1. For RDS: peeking and poking WORDs
- Posted by David Guy <dguy at MINDSPRING.COM>
Feb 16, 1999
-
Last edited Feb 17, 1999
Hi,
Any chance of adding routines to poke & peek WORDs in additions to the ones to
poke/peek BYTEs and DWORDs.
I ask this because when using Euphoria to access 16bit DIBs or DirectDraw
Surfaces, the ability to poke/peek single WORDs would be very nice/helpful. As
it stands, I have to break my 16bit color into bytes and poke then into memory as
a sequence. When reading colors, I either have to read two bytes and re-combine
them or read four bytes and pull out/re-combine the bytes.
In addition, some Windows structures, BMPINFOHEADER for instance, have WORD
sized elements. Instead of being able to do something simple like this:
poke2( pBIH + BIH_biBitCount, wordVal )
I have to do something like:
poke( pBIH + BIH_biBitCount, {wordVal, floor(wordVal/256)}) -- being sure to
poke the low byte first
I think code would be simpler and clearer if there where WORD poke'ing/peek'ing
routines available.
Thanks for reading,
David
2. Re: For RDS: peeking and poking WORDs
- Posted by Robert Craig <rds at ATTCANADA.NET>
Feb 16, 1999
-
Last edited Feb 17, 1999
David Guy writes:
> Any chance of adding routines to poke & peek WORDs in
> additions to the ones to poke/peek BYTEs and DWORDs.
I'm not really inclined to add peek2()/poke2(), since
reading/writing 2 bytes at a time isn't nearly as common
on 32-bit machines, as reading/writing 1 or 4 bytes.
You can easily make your own peek2/poke2, and you will
only suffer if they are critical to performance.
> In addition, some Windows structures, BMPINFOHEADER
> for instance, have WORD sized elements.
It would not be a performance problem, if you
are just reading a few words from the header of a bitmap file.
> poke( pBIH + BIH_biBitCount, {wordVal, floor(wordVal/256)})
floor(a/b) is pretty efficient - it just does a single integer divide
at the machine level - the floor operation is optimized out.
I'm not sure if it's faster to poke (or peek) a sequence of
2 elements, as you have done, or do two separate pokes.
Regards,
Rob Craig
Rapid Deployment Software
http://members.aol.com/FilesEu/
