1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
|
##############################################################################
# The Faq-O-Matic is Copyright 1997 by Jon Howell, all rights reserved. #
# #
# This program is free software; you can redistribute it and/or #
# modify it under the terms of the GNU General Public License #
# as published by the Free Software Foundation; either version 2 #
# of the License, or (at your option) any later version. #
# #
# This program is distributed in the hope that it will be useful, #
# but WITHOUT ANY WARRANTY; without even the implied warranty of #
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the #
# GNU General Public License for more details. #
# #
# You should have received a copy of the GNU General Public License #
# along with this program; if not, write to the Free Software #
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.#
# #
# Jon Howell can be contacted at: #
# 6211 Sudikoff Lab, Dartmouth College #
# Hanover, NH 03755-3510 #
# jonh@cs.dartmouth.edu #
# #
# An electronic copy of the GPL is available at: #
# http://www.gnu.org/copyleft/gpl.html #
# #
##############################################################################
use strict;
package FAQ::OMatic::ColorPicker;
sub findRGB {
my $horizFrac = shift; # fraction of distance along horizontal of image
my $vertFrac = shift;
my $f16 = 1/6;
my $f26 = 2/6;
my $f36 = 3/6;
my $f46 = 4/6;
my $f56 = 5/6;
my $f66 = 1;
my ($hue, $red, $green, $blue);
$hue = $horizFrac;
if ($hue<$f16) {
$red = 1;
$green = $hue*6;
$blue = 0;
} elsif ($hue<$f26) {
$red = ($f26-$hue)*6;
$green = 1;
$blue = 0;
} elsif ($hue<$f36) {
$red = 0;
$green = 1;
$blue = 1-($f36-$hue)*6;
} elsif ($hue<$f46) {
$red = 0;
$green = ($f46-$hue)*6;
$blue = 1;
} elsif ($hue<$f56) {
$red = 1-($f56-$hue)*6;
$green = 0;
$blue = 1;
} else { # $hue<$f66
$red = 1;
$green = 0;
$blue = ($f66-$hue)*6;
}
if ($vertFrac<0.5) { # blend toward white
my $trans = 2*$vertFrac; # at middle, $trans = 1
$red = $trans*$red + (1-$trans)*1;
$green = $trans*$green + (1-$trans)*1;
$blue = $trans*$blue + (1-$trans)*1;
} else {
my $trans = 2*(1-$vertFrac); # at middle, $trans = 1
$red = $trans*$red + 0;
$green = $trans*$green + 0;
$blue = $trans*$blue + 0;
}
return ($red,$green,$blue);
}
1;
|
