -= planeX * moveSpeed;
}
if (worldMap[floor(posX)][floor(posY - planeY * moveSpeed)] == false) {
posY -= planeY * moveSpeed;
}
}
//rotate to the right
mouseX = -mouseX / 75;
var oldDirX = dirX;
dirX = dirX * cos(mouseX) - dirY * sin(mouseX);
dirY = oldDirX * sin(mouseX) + dirY * cos(mouseX);
var oldPlaneX = planeX;
planeX = planeX * cos(mouseX) - planeY * sin(mouseX);
planeY = oldPlaneX * sin(mouseX) + planeY * cos(mouseX);
mouseX = 0;
if (keys["d"]) {
//both camera direction and camera plane must be rotated
var oldDirX = dirX;
dirX = dirX * cos(-rotSpeed) - dirY * sin(-rotSpeed);
dirY = oldDirX * sin(-rotSpeed) + dirY * cos(-rotSpeed);
var oldPlaneX = planeX;
planeX = planeX * cos(-rotSpeed) - planeY * sin(-rotSpeed);
planeY = oldPlaneX * sin(-rotSpeed) + planeY * cos(-rotSpeed);
}
//rotate to the left
if (keys["a"]) {
//both camera direction and camera plane must be rotated
var oldDirX = dirX;
dirX = dirX * cos(rotSpeed) - dirY * sin(rotSpeed);
dirY = oldDirX * sin(rotSpeed) + dirY * cos(rotSpeed);
var oldPlaneX = planeX;
planeX = planeX * cos(rotSpeed) - planeY * sin(rotSpeed);
planeY = oldPlaneX * sin(rotSpeed) + planeY * cos(rotSpeed);
}
};
var run = function() {
try {
if (document.pointerLockElement === canvas || document.mozPointerLockElement === canvas) {
document.addEventListener("mousemove", mouseMove, false);
} else {
document.removeEventListener("mousemove", mouseMove, false);
} //Mouse stuff
translate(0, 0);
scale(scaler, scaler);
fill(40, 40, 40);
rect(0, 0, w, h / 2);
fill(80, 80, 80);
rect(0, h / 2, w, h / 2);
if (keys["C"]) {
rotSpeed = 0.04;
} else {
rotSpeed = 0.1;
}
/*if (keys["W"]) {fill(255, 0, 0);}
if (keys["A"]) {fill(0, 255, 0);}
if (keys["S"]) {fill(0, 0, 255);}
if (keys["D"]) {fill(255, 0, 255);}
if (keys["X"]) {fill(255, 255, 0);}
if (keys["Z"]) {fill(0, 255, 255);}*/
castRays();
trestore();
requestAnimationFrame(run);
} catch (e) {
alert(e);
}
};
run();
<html>
<title>Jailbreak</title>
<div class="center">
<canvas width="640" height="480" id="canva"></canvas>
<br>
<img id="barrel" src="https://lodev.org/cgtutor/images/wolftexturesobj.gif">
<img id="pillar" src="https://lodev.org/cgtutor/images/wolftexturesobj.gif">
<img id="greenlight" src="https://lodev.org/cgtutor/images/wolftexturesobj.gif">
<img id="bluestone" src="https://lodev.org/cgtutor/images/wolftexturesobj.gif">
<img id="greystone" src="https://lodev.org/cgtutor/images/wolftexturesobj.gif">
<img id="wood" src="https://lodev.org/cgtutor/images/wolftexturesobj.gif">
<img id="colorstone" src="https://lodev.org/cgtutor/images/wolftexturesobj.gif">
<img id="eagle" src="https://lodev.org/cgtutor/images/wolftexturesobj.gif">
<img id="mossy" src="https://lodev.org/cgtutor/images/wolftexturesobj.gif">
<img id="redbrick" src="https://lodev.org/cgtutor/images/wolftexturesobj.gif">
<img id="purplestone" src="https://lodev.org/cgtutor/images/wolftexturesobj.gif">
</div>
</html>
UPDATE: I tried changing
if (
transformY > 0 &&
stripe > 0 &&
stripe < w &&
transformY < ZBuffer[stripe]//Pay attention to this line
) {
to:
if (
transformY > 0 &&
stripe > 0 &&
stripe < w &&
transformY > ZBuffer[stripe]//Now look
) {
Which basically reverses the check to see if it is behind a wall. Surprisingly, the blinking continues.
The answer was pretty simple. It was because stripe is not an even value, and if you were to have an array like this: var thisArray = [1, 2, 3, 4]; and you were to try and grab var money = thisArray[1.5]; the value undefined would be returned.
So I changed this:
if (
transformY > 0 &&
stripe > 0 &&
stripe < w &&
transformY < ZBuffer[stripe]
) {
To this:
if (
transformY > 0 &&
stripe > 0 &&
stripe < w &&
transformY < ZBuffer[Math.round(stripe)]
) {
Math.floor also works, since it also returns an integer value.
