resolution scaling for high-res panels

[dhardy]

Some type of resolution scaling is needed in my case, I think. The framerate in windowed mode is nearly playable (sometimes, very little testing), while fullscreen is a slideshow.

3200x1800 laptop with only integrated graphics (i5 4200); not really a gaming machine but I figured minecraft-style graphics should work (minetest runs smoothly, though admittedly it is a lot less pretty).

[Cervator]

That still sounds like a pretty badass laptop to me! :)

As I mentioned in the other issue there's a known performance issue pretty much rendering all other performance tweaks moot when it comes to big fixes right now. We should certainly support this one day - I do believe we have some related code already, but I'm not sure we intelligently shrink textures as range increases.

Maybe related: #319 or #126

[Calinou]

I'll clarify what OP meant:

Something that works like Tesseract's /gscale command: it renders the whole thing with a lower resolution, but keeps the HUD elements at native resolution.

[dhardy]

Drawing the HUD at native resolution might require increasing font sizes a lot... I usually use effectively 250 DPI fonts on the desktop. So maybe high-res support is a bit more complicated (and needn't be high-priority to fix).

[shartte]

Probably the best option to achieve this is to render the actual game viewport to a texture that can be resized indepentently of the window size. You can see this in games such as Battlefield 4, where the game viewport can be rendered at 50% screen resolution, while the UI is overlayed at 1:1 resolution.

[Calinou]

This is exactly what I was saying, @shartte. :P

[shartte]

Added a pull request that allows resolution scaling between 25% to 200%

[Cervator]

Merged! Closing as fixed :-)

@dhardy if you get a chance to see if this helps let us know!

[dhardy]

I just built the latest source, and yes it works! As expected, resolution scaling at 100% is sharper (rediculously so!) and much slower than at 25%.

Two comments: 25% is playable (at least so far) but not enough for high framerates; and I don't understand why you allow >100% (unless that's antialiasing?).

[shartte]

Yeah, > 100% is essentially supersampling, as far as I understand it. There are some other performance improvements in the pipeline. I think 25% resolution should be enough for now, since it would essentially scale from 4K resolution down to 960x540.

We do have to do some performance measurements with newer Intel IGPUs, since they are quite widespread and actually support rather recent OpenGL features.