Routines (alphabetical) > Routines: C > COLORMAP_APPLICABLE

# COLORMAP_APPLICABLE

The COLORMAP_APPLICABLE function determines whether the current visual class supports the use of a colormap, and if so, whether colormap changes affect pre-displayed Direct Graphics or if the graphics must be redrawn to pick up colormap changes.

This routine is written in the IDL language. Its source code can be found in the file `colormap_applicable.pro` in the `lib` subdirectory of the IDL distribution.

## Examples

To determine whether to redisplay an image after a colormap change:

result = COLORMAP_APPLICABLE(redrawRequired)

IF ((result GT 0) AND (redrawRequired GT 0)) THEN BEGIN

my_redraw

ENDIF

## Syntax

Result = COLORMAP_APPLICABLE( redrawRequired )

## Return Value

The function returns a long value of 1 if the current visual class allows modification of the color table, and 0 otherwise.

## Arguments

### redrawRequired

A named variable to retrieve a value indicating whether the visual class supports automatic updating of graphics. The value is 0 if the graphics are updated automatically, or 1 if the graphics must be redrawn to pick up changes to the colormap.

## Keywords

None.

## Version History

5.2 | Introduced