Description:
This application selects the first,
i.e. oldest, unobstructed FRAME
picture in the
graphics database for a graphics device. Unobstructed means that there
is no younger picture overlying it either wholly or in part.
Usage:
picvis [device]
Parameters:
DEVICE = DEVICE (Read)
The graphics workstation. [
The current
graphics device]
Examples:
picvis
This selects the first unobscured FRAME
picture for the current graphics device. picvis xwindows
This selects the
first unobscured FRAME picture for the xwindows graphics device. Notes:
-
An error is returned if there is no unobscured FRAME picture, and the current picture
remains unchanged.
-
This routine cannot know whether or a picture has been cleared, and hence is safe
to reuse, as such information is not stored in the graphics database.
Related Applications
Timing
The execution time is approximately proportional to a linear
combination of the number of pictures in the database before the unobstructed FRAME
picture is found, and the square of the number of pictures in the database.