Perl Graphics Programming

Colors and Fonts in GD::Graph

All GD::Graph color routines that take colorname as a parameter expect a string with the name of a valid color. GD::Graph comes bundled with the GD::Graph::colour^[5] package, which provides some methods for organizing and manipulating color name strings. GD::Graph has 29 predefined color name strings (see Table 4-1). The module is normally used simply to provide access to the standard color names, but it also provides methods for converting between color representations. You can define additional strings in an external file by using the read_rgb( ) method.

Table 4-1. The 29 predefined GD::Graph color names and their hex representations

Color name string	Red	Green	Blue	Hex representation
white	255	255	255	#FFFFFF
lyellow	255	255	0	#FFFF00
gold	255	215	0	#FFD700
cyan	0	255	255	#00FFFF
pink	255	183	193	#FFB7C1
lgray	191	191	191	#BFBFBF
lorange	255	183	0	#FFB700
lbrown	210	180	140	#D2B48C
lgreen	0	255	0	#00FF00
yellow	191	191	0	#BFBF00
orange	255	127	0	#FF7F00
dpink	255	105	180	#FF69B4
green	0	191	0	#00BF00
marine	127	127	255	#7F7FFF
gray	127	127	127	#7F7F7F
dyellow	127	127	0	#7F7F00
dgreen	0	127	0	#007F00
lpurple	255	0	255	#FF00FF
dbrown	165	42	42	#A52A2A
dgray	63	63	63	#3F3F3F
purple	191	0	191	#BF00BF
lred	255	0	0	#FF0000
red	191	0	0	#BF0000
dpurple	127	0	127	#7F007F
dred	127	0	0	#7F0000
lblue	0	0	255	#0000FF
blue	0	0	191	#0000BF
dblue	0	0	127	#00007F
black	0	0	0	#000000

Call the use method with the :colours tag to import the functions _rgb( ), _hue( ), and _luminance( ). The :lists tag imports only colour_list( ) and sorted_colour_list( ), and the :files tag imports the read_rgb( ) function.

The various ...