From 6a129b2cd281947cfc8c0f7168c9f7d3c949d33e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Vladim=C3=ADr=20Vondru=C5=A1?= <mosra@centrum.cz>
Date: Wed, 5 Apr 2023 18:47:05 +0200
Subject: [PATCH] Animation: add TrackViewStorage::interpolator().

It was the last remaining field that wasn't queryable from this
type-erased base.
---
 doc/changelog.dox                           |  3 +++
 src/Magnum/Animation/Test/TrackViewTest.cpp |  1 +
 src/Magnum/Animation/Track.h                | 12 ++++++++++++
 3 files changed, 16 insertions(+)

diff --git a/doc/changelog.dox b/doc/changelog.dox
index 42b37a40d..13941357a 100644
--- a/doc/changelog.dox
+++ b/doc/changelog.dox
@@ -438,6 +438,9 @@ See also:
     @ref Animation::BasicEasing "easing functions" implemented with
     double precision, in addition to single-precision @ref Animation::Easing,
     and similar in spirit to the @ref Constants and @ref Constantsd typedefs.
+-   Added @ref Animation::TrackViewStorage::interpolator() for getting a
+    type-erased interpolator pointer without having to cast to a concrete
+    @ref Animation::TrackView type
 
 @subsubsection changelog-latest-changes-debugtools DebugTools library
 
diff --git a/src/Magnum/Animation/Test/TrackViewTest.cpp b/src/Magnum/Animation/Test/TrackViewTest.cpp
index 0e5206385..dad64bae8 100644
--- a/src/Magnum/Animation/Test/TrackViewTest.cpp
+++ b/src/Magnum/Animation/Test/TrackViewTest.cpp
@@ -569,6 +569,7 @@ void TrackViewTest::constructCopyStorage() {
         Extrapolation::Extrapolated, Extrapolation::DefaultConstructed};
 
     const TrackViewStorage<Float> b = a;
+    CORRADE_COMPARE(b.interpolator(), reinterpret_cast<void(*)()>(customLerp));
     CORRADE_COMPARE(b.keys().size(), 2);
     CORRADE_COMPARE(b.values().size(), 2);
     CORRADE_COMPARE(Containers::arrayCast<Float>(b.keys())[1], 5.0f);
diff --git a/src/Magnum/Animation/Track.h b/src/Magnum/Animation/Track.h
index 4096e49ce..a9f9f679c 100644
--- a/src/Magnum/Animation/Track.h
+++ b/src/Magnum/Animation/Track.h
@@ -482,6 +482,18 @@ template<class K> class TrackViewStorage {
             return _keys.size();
         }
 
+        /**
+         * @brief Type-erased interpolation function
+         * @m_since_latest
+         *
+         * Has to be cast to a type corresponding to the value type before use.
+         * Use @ref TrackView and @ref TrackView::interpolator() to get the
+         * interpolator function in a concrete type.
+         */
+        void(*interpolator() const)() {
+            return _interpolator;
+        }
+
         /**
          * @brief Key data
          *