为什么实现不了讲课的效果

Question

var WINDOW_HEIGHT = 768;

var RADIUS = 8;

var MARGIN_TOP = 60;

var MARGIN_LEFT = 30;

const endTime = new Date(2014,6,11,18,47,52);

var curShowTimeSeconds = 0

window.onload = function(){

    var canvas = document.getElementById('canvas');

    var context = canvas.getContext("2d");

    canvas.width = WINDOW_WIDTH;

    canvas.height = WINDOW_HEIGHT;

    curShowTimeSeconds = getCurrentShowTimeSeconds()

    render( context )

}

function getCurrentShowTimeSeconds() {

    var curTime = new Date();

    var ret = endTime.getTime() - curTime.getTime();

    ret = Math.round( ret/1000 )

    return ret >= 0 ? ret : 0;

}

function render( cxt ){

    var hours = parseInt( curShowTimeSeconds / 3600);

    var minutes = parseInt( (curShowTimeSeconds - hours * 3600)/60 )

    var seconds = curShowTimeSeconds % 60

    renderDigit( MARGIN_LEFT , MARGIN_TOP , parseInt(hours/10) , cxt )

    renderDigit( MARGIN_LEFT + 15*(RADIUS+1) , MARGIN_TOP , parseInt(hours%10) , cxt )

    renderDigit( MARGIN_LEFT + 30*(RADIUS + 1) , MARGIN_TOP , 10 , cxt )

    renderDigit( MARGIN_LEFT + 39*(RADIUS+1) , MARGIN_TOP , parseInt(minutes/10) , cxt);

    renderDigit( MARGIN_LEFT + 54*(RADIUS+1) , MARGIN_TOP , parseInt(minutes%10) , cxt);

    renderDigit( MARGIN_LEFT + 69*(RADIUS+1) , MARGIN_TOP , 10 , cxt);

    renderDigit( MARGIN_LEFT + 78*(RADIUS+1) , MARGIN_TOP , parseInt(seconds/10) , cxt);

    renderDigit( MARGIN_LEFT + 93*(RADIUS+1) , MARGIN_TOP , parseInt(seconds%10) , cxt);

}

function renderDigit( x , y , num , cxt ){

    cxt.fillStyle = "rgb(0,102,153)";

    for( var i = 0 ; i < digit[num].length ; i ++ )

        for(var j = 0 ; j < digit[num][i].length ; j ++ )

            if( digit[num][i][j] == 1 ){

                cxt.beginPath();

                cxt.arc( x+j*2*(RADIUS+1)+(RADIUS+1) , y+i*2*(RADIUS+1)+(RADIUS+1) , RADIUS , 0 , 2*Math.PI )

                cxt.closePath()

                cxt.fill()

            }

}

Answer 1

给一个完整的代码来看看，你这代码实在跑不起来。