The Pawn is back. And it's not alone!

Anything QL Software or Programming Related.
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tofro
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Re: The Pawn is back. And it's not alone!

Postby tofro » Sun Nov 10, 2019 10:08 pm

Sparrowhawk wrote:I should add that I have never managed to finish ANY of the Magnetic Scrolls games :D

But I still love playing them.


Yes, the games are really, really hard to solve. Later games, like Fish! even have sequences where you have to solve a task within a limited amount of time - You need to solve some of the puzzles by trial and error, and once you know the solution, "run through" it again starting from a saved game in order to proceed.

But, please don't be tempted to use the walkthroughs and solutions from the Magnetic Scrolls memorial site (Like I had to when testing the games for the Q68) - They will spoil the games for you. Most of the fun can be had (and most of the humourous twists) can only be experienced when actually failing.

Tobias


ʎɐqǝ ɯoɹɟ ǝq oʇ ƃuᴉoƃ ʇou sᴉ pɹɐoqʎǝʞ ʇxǝu ʎɯ 'ɹɐǝp ɥO
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tofro
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Re: The Pawn is back. And it's not alone!

Postby tofro » Sat Nov 16, 2019 11:40 pm

Another teaser, maybe?

This time not only for Q68 users:

IMG_0895.JPG


Who can guess what machine this is running on? ;)

Stay tuned.

Tobias


ʎɐqǝ ɯoɹɟ ǝq oʇ ƃuᴉoƃ ʇou sᴉ pɹɐoqʎǝʞ ʇxǝu ʎɯ 'ɹɐǝp ɥO
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vanpeebles
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Re: The Pawn is back. And it's not alone!

Postby vanpeebles » Sun Nov 17, 2019 8:22 am

BBQL?!


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tofro
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Re: The Pawn is back. And it's not alone!

Postby tofro » Sun Nov 17, 2019 9:05 am

Of course!

Tobias


ʎɐqǝ ɯoɹɟ ǝq oʇ ƃuᴉoƃ ʇou sᴉ pɹɐoqʎǝʞ ʇxǝu ʎɯ 'ɹɐǝp ɥO
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Andrew
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Re: The Pawn is back. And it's not alone!

Postby Andrew » Sun Nov 17, 2019 10:13 am

Now it's really getting interesting !
Tobias, if you need help in converting the graphics to mode 8, I can lend a hand !


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tofro
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Re: The Pawn is back. And it's not alone!

Postby tofro » Sun Nov 17, 2019 10:19 am

For the picture display on the QL I had to dig out memories of 25 years ago when I was working on image processing software as a young developer.

Now, In fact, I'm a bit at a crossroads here:

The pictures in the MS games have been treated differently in different games, apparently. For older games, the quality of the colour-reduction from 16 (palettized, nearly true color RRR GGG BBB pictures) to 8 fixed QL MODE 8 colours apparently benefits from application of the Floyd-Steinberg algorithm (That spreads the error that one pixel is off by in colour values to neighboring pixels)

This is how Mr. Guru was supposed to look like by Magnetic Scrolls (Picture taken from Q68 version):
Guru RGB.png


Guru with a simple "nearest colour display" (no dithering, QL MODE 8):
Guru NCA.png

See how the background details (blue carpet and green(ish) wall vs. brown door) had to vanish because poor QL simply has no proper colour left to display them. (also see the slightly different aspect ratio of the QL display - Mr. Guru looks a bit more well-fed than in the original...)

And after being run through the algorithm by Misters Floyd and Steinberg (still QL MODE 8, obviously):
Guru Dithered.png

Obviously, the algorithm has created a lot of dithering artefacts (nothing is for free) but was able to pick up the more subtile background details, and at least displays them as patterns. Half-tones between colours are approximated by alternating pixels, Mr. Guru seems to be a lot less close to a heart attack than before. Also the wall vs. door contrast is visible, and even some of the blue carpet is back again. If you stand back far enough, the artifacts blur into each other and give a pretty good rendition of the original colours. Note the example pictures are magnified here. (I can simply remove my glasses for the same effect - There must be at least some benefit that comes with age...)

Unfortunately, in later games, the guys at Magnetic Scrolls apparently had the same idea. And one of the main traits of error diffusion algoriths is: "Don't do it twice, or you'll get a mess". See how this mess looks like in newer games:

(Bus scene from Jinxter, Floyd-Steinberg dithering, same code as above Guru)
Bus dithered.png


Because the picture was already dithered, further error diffusion flattens everything to the average red, all details are lost.

And this is how the same picture looks in MODE 8 with a more straightforward (and much faster) nearest colour display:
Bus NCA.png


Note these are just two examples of many, many pictures. Some look better with one algorithm, some benefit from the other.

I am leaning towards not applying any dithering at all at the moment, even if that means some details is lost. For reasons above, and because the dithering slows down the picture display quite a bit - implementing it would probably limit the program to SGC users.

Tobias
Last edited by tofro on Sun Nov 17, 2019 10:59 am, edited 6 times in total.


ʎɐqǝ ɯoɹɟ ǝq oʇ ƃuᴉoƃ ʇou sᴉ pɹɐoqʎǝʞ ʇxǝu ʎɯ 'ɹɐǝp ɥO
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tofro
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Re: The Pawn is back. And it's not alone!

Postby tofro » Sun Nov 17, 2019 10:23 am

Andrew wrote:Now it's really getting interesting !
Tobias, if you need help in converting the graphics to mode 8, I can lend a hand !


Thanks for offering help, but I'm actually not converting the pictures statically, but rather on-the fly from the originals (I want to refrain from distributing the pictures or any converted versions thereof with the software for legal reasons, so the interpreter must be able to display the pictures based on the originals in an acceptable way).

Tobias


ʎɐqǝ ɯoɹɟ ǝq oʇ ƃuᴉoƃ ʇou sᴉ pɹɐoqʎǝʞ ʇxǝu ʎɯ 'ɹɐǝp ɥO
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Andrew
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Re: The Pawn is back. And it's not alone!

Postby Andrew » Sun Nov 17, 2019 12:55 pm

The same Guru - dithered "by hand" in Photoshop, scaled for QL pixel ratio and loaded in QPC mode 8
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guruQL.jpg


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tofro
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Re: The Pawn is back. And it's not alone!

Postby tofro » Sun Nov 17, 2019 1:06 pm

Andrew wrote:The same Guru - dithered "by hand" in Photoshop, scaled for QL pixel ratio and loaded in QPC mode 8


Impressive.
Do you know by any chance what algorithm for dithering Photoshop is using?

And could you try to do the same thing to the jinxter bus picture?


ʎɐqǝ ɯoɹɟ ǝq oʇ ƃuᴉoƃ ʇou sᴉ pɹɐoqʎǝʞ ʇxǝu ʎɯ 'ɹɐǝp ɥO
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Peter
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Re: The Pawn is back. And it's not alone!

Postby Peter » Sun Nov 17, 2019 3:17 pm

I fear the good impression comes mostly from occupying the whole screen. In the size Tobias as using, which allows enough text, it's a different science.



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