clipping mask

基本解释

Additionally cairo implements the normal complement of clipping, masks, and gradients.
另外，cairo 还实现了剪切、蒙板和渐变等补充特性。
You should know your way around the Layers palette and know how to add Layer Styles, use Custom Shapes and Clipping Masks without much explanation.
你需要了解图层调色板和如何添加图层样式，并且会使用自定义图形和剪切遮罩。
SVG's feature set includes nested transformations, clipping paths, alpha masks, raster filter effects, template objects, and of course extensibility.
SVG 的特性包括：嵌套转换、剪辑路径、alpha 蒙板、光栅过滤效果、模板对象，当然还有可扩展性。