Question: why does the new full size darkroom preview trigger a recompute when zooming/panning?

[pedrorrodriguez]

I thought it's slow because it's rendered at full size. @aurelienpierre unsure if this is a bug or intended behavior

[aurelienpierre]

Full size darkroom preview ? What do you mean ?

[aurelienpierre]

Panning implies you crop a visible frame out of the larger image, and you change that frame by drag and drop. So, yes, if cropping at the end of the pipe, that should be fast, but we crop early.

[pedrorrodriguez]

To be able to have just one pipeline?

[pedrorrodriguez]

I don't mean to be a bother, but over here on an i5 2017 surface tablet with no GPU the main difference between scaled/full size is an ever so slight delay for full res preview, but you gain an accurate preview.

If we could crop at the end for fast zoom/pan I would not have a reason to use the scaled preview. I would also imagine that full size preview means a fast export, right?

[aurelienpierre]

The pipeline is not wired like this at the moment. To introduce this new full-res option, I already had to track and fix a silent 12-years-old bug into the scaling method, on top of the one I had already fixed when introducing inital scale/full-res early pipeline.

So, one harmful architectural change at a time. Introducing base buffer broke IOP order and corrupted histories for no valid reason, whereas it has no connection to it. It also introduced a cropping frame mismatch between export and darkroom. The lesson here is to proceed carefully with large changes.

Right now, initial scale handles scaling to display resolution and cropping the ROI, and final scale handles scaling only and only in the full-res preview mode (slow). Once the dust has settled, it will always be time to break more things.

[pedrorrodriguez]

So, one harmful architectural change at a time.

I agree. I'm merely pointing out that there is not much of a performance penalty to full size preview, which is good. And recompute when zooming/panning is definitely not a bug. Whenever you guys feel like breaking more things, this is a very good candidate imo, since it has the potential to feel like a massive speedup when using the app, particularly on lower end PCs

[aurelienpierre]

Well, you really don't want diffuse or sharpen processed at full res though. Sure, once it's in cache, panning and zooming is free, but that's going to be an hassle.

[pedrorrodriguez]

It's really not that bad on my computer unless you use 50 iterations or more. My computer is 9 years old, and can handle 3 instances of diffuse or sharpen no problem (even though it slows down). Not the worst, but definitely not a media editing workhorse. I'd say well below average by today's standards.

[pedrorrodriguez]

Also, color work happens post diffuse or sharpen in the pipeline, so that would avoid recomputing diffuse or sharpen every time you zoom/pan.