给定一组向量（x / y坐标），我如何将其转换为PNG文件（android canvas缺陷）？

Question

I am writing a javascript app that uses the canvas tag. It seems that android prior to 3.0 has no support for the toDataURL() method. This basically means that you can't save the canvas to an image. I'd like to fake this functionality. Currently, I wrote some routines to save the vector coordinates so i have a set like this:

moveTo,1,1 lineTo,1,10 lineTo,40,50 moveTo,100,200 lineTo,1,1

this is enough to reproduce the drawn canvas, however, I'd like to actually output a png file.

1 - how do I convert vectors to a bitmap 2 - how do I make that into a png 3 - how do I do this all in javascript :)

Answer 1

I've got the same problem and came across this (JavaScript) code that will convert a canvas to a BMP, not using the native .toDataURL

http://devpro.it/code/216.html

Another possibility I'm entertaining is building the image on the server from instructions (similar to your approach, but bypassing JavaScript)