键盘上下左右控制
源码
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<style>
.map {
width: 800px;
height: 800px;
background-color: #ccc;
position: relative;
}
</style>
</head>
<body>
<div class="map">
</div>
<script>
//food div
(function () {
var elements = [];
function Food(x, y, width, height, color) {
// 横纵坐标 width height backgroundColor
this.x = x || 0;
this.y = y || 0;
this.width = width || 20;
this.height = height || 20;
this.color = color || "green";
}
Food.prototype.init = function (map) {
// delete div
reomve();
// creat div
var div = document.createElement('div');
// add div
map.appendChild(div);
// set div style
div.style.width = this.width + "px";
div.style.height = this.height + "px";
div.style.backgroundColor = this.color;
// Out of document stream 脱离文档流
div.style.position = "absolute";
// random横纵坐标
this.x = parseInt(Math.random() * (map.offsetWidth / this.width)) * this.width;
this.y = parseInt(Math.random() * (map.offsetHeight / this.height)) * this.height;
div.style.left = this.x + "px";
div.style.top = this.y + "px";
elements.push(div)
};
// private func delete div
function reomve() {
for (var i = 0; i < elements.length; i++) {
var ele = elements[i];
// find child element's father remove this
ele.parentNode.removeChild(ele);
// delete child
elements.splice(i, 1);
}
}
// global
window.Food = Food;
}());
// snake
(function () {
var elements = [];
function Snake(width, height, direction) {
// snack Each part width
this.width = width || 20;
this.height = height || 20;
// snack's body
this.body = [
{x: 3, y: 2, color: "red"}, //head
{x: 2, y: 2, color: "black"}, //body
{x: 1, y: 2, color: "black"} //tail
];
// direction
this.direction = direction || "right"
}
Snake.prototype.init = function (map) {
// delete snake
remove();
// loop body
for (var i = 0; i < this.body.length; i++) {
var obj = this.body[i];
var div = document.createElement("div");
// add div to map
map.appendChild(div);
// set div style
div.style.position = "absolute";
div.style.width = this.width + "px";
div.style.height = this.height + "px";
// x,y
div.style.left = obj.x * this.width + "px";
div.style.top = obj.y * this.height + "px";
div.style.backgroundColor = obj.color;
// add div to elements
elements.push(div);
}
};
Snake.prototype.move = function (food, map) {
// change body x, y
for (i = this.body.length - 1; i > 0; i--) {
this.body[i].x = this.body[i - 1].x;
this.body[i].y = this.body[i - 1].y;
}
// select direction change x,y
switch (this.direction) {
case "right":
this.body[0].x += 1;
break;
case "left":
this.body[0].x -= 1;
break;
case "top":
this.body[0].y -= 1;
break;
case "bottom":
this.body[0].y += 1;
break;
}
// judgement food x,y snake x,y
let snakeX = this.body[0].x * this.width;
let snakeY = this.body[0].y * this.height;
let foodX = food.x;
let foodY = food.y;
// judgement snake or food x,y
if (snakeX == foodX && snakeY == foodY) {
// get last body
var last = this.body[this.body.length - 1];
this.body.push({
x: last.x,
y: last.y,
color: last.color,
});
// delete food init food
food.init(map)
}
// console.log(foodX, foodY)
};
function remove() {
for (var i = elements.length - 1; i > -1; i--) {
// find parent remove child element
var ele = elements[i];
//from map remove child element
ele.parentNode.removeChild(ele);
elements.splice(i, 1)
}
}
// Snake.prototype.init(document.querySelector(".map"));
// global
window.Snake = Snake;
}());
// game
(function () {
function Game(map) {
this.food = new Food();
this.snake = new Snake();
this.map = map;
}
// init game food snake
Game.prototype.init = function () {
this.food.init(this.map);
this.snake.init(this.map);
// console.log(this);
this.RunSnake();
this.bindkey();
};
// run snake
Game.prototype.RunSnake = function () {
// run
var IntervalId = setInterval(function () {
// 此时this为window
this.snake.move(this.food, this.map);
this.snake.init(this.map);
// max x,y
let MaxX = this.map.offsetWidth / this.snake.width;
let MaxY = this.map.offsetHeight / this.snake.height;
let x = this.snake.body[0].x;
let y = this.snake.body[0].y;
// console.log(this.snake.body[0].x + " " + this.snake.body[0].y + "X" + MaxX + "Y" + MaxY);
if (x < 0 || x > MaxX || y < 0 || y > MaxY) {
// console.log(this.x+" "+this.y);
clearInterval(IntervalId);
window.alert("ganmeover!")
}
// 使用bindl改变this的指向
}.bind(this), 150)
};
//keyboard down event
Game.prototype.bindkey = function () {
// get keyboard down
document.addEventListener('keydown', function (e) {
//获取按键的值
switch (e.keyCode) {
case 37:
this.snake.direction = "left";
break;
case 38:
this.snake.direction = "top";
break;
case 39:
this.snake.direction = "right";
break;
case 40:
this.snake.direction = "bottom";
break;
}
}.bind(this), false)
};
window.Game = Game
}());
var gm = new Game(document.querySelector(".map"));
gm.init()
// console.log(fd.x+"===="+fd.y)
// console.log(fd.width)
</script>
</body>
</html>
Q.E.D.