--- WorldMap.pm.old     Fri Jun 17 10:33:43 2016
+++ WorldMap.pm Wed Dec 14 12:18:17 2022
@@ -500,7 +500,7 @@
     my ($wtab, $noon, $width, $height) = @_;
     my $illumMap = Imager->new(ysize => $height, xsize => $width);
     $illumMap = $illumMap->convert(preset => 'addalpha');
-    my $day = Imager::Color->new(255, 255, 255, 10);
+    my $day_p = pack 'C4', 255, 255, 255, 10;
     my ($i, $j, $oh, $nl, $nh);

     for ($i = 0; $i < $height; $i++) {
@@ -510,16 +510,13 @@

             $oh = ($nh - $nl) + 1;
             if (($nl + $oh) > $width) {
-                for ($j = $nl; $j < $width; $j++) {
-                    $illumMap->setpixel(x => $j, y => $i, color => $day);
-                }
-                for ($j = 0; $j < ((($nl + $oh) - $width) + 1); $j++) {
-                    $illumMap->setpixel(x => $j, y => $i, color => $day);
-                }
+                $illumMap->setscanline(x => $nl, y => $i,
+                    pixels => $day_p x ($width - $nl));
+                $illumMap->setscanline(x => 0, y => $i,
+                    pixels => $day_p x ($nl + $oh - $width + 1));
             } else {
-                for ($j = $nl; $j < (($nl + $oh) + 1); $j++) {
-                    $illumMap->setpixel(x => $j, y => $i, color => $day);
-                }
+                $illumMap->setscanline(x => $nl, y => $i,
+                    pixels => $day_p x ($oh + 1));
             }
         }
     }