I'm trying to get my head around using javascript in the html < canvas >, and I started with the MDN Breakout game tutorial. Here is how the complete game looks like. I'm stuck with one of the exercises and I really could not find any solution to my issue after an hour of googling!! :((. The following code generates a ball on the canvas.
ctx.beginPath();
ctx.arc(x, y, radius, 0, Math.PI * 2);
ctx.fillStyle = '#FFFFF';
ctx.fill();
ctx.closePath();
I needed the ball to change its colour after it collides with one of the bricks. In order to achieve that, I created a variable to store the colour value: let colour = '#FFFFF';, and later in a function which detects collisions, changed the value of this variable. It worked fine, however, whenever the ball changed its colour, so did the bricks and the paddle. As I tried to fix this, I found out that whenever I manually change the colour of either a ball, a brick or a paddle (all of which are set in different functions), all of the objects change the colour as well.
This is very strange, because if in an emply .js file I make just two shapes and colour them differently it works fine:
const canvas = document.getElementById('canvas');
const ctx = canvas.getContext('2d');
ctx.beginPath();
ctx.rect(0, 0, 20, 40);
ctx.fillStyle = 'cyan';
ctx.fill();
ctx.closePath();
ctx.beginPath();
ctx.arc(50, 50, 20, 0, Math.PI*2);
ctx.fillStyle = 'black';
ctx.fill();
ctx.closePath();
But with all the game code I have right now, I can not assign different colour to different objects, they all change colour instead! I have no idea how to fix this and change just the colour of the ball! Anyone knows what might be causing the issue? Please help, thank you so much in advance 🙏
const canvas = document.getElementById('canvas');
const ctx = canvas.getContext('2d');
//Ball variables
const radius = 10;
let colour = '#FFFFF';
let x = canvas.width / 2;
let y = canvas.height - 30;
let dx = 2;
let dy = -2;
//Paddle
const paddleHeight = 10;
let paddleWidth = 100;
let paddleX = (canvas.width - paddleWidth) / 2;
//Paddle movement
var rightPressed = false;
var leftPressed = false;
//Bricks
var brickRowCount = 3;
var brickColumnCount = 5;
var brickWidth = 75;
var brickHeight = 20;
var brickPadding = 10;
var brickOffsetTop = 30;
var brickOffsetLeft = 30;
var bricks = [];
for (var c = 0; c < brickColumnCount; c++) {
bricks[c] = [];
for (var r = 0; r < brickRowCount; r++) {
bricks[c][r] = {
x: 0,
y: 0,
status: 1
};;
}
}
function draw() {
ctx.clearRect(0, 0, canvas.width, canvas.height);
drawBall();
drawPaddle();
drawBricks();
collisionDetection();
x += dx;
y += dy;
if (rightPressed && paddleX < canvas.width - paddleWidth) {
paddleX += 7;
} else if (leftPressed && paddleX > 0) {
paddleX -= 7;
}
}
function drawBall() {
ctx.beginPath();
ctx.arc(x, y, radius, 0, Math.PI * 2);
ctx.fillStyle = colour;
ctx.fill();
ctx.closePath();
//Bounce off the walls
if (x + dx > canvas.width - radius || x + dx < radius) {
dx = -dx;
}
if (y + dy < radius) {
dy = -dy;
} else if (y + dy > canvas.height - radius) {
//Collision detection (ball + paddle)
if (x > paddleX && x < paddleX + paddleWidth) {
dy = -dy;
} else {
//alert("GAME OVER");
document.location.reload();
}
}
}
function drawPaddle() {
ctx.beginPath();
ctx.rect(paddleX, canvas.height - paddleHeight, paddleWidth, paddleHeight);
ctx.fillStyle = '#FFFFF';
ctx.fill();
ctx.closePath();
}
function drawBricks() {
for (var c = 0; c < brickColumnCount; c++) {
for (var r = 0; r < brickRowCount; r++) {
if (bricks[c][r].status == 1) {
var brickX = (c * (brickWidth + brickPadding)) + brickOffsetLeft;
var brickY = (r * (brickHeight + brickPadding)) + brickOffsetTop;
bricks[c][r].x = brickX;
bricks[c][r].y = brickY;
ctx.beginPath();
ctx.rect(brickX, brickY, brickWidth, brickHeight);
ctx.fillStyle = "#FFFFF";
ctx.fill();
ctx.closePath();
}
}
}
}
document.addEventListener("keydown", keyDownHandler, false);
document.addEventListener("keyup", keyUpHandler, false);
function keyDownHandler(e) {
if (e.key == "Right" || e.key == "ArrowRight") {
rightPressed = true;
} else if (e.key == "Left" || e.key == "ArrowLeft") {
leftPressed = true;
}
}
function keyUpHandler(e) {
