js学习之地图生成

首先，上地图图片

接着，js，我们可以把图片看成一块块32*32像素的

var i;
var j;window.onload = function () {gamemap(15, 10, 10, "map.jpg");
}var mapimg = new Image();
var map = [[18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 55, 55, 18],[18, 18, 18, 17, 17, 17, 17, 17, 17, 17, 17, 17, 55, 55, 18],[18, 18, 17, 17, 17, 17, 18, 18, 17, 17, 17, 17, 55, 55, 18],[18, 17, 17, 17, 18, 18, 18, 18, 18, 17, 17, 55, 55, 17, 18],[18, 17, 17, 18, 22, 23, 23, 23, 24, 18, 17, 55, 55, 17, 18],[18, 17, 17, 18, 25, 28, 26, 79, 27, 18, 55, 55, 17, 17, 18],[18, 17, 17, 17, 17, 10, 11, 12, 18, 18, 55, 55, 17, 17, 18],[18, 18, 17, 17, 10, 16, 16, 16, 11, 55, 55, 17, 17, 17, 18],[18, 18, 17, 17, 77, 16, 16, 16, 16, 21, 21, 17, 17, 17, 18],[18, 18, 18, 18, 18, 18, 18, 18, 18, 55, 55, 18, 18, 18, 18]
];
//创建构成地图的二维数组  function gamemap(x, y, num, url) {  //长个数，宽个数，一行个数，图片路径var canvas = document.getElementById("map");var context = canvas.getContext("2d");mapimg.src = url;mapimg.onload = function () {context.fillRect(0, 0, x * 32, y * 32);//画一个长480，宽320的矩形  for (i = 0; i < x; i++) {for (j = 0; j < y; j++) {drawTile(i * 32, j * 32, map[j][i], num);}}//循环调用绘制地图的函数，直到画完为止  
    }
}function drawTile(x, y, type, num) {var canvas = document.getElementById("map");var context = canvas.getContext("2d");context.drawImage(mapimg, type % num * 32, parseInt(type / num) * 32, 32, 32, x, y, 32, 32);
}

最后，页面调用

<!DOCTYPE html>
<html>
<head><title>地图生成</title><meta http-equiv="Content-Type" content="text/html; charset=utf-8" />  <meta name="viewport" content="width=device-width,initial-scale=1,maximum-scale=1,user-scalable=no" /><script type="text/javascript" src="map.js"></script>
</head>
<body><canvas id="map" width="480px" height="320px" style="border: 1px solid gray;"></canvas>
</body>
</html>