@node Colors
@section Colors

Colors store RGBA data in OpenGL format. Each color channel has a
value in the range [0, 1].

@anchor{2d color make-color}@defspec make-color
@end defspec

@anchor{2d color color?}@defspec color?
@end defspec

@anchor{2d color color-r}@defspec color-r
@end defspec

@anchor{2d color color-g}@defspec color-g
@end defspec

@anchor{2d color color-b}@defspec color-b
@end defspec

@anchor{2d color color-a}@defspec color-a
@end defspec

@anchor{2d color use-color}@defun use-color color
Set the current OpenGL color state to the contents of COLOR.

@end defun

A lot of people are used to working with colors as hexadecimal values,
so the following procedures are provided to convert hexadecimal color
codes into color objects.

@anchor{2d color rgba}@defun rgba color-code
Translate an RGBA format string COLOR-CODE into a color object.  For
example: #xffffffff will return a color with RGBA values 1, 1, 1, 1.

@end defun

@anchor{2d color rgb}@defun rgb color-code
Translate an RGB format string COLOR-CODE into a color object.  For
example: #xffffff will return a color with RGBA values 1, 1, 1, 1.

@end defun

Commonly used colors are predefined for convenience.

@anchor{2d color white}@defvar white
@end defvar

@anchor{2d color black}@defvar black
@end defvar

@anchor{2d color red}@defvar red
@end defvar

@anchor{2d color green}@defvar green
@end defvar

@anchor{2d color blue}@defvar blue
@end defvar

@anchor{2d color magenta}@defvar magenta
@end defvar