小编Jul*_*ima的帖子

我的屏幕每25毫秒重绘一次,图像闪烁,这是我的代码

                var FRAME_RATE = 40;
                var intervalTime = 1000/FRAME_RATE;
                gameLoop();

                function gameLoop(){
                    context.clearRect(0, 0, 640, 640);
                    renderMap();
                    window.setTimeout(gameLoop, intervalTime);  
                }

这里是renderMap()函数

function renderMap(){
                    var startX = playerX - (screenW / 2);
                    var startY = playerY - (screenH / 2);

                    maxX = playerX + (screenW / 2);
                    maxY = playerY + (screenH / 2);
                    $.getJSON('mapa3.json', function(json){
                        for (x = startX; x < maxX; x=x+32){ 
                            for (y = startY; y < maxY; y=y+32){
                                intTile = json.layers[0].data[((y/32)* 100) + (x/32)];
                                context.putImageData(getTile(intTile - 1), …

我有一个函数loadTileSet().此函数必须返回arrTiles(图像数据数组),但函数返回UNDEFINED.我正在使用push将数据放入数组中..

function loadTileSet(){
        var canvas = document.getElementById('fakeCanvas');
        $('#fakeCanvas').hide();
        var ctx = $("canvas")[0].getContext('2d');
        var imgTileSet = new Image();
        imgTileSet.src = 'tileset.png';
        var imageTileNumWidth = 23;
        var imageTileNumHeight = 21;

        var arrTiles = [];

        imgTileSet.onload = function(){

            var imageWidth = imgTileSet.width;
            var imageHeight = imgTileSet.height;
            sndCanvasWidth = imageWidth/imageTileNumWidth;
            sndCanvasHeight = imageHeight/imageTileNumHeight;
            canvas.width = imageWidth;
            canvas.height = imageHeight;
            ctx.drawImage(imgTileSet,0,0,imageWidth,imageHeight);

            var i=0;
            var j=0;
            var t=0;
            for(i=0;i<imageWidth;i+=sndCanvasWidth){
                for(j=0;j<imageHeight;j+=sndCanvasHeight){
                    var myImageData = ctx.getImageData(j,i,sndCanvasWidth,sndCanvasHeight); 
                    arrTiles.push(myImageData);  
                }
            }
            return arrTiles;
        }
    }

在这里我尝试将数组放入另一个

var arrNew = loadTileSet(); …