SketchMan3
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NC in the US of America

Here is a quote from McAlby's soundcloud page for the track "Metal Masters prototype":

"This song was composed for a very rare Game Boy game named Metal Masters, but it was never used. The game suffered many delays during the development (years!), and in the end I composed a completely different soundtrack for the final release.

It is one of my first where I used pseudo stereo effects on the Game Boy. Recorded from my own GB emulator.

Anecdote: The original game boy console had 4 shades of grey to represent the graphics. We developed a technique to show up to 7 shades of grey on this game, taking advantage of the LCD persistence, but at the end Nintendo didn't allow us to use it, arguing future compatibility. Needless to say, the game looked amazing (for a Game Boy) with 7 "colours" instead of 4!"

I know you experiment with Gameboy stuff a lot, so, nitro2k01, what have ye to say about this? Do you think you could replicate this? Or have you already? I remember you had a thread about a picture of a cat or something...

Anyway, that's a pretty interesting little tidbit of information. Just thought I'd share.

Edit: Link to the tune.

Last edited by SketchMan3 (May 20, 2013 2:22 am)

ShmallowMan
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Wisconsin and Minnesota

Sounds interesting to me. I think I recall seeing something like that on here at some point, exploiting the screen for more shades.

Saskrotch
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Chicago IL

http://blog.gg8.se/wordpress/2013/01/06 … -of-green/

SketchMan3
Offline
NC in the US of America

Thanks Saskrotch. I probably should have pm'd him. But the thing that I find interesting is that this technique was going to be used in a game, but Nintendo blocked it.

I wonder if this thread is in the wrong section...

Saskrotch
Offline
Chicago IL

It looks like they blocked that idea because of how it would've ended up looking on a GBC

thebitman
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Saskrotch wrote:

It looks like they blocked that idea because of how it would've ended up looking on a GBC

To build on this, I think it has less to do with the colors and more to do with the methods for drawing the pixels on the screen.

nitro2k01
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Sweeeeeeden

I know nothing about that game, but as linked above, I have experimented with this technique. Nintendo were right in not allowing it, as doing this on a GBC and above looks like a proper flickering mess. The LCD is fast enough to respond to change each frame, meaning that instead of seeing the average of the two shades you're aswitching between, you now see a 30 Hz flicker.

However, Nintendo may have had more immediate concerns, namely with the Super Gameboy. First off switching colors on each frame on a CRT TV gives you annoying flicker, just like on a fast LCD.
Moreover, the SGB works by copying data generated by a Gameboy CPU in the cartridge, into SNES video RAM. However, as far as I'm aware, the SNES and GB CPUs are not running in sync. Instead, I believe the data is double or triple buffered, so one buffer is displayed while another one is being filled up.

However, the almost 60 Hz generated by the GB CPU might not always line up with the almost 60 Hz. So every once in a while, a frame might be skipped or duplicated. Instead of getting an even flicker, you get flashes of darker or lighter color when the same pixel is drawn with the same color for two frames in a row.

Even worse, is what (I believe) happens on a PAL SGB, where the SNES side of things generates video at 50 Hz and the GB side of things still at ~60 Hz. Now duplication of blinking frames will happen all the time you will get a truly flickering mess.
If anyone is able to try my gradient ROM in the post linked above on a PAL SGB, please do so and report exactly how much of a flickering mess it becomes.

Imnikola
Offline
Serbia,Belgrade

I was expecting some refference to 50 shades of gray...Kinda disappointed





Lol jk nope

Alley Beach
Offline
clovis CA

what happened to a project a week sad

paulc
Offline

I'm currently working on a project that incorporates flicker in an actual game (dual compatible), so I can share some info from experience.

60 fps flicker is virtually imperceptible on the DMG, so it looks really great; 30 fps, not so much.

Flicker on the GBC only blends at 60 fps, but even then it produces vertical or horizontal lines (probably because the GBC LCD is interlaced). You can see these lines if you load up Nitro's flicker example. But in some special circumstances, this effect can still be beneficial. In my project I'm flickering between red and black to get dark red, allowing a sprite with more than 3 tones without sprite stacking.

As for Nintendo's claim; the effect is fine if you're making a duel compatible game (so that color palettes are used instead of black&white flickering). Really only issue I've found with a DMG game played on the GBC is, like I said, the horizontal lines. 

Now as Nitro said, the Super GameBoy playing on a CRT monitor will ruin the blending illusion and look awful. But I'd say the pros far outweigh this one con. And a developer COULD theoretically run special code to turn OFF the flicker effects if played on a Super GameBoy, so I don't see why they didn't go that route. Nintendo probably didn't like a non-Nintendo company putting out a game that exceeded their own standards.

In my project you can see an actual screenshot of the GBC using flicker to give the Shao Kahn character (center) more than 3 hues (namely the red armor). Screenshots here: http://chipmusic.org/forums/topic/11139 … w-project/

I've also tried to extend the palette past 7 shades by using other combinations at 60 fps, such as mixing black with light grey.  If light grey is 25% and black is %100 then that should provide at tone of %62.5, theoretically. But in practice these additional combinations aren't visually distinguishable from the regular 7 shades.

In summary, 7 shades is indeed far superior to the regular 4. It especially helps make the characters pop from the background.

b-knox
Offline
austin, tx not Detroit no mo

Commodore demo scene does the image blitting thing too in order to create a larger palette.  I don't know why they went for 3 frames instead of 2 in that blog article.  Proof of concept I suppose.  They flicker in emulators; I had assumed the CRTs could handle it though. . .