NAME

DdSetPickAperture − Set the pick aperture of a device

SYNOPSIS

C:

void DdSetPickAperture(device, aperture)
DtObject device;
DtSize3 ∗aperture;

FORTRAN:

CALL DDSPA(DEVICE, APRTUR)
INTEGER∗4 DEVICE
REAL∗8 APRTUR(3)

DESCRIPTION

DdSetPickAperture sets the pick aperture on a specified device, device, for use during picking. 

When a pick is initiated on a device (via DdPickObjs <DDPO>), a volume of space centered around the pick point is searched for drawable objects.  The dimensions of that volume define that device’s pick aperture which is always at right angles to the device.  The width, height, and depth fields <three consecutive values in FORTRAN array> are given in device coordinates where one unit is the distance between adjacent pixel centers. 

ERRORS

DdSetPickAperture will fail if passed an invalid device handle. 

[WARNING - invalid device handle]

DEFAULTS

The default pick aperture, in x,y,z format, is 10.0 by 8.0 by 4 ∗ (entire Z depth of the device viewport). 

SEE ALSO

DdInqViewport(3D), DdInqPickAperture(3D), DdPickObjs(3D)

September 02, 1992