core: rename mbgl directories to mln (#4511)

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

include/mln/map/camera.hpp

@@ -0,0 +1,180 @@
+#pragma once
+
+#include <mln/util/chrono.hpp>
+#include <mln/util/geo.hpp>
+#include <mln/util/unitbezier.hpp>
+#include <mln/util/vectors.hpp>
+
+#include <optional>
+
+#include <functional>
+
+namespace mln {
+
+/** Various options for describing the viewpoint of a map. All fields are
+    optional.
+    Anchor and center points are mutually exclusive, with preference for the
+    center point when both are set.
+    */
+struct CameraOptions {
+    CameraOptions& withCenter(const std::optional<LatLng>& o) {
+        center = o;
+        return *this;
+    }
+    CameraOptions& withCenterAltitude(const std::optional<double>& o) {
+        centerAltitude = o;
+        return *this;
+    }
+    CameraOptions& withPadding(const std::optional<EdgeInsets>& p) {
+        padding = p;
+        return *this;
+    }
+    CameraOptions& withAnchor(const std::optional<ScreenCoordinate>& o) {
+        anchor = o;
+        return *this;
+    }
+    CameraOptions& withZoom(const std::optional<double>& o) {
+        zoom = o;
+        return *this;
+    }
+    CameraOptions& withBearing(const std::optional<double>& o) {
+        bearing = o;
+        return *this;
+    }
+    CameraOptions& withPitch(const std::optional<double>& o) {
+        pitch = o;
+        return *this;
+    }
+    CameraOptions& withRoll(const std::optional<double>& o) {
+        roll = o;
+        return *this;
+    }
+    CameraOptions& withFov(const std::optional<double>& o) {
+        fov = o;
+        return *this;
+    }
+
+    /** Coordinate at the center of the map. */
+    std::optional<LatLng> center;
+
+    /** Altitude of the center of the map, in meters above sea level. */
+    std::optional<double> centerAltitude;
+
+    /** Padding around the interior of the view that affects the frame of
+        reference for `center`. */
+    std::optional<EdgeInsets> padding;
+
+    /** Point of reference for `zoom` and `angle`, assuming an origin at the
+        top-left corner of the view. */
+    std::optional<ScreenCoordinate> anchor;
+
+    /** Zero-based zoom level. Constrained to the minimum and maximum zoom
+        levels. */
+    std::optional<double> zoom;
+
+    /** Bearing, measured in degrees from true north. Wrapped to [0, 360). */
+    std::optional<double> bearing;
+
+    /** Pitch toward the horizon measured in degrees , with 0 deg resulting in a
+        two-dimensional map. */
+    std::optional<double> pitch;
+
+    /** Camera roll, measured in degrees. */
+    std::optional<double> roll;
+
+    /** Camera vertical field of view, measured in degrees. */
+    std::optional<double> fov;
+};
+
+constexpr bool operator==(const CameraOptions& a, const CameraOptions& b) {
+    return a.center == b.center && a.padding == b.padding && a.anchor == b.anchor && a.zoom == b.zoom &&
+           a.bearing == b.bearing && a.pitch == b.pitch && a.roll == b.roll && a.fov == b.fov &&
+           a.centerAltitude == b.centerAltitude;
+}
+
+constexpr bool operator!=(const CameraOptions& a, const CameraOptions& b) {
+    return !(a == b);
+}
+
+/** Various options for describing a transition between viewpoints with
+    animation. All fields are optional; the default values depend on how this
+    struct is used. */
+struct AnimationOptions {
+    /** Time to animate to the viewpoint defined herein. */
+    std::optional<Duration> duration;
+
+    /** Average velocity of a flyTo() transition, measured in screenfuls per
+        second, assuming a linear timing curve.
+
+        A <i>screenful</i> is the visible span in pixels. It does not correspond
+        to a fixed physical distance but rather varies by zoom level. */
+    std::optional<double> velocity;
+
+    /** Zero-based zoom level at the peak of the flyTo() transition’s flight
+        path. */
+    std::optional<double> minZoom;
+
+    /** The easing timing curve of the transition. */
+    std::optional<mln::util::UnitBezier> easing;
+
+    /** A function that is called on each frame of the transition, just before a
+        screen update, except on the last frame. The first parameter indicates
+        the elapsed time as a percentage of the duration. */
+    std::function<void(double)> transitionFrameFn;
+
+    /** A function that is called once on the last frame of the transition, just
+        before the corresponding screen update. */
+    std::function<void()> transitionFinishFn;
+
+    /** Creates an animation with no options specified. */
+    AnimationOptions() = default;
+
+    /** Creates an animation with the specified duration. */
+    AnimationOptions(Duration d)
+        : duration(d) {}
+};
+
+/** Various options for accessing physical properties of the underlying camera
+   entity. A direct access to these properties allows more flexible and precise
+   controlling of the camera while also being fully compatible and
+   interchangeable with CameraOptions. All fields are optional. */
+struct FreeCameraOptions {
+    /** Position of the camera in slightly modified web mercator coordinates
+        - The size of 1 unit is the width of the projected world instead of the
+       "mercator meter". Coordinate [0, 0, 0] is the north-west corner and [1,
+       1, 0] is the south-east corner.
+        - Z coordinate is conformal and must respect minimum and maximum zoom
+       values.
+        - Zoom is automatically computed from the altitude (z)
+    */
+    std::optional<vec3> position = std::nullopt;
+
+    /** Orientation of the camera represented as a unit quaternion [x, y, z, w].
+        The default pose of the camera is such that the forward vector is
+       looking up the -Z axis and the up vector is aligned with north
+       orientation of the map: forward: [0, 0, -1] up:      [0, -1, 0] right [1,
+       0, 0]
+
+        Orientation can be set freely but certain constraints still apply
+         - Pitch has an upper limit */
+    std::optional<vec4> orientation = std::nullopt;
+
+    /** Helper function for setting the mercator position as Lat&Lng and altitude in meters */
+    void setLocation(const LatLngAltitude& location) noexcept;
+
+    /** Helper function for converting mercator position into Lat&Lng and
+       altitude in meters. This function fails to return a value if `position`
+       is invalid or is not set */
+    std::optional<LatLngAltitude> getLocation() const noexcept;
+
+    /** Helper function for setting orientation of the camera by defining a
+       focus point on the map. Up vector is required in certain scenarios where
+       bearing can't be deduced from the viewing direction */
+    void lookAtPoint(const LatLng& location, const std::optional<vec3>& upVector = std::nullopt) noexcept;
+
+    /** Helper function for setting the orientation of the camera as a roll, pitch, and
+       a bearing. All values are in degrees */
+    void setRollPitchBearing(double roll, double pitch, double bearing) noexcept;
+};
+
+} // namespace mln