Adding support for textures

[sunnygoyal]

Adding texture support for flat surfaces (rects, boxes, front/back face of cylinder...)
Textures can be images or linear/radial gradients

#38

[webocs]

This is interesting, I like it.. I'm not sure if anybody is merging PRs anymore tho..

Here's there rendered version of the demo if anybody wants to have a quick peek

https://htmlpreview.github.io/?https://github.com/metafizzy/zdog/blob/0a91d78df8b5653d2c5d36793b22b7bc10c7f7f0/demos/textures/index.html

[sunnygoyal]

Opps, forgot to host the repo.
Demo link: http://sunnygoyal.com/zdog/demos/textures/ in case the above link is not working

[turbo]

Woooh, awesome. Thanks for implementing this :)

[desandro]

Excellent work! Thanks so much for this work here. I'll be evaluating this when I revisit Zdog in the future.