Support psd format

[ryan-de-boer]

Although I like the ora format, it is limiting for layer masks. All the other programs that support layer masks do not save (or load) the mask separately. So unfortunately I can't save an ora file and load it properly in other applications. The spec is missing layer masks which makes it hard for interop. Also Affinity doesn't support ora which is a shame. PSD files seem to have better support across applications, and I assume they support layer masks (Krita saves masks successfully in PSD). Any objections to implementing PSD support in Pinta? Alternatively I could add better ora support to Krita, then we can interop between those apps, Krita can save to psd for Affinity to work. I've been working on better mask support in ora format for Pinta, maybe I could do the same for Krita.

I had a look around and found these C# library for psd io. It would make sense to use a library to do the heavy lifting.
https://github.com/manju-summoner/PsdParser - this one does not support saving
Magick.NET - this one does not support separate masks

[ryan-de-boer]

I'm currently working on this. Its a shame Magick.NET doesn't support separate masks, it seemed pretty good. At the moment I'm writing my own parser, we'll see how it goes.

PsdParser looks pretty good too - it was missing the composite image (background layer) though (and no save) - but I might use its model. Saving the model might be better code, we'll see.

[cameronwhite]

PSD support would be a great idea for a file format add-in 👍 I'd be unsure about adding it into core Pinta due to the extra library dependencies and/or maintenance of keeping a custom parser up to date

But putting together a proposal for extending ORA support is also a great idea since that's a open format

[ryan-de-boer]

I decided to go with PsdParser and add the missing features. Its 34 files, so yeah it might be nice having it as a file format addin. I can fork PsdParser and then turn it into an addin. Yeah I'll work on a proposal for extending ORA support, its such a nice simple format.