PICK_WINDOW(3G)

NAME

pick_window − define pick window for pick_from_segment(3G) and hit_mode(3G)

SYNOPSIS

C Syntax:

void set_pick_window(fildes,px_min,py_min,px_max,py_max)
int fildes;
float px_min,py_min,px_max,py_max;

void inq_pick_window(fildes,px_min,py_min,px_max,py_max)
int fildes;
float *px_min,*py_min,*px_max,*py_max;

FORTRAN77 Syntax:

subroutine set_pick_window(fildes,px_min,py_min,px_max,py_max)
integer*4 fildes
real px_min,py_min,px_max,py_max

subroutine inq_pick_window(fildes,px_min,py_min,px_max,py_max)
integer*4 fildes
real px_min,py_min,px_max,py_max

Pascal Syntax:

procedure set_pick_window(fildes:integer;
px_min,py_min,px_max,py_max:real);

procedure inq_pick_window(fildes:integer;
var px_min,py_min,px_max,py_max:real);

DESCRIPTION

Input Parameters

fildes Integer file descriptor returned by gopen when an I/O path to a graphics device is opened.

px_min minimum x limit for pick window in VDC units.

py_min minimum y limit for pick window in VDC units.

px_max maximum x limit for pick window in VDC units.

py_max maximum y limit for pick window in VDC units.

Discussion

Set_pick_window sets a 2-dimensional rectangular window which together with pick_depth defines a pick aperture. Inq_pick_window returns the current set values for the pick window.

The pick window is used for hit testing when the Starbase hit mode is enabled (see hit_mode(3G)). Hit testing is also done by pick_from_segment(3G).

Note that some picking modes (see set_pick_mode(3G) in the Starbase Display List Programmers Manual ) may cause pick_from_segment(3G) to alter the pick window.

ERRORS

1 Graphics device is not initialized for this operation.

DEFAULTS

px_min: 0.0

py_min: 0.0

px_max: 1.0

py_max: 1.0

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