From 1d19687f3e89d4b5de10830a6210dd6c7e72225c Mon Sep 17 00:00:00 2001
From: Ed J <mohawk2@users.noreply.github.com>
Date: Mon, 1 Jul 2024 23:38:35 +0100
Subject: [PATCH] extract out image-regularising func

---
 lib/PDL/Graphics/Gnuplot.pm | 41 +++++++++++++++++++------------------
 t/plot.t                    |  4 ++++
 2 files changed, 25 insertions(+), 20 deletions(-)

diff --git a/lib/PDL/Graphics/Gnuplot.pm b/lib/PDL/Graphics/Gnuplot.pm
index 13b32e5..bf1434f 100644
--- a/lib/PDL/Graphics/Gnuplot.pm
+++ b/lib/PDL/Graphics/Gnuplot.pm
@@ -3534,26 +3534,10 @@ EOF
     if ( $cdims==2 ) {
       if ($chunk{options}{with}[0] eq 'image') {
         my $dp = $dataPiddles[-1];
-        if ($dp->ndims==3) {
-          if ($dp->dim(1) >= 5) {
-            if ($dp->dim(0) ==3 && $dp->dim(1) >= 5 && $dp->dim(2) >= 5) {
-              $chunk{options}{with}[0] = 'rgbimage';
-              pop @dataPiddles;
-              push @dataPiddles,$dp->using(0,1,2);
-            } elsif ($dp->dim(2)==3 && $dp->dim(1)>=5 && $dp->dim(0) >= 5) {
-              $chunk{options}{with}[0] = 'rgbimage';
-              pop @dataPiddles;
-              push @dataPiddles,$dp->mv(2,0)->using(0,1,2);
-            } elsif ($dp->dim(0)==4 && $dp->dim(1) >= 5 && $dp->dim(2) >= 5) {
-              $chunk{options}{with}[0] = 'rgbalpha';
-              pop @dataPiddles;
-              push @dataPiddles,$dp->using(0,1,2,3);
-            } elsif ($dp->dim(2)==4 && $dp->dim(0) >= 5 && $dp->dim(1) >= 5) {
-              $chunk{options}{with}[0] = 'rgbalpha';
-              pop @dataPiddles;
-              push @dataPiddles, $dp->mv(2,0)->using(0,1,2,3);
-            }
-          }
+        if ($dp->ndims==3 and $dp->dim(1) >= 5) {
+          my ($with, @ndarrays) = _regularise_image($dp);
+          $chunk{options}{with}[0] = $with;
+          splice @dataPiddles, -1, 1, @ndarrays;
         }
       }
     }
@@ -3677,6 +3661,23 @@ FOO
   return (\@chunks, $Ncurves);
 }
 
+sub _regularise_image {
+  my ($dp) = @_;
+  my $with = $dp->dim(0) == 3 || $dp->dim(2) == 3 ? 'rgbimage' :
+    $dp->dim(0) == 4 || $dp->dim(2) == 4 ? 'rgbalpha' : undef;
+  my @ndarrays;
+  if ($dp->dim(0) == 3 && $dp->dim(2) >= 5) {
+    @ndarrays = $dp->using(0..2);
+  } elsif ($dp->dim(2) == 3 && $dp->dim(0) >= 5) {
+    @ndarrays = $dp->mv(2,0)->using(0..2);
+  } elsif ($dp->dim(0) == 4 && $dp->dim(2) >= 5) {
+    @ndarrays = $dp->using(0..3);
+  } elsif ($dp->dim(2) == 4 && $dp->dim(0) >= 5) {
+    @ndarrays = $dp->mv(2,0)->using(0..3);
+  }
+  ($with, @ndarrays);
+}
+
 ##########
 # matchDims: nested sub inside plot - kludge up thread style matching across
 # the data arguments to a given chunk.
diff --git a/t/plot.t b/t/plot.t
index c8d6a52..7a77c05 100644
--- a/t/plot.t
+++ b/t/plot.t
@@ -150,6 +150,10 @@ unlink($testoutput) or warn "\$!: $! for '$testoutput'";
   my $r9 = rvals(9,9);
   eval {$w->plot({colorbox => 1},{with => 'image'},$r9->xvals,$r9->yvals,$r9)};
   is($@, '', "colorbox succeeded");
+  for my $dims ([3,9,9],[4,9,9],[9,9,3],[9,9,4]) {
+    eval {$w->plot({colorbox => 1},{with => 'image'},$r9->xvals,$r9->yvals,rvals(@$dims))};
+    is($@, '', "regularising image succeeded (@$dims)");
+  }
 }
 
 {