NAME

DdInqVisualType − Return the visual type of a device

SYNOPSIS

C:

DtVisualType DdInqVisualType(device)
DtObject device;

FORTRAN:

INTEGER∗4 DDQVT(DEVICE)
INTEGER∗4 DEVICE

DESCRIPTION

DdInqVisualType returns the visual type of the device named device.  You can set the visual type with DoDevice <DOD>.  Dor´
e defines the following visual types:

DcPseudoColor <DCPSUC>
A pixel value indexes a color map to determine the color to be displayed; the entries in the color map can be changed dynamically.

DcGreyScale <DCGRYS>
These devices are the same as pseudocolor devices, except that only the intensities of the entries specified in the lookup table are displayed.

DcDirectColor <DCDRCC>
A pixel value is decomposed into separate subfields, and each subfield separately indexes the color map for the corresponding value. The entries in the color map can be changed dynamically. Typically, the color map is used for displaying false color or for performing gamma correction.

DcTrueColor <DCTRUC>
A true color device is similar to a directcolor device except that the color map has predefined read-only values that provide a (near-) linear ramp in each color coordinate (e.g. a direct RGB device).

DcStaticColor <DCSTCC>
A static color device is similar to a pseudocolor device except that the color map has predefined read-only values that are device dependent (such as a fixed 16 color system).

DcStaticGrey <DCSTCG>
A static grey scale device is similar to a static color device except that only a fixed set of device-dependent intensities is supported.  (A "black and white only" display is of this type.)

ERRORS

DdInqVisualType will fail if the device handle is invalid; the returned value is undefined. 

[WARNING - invalid device handle]

SEE ALSO

DdInqColorEntries(3D), DdInqColorTableSize(3D), DoDevice(3D)

September 02, 1992