[comp.terminals] Test for status of a pixel on DMD terminal.

kimcm@olamb.UUCP (Kim Chr. Madsen) (12/08/86)

Is there a way of telling whether a pixel is set or not, on the
the AT&T 5620 Terminal (aka DMD & Blit) ?

What I need is something like:

	int pixel(p)
	Point p;

Returning information on the status of the pixel (on/off), I know, I can
get the 32-bit word containing the pixel-bit - but calculating which bit's
the right isn't easy when you don't know the size of the layer running the
application.

BTW:

Is there something wrong with <blitio.h>, since when I include it - my
program won't run and I have to make do without the routines needing the
header file to be included - Making I/O to the UNIX host a pain in the a**!

				Best Regards
				Kim Chr. Madsen

gwyn@brl-smoke.ARPA (Doug Gwyn ) (12/16/86)

In article <182@olamb.UUCP> kimcm@olamb.UUCP (Kim Chr. Madsen) writes:
>Is there a way of telling whether a pixel is set or not, on the
>the AT&T 5620 Terminal (aka DMD & Blit) ?

There isn't any standard function that I know of,
probably due to this being a fairly rare need.
A simple kludge that will suffice is to clear a
scratch word then bitblt() the point into it,
followed by testing the scratch word for nonzero.

>Is there something wrong with <blitio.h>, since when I include it - my
>program won't run and I have to make do without the routines needing the
>header file to be included - Making I/O to the UNIX host a pain in the a**!

<blitio.h> works okay here.  You didn't supply enough
information to permit remote debugging.