if (e.key == "Right" || e.key == "ArrowRight") {
rightPressed = false;
} else if (e.key == "Left" || e.key == "ArrowLeft") {
leftPressed = false;
}
}
function collisionDetection() {
for (var c = 0; c < brickColumnCount; c++) {
for (var r = 0; r < brickRowCount; r++) {
var b = bricks[c][r];
if (b.status == 1) {
if (x > b.x && x < b.x + brickWidth && y > b.y && y < b.y + brickHeight) {
dy = -dy;
b.status = 0;
colour = '#ff9ecb';
}
}
}
}
}
var interval = setInterval(draw, 10);
<!DOCTYPE html>
<html>
<head>
<title>Breakout Game</title>
</head>
<body>
<canvas id='canvas' height='320' width='480'></canvas>
<script src="app.js"></script>
</body>
</html>
Looks like a minor error with the colour hex codes you're using for your fillStyle, which are invalid. See the corrections in the snippet below from:
let colour = '#FFFFF'; // Six characters invalid
To:
let colour = '#FF0000'; // Seven characters valid
const canvas = document.getElementById('canvas');
const ctx = canvas.getContext('2d');
//Ball variables
const radius = 10;
// Fix colour
let colour = '#FF0000';
let x = canvas.width / 2;
let y = canvas.height - 30;
let dx = 2;
let dy = -2;
//Paddle
const paddleHeight = 10;
let paddleWidth = 100;
let paddleX = (canvas.width - paddleWidth) / 2;
//Paddle movement
var rightPressed = false;
var leftPressed = false;
//Bricks
var brickRowCount = 3;
var brickColumnCount = 5;
var brickWidth = 75;
var brickHeight = 20;
var brickPadding = 10;
var brickOffsetTop = 30;
var brickOffsetLeft = 30;
var bricks = [];
for (var c = 0; c < brickColumnCount; c++) {
bricks[c] = [];
for (var r = 0; r < brickRowCount; r++) {
bricks[c][r] = {
x: 0,
y: 0,
status: 1
};;
}
}
function draw() {
ctx.clearRect(0, 0, canvas.width, canvas.height);
drawBall();
drawPaddle();
drawBricks();
collisionDetection();
x += dx;
y += dy;
if (rightPressed && paddleX < canvas.width - paddleWidth) {
paddleX += 7;
} else if (leftPressed && paddleX > 0) {
paddleX -= 7;
}
}
function drawBall() {
// Update to valid colour
ctx.fillStyle = colour;
ctx.beginPath();
ctx.arc(x, y, radius, 0, Math.PI * 2);
ctx.fill();
ctx.closePath();
//Bounce off the walls
if (x + dx > canvas.width - radius || x + dx < radius) {
dx = -dx;
}
if (y + dy < radius) {
dy = -dy;
} else if (y + dy > canvas.height - radius) {
//Collision detection (ball + paddle)
if (x > paddleX && x < paddleX + paddleWidth) {
dy = -dy;
} else {
//alert("GAME OVER");
document.location.reload();
}
}
}
function drawPaddle() {
// Update to valid colour
ctx.fillStyle = '#00FF00';
// Consider using fillRect
ctx.fillRect(paddleX, canvas.height - paddleHeight, paddleWidth, paddleHeight);
}
function drawBricks() {
for (var c = 0; c < brickColumnCount; c++) {
for (var r = 0; r < brickRowCount; r++) {
if (bricks[c][r].status == 1) {
var brickX = (c * (brickWidth + brickPadding)) + brickOffsetLeft;
var brickY = (r * (brickHeight + brickPadding)) + brickOffsetTop;
bricks[c][r].x = brickX;
bricks[c][r].y = brickY;
// Update to valid colour
ctx.fillStyle = "#FFFFaa";
// Consider using fillRect
ctx.fillRect(brickX, brickY, brickWidth, brickHeight);
}
}
}
}
document.addEventListener("keydown", keyDownHandler, false);
document.addEventListener("keyup", keyUpHandler, false);
function keyDownHandler(e) {
if (e.key == "Right" || e.key == "ArrowRight") {
rightPressed = true;
} else if (e.key == "Left" || e.key == "ArrowLeft") {
leftPressed = true;
}
}
function keyUpHandler(e) {
if (e.key == "Right" || e.key == "ArrowRight") {
rightPressed = false;
} else if (e.key == "Left" || e.key == "ArrowLeft") {
leftPressed = false;
}
}
function collisionDetection() {
for (var c = 0; c < brickColumnCount; c++) {
for (var r = 0; r < brickRowCount; r++) {
var b = bricks[c][r];
if (b.status == 1) {
if (x > b.x && x < b.x + brickWidth && y > b.y && y < b.y + brickHeight) {
dy = -dy;
b.status = 0;
colour = '#ff9ecb';
}
}
}
}
}
var interval = setInterval(draw, 10);
<!DOCTYPE html>
<html>
<head>
<title>Breakout Game</title>
</head>
<body>
<canvas id='canvas' height='320' width='480'></canvas>
<script src="app.js"></script>
</body>
</html>
Also, consider using fillRect() as shown above, for a slightly simpler implementation. Hope that helps!