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| <script src="http://apps.bdimg.com/libs/jquery/1.11.3/jquery.min.js"></script>
<script type="text/javascript">
$(function () {
var canvas = document.getElementById("myCanvas");
var context = canvas.getContext("2d");
var d=12;
var a=60;
var directMap = {
'W':0,
'S':1,
'A':2,
'D':3,
'&':0,
'(':1,
'%':2,
'\'':3
};
//当前屏幕上所有的块
var blocks = [
0, 0, 0, 0,
2, 0, 0, 0,
0, 0, 2, 0,
0, 0, 0, 2
];
var newBlocks=[];//blocks的备份，用来保存目标状态
var newIndex=[];//保存每个块的目标位置，如newIndex[4]=8表示第4个块移动到第8个块的位置（下移一格）
//生成新数字
var another_num = function(){
var empty = [];
for(var i = 0 ; i < blocks.length; i++){
if(blocks[i]==0){
empty.push(i)
}
}
var idx = empty[parseInt(Math.random() * empty.length)];
blocks[idx] = Math.random() < 0.8 ? 2 : 4;
drawBlock(idx)
};
//通过数组下标（0-15）计算4个相关的值
var getPositon = function(n){
var obj = {};
obj.i = n%4;//第几列（从0开始）
obj.j = parseInt(n/4);//第几行（从0开始）
obj.x = (obj.i+1)*d+obj.i*a;//横坐标
obj.y = (obj.j+1)*d+obj.j*a;//纵坐标
return obj;
};
//画单个块和数字，若不指定x，y的值，则由index计算得出
var drawBlock = function(index,dx,dy){
context.fillStyle = '#ECE0C8';
var num = blocks[index];
if(num==0)return;
var x = getPositon(index).x;
var y = getPositon(index).y;
if (dx != null)x = dx;
if (dy != null)y = dy;
context.fillRect(x,y,a,a);
var fontSize = 30;
var l = num.toString().length;
if(l==4){
fontSize=25
}else if(l==5){
fontSize=20
}
context.font='bold '+fontSize+'px Meiryo';
context.fillStyle = '#7C736A';
x=x+(a-fontSize*2*l/3)/2;
y=y+(fontSize+a)/2;
context.fillText(num.toString(),x,y);
};
var merged=[];
//将cur合并到pre,若成功合并则返回pre，没合并则返回cur
var merge=function(pre , cur){
if(newBlocks[cur]!=0){
if(newBlocks[pre]==0){
newBlocks[pre]=newBlocks[cur];
newBlocks[cur]=0;
return pre
}else if(newBlocks[pre]==newBlocks[cur]&&merged.indexOf(pre)==-1){//已经合并过一此的pre块不再合并
newBlocks[pre]*=2;
newBlocks[cur]=0;
merged.push(pre);
return pre
}else{
return cur
}
}else{
return cur
}
};
//块的合并；计算本次操作后每个块目标位置（保存至newIndex数组）
var getNewIndex = function (direct) {
merged=[];
switch (direct) {
case 0:
for (var j = 0; j < 4; j++) {
for (var i = 0; i < 4; i++) {
var k = 1;
var index = 4*i+j;
while (4 * (i - k) + j >= 0) {
index = merge(4 * (i - k) + j, 4 * (i - k + 1) + j);
if(index==4*i+j)break;
k++;
}
newIndex[4*i+j]=index;
}
}
break;
case 1:
for (var j = 0; j < 4; j++) {
for (var i = 3; i >= 0; i--) {
var k = 1;
var index = 4*i+j;
while (4 * (i + k) + j < blocks.length) {
index = merge(4 * (i + k) + j, 4 * (i + k - 1) + j);
if(index==4*i+j)break;
k++;
}
newIndex[4*i+j]=index;
}
}
break;
case 2:
for (var i = 0; i < 4; i++) {
for (var j = 0; j < 4; j++) {
var k = 1;
var index = 4*i+j;
while (j - k >= 0) {
index = merge(4 * i + j - k, 4 * i + j - k + 1);
if(index==4*i+j)break;
k++;
}
newIndex[4*i+j]=index;
}
}
break;
case 3:
for (var i = 0; i < 4; i++) {
for (var j = 3; j >= 0; j--) {
var k = 1;
var index = 4*i+j;
while (j + k < 4) {
index = merge(4 * i + j + k, 4 * i + j + k - 1);
if(index==4*i+j)break;
k++;
}
newIndex[4*i+j]=index;
}
}
break;
default:
break;
}
};
//动画结束后刷新每个块的信息，产生一个新的块
var stopMoving = function(){
init();
for(var n=0;n<blocks.length;n++){
blocks[n]=newBlocks[n]+0;
drawBlock(n)
}
another_num()
};
//滑动操作
var moveBlocks = function(direct) {
//先将所有块的当前状态复制到新数组中
