SCUMM: Curse of Monkey Island Sprite Vertical Colour Artifacts

[mohabs]

there is a noticeable difference between scummvm & original exe at the very first sprite frame of guybrush, and it is noticeable on other guybrush frames.

here a lossless screenshot captures on native 640x480, non upscaled, with 3 raw ripped sprites as a reference.
apps used: scummvm latest nightly (OGL) - dgvoodo - virtualbox (windows 95).
scummvm stable versions provide same issue, even the earliest.

[antoniou79]

For more context on this ticket, here's some extra findings from the related forum thread:

​https://forums.scummvm.org/viewtopic.php?p=95278#p95278

[athrxx]

I have committed a fix. If you find the time, please test whether the rendering is now accurate.

[AndywinXp]

I have tested and compared against the original exe, and indeed it appears to be fixed. Let's wait for mohabs, though

[mohabs]

Replying to AndywinXp:

I have tested and compared against the original exe, and indeed it appears to be fixed. Let's wait for mohabs, though

greetings.
sorry for the very late reply, i just realized the change when i was playing the new scummvm build, so i decided to check here again, and found out that you mentioned the fix.

and i can confirm that it is fixed.
however there is still some minor inaccuracy in the lemonade boy area, i think it is related to scrolling.
i will share the comparison soon with you

[mohabs]

there you go
​https://drive.google.com/file/d/19tcp8ug3YKagclXeDS9jMkkVBoI4tXdA/view?usp=sharing

[athrxx]

This seems to be a completely different issue. You're talking about the horizontally "shaking" background, right? (which somehow doesn't even affect Guybrush)

[mohabs]

Replying to athrxx:

This seems to be a completely different issue. You're talking about the horizontally "shaking" background, right? (which somehow doesn't even affect Guybrush)

that's right, it is completely different.
however the video shows the difference between guybrush standing in the exact same position via scummvm, and the other via dgvoodo & virtual box.
so whats happening is that the camera is not in the same positioning as in the original exe, even guybrush's stand point is affected as seen.

[athrxx]

Okay, I am glad that we don't really have a shaking background (and nobody caring about it for 20 years) :-).

Yes, I am pretty sure I noticed in several SCUMM games (even MI2) that the camera/actor positions are not exactly in match with the originals. I found it just too irrelevant and boring to investigate, but maybe it's time to put an end to that, too.

[athrxx]

I have made a fix that should fix the inaccurate positioning. Please test if you find the time...

[AndywinXp]

Replying to athrxx:

I have made a fix that should fix the inaccurate positioning. Please test if you find the time...

Great job, as usual! :-)

[mohabs]

Replying to athrxx:

I have made a fix that should fix the inaccurate positioning. Please test if you find the time...

awesome, i tested, and indeed it got fixed.

i think now i can replay the whole game without worrying about this stuff, and just enjoy the real thing like it was meant to be!

and as a matter of fact: all games with akos seems to be fixed, cuz i tested full throttle - which had the same scaling artifacts as COMI - now fixed

[mohabs]

Replying to AndywinXp:

Replying to athrxx:

I have made a fix that should fix the inaccurate positioning. Please test if you find the time...

Great job, as usual! :-)

both of you are appreciated for your passion in these