1 files changed, 68 insertions, 0 deletions
diff --git a/src/lib/font_comparator.h b/src/lib/font_comparator.h
new file mode 100644
index 000000000..07ad15b6a
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+++ b/src/lib/font_comparator.h
@@ -0,0 +1,68 @@
+/*
+    Copyright (C) 2023 Carl Hetherington <cth@carlh.net>
+
+    This file is part of DCP-o-matic.
+
+    DCP-o-matic 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.
+
+    DCP-o-matic 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 DCP-o-matic.  If not, see <http://www.gnu.org/licenses/>.
+
+*/
+
+
+#include "dcpomatic_assert.h"
+
+
+/** Comparator to allow dcpomatic::Font::Content to be compared for use in a map */
+struct FontComparator
+{
+	bool operator()(dcpomatic::Font::Content const& a, dcpomatic::Font::Content const& b) const {
+		auto const a_has_file = static_cast<bool>(a.file);
+		auto const b_has_file = static_cast<bool>(b.file);
+		auto const a_has_data = static_cast<bool>(a.data);
+		auto const b_has_data = static_cast<bool>(b.data);
+
+		if (!a_has_file && !a_has_data && !b_has_file && !b_has_data) {
+			/* Neither font has any font data: a == b */
+			return false;
+		} else if (!a_has_file && !a_has_data) {
+			/* Fonts with no data are the "lowest": a < b */
+			return true;
+		} else if (!b_has_file && !b_has_data) {
+			/* ... so here b < a */
+			return false;
+		} else if (a_has_file && !b_has_file) {
+			/* Fonts with file are lower than fonts with data: a < b */
+			return true;
+		} else if (!a_has_file && b_has_file) {
+			/* ... so here b < a */
+			return false;
+		} else if (a_has_file && b_has_file) {
+			/* Compared as "equals" */
+			return a.file->string() < b.file->string();
+		} else if (a_has_data && b_has_data) {
+			/* Compared as "equals" */
+			auto const a_size = a.data->size();
+			auto const b_size = b.data->size();
+			if (a_size != b_size) {
+				return a_size < b_size;
+			}
+			return memcmp(a.data->data(), b.data->data(), a_size) < 0;
+		}
+
+		/* Should never get here */
+		DCPOMATIC_ASSERT(false);
+		return false;
+	};
+};
+
+