为什么忽略这两个职位？

Question

我正在编写一些javascript来从数组中创建x和y coodinates，所以我有这个代码：

var map1 = [
    gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,
    gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,
    gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,
    gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,
    gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,
    gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,
    gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,
    gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,
    gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,
    gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,
    gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,
    gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,
    gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,
    gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,
    gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,gg,
];
  for (var i=0; i<map1.length; i++) {
    if (i > 16) {
        dy = Math.floor(i / 15) * 16;
    }
    dx = i * 16
    while (dx >= 240) {
        dx = dx - 240;
    }   
  }

代码工作得非常好，除了坐标0,1和1,1不起作用？这些坐标使用此页面here上的主体构建一个包含16px块的画布。 dx和dy符合此等式，ctx.drawImage(tileset, sx, sy, sWidth, sHeight, dx, dy, dWidth, dHeight);谢谢！

Answer 1

不确定这是否有帮助 - 但控制台中的以下代码段似乎为所有职位提供了正确的结果。您是否可以解释一下您期望的输出与您获得的实际输出相比？

var map1 = new Array(225);
var dx, dy;

for (var i=0; i<map1.length; i++) {
    if (i > 16) {
       dy = Math.floor(i / 15) * 16;
    }
    dx = i * 16
    while (dx >= 240) {
        dx = dx - 240;
    }
    console.log(dx + ',' + dy); //Seems to print all positions ok
}