Webp support

[hkmaly]

Hello,

according to https://libgd.github.io/manuals/2.2.4/files/gd_webp-c.html the libGD supports webP format now. Would there be any problem in adding that support to gd2-ffij? (There is also tiff support, but I guess noone cares about that).

[dark-panda]

Adding either webp or tiff support should be pretty simple unless there’s some additional functionality specific to either of those formats that require adding some more extensive code changes. I don’t have access to library docs right now, but I can take a look once I get back to a machine to check.

[hkmaly]

Seems that it will be more and more important. Any progress on this?

[hkmaly]

Would mentioning we are evaluating switch to https://github.com/libvips/ruby-vips make more or less likely this ticket would be worked on?

[dark-panda]

I can likely put some time into this soon as I have some PRs that need merging as well.

[dark-panda]

Just as a heads up, I have started on support for webp, more to come very soon, hopefully before the weekend is out.

[hkmaly]

Good. We are still evaluating (or rather, the project was interrupted by something else).

[dark-panda]

@hkmaly and anyone else interested -- see #26 for some initial WebP support and see what you think.