Native js canvas Implementation of Simple Snake
- 2021-11-01 02:17:54
- OfStack
This article example for everyone to share js canvas implementation of simple snake specific code, for your reference, the specific content is as follows
Js Native Snake: canvas
HTML
<canvas id="can"></canvas>
CSS
#can{
background: #000000;
height: 400px;
width: 850px;
}
JS
// Public sector
var blockSize = 10;
// The height and width of a map
var mapW = 300;
var mapH = 150;
// Historical food var
var historyfood = new Array();
// Food array
var img = new Image()
var arrFood = ["ananas.png","hamburg.png","watermelon.png"]
historyfood =[{x: 0,y:0}];
// Snake Default
var snake = [{x:3,y:0},{x:2,y:0},{x:1,y:0}]
// Snake-eating direction
var directionX = 1;
var directionY = 0;
// Add 1 Tags , Mark whether the food has been eaten
// Default: Not eaten
var isFood = false;
// Judge the state of the game
// The default game continues
var gameState = false;
// Restrict the direction in which the snake moves. You can't operate in the opposite direction
var lockleft = true;
var lockright = true;
var lockup = true;
var lockdown = true;
// Snake score
var count = 0;
// Snake speed
var speed = 1000 - (count + 5);
$(function () {
$("#divContainer").height($("#can").height());
//1, Get to Canvas Object
var can = document.getElementById("can");
//2, Get to the Drawing Toolbox
var tools = can.getContext('2d');
tools.beginPath();
// Set food defaults
var XY = Randomfood();
console.log(XY);
var x1 = Randomfood().x;
var y1 = Randomfood().y;
img.src = "/aimless/img/GluttonousSnakeFood/"+ arrFood[Math.floor(Math.random() * arrFood.length)];
// Control the movement of gluttonous snakes
document.addEventListener('keydown',function (e){
switch (e.keyCode) {
case 38:
if (lockup){
directionX = 0;
directionY = -1;
lockdown = false;
lockleft = true;
lockright = true;
}
break;
case 40:
if (lockdown){
directionX = 0;
directionY = 1;
lockup = false;
lockleft = true;
lockright = true;
}
break;
case 37:
if (lockleft){
directionX = - 1;
directionY = 0;
lockright = false;
lockup = true;
lockdown = true;
}
break;
case 39:
if (lockright){
directionX = 1;
directionY = 0;
lockleft = false;
lockup = true;
lockdown = true;
}
break;
}
})
setIntervalSnake(tools,x1,y1);
//4, Find a position
})
function setIntervalSnake(tools,x1,y1){
setInterval(function (){
if (gameState){
return;
}
//1, Erase the drawing board
tools.clearRect(0,0,850,420);
var oldHead = snake[0];
if (oldHead.x < 0 || oldHead.y < 0 || oldHead.x * blockSize >= mapW || oldHead.y * blockSize >= mapH){
gameState = true;
alert(" Game over ");
}else {
// Snake movement
if (snake[0].x * blockSize === x1 && snake[0].y * blockSize === y1){
isFood = true;
} else {
snake.pop()
}
var newHead = {
x: oldHead.x + directionX,
y: oldHead.y + directionY
}
snake.unshift(newHead);
}
//2, Judge whether the food has been eaten, eat and refresh , Don't eat, don't refresh
if (isFood){
count = count + 1;
$("#count").html(count);
x1 = Randomfood().x;
y1 = Randomfood().y;
img.src = "/aimless/img/GluttonousSnakeFood/"+ arrFood[Math.floor(Math.random() * arrFood.length)];
isFood = false;
}
tools.drawImage(img,x1,y1,blockSize,blockSize);
// Snake body array
var Thesnakebody = new Array();
//3, Draw a snake
for (var i = 0; i < snake.length; i++){
if (i == 0){
tools.fillStyle = "#9933CC";
} else {
var newHead1 = {
x: snake[i].x,
y: snake[i].y
}
Thesnakebody.unshift(newHead1);
tools.fillStyle = "#33adcc";
}
tools.fillRect(snake[i].x * blockSize,snake[i].y * blockSize,blockSize,blockSize);
}
// // Judge that the snake head bit the snake body
Thesnakebody.forEach(item=>{
if(item.x == snake[0].x && item.y == snake[0].y){
gameState = true;
setIntervalSnake(tools,x1,y1);
}
})
//4, Draw a map
var width = Math.round($("#can").width() / blockSize);
var height = Math.round($("#can").height() / blockSize);
for (var i = 1; i < width;i++){
tools.moveTo(0,blockSize * i);
tools.lineTo($("#can").width(),blockSize * i);
}
for (var i = 1; i < height;i++){
tools.moveTo(blockSize * i,0);
tools.lineTo(blockSize * i,$("#can").height());
}
tools.strokeStyle = "#FFFFFF";
//5, Draw
tools.stroke();
},speed / 3);
}
// Random food does not
function Randomfood() {
var RandomX = Math.floor(Math.random() * mapW / blockSize) * blockSize;
var RandomY = Math.floor(Math.random() * mapH / blockSize) * blockSize;
setInterval(function (){
snake.forEach(item=>{
console.log(RandomX / blockSize,RandomY / blockSize);
// console.log(item.x,item.y);
if(item.x == RandomX / blockSize && item.y == RandomY / blockSize){
return Randomfood();
} else {
return ;
}
})
}, 10 / 3);
var newRandom = {
x: RandomX,
y: RandomY
}
return newRandom;
}