As I'm doing something very similar (but different) for my new product so I definitely checked it out.
What I like:
* Image orientation (from EXIF) support
* I like how intuitive it is
* I will absolutely use some minor ideas in my product that I have not considered using.
What I dislike:
* I have uploaded 10000 x 6672 image (this one https://unsplash.com/photos/2S4FDh3AtGw) and I see that you scale it down. My experience shows that both Firefox and Chrome handles such large image without problems.
* Delay between action and reaction is too high for my taste. It feels unnecessary sluggish. UPDATE: tested with Chromium and it feels response. Only Firefox is sluggish.
* Flip does not center around zoom
Anyway, awesome work as I know some pain points you might have experienced :)
In my experience loading huge images like those and animating them is way too slow so the preview is limited to 1500x1500 pixels (I'm testing on a MacBook from 2014). I have some ideas to work around that. With the recent switch from CSS transforms to WebGL (for the image preview) I've added some additional options.
I don't work with webgl much but I remember there being a max texture size of around 2048 or 4096 on many devices. Wouldn't you end up needing to tile the texture and stuff?
There is a limit on canvas size in most browsers, unfortunately it's rather low on iOS, more than 12 megapixels (4000x3000) will result in empty canvas elements.
Indeed progressively loading high res textures or tiling is a solution to this.
I usually do when I am sure that it is not me who did something wrong. The last time I did naive JSON.parse(JSON.stringify(x)) and Chromium was way faster than Firefox if there are a lot of data in x. I don't feel that this is Firefox bug even if it is slower. In this situation I don't know what might be causing slower behavior on Firefox so I don't feel like a could write good bug report :)
What I like:
* Image orientation (from EXIF) support
* I like how intuitive it is
* I will absolutely use some minor ideas in my product that I have not considered using.
What I dislike:
* I have uploaded 10000 x 6672 image (this one https://unsplash.com/photos/2S4FDh3AtGw) and I see that you scale it down. My experience shows that both Firefox and Chrome handles such large image without problems.
* Delay between action and reaction is too high for my taste. It feels unnecessary sluggish. UPDATE: tested with Chromium and it feels response. Only Firefox is sluggish.
* Flip does not center around zoom
Anyway, awesome work as I know some pain points you might have experienced :)