Path: chuka.playstation.co.uk!news1.scei.co.jp!scea!greg_labrec@interactive.sony.com
From: mperdue@iquest.net (Mario Perdue)
Newsgroups: scea.yaroze.programming.2d_graphics
Subject: Re: How do I set attributes?
Date: Wed, 30 Apr 1997 03:36:12 GMT
Organization: SCEA Net Yaroze News
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Manny,

It's really pretty simple to set bits in a field. Here's what you do:

To set the (i.e. make it a 1) you OR the bits you want set with the
original data. Suppose you have a variable called attribute, and you
want to set bit 3 (counting from 0, that would be the fourth bit.)
Here's what you do:

attribute |= 0x0008;

To clear the bit (i.e. make it 0) you AND the compliment of the bits
you want set with the original data, like this:

attribute &= 0xFFF7;

These examples are for 16 bits, but it works the same for 32 bits or
any other number of bits for that matter.


You could also define a bit-mapped field and reference each bit by
name, but that would make your code less portable.

Mario

On 30 Apr 1997 01:37:23 GMT, "Manny Najera" <mnajera@ix.netcom.com>
wrote:

>I'm not too keen on how to set induvidual bits in a 32 bit number, can
>someone show me how this is done?
>
>Manny Najera