add macOS implementation

macos/include/camutils/Bookmark.h

@@ -0,0 +1,85 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed 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
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef CAMUTILS_BOOKMARK_H
+#define CAMUTILS_BOOKMARK_H
+
+#include <camutils/compiler.h>
+
+#include <math/vec2.h>
+#include <math/vec3.h>
+
+namespace filament {
+namespace camutils {
+
+template <typename FLOAT> class FreeFlightManipulator;
+template <typename FLOAT> class OrbitManipulator;
+template <typename FLOAT> class MapManipulator;
+template <typename FLOAT> class Manipulator;
+
+enum class Mode { ORBIT, MAP, FREE_FLIGHT };
+
+/**
+ * Opaque memento to a viewing position and orientation (e.g. the "home" camera position).
+ *
+ * This little struct is meant to be passed around by value and can be used to track camera
+ * animation between waypoints. In map mode this implements Van Wijk interpolation.
+ *
+ * @see Manipulator::getCurrentBookmark, Manipulator::jumpToBookmark
+ */
+template <typename FLOAT>
+struct CAMUTILS_PUBLIC Bookmark {
+    /**
+     * Interpolates between two bookmarks. The t argument must be between 0 and 1 (inclusive), and
+     * the two endpoints must have the same mode (ORBIT or MAP).
+     */
+    static Bookmark<FLOAT> interpolate(Bookmark<FLOAT> a, Bookmark<FLOAT> b, double t);
+
+    /**
+     * Recommends a duration for animation between two MAP endpoints. The return value is a unitless
+     * multiplier.
+     */
+    static double duration(Bookmark<FLOAT> a, Bookmark<FLOAT> b);
+
+private:
+    struct MapParams {
+        FLOAT extent;
+        filament::math::vec2<FLOAT> center;
+    };
+    struct OrbitParams {
+        FLOAT phi;
+        FLOAT theta;
+        FLOAT distance;
+        filament::math::vec3<FLOAT> pivot;
+    };
+    struct FlightParams {
+        FLOAT pitch;
+        FLOAT yaw;
+        filament::math::vec3<FLOAT> position;
+    };
+    Mode mode;
+    MapParams map;
+    OrbitParams orbit;
+    FlightParams flight;
+    friend class FreeFlightManipulator<FLOAT>;
+    friend class OrbitManipulator<FLOAT>;
+    friend class MapManipulator<FLOAT>;
+};
+
+} // namespace camutils
+} // namespace filament
+
+#endif // CAMUTILS_BOOKMARK_H