3 RGB, readcolmap, writecolmap \- access display color map
15 void readcolmap(Display *d, RGB *map)
18 void writecolmap(Display *d, RGB *map)
21 Colors are described by their red, green, and blue
22 light intensities, in an
36 Black is represented by zero in all three positions and
40 value in all three positions.
42 A color map is an array of
45 .if t \x'-.8n'2\u\s-1\fIdepth\fP\s+1\d,
47 giving the colors for pixels 0, 1, 2, etc.
48 On displays with color mapped pixels
49 (typically 8-bit displays),
50 one retrieves RGB color information
51 by treating the pixel data as an offset
55 reads the color map for the given display into the provided
57 which must have enough space to hold it.
59 associates the given color map with the given display, if possible.
60 (The hardware might not allow this.)
61 Both return 0 on success, or \-1 on error, setting
64 Changing the hardware color map does not change
65 the color map used by the
67 operator to convert between
68 mapped and true color or greyscale images,