A reusable function to clip images into polygons using html5 canvas
问题 Guess the title of the post may need editing, but for now I don't know where the problems are. I have read pages and answers to similar questions, here and elsewhere. One Stack Overflow answer is especially close, but I don't understand it. I want a function, to draw polygons on canvas at desired coordinates and to fill them with some background image loaded from a file (large enough that no tiling is needed). Triangles would be fine for a test. Apparently I should use drawImage and clip, and