youngdahl@gacvx1.gac.edu (01/18/91)
Ok, I posted a message on this subject earlier with sort of a "rediculous"
subject line, and nobody replied... so I'll try it again...
Does anyone know if it is possible to:
1. Achieve a 32 color grey scale by "bleeding" together the current 16 color
grey scale. i.e. You display the following the first time the computer
refreshes the screen:
black black grey1 grey1 grey2 grey2 ... grey14 grey14 white white
and then change the scan line to:
black grey1 grey1 grey2 grey2 grey3 ... grey13 grey14 grey14 white
thus creating the illusion of 32 shades of grey to the naked eye??
I think I read about this being illustrated in some demo somewhere, but I
have yet to see it. I mean, even if the overhead is very high on the CPU,
and there is a slight flicker, it would be nice for displaying GIFs that
utilize a high number of colors in B/W.
2. If the above is possible, then it should also follow that one could change
between 2 different sets of 16 colors on a line and change a few pixels in
that line to achieve the illusion of 32 colors/line...
right?
3. If the gs can display 640x200x"800" and 320x200x"3200", then it should also
be able to split 3/4 of the screen into 320x200x"3200" and the bottom 1/4
into 640x200x"800", right? This would be great for an adventure game, with
limited/no animation ... good graphics and 80 column text below...
Ben
youngdahl@gacvx1.gac.eduifar355@ccwf.cc.utexas.edu (David H. Huang) (01/18/91)
In article <1991Jan18.004931.1@gacvx1.gac.edu> youngdahl@gacvx1.gac.edu writes: |Ok, I posted a message on this subject earlier with sort of a "rediculous" |subject line, and nobody replied... so I'll try it again... | |Does anyone know if it is possible to: | |1. Achieve a 32 color grey scale by "bleeding" together the current 16 color | grey scale. i.e. You display the following the first time the computer | refreshes the screen: | | black black grey1 grey1 grey2 grey2 ... grey14 grey14 white white | | and then change the scan line to: | | black grey1 grey1 grey2 grey2 grey3 ... grey13 grey14 grey14 white | | thus creating the illusion of 32 shades of grey to the naked eye?? | | I think I read about this being illustrated in some demo somewhere, but I | have yet to see it. I mean, even if the overhead is very high on the CPU, | and there is a slight flicker, it would be nice for displaying GIFs that | utilize a high number of colors in B/W. I'm sure this is possible, since there is a demo called Kompressor (or something like that) which switches (normal) hires pages back and forth very rapidly, so it seems to blend the two hires pages together. If you mix a green screen (color 1) and a violet screen (2), you get this grayish screen. It does flicker slightly, but it isn't too bad. BTW, the demo runs on a ][+ or higher. |2. If the above is possible, then it should also follow that one could change | between 2 different sets of 16 colors on a line and change a few pixels in | that line to achieve the illusion of 32 colors/line... | | right? I would think so... |3. If the gs can display 640x200x"800" and 320x200x"3200", then it should also | be able to split 3/4 of the screen into 320x200x"3200" and the bottom 1/4 | into 640x200x"800", right? This would be great for an adventure game, with | limited/no animation ... good graphics and 80 column text below... Not quite... 640x200x"800" is 640x200x4 per scan line. If you use the whole screen, you have 200 scanlines, so you get 640x200x800. If you're only using the bottom 1/4 of the screen, you have 50 scanlines, which is 200 colors on that part of the screen. Same applies to the top 3/4... 2400 colors. But if you only want 80 column text below, you could just let the top be 320x200x2400 and the bottom be 640x200x4. |Ben | |youngdahl@gacvx1.gac.edu -- David Huang | Internet: ifar355@ccwf.cc.utexas.edu | "My ganglion is stuck in UUCP: ...!ut-emx!ccwf.cc.utexas.edu!ifar355 | a piece of chewing gum!" America Online: DrWho29 |
toddpw@nntp-server.caltech.edu (Todd P. Whitesel) (01/19/91)
The gray scale trick has been done, I believe in an ACS demo disk that was out last summer (if not before). They called it 'IIgs HAM mode' which is not accurate. Well, we will eventually be able to add something like this to LHG as an option. However, I'm a bit skeptical as to how practical it will turn out to be... Todd Whitesel toddpw @ tybalt.caltech.edu