我的时间进度条为什么不能精确到秒，最多鼠标只能30分钟滑一次

悬赏园豆：15 [待解决问题]

//var timeWidthTbls = new Array(60,1800,3600,86400);
/*
60 5 秒钟一个刻度值 (12个)
1800 30分钟 5 分钟一个刻度值（6个）
3600 1小时 10 分钟一个刻度值（6个）
86400 24小时 2 小时一个刻度值（12个）
*/

var timeWidth = timeWidthTbls[timeWidthTblIndex];
var curScale = 0;
var scaleStrPixlen = 18; //经验值
var lx,ly;
switch (timeWidth) {
case 60:
var date = new Date(startTime * 1000);
var startSecond = date.getSeconds();
for (var i = 0; i < 60; i++) {
curScale = startSecond + i;
if (curScale >= 60)
curScale = curScale - 60;
if (curScale % 5 == 0) {
//画刻度值
myPen.setColor("#363636");
if((i * maxWidth / 60 - scaleStrPixlen / 2) >0)
myPen.drawString(curScale, i * maxWidth / 60 - scaleStrPixlen / 2, maxHeight /5);
myPen.paint();

//画刻度线
myPen.setColor("#363636");
myPen.drawLine(i * maxWidth / 60, maxHeight / 3, i * maxWidth / 60, maxHeight);
myPen.paint();

}
}
break;
case 1800:
var date = new Date(startTime * 1000);
var startHour = date.getHours();
var startMin = date.getMinutes();
var startSec = date.getSeconds();

var curSecOffset = startSec; //重点

for (var i = 0; i < 30; i++) {
curScale = startMin + i;
if (curScale >= 60)
curScale = curScale - 60;
if (curScale % 5 == 0) {
lx=(i * 60 - curSecOffset) * maxWidth / 1800;
//画刻度值
myPen.setColor("#363636");
if(lx>=0)
myPen.drawString(curScale, lx - scaleStrPixlen / 2, maxHeight / 5);
myPen.paint();
//画刻度线
myPen.setColor("#363636");
if(lx>=0)
myPen.drawLine(lx, maxHeight / 3, lx, maxHeight);
myPen.paint();
}
}
break;
case 3600:
var date = new Date(startTime * 1000);
var startHour = date.getHours();
var startMin = date.getMinutes();
var startSec = date.getSeconds();

var curSecOffset = startSec;
//var curSecOffset = 60- startSec;
//if(curSecOffset==60)
//curSecOffset = 0;
for (var i = 0; i < 60; i++) {
curScale = startMin + i;
if (curScale >= 60)
curScale = curScale - 60;
if (curScale % 10 == 0) {
lx = (i * 60 - curSecOffset) * maxWidth / 3600;
//画刻度值
myPen.setColor("#363636");
if(lx>=0)
myPen.drawString(curScale, lx - scaleStrPixlen / 2, maxHeight / 5);
myPen.paint();

//画刻度线
myPen.setColor("#363636");
if(lx>=0)
myPen.drawLine(lx, maxHeight / 3, lx, maxHeight);
myPen.paint();
}
}

break;
case 86400:
var date = new Date(startTime * 1000);
var startHour = date.getHours();
var startMin = date.getMinutes();
var startSec = date.getSeconds();
//var curSecOffset = 3600 - startMin*60- startSec;
var curSecOffset = startMin * 60 + startSec;
//if(curSecOffset==3600)
//curSecOffset = 0;
for (var i = 0; i < 24; i++) {
curScale = startHour + i;
if (curScale >= 24)
curScale = curScale - 24;
if (curScale % 2 == 0) {
lx = (i * 3600 - curSecOffset) * maxWidth / 86400;
//画刻度值
myPen.setColor("#363636");
if(lx>=0){
myPen.drawString(curScale+':00', lx - scaleStrPixlen / 2, maxHeight / 5);
myPen.paint();

}
//画刻度线
myPen.setColor("#363636");
if(lx>=0)
myPen.drawLine(lx, maxHeight / 3, lx,maxHeight / 2);

myPen.paint();
}
}
break;
}
}