From 25101ecd2cfaf0634a6c4f65b1933d770f53c2a5 Mon Sep 17 00:00:00 2001
From: smoogipoo <smoogipoo@smgi.me>
Date: Tue, 13 Nov 2018 14:13:29 +0900
Subject: [PATCH] Snap placement blueprint to columns

---
 .../Blueprints/ManiaPlacementBlueprint.cs     | 32 +++++++++++++++++++
 .../Edit/Blueprints/NotePlacementBlueprint.cs |  7 ++--
 osu.Game.Rulesets.Mania/UI/Column.cs          |  5 +++
 3 files changed, 41 insertions(+), 3 deletions(-)

diff --git a/osu.Game.Rulesets.Mania/Edit/Blueprints/ManiaPlacementBlueprint.cs b/osu.Game.Rulesets.Mania/Edit/Blueprints/ManiaPlacementBlueprint.cs
index 305c92671f..bfa07d0014 100644
--- a/osu.Game.Rulesets.Mania/Edit/Blueprints/ManiaPlacementBlueprint.cs
+++ b/osu.Game.Rulesets.Mania/Edit/Blueprints/ManiaPlacementBlueprint.cs
@@ -3,6 +3,8 @@
 
 using osu.Framework.Allocation;
 using osu.Framework.Graphics;
+using osu.Framework.Input.Events;
+using osu.Framework.Threading;
 using osu.Game.Rulesets.Edit;
 using osu.Game.Rulesets.Mania.Objects;
 using osu.Game.Rulesets.Mania.UI;
@@ -16,6 +18,11 @@ namespace osu.Game.Rulesets.Mania.Edit.Blueprints
     {
         protected new T HitObject => (T)base.HitObject;
 
+        /// <summary>
+        /// The current mouse position, snapped to the closest column.
+        /// </summary>
+        protected Vector2 SnappedMousePosition { get; private set; }
+
         [Resolved]
         private IManiaHitObjectComposer composer { get; set; }
 
@@ -28,6 +35,31 @@ namespace osu.Game.Rulesets.Mania.Edit.Blueprints
             RelativeSizeAxes = Axes.None;
         }
 
+        protected override bool OnMouseMove(MouseMoveEvent e)
+        {
+            updateSnappedPosition(e);
+            return true;
+        }
+
+        private ScheduledDelegate scheduledSnappedPositionUpdate;
+
+        private void updateSnappedPosition(MouseMoveEvent e)
+        {
+            scheduledSnappedPositionUpdate?.Cancel();
+            scheduledSnappedPositionUpdate = Schedule(() =>
+            {
+                Column column = ColumnAt(e.ScreenSpaceMousePosition);
+                if (column == null)
+                    SnappedMousePosition = e.MousePosition;
+                else
+                {
+                    // Snap to the column
+                    var parentPos = Parent.ToLocalSpace(column.ToScreenSpace(new Vector2(column.DrawWidth / 2, 0)));
+                    SnappedMousePosition = new Vector2(parentPos.X, e.MousePosition.Y);
+                }
+            });
+        }
+
         protected double TimeAt(Vector2 screenSpacePosition)
         {
             var column = ColumnAt(screenSpacePosition);
diff --git a/osu.Game.Rulesets.Mania/Edit/Blueprints/NotePlacementBlueprint.cs b/osu.Game.Rulesets.Mania/Edit/Blueprints/NotePlacementBlueprint.cs
index 1549b0ae45..0a904d962e 100644
--- a/osu.Game.Rulesets.Mania/Edit/Blueprints/NotePlacementBlueprint.cs
+++ b/osu.Game.Rulesets.Mania/Edit/Blueprints/NotePlacementBlueprint.cs
@@ -22,10 +22,11 @@ namespace osu.Game.Rulesets.Mania.Edit.Blueprints
             InternalChild = new EditNotePiece { RelativeSizeAxes = Axes.X };
         }
 
-        protected override bool OnMouseMove(MouseMoveEvent e)
+        protected override void Update()
         {
-            Position = e.MousePosition;
-            return true;
+            base.Update();
+
+            Position = SnappedMousePosition;
         }
 
         protected override bool OnClick(ClickEvent e)
diff --git a/osu.Game.Rulesets.Mania/UI/Column.cs b/osu.Game.Rulesets.Mania/UI/Column.cs
index da3ee8dddf..4c1929f182 100644
--- a/osu.Game.Rulesets.Mania/UI/Column.cs
+++ b/osu.Game.Rulesets.Mania/UI/Column.cs
@@ -13,6 +13,7 @@ using osu.Framework.Input.Bindings;
 using osu.Game.Rulesets.Judgements;
 using osu.Game.Rulesets.Mania.UI.Components;
 using osu.Game.Rulesets.UI.Scrolling;
+using OpenTK;
 
 namespace osu.Game.Rulesets.Mania.UI
 {
@@ -172,5 +173,9 @@ namespace osu.Game.Rulesets.Mania.UI
         }
 
         public bool OnReleased(ManiaAction action) => false;
+
+        public override bool ReceivePositionalInputAt(Vector2 screenSpacePos)
+            // This probably shouldn't exist as is, but the columns in the stage are separated by a 1px border
+            => DrawRectangle.Inflate(new Vector2(1, 0)).Contains(ToLocalSpace(screenSpacePos));
     }
 }