Before using the definition described here, you should evaluate the form:
(require "color-defmodel")
The macro
define-color-models
can be used to define new color models for use in the color system.
The default color models are defined by the following form:
(define-color-models ((:rgb (red 0.0 1.0)
(green 0.0 1.0)
(blue 0.0 1.0))
(:hsv (hue 0.0 5.99999)
(saturation 0.0 1.0)
(value 0.0 1.0))
(:gray (level 0.0 1.0))))
For example, to define a new color model YMC and keep the existing RGB, HSV and GRAY models:
(define-color-models ((:rgb (red 0.0 1.0)
(green 0.0 1.0)
(blue 0.0 1.0))
(:hsv (hue 0.0 5.99999)
(saturation 0.0 1.0)
(value 0.0 1.0))
(:gray (level 0.0 1.0))
(:ymc (yellow 0.0 1.0)
(magenta 0.0 1.0)
(cyan 0.0 1.0))))
You must then define some functions to convert YMC color-specs to other color-specs. In this example, those functions are named
make-ymc-from-rgb
make-ymc-from-hsv
make-ymc-from-gray
make-rgb-from-ymc
make-hsv-from-ymc
make-gray-from-ymc
You can make this easier, of course, by defining the functions
make-ymc-from-hsv
make-ymc-from-gray
make-hsv-from-ymc
make-gray-from-ymc
in terms of
make-ymc-from-rgb
and
make-rgb-from-ymc
.
If you never convert between YMC and any other model, you need only define the function
make-rgb-from-ymc
.
CAPI User Guide (Unix version) - 30 Aug 2011