Difference between revisions of "Talk:PLAYPAL"

Revision as of 22:34, 1 July 2015

See also http://www.zdoom.org/wiki/index.php?title=Image:Doompal.png Ducon 06:35, 18 Feb 2005 (GMT)

I've put the article under protection from unregistered users for the time being -- TheDarkArchon 15:22, 16 April 2006 (UTC)

You should protect the article and the talk page. Both of them are vandalized. Ducon 15:26, 16 April 2006 (UTC)

As far as I can tell, it's not possible to protect talk pages. Bloodshedder 18:22, 16 April 2006 (UTC)

No, wait...it already is protected. Administrators can edit it just fine.Bloodshedder 18:24, 16 April 2006 (UTC)

I’m no sysop and I seem to be able to edit it. Maybe it’s restricted to registered users. Ducon 18:36, 16 April 2006 (UTC)

I restricted it to registered users since all the vandalism came from unregistered users. I should've made that clear. -- TheDarkArchon 18:47, 16 April 2006 (UTC)

Same here (for the article): I'll upgrade them if necessary. -- Jdowland 23:25, 16 April 2006 (UTC)

Why is COLORMAP info in PLAYPAL?

Why is COLORMAP info in PLAYPAL? GhostlyDeath 19:35, June 26, 2010 (UTC)

VGA register values

Please note that Doom *rounds down* its palette colors via a right-shift by two bits (c >> 2) when writing the PLAYPAL to the VGA registers. The colors as stored in the PLAYPAL itself are full 8-bit color values. --Quasar (talk) 17:25, 1 July 2015 (CDT)

Possibly beyond the scope of this article, but do you happen to know why? This is something I've wondered ever since I found out that the RGB components in VGA didn't use the full range of a byte. Surely it's more efficient to store the "real values" rather than recalculate at run-time? Yet Doom is far from the only game to store a 0-255 range for the components. Does it have to do with the way Deluxe Paint works, perhaps? Or planning ahead to porting for other graphics hardware? -- ETTiNGRiNDER (talk) 19:00, 1 July 2015 (CDT)

"The VGA's DAC contains 256 storage locations, each of which holds one 18-bit value representing a RGB triplet. Every pixel generated by the VGA is fed into the DAC as an 8-bit value, and each 8-bit value is used to look up one of the 256 values stored in the DAC." - quoting from the abrash black book --Linguica (talk) 20:15, 1 July 2015 (CDT)

Compared to the time required to write all 768 values to the VGA hardware, the extra time for a >> 2 on each is pretty negligible, and would only matter *maybe* if you were changing the palette every frame. Doom only changes palettes relatively occasionally, for special effects. Not all games did this, though. The game I am currently working on for NDS stores all of its palettes using 0-63 color components so that it can just use x86 out together with loop to copy from the source palette to the VGA register ports. --Quasar (talk) 22:29, 1 July 2015 (CDT)