Change snapping to be screen space coordinate based

osu.Game/Rulesets/Edit/IPositionSnapProvider.cs

@@ -0,0 +1,58 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using osuTK;
+
+namespace osu.Game.Rulesets.Edit
+{
+    public interface IPositionSnapProvider
+    {
+        /// <summary>
+        /// Given a position (local to the provider), find a valid time snap
+        /// </summary>
+        /// <param name="position">The local position to be snapped.</param>
+        /// <returns>The time and position post-snapping.</returns>
+        (Vector2 position, double time) SnapPositionToValidTime(Vector2 position);
+
+        (Vector2 position, double time) SnapScreenSpacePositionToValidTime(Vector2 screenSpacePosition);
+
+        /// <summary>
+        /// Retrieves the distance between two points within a timing point that are one beat length apart.
+        /// </summary>
+        /// <param name="referenceTime">The time of the timing point.</param>
+        /// <returns>The distance between two points residing in the timing point that are one beat length apart.</returns>
+        float GetBeatSnapDistanceAt(double referenceTime);
+
+        /// <summary>
+        /// Converts a duration to a distance.
+        /// </summary>
+        /// <param name="referenceTime">The time of the timing point which <paramref name="duration"/> resides in.</param>
+        /// <param name="duration">The duration to convert.</param>
+        /// <returns>A value that represents <paramref name="duration"/> as a distance in the timing point.</returns>
+        float DurationToDistance(double referenceTime, double duration);
+
+        /// <summary>
+        /// Converts a distance to a duration.
+        /// </summary>
+        /// <param name="referenceTime">The time of the timing point which <paramref name="distance"/> resides in.</param>
+        /// <param name="distance">The distance to convert.</param>
+        /// <returns>A value that represents <paramref name="distance"/> as a duration in the timing point.</returns>
+        double DistanceToDuration(double referenceTime, float distance);
+
+        /// <summary>
+        /// Converts a distance to a snapped duration.
+        /// </summary>
+        /// <param name="referenceTime">The time of the timing point which <paramref name="distance"/> resides in.</param>
+        /// <param name="distance">The distance to convert.</param>
+        /// <returns>A value that represents <paramref name="distance"/> as a duration snapped to the closest beat of the timing point.</returns>
+        double GetSnappedDurationFromDistance(double referenceTime, float distance);
+
+        /// <summary>
+        /// Converts an unsnapped distance to a snapped distance.
+        /// </summary>
+        /// <param name="referenceTime">The time of the timing point which <paramref name="distance"/> resides in.</param>
+        /// <param name="distance">The distance to convert.</param>
+        /// <returns>A value that represents <paramref name="distance"/> snapped to the closest beat of the timing point.</returns>
+        float GetSnappedDistanceFromDistance(double referenceTime, float distance);
+    }
+}