not accurate scaling?

[eriktorbjorn]

Not COMI specific!
looks like it is an AKOS issue on scummvm

Right, I should have said late-era SCUMM specific. What I was trying to say was that this particular issue would not show up in the other two games specifically mentioned, Blade Runner and Discworld 2, since they use completely different game engines.

But if it also appears in Full Throttle, that may actually be a good thing (from a debugging point of view). It may be easier to run the original (since DOSBox tends to be easy to set up), and there are fewer pixels to compare.

[gos]

greetings again guys
i wanted to ask about grim fandango's opengl 3d accel, did anybody search this subject before? because today i was looking closely at this game in the latest scummvm and i felt like it is blurrier than i remember, i played it like 2-3 years ago on an old windows 7 laptop that supported Directx6, so i can run it through the original exe, and i did finish the game. the game forced 16-bit color on the system i used, and i really liked it better, the banding made some good depth on the 3d models.
anyways, today i was re-looking in scummvm and felt like the image is blurry using opengl, so i switched to software rendering, and it was much sharper. then after taking lossless screenshots and comparing openGL and software on scummvm with the original exe's 3d accel: the scummvm's opengl is absolutely using kind of bi-linear filtering which affects the character and the background. i also made sure AA is off, no dice.
now this is not present in the software mode on scummvm but you know, even tho it is sharper, the character model is paralyzed.

EDIT: turns out that this problem only occurs in fullscreen mode, so it is a scaling issue particularly in this game.
i even tried to set it to perfect pixel scaling with my desktop res height to 1440 VSR, still same blurry opengl output, tho this trick worked perfectly on other games that doesn't scale correctly to 1080p (my actual desktop res), COMI for example - or any 480p game because the X3 of 480=1440

[Praetorian]

anyways, today i was re-looking in scummvm and felt like the image is blurry using opengl, so i switched to software rendering, and it was much sharper. then after taking lossless screenshots and comparing openGL and software on scummvm with the original exe's 3d accel: the scummvm's opengl is absolutely using kind of bi-linear filtering which affects the character and the background. i also made sure AA is off, no dice.
now this is not present in the software mode on scummvm but you know, even tho it is sharper, the character model is paralyzed.

EDIT: turns out that this problem only occurs in fullscreen mode, so it is a scaling issue particularly in this game.
i even tried to set it to perfect pixel scaling with my desktop res height to 1440 VSR, still same blurry opengl output, tho this trick worked perfectly on other games that doesn't scale correctly to 1080p (my actual desktop res), COMI for example - or any 480p game because the X3 of 480=1440

I think it would be helpful to attach the relevant screenshots here showing the issue.

[criezy]

It’s possible that the situation would be improved by the following pull request if it gets merged:
https://github.com/scummvm/scummvm/pull/3826

[gos]

sure, here goes nothing
you can clearly see the smearing over his face and on the background in the OGL 3d accel fullscreen

[sev]

sure, here goes nothing
you can clearly see the smearing over his face and on the background in the OGL 3d accel fullscreen

ScummVM requests a certain screen resolution, so-called scaling, against the original game resolution. When you switch to full screen, that does not affect the requested resolution, thus, it is your video card drivers which do that scaling. The soapy image in this case is completely expected. Thus, switch to a higher scaler (we offer up to 4) for decreasing the granularity in full screen.

If you've already switched to max resolution, there is not much that you can do: the original game meant to run in 640480 resolution.


Eugene

[gos]

sure, here goes nothing
you can clearly see the smearing over his face and on the background in the OGL 3d accel fullscreen

ScummVM requests a certain screen resolution, so-called scaling, against the original game resolution. When you switch to full screen, that does not[i/] affect the requested resolution, thus, it is your video card drivers which do that scaling. The soapy image in this case is completely expected. Thus, switch to a higher scaler (we offer up to 4) for decreasing the granularity in full screen.

If you've already switched to max resolution, there is not much that you can do: the original game meant to run in 640480 resolution.


Eugene

hi Eugene, how you doin
i did some tests regrading your theory, and i can confirm that my gpu has nothing to do with this, for 2 main reasons:

1st: is that gpu scaling is not turned on.
2nd: i stated above that this problem doesn't occur on software 3d renderer. graphics mode is always on opengl, what mattering is the 3d renderer, when 3d renderer is on opengl it does this weird smudgy scaling when using anything but native res.

and to make myself sure this is scummvm's 3d renderer issue, i brought up my crt monitor to test this scaling issue. so i decided to use a 1280x960 res on my crt (which is the X2 of 640x480) and captured 2 screenshots, one from scummvm (with opengl gfx mode and opengl 3d renderer - pixel perfect scaling enabled) and the other from dgvoodo using the original exe.