convert-color Function

Summary

Return the representation of a color specification on a given graphics port.

Package

color

Signature

convert-color port color &key errorp => color-rep

Arguments

port⇩	A graphics port.
color⇩	A color specification.
errorp⇩	A generalize boolean.

Values

color-rep⇩

Representation of color on port.

Description

The function convert-color returns the representation of color on the given graphics port port.

If errorp is t (the default), then convert-color checks for errors. Otherwise nil might be returned.

Notes

color-rep might be a "pixel" value, which corresponds to an index into the default colormap. It is more efficient to use the result of convert-color in place of its argument in drawing function calls, but the penalty is the risk of erroneous colors being displayed should the colormap or the colormap entry be changed.

See also

colors=
ensure-color
ensure-rgb
unconvert-color
13.10.8 Image access
15 The Color System