1 files changed, 43 insertions, 0 deletions
diff --git a/include/basegfx/utils/lerp.hxx b/include/basegfx/utils/lerp.hxx
new file mode 100644
index 000000000..e02b3b0fa
--- /dev/null
+++ b/include/basegfx/utils/lerp.hxx
@@ -0,0 +1,43 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * This file incorporates work covered by the following license notice:
+ *
+ *   Licensed to the Apache Software Foundation (ASF) under one or more
+ *   contributor license agreements. See the NOTICE file distributed
+ *   with this work for additional information regarding copyright
+ *   ownership. The ASF licenses this file to you under the Apache
+ *   License, Version 2.0 (the "License"); you may not use this file
+ *   except in compliance with the License. You may obtain a copy of
+ *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
+ */
+
+#pragma once
+
+namespace basegfx::utils
+{
+    /** Generic linear interpolator
+
+        @tpl ValueType
+        Must have operator+ and operator* defined, and should
+        have value semantics.
+
+        @param t
+        As usual, t must be in the [0,1] range
+    */
+    template< typename ValueType > ValueType lerp( const ValueType&     rFrom,
+                                                   const ValueType&     rTo,
+                                                   double               t )
+    {
+        // This is only to suppress a double->int warning. All other
+        // types should be okay here.
+        return static_cast<ValueType>( (1.0-t)*rFrom + t*rTo );
+    }
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */