wmud/old-codebase/doc/OLD-DOCS/color.doc

/**************************************************************************
*  Copyright (C) 1993 - see 'license.doc' for complete information.       *
**************************************************************************/

			USING COLOR IN CIRCLEMUD
 			       "color.doc"

CircleMUD allows you to create colorful messages by using ANSI control
sequences.  Each player may select what "level" of color he/she desires
from the four levels "off", "sparse", "normal", and "complete."  Each
player can select his/her color level by using the COLOR command from
within the MUD; you as the programmer must decide which messages will be
colored for each of the color levels.

All files in which you wish to use color must have the line:

#include "screen.h"

after all other includes in the beginning of the file.

There are 8 colors available -- "normal", red, green, yellow, blue, magenta,
cyan and white.  They are accessible by sending control sequences as part of
another string, for example:

sprintf(buf, "If you're %shappy%s and you know it clap %d of your hands.\n\r",
	x, y, num_of_hands);
send_to_char(buf, ch);

In this example, x and y are the "on" and "off" sequences for the color you
want.  There are 2 main series of color macros available for you to use
(don't actually use "x" and "y", of course!): the K series and the CC series.
The CC (Conditional Color) series is recommended for most general use.

The name of the actual sequence starts with the name of its series, plus
a 3-letter color code, as follows:

Normal : NRM
Red    : RED
Yellow : YEL
Green  : GRN
Blue   : BLU
Magenta: MAG
Cyan   : CYN
White  : WHT

For example, white in the K series is KWHT; blue in the CC series
is CCBLU() (arguments defined below).

The K series requires no arguments, and is simply a macro to the ANSI
color code.  Therefore, if you use a K-series color code, the color will
ALWAYS be sent, even if the person you're sending it to has color off.
This is very bad -- people who do not have ANSI-compatible terminals
will see garbage characters instead of colors.  The K series is mainly
used to print colors to a string if the player's color level will later
be tested manually (for an example, see do_gen_com in act.comm.c).

The recommended series is the CC series (i.e. CCNRM(), CCRED(), etc.)
The CC series macros require two arguments -- a pointer to the character
to whom the string is being sent, and the minimum color level the player
must be set to in order to see the color.  Color sent as 'sparse' (C_SPR)
will be seen by people with color set to sparse, normal, or complete;
color sent as 'normal' (C_NRM) will be seen only by people with color
set to normal or complete; color sent as 'complete' (C_CMP) will be seen
only by people with color set to complete.

To illustrate the above, an example is in order:

#include "screen.h" /* include screen.h in all files that you use color in */

ACMD(do_showcolor)
{
    char buf[300];

    sprintf(buf, "Don't you just love %scolor%s, %scolor%s, %sCOLOR%s!\n\r",
	CCBLU(ch, C_CMP), CCNRM(ch, C_CMP),
	CCYEL(ch, C_NRM), CCNRM(ch, C_NRM),
	CCRED(ch, C_SPR), CCNRM(ch, C_SPR));
    send_to_char(buf, ch);
}

What does this do?  For people with color set to Complete, it prints:

	Don't you just love color, color, COLOR!
			   (blue) (yellow) (red)

People who have color set to Normal will see:

	Don't you just love color, color, COLOR!
		                  (yellow) (red)

People who have color set to Sparse will see:

	Don't you just love color, color, COLOR!
		                           (red)

People who have color set to Off will see:

	Don't you just love color, color, COLOR!
			(no color, as you'd expect)


There are several common pitfalls with using the CC series of color macros:

*  Do not confuse CCNRM with C_NRM.  CCNRM() is a macro to turn the color
   back to normal; C_NRM is a color level of "normal".

*  Always make sure that every pair of "on" and "off" codes are at the
   same color level.  For example:

   WRONG:  sprintf(buf, "%sCOLOR%s\n\r", CCBLU(ch, C_NRM), CCNRM(ch, C_CMP));

   This is wrong because if someone has their color level set to Normal,
   the CCBLU code will be sent but the CCNRM command will not, causing all
   subsequent output to be blue.

   WRONG:  sprintf(buf, "%sCOLOR%s\n\r", CCBLU(ch, C_CMP), CCNRM(ch, C_NRM));

   The above statement is also wrong, although not as bad.  In this case,
   someone with color set to Normal will (correctly) not get the CCBLU code,
   but will then unnecessarily get the CCNRM code.  Never send a color code if
   you don't have to -- the codes are several bytes long, and cause a noticable
   pause at 2400 baud.

*  This should go without saying, but don't ever send color at the C_OFF
   level.

*  Special precautions must be taken when sending a colored string to a
   large group of people -- you can't use the color level of "ch" (the
   person sending the string) -- each person receiving the string must
   get a string appropriately colored for his/her level.  In such cases,
   it's usually best to set up two strings (one colored and one not),
   and test each player's color level individually (see do_gen_com in
   act.comm.c for an example).