帮助你获得背景-位置，宽度和精灵的高度一点可复制的css。
加载示例图像, 点击一下 在附近。很明显。
Automated spritesheet generators are pretty cool, but I prefer the control over optimisation and compression you get by making them manually.
However, copying all the positions & sizes from graphics apps wasted a ton of my time, so I made this!
