Synopsis: Easier specification of bitfield values. July 96
Date: Tue, 9 Jul 1996 21:42:22 +0200 (MET DST)
From: erwin@pip.dknet.dk
To: MERC/Envy Mailing List <merc-l@webnexus.com>
Subject: Bits!

I got tired of computing 2^28, so I defined this:

It's not a novel idea, as Russ has already done something much like this 
for ROM, but I like numbers better than letters.. :) His system, however, 
has the advantage that flags are saved as letters, so you can quickly 
find out what 'E' on act means. I'm planning to save the whole word 
instead, so that the format becomes truly bit-independent.

But under any circumstances, typing:

#define COMM_NEW_FANCY_CHANNEL   BIT_18

is better than finding the next power of 2 :)

If you change your current act/aff/etc. bits to these new defines, to 
more easily see what bit to use next, be careful to make sure that you 
use exactly the same values.

Oh, and note that the values themselves are in hexadecimal. This is was 
what I used to do, before I decided to define all bits in a central place 
(even though 0x8000000 is easier to type than some decimal number, BIT_20 
is even easier :)

And yes, you could use something like (1 << 15) as well - but when I 
thought of that, I was too far in the table :)

PS: If you tried getting files of pip.dknet.dk/pub/pip1773 and couldn't - 
well, it's fixed now. The permission were incorrect. I've also fixed and 
updated my home page :)

{bitvalues.h}

/* This file contains all the bits, making it easier to create those bfields */

#define BIT_0               0x00000001      /*             1 */
#define BIT_1               0x00000002      /*             2 */
#define BIT_2               0x00000004      /*             4 */
#define BIT_3               0x00000008      /*             8 */
#define BIT_4               0x00000010      /*            16 */
#define BIT_5               0x00000020      /*            32 */
#define BIT_6               0x00000040      /*            64 */
#define BIT_7               0x00000080      /*           128 */
#define BIT_8               0x00000100      /*           256 */
#define BIT_9               0x00000200      /*           512 */
#define BIT_10              0x00000400      /*         1 024 */
#define BIT_11              0x00000800      /*         2 048 */
#define BIT_12              0x00001000      /*         4 096 */
#define BIT_13              0x00002000      /*         8 192 */
#define BIT_14              0x00004000      /*        16 384 */
#define BIT_15              0x00008000      /*        32 768 */
#define BIT_16              0x00010000      /*        65 536 */
#define BIT_17              0x00020000      /*       131 072 */
#define BIT_18              0x00040000      /*       262 144 */
#define BIT_19              0x00080000      /*       524 288 */
#define BIT_20              0x00100000      /*     1 048 576 */
#define BIT_21              0x00200000      /*     2 097 152 */
#define BIT_22              0x00400000      /*     4 194 304 */
#define BIT_23              0x00800000      /*     8 388 608 */
#define BIT_24              0x01000000      /*    16 777 216 */
#define BIT_25              0x02000000      /*    33 554 432 */
#define BIT_26              0x04000000      /*    67 108 864 */
#define BIT_27              0x08000000      /*   134 217 728 */
#define BIT_28              0x10000000	    /*   268 435 456 */
#define BIT_29              0x20000000	    /*   536 870 912 */
#define BIT_30              0x40000000	    /* 1 073 741 824 */

/* the 31st is the sign bit - we'll leave it alone */

==============================================================================
Erwin Andreasen  Viby J, Denmark   Computer Science Student at Aarhus Business
4u2@aabc.dk   <A HREF="http://pip.dknet.dk/~pip1773">Click here!</A>   College
==============================================================================