Editing Talk:Text Mode Doom


I'm digging out old screenshots in order to write this article. -- [[User:Jdowland|Jdowland]] 10:36, 19 Jun 2005 (UTC)

== Lib caca Images ==

The second picture is Doom Legacy! [[Image:doomlegacylibcacmatch.png]] [[User:GhostlyDeath|GhostlyDeath]] 10:15, 14 July 2008 (UTC)

== smmu's textmode implementation ==

Fraggle, your original textmode smmu page had a really good detailed look at how you implemented the color-shifting, etc., which would be nice for this page. Do you still have it? Either way, would you grant a licence on the material so that we could use it in this article? I can probably find it.

Note that the three SMMU pics there I think I took in the first place, but I found them on a page which had mirrored some of your old page. I remember there were two tiers of shots, those from before and those from after you implemented background dithering.

I'm building a win95 box in order to actually run SMMU/DOS and take  some proper shots :-)

-- [[User:Jdowland|Jdowland]] 21:31, 20 Jun 2005 (UTC)

I've lost the original page and images I had, unfortunately.

The system works by using the extended ASCII text mode "gradient" characters (there are ~4-5 of them).  When the palette is set, the hue and brightness of each colour is calculated from the palette entries.  The hue is then used to select the text-mode colour to use for the character, while the brightness is used to select the character to use.

The extended mode ascii characters used are (descriptions I ''think'' are correct):

* "space" character (32): all background
* 0xb0: 20% foreground
* 0xb1: 40% foreground
* 0xb2: 60% foreground
* 0xdb: 80% foreground

The original version of the SMMU textmode renderer used black as the background, and the selected colour as the foreground (ie, 5 steps).  I later improved on it by adding greater colour depth and using the background colour.  Basically text mode has two sets of colours; the second are the same as the first but brighter (1 is blue, 9 is "bright blue").  So instead of going from black -> colour, I made it go black -> colour -> bright colour (the first stage having black background + colour foreground, the second stage having colour background + bright colour foreground).  This effectively doubles the colour depth.

[[User:Fraggle|Fraggle]] 08:20, 21 Jun 2005 (UTC)