for (var n = 0; n < blocks.length; n++) {
newBlocks[n] = blocks[n] + 0
}
//合并，计算本次操作后每个块目标位置
getNewIndex(direct);
//动画开始
var t = 0;
var int = setInterval(function () {
//初始化背景
init();
//画有数字的块
switch (direct) {
case 0:
var stop = true;
for (var n = 0; n < blocks.length; n++) {
if (blocks[n] == 0)continue;
var x = getPositon(n).x;
var y = getPositon(n).y;
y -= d * 4 * t;//一点点地改变坐标 实现动画效果
if (y <= getPositon(newIndex[n]).y) {//本块到达目标位置，不再动了
y = getPositon(newIndex[n]).y
} else {//本块没有到达目标位置，动画不能停
stop = false
}
drawBlock(n, null, y)
}
if (stop) {
//动画结束，重新给数组赋值
clearInterval(int);
stopMoving()
}
break;
case 1:
var stop = true;
for (var n = 0; n < blocks.length; n++) {
if (blocks[n] == 0)continue;
var x = getPositon(n).x;
var y = getPositon(n).y;
y += d * 4 * t;
//停止移动的条件：该块到达最终位置
if (y >= getPositon(newIndex[n]).y) {
y = getPositon(newIndex[n]).y
} else {
stop = false
}
drawBlock(n, null, y)
}
if (stop) {
//动画结束，重新给数组赋值
clearInterval(int);
stopMoving();
}
break;
case 2:
var stop = true;
for (var n = 0; n < blocks.length; n++) {
if (blocks[n] == 0)continue;
var x = getPositon(n).x;
var y = getPositon(n).y;
x -= d * 4 * t;
if (x <= getPositon(newIndex[n]).x) {
x = getPositon(newIndex[n]).x
} else {
stop = false
}
drawBlock(n, x, null)
}
if (stop) {
//动画结束，重新给数组赋值
clearInterval(int);
stopMoving()
}
break;
case 3:
var stop = true;
for (var n = 0; n < blocks.length; n++) {
if (blocks[n] == 0)continue;
var x = getPositon(n).x;
var y = getPositon(n).y;
x += d * 4 * t;
if (x >= getPositon(newIndex[n]).x) {
x = getPositon(newIndex[n]).x
} else {
stop = false
}
drawBlock(n, x, null)
}
if (stop) {
//动画结束，重新给数组赋值
clearInterval(int);
stopMoving()
}
break;
}
t++
}, 20)
};
//滑屏监听
var startX,startY;
$('#myCanvas').bind("touchstart", function(e) {
e.preventDefault();
startX = e.originalEvent.changedTouches[0].pageX;
startY = e.originalEvent.changedTouches[0].pageY;
});
$('#myCanvas').bind("touchend", function(e) {
e.preventDefault();
var moveEndX = e.originalEvent.changedTouches[0].pageX;
var moveEndY = e.originalEvent.changedTouches[0].pageY;
var X = moveEndX - startX;
var Y = moveEndY - startY;
if ( Math.abs(Y) > Math.abs(X) && Y < 0 ) {//上
moveBlocks(0)
}else if ( Math.abs(Y) > Math.abs(X) && Y > 0) {//下
moveBlocks(1)
}else if ( Math.abs(X) > Math.abs(Y) && X < 0 ) {//左
moveBlocks(2)
}else if ( Math.abs(X) > Math.abs(Y) && X > 0 ) {//右
moveBlocks(3)
}
});
//键盘监听
document.onkeydown = function (e) {
var keynum, keychar;
if(window.event){ // IE
keynum = e.keyCode;
}
else if(e.which){ // Netscape/Firefox/Opera
keynum = e.which;
}
keychar = String.fromCharCode(keynum);
if(['W', 'S', 'A', 'D','&','(','%','\''].indexOf(keychar) > -1){
moveBlocks(directMap[keychar])
}
};
//按钮监听
var btns = document.getElementsByClassName("con");
for(var i=0;i<btns.length;i++){
btns[i].onclick = function() {
moveBlocks(directMap[this.id])
}
}
//初始化 开始
var init = function() {
//画背景
context.clearRect(0, 0, 300, 300);
context.fillStyle = '#B8AF9E';
context.fillRect(0, 0, 300, 300);
context.fillStyle = '#CCC0B2';
for (var i = 1; i <= 4; i++) {
for (var j = 1; j <= 4; j++) {
context.fillRect(i * d + (i - 1) * a, j * d + (j - 1) * a, a, a)
}
}
};
init();
//画有数字的块
for (var n = 0; n < blocks.length; n++) {
drawBlock(n)
}
})
</script>
|