From 11ddce3271ecafca9e966b462aafe308fd134f29 Mon Sep 17 00:00:00 2001
From: Mischa POSLAWSKY <perl@shiar.org>
Date: Sun, 15 Aug 2021 04:32:42 +0200
Subject: [PATCH] word/edit: experimental thumb crop calculations

Determine dimensions before imagemagick to try out different formulas.
---
 Shiar_Sheet/ImagePrep.pm | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/Shiar_Sheet/ImagePrep.pm b/Shiar_Sheet/ImagePrep.pm
index 0c7489b..6457a83 100644
--- a/Shiar_Sheet/ImagePrep.pm
+++ b/Shiar_Sheet/ImagePrep.pm
@@ -23,13 +23,25 @@ sub download {
 		or die "Download from <q>$download</q> failed: ".$status->status_line."\n";
 }
 
+sub dimensions {
+	my ($imgpath) = @_;
+	require IPC::Run;
+	IPC::Run::run(
+		[identify => -format => '%w %h', $$imgpath],
+		'<' => \undef, '>&' => \my $xy
+	) or die ["Image dimensions could not be determined.", $$imgpath];
+	return split /\s/, $xy, 3;
+}
+
 sub convert {
 	my ($imgpath, $thumbpath, $cmds) = @_;
 	if (not -e $$imgpath) {
 		return !-e $thumbpath || unlink $thumbpath;
 	}
 
+	#my ($w, $h) = $imgpath->dimensions;
 	my $xyres = 0 ? '600x400' : '300x200'; # cover
+	my $aspect = 3/2;
 	my @cmds = @{ $cmds // [] };
 	if (my ($cmdarg) = grep { $cmds[$_] eq '-area' } 0 .. $#cmds) {
 		# replace option by permillage crop
@@ -37,9 +49,13 @@ sub convert {
 		$dim[$_] ||= 1 for 2, 3; # optional end
 		push @dim, $dim[2 + $_] - $dim[$_] for 0, 1; # add width, height
 		splice @cmds, $cmdarg, 2, (
+			#crop="%[fx:floor(w*$ratio)]x%[fx:floor(h*$ratio)]"
+			#crop="$crop+%[fx:ceil((w-w*$ratio)/2)]+%[fx:ceil((h-h*$ratio)/2)]"
 			-set => 'option:distort:viewport' => sprintf(
 				'%%[fx:%s]x%%[fx:%s]+%%[fx:%s]+%%[fx:%s]',
 				"w*$dim[4]", "h*$dim[5]", # width x height
+				#"max(w*$dim[4], h*$dim[5]*$aspect)", # width
+				#"max(h*$dim[5], w*$dim[4]/$aspect)", # height
 				"w*$dim[0]", "h*$dim[1]", # x+y offset
 			),
 			-distort => SRT => 0, # noop transform to apply viewport
-- 
2.30.0