gselec(3G)gselec(3G)NAMEgselec - puts the system in selecting mode
FORTRAN 77 SPECIFICATION
subroutine gselec(buffer, numnam)
integer*2 buffer(*)
integer*4 numnam
PARAMETERS
buffer expects the buffer into which you want the system to save the
contents of the names stack. A name is a 16-bit number, that
you load on the name stack just before you called a drawing
routine.
numname expects the maximum number of names that you want the system to
save. This number must not exceed the number of elements in
buffer.
DESCRIPTIONgselec turns on the selecting mode. When in selecting mode, the system
notes when a drawing routine intersects the selecting region and writes
the contents of the names stack to the specified buffer. If you push a
name onto the names stack just before you call each drawing routine, you
can record which drawing routines intersected the selecting region.
Use the current viewing matrix to define the selecting region.
gselec and pick are identical except gselec allows you to create a
viewing matrix in selecting mode. To end select mode, call endsel.
SEE ALSO
endpic, endsel, pick, picksi, initna pushna, popnam, loadna
NOTE
This routine is available only in immediate mode.
In order to select a large point or a wide line in selecting mode, the
selecting region must intersect the displayed point center or the
displayed line center respectively. The displayed point center is the
imaginary point of size 1 specified by the same vertex as the displayed
point. The displayed line center is the imaginary line of width 1
specified by the same vertices as the displayed line. In case of a very
large point or very wide line, you may want to consider drawing a filled
circle or a filled rectangle respectively instead.
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