termcol: use rgb index instead of value for hsv calculation

Final colour value may not map well to table position; prefer original
coordinates to prevent outrageous transforms from breaking grouping
at the cost of adjusting for cumulative exceptions.

diff --git a/termcol.plp b/termcol.plp
index a93069853979c9c22a12e91969f72d2802cc78c2..fd2bc9bf0107d36fd2f5c3ff21ef6c3a967c39b3 100644 (file)
--- a/termcol.plp
+++ b/termcol.plp
@@ -243,7 +243,7 @@ print coltable_hsv(4,
 sub coltable_hsv {
        my ($dim, $rgbval, $greyramp) = @_;
 
 sub coltable_hsv {
        my ($dim, $rgbval, $greyramp) = @_;
 

-       my $hmax = ($dim + $dim - 1) * 2 + ($dim - 2) * 2 + 3;
+       my $hmax = 2 * $dim * 3;  # each face of the rgb cube

        my $vmax = $dim - 1;
        my $smax = $dim - 1;
 
        my $vmax = $dim - 1;
        my $smax = $dim - 1;
 


@@ -255,21 +255,21 @@ sub coltable_hsv {
                for my $g (0 .. $dim - 1) {
                        for my $b (0 .. $dim - 1) {
                                my $index = $r*$dim*$dim + $g*$dim + $b + $offset;
                for my $g (0 .. $dim - 1) {
                        for my $b (0 .. $dim - 1) {
                                my $index = $r*$dim*$dim + $g*$dim + $b + $offset;

-                               my @rgb = map { $rgbval->($_) } $r, $g, $b;
+                               my @rgb = ($r, $g, $b);

 
                                my $h = Shiar_Sheet::Colour->new(@rgb)->hue * $hmax;
 
                                my $h = Shiar_Sheet::Colour->new(@rgb)->hue * $hmax;

-                               my $v = int(max(@rgb) / 255 * $vmax);
-                               my $s = abs(min(@rgb) - max(@rgb)) / 255 * $smax;
+                               my $v = max(@rgb);
+                               my $s = abs(min(@rgb) - max(@rgb));

 
                                if (!$s) {
 
                                if (!$s) {

-                                       $greymap{$index} = $rgb[0];
+                                       $greymap{$index} = $rgbval->($r);

                                        next;
                                }
 
                                $v = $vmax - $v;
                                $s = $smax - $s - $v;
 
                                        next;
                                }
 
                                $v = $vmax - $v;
                                $s = $smax - $s - $v;
 

-                               $colmap[$s][$v][$h] = [$index, @rgb];
+                               $colmap[$s][$v][$h] = [$index, map { $rgbval->($_) } @rgb];

                        }
                }
        }
                        }
                }
        }