Messages in this thread |  | | Date | Fri, 15 Nov 1996 06:52:36 -0500 (EST) | From | Kenneth Albanowski <> | Subject | Re: RFC: A generic pointer protocol |
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On Fri, 15 Nov 1996, . Tethys SYSTEM ADMIN X wrote:
> Why does pressure have to be treated differently? Surely, it's just > another dimension? If we're trying to develop a generic pointer > protocol, why make it specific? > > Tet
Because it isn't obvious which dimension (if any) is pressure. On a mouse, "pressure" is derived from the buttons. On a pressure sensitive tablet, it's derived from the pen transducer, and thus the "Z" coordinate. If you imagine a 3-D digitizing device (such exist) that also includes pen pressure, then it would be the "A" coordinate.
I'm just saying that pressure is distinct enough from all the other dimensions to deserve being copied into a specific field. Otherwise programs would need to be littered with code like:
if(PointerStat->z_is_pressure) pressure = PointerRec->dimen[2]; else if(PointerStat->a_is_pressure) pressure = PointerRec->dimen[3]; else pressure = PointerRec->buttons ? 255 : 0;
-- Kenneth Albanowski (kjahds@kjahds.com, CIS: 70705,126)
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