fix cursor position incorrectly handling UI mode (#741)

docs/release-notes.md

@@ -16,6 +16,7 @@
 * For modders:
   * When a mod is blocked by SMAPI's internal compatibility list, the `TRACE` messages while loading it now indicates that and specifies the reason.
   * Message data from the `ModMessageReceived` event now uses the same serializer settings as the rest of SMAPI. This mainly adds support for sending crossplatform `Color`, `Point`, `Vector2`, `Rectangle`, and `SemanticVersion` fields through network messages.
+  * Fixed how the input API handles UI scaling. This mainly affects `ICursorPosition` values returned by the API; see [the wiki docs](https://stardewvalleywiki.com/Modding:Modder_Guide/APIs/Input#ICursorPosition) for how to account for UI scaling.
 
 ## 3.8.1
 Released 26 December 2020 for Stardew Valley 1.5.1 or later.

src/SMAPI/Framework/CursorPosition.cs

@@ -1,4 +1,5 @@
 using Microsoft.Xna.Framework;
+using StardewValley;
 
 namespace StardewModdingAPI.Framework
 {
@@ -25,8 +26,8 @@ namespace StardewModdingAPI.Framework
         ** Public methods
         *********/
         /// <summary>Construct an instance.</summary>
-        /// <param name="absolutePixels">The pixel position relative to the top-left corner of the in-game map, adjusted for pixel zoom.</param>
+        /// <param name="absolutePixels">The pixel position relative to the top-left corner of the in-game map, adjusted for zoom but not UI scaling.</param>
-        /// <param name="screenPixels">The pixel position relative to the top-left corner of the visible screen, adjusted for pixel zoom.</param>
+        /// <param name="screenPixels">The pixel position relative to the top-left corner of the visible screen, adjusted for zoom but not UI scaling.</param>
         /// <param name="tile">The tile position relative to the top-left corner of the map.</param>
         /// <param name="grabTile">The tile position that the game considers under the cursor for purposes of clicking actions.</param>
         public CursorPosition(Vector2 absolutePixels, Vector2 screenPixels, Vector2 tile, Vector2 grabTile)
@@ -42,5 +43,21 @@ namespace StardewModdingAPI.Framework
         {
             return other != null && this.AbsolutePixels == other.AbsolutePixels;
         }
+
+        /// <inheritdoc />
+        public Vector2 GetScaledAbsolutePixels()
+        {
+            return Game1.uiMode
+                ? Utility.ModifyCoordinatesForUIScale(this.AbsolutePixels)
+                : this.AbsolutePixels;
+        }
+
+        /// <inheritdoc />
+        public Vector2 GetScaledScreenPixels()
+        {
+            return Game1.uiMode
+                ? Utility.ModifyCoordinatesForUIScale(this.ScreenPixels)
+                : this.ScreenPixels;
+        }
     }
 }

src/SMAPI/Framework/Input/SInputState.cs

@@ -63,18 +63,16 @@ namespace StardewModdingAPI.Framework.Input
             base.Update();
 
             // update SMAPI extended data
+            // note: Stardew Valley is *not* in UI mode when this code runs
             try
             {
-                float scale = Game1.options.uiScale;
+                float zoomMultiplier = (1f / Game1.options.zoomLevel);
 
                 // get real values
                 var controller = new GamePadStateBuilder(base.GetGamePadState());
                 var keyboard = new KeyboardStateBuilder(base.GetKeyboardState());
                 var mouse = new MouseStateBuilder(base.GetMouseState());
-                Vector2 cursorAbsolutePos = new Vector2(
+                Vector2 cursorAbsolutePos = new Vector2((mouse.X * zoomMultiplier) + Game1.viewport.X, (mouse.Y * zoomMultiplier) + Game1.viewport.Y);
-                    x: (mouse.X / scale) + Game1.uiViewport.X,
-                    y: (mouse.Y / scale) + Game1.uiViewport.Y
-                );
                 Vector2? playerTilePos = Context.IsPlayerFree ? Game1.player.getTileLocation() : (Vector2?)null;
                 HashSet<SButton> reallyDown = new HashSet<SButton>(this.GetPressedButtons(keyboard, mouse, controller));
 
@@ -109,7 +107,7 @@ namespace StardewModdingAPI.Framework.Input
                 if (cursorAbsolutePos != this.CursorPositionImpl?.AbsolutePixels || playerTilePos != this.LastPlayerTile)
                 {
                     this.LastPlayerTile = playerTilePos;
-                    this.CursorPositionImpl = this.GetCursorPosition(this.MouseState, cursorAbsolutePos, scale);
+                    this.CursorPositionImpl = this.GetCursorPosition(this.MouseState, cursorAbsolutePos, zoomMultiplier);
                 }
             }
             catch (InvalidOperationException)
@@ -202,11 +200,11 @@ namespace StardewModdingAPI.Framework.Input
         /// <summary>Get the current cursor position.</summary>
         /// <param name="mouseState">The current mouse state.</param>
         /// <param name="absolutePixels">The absolute pixel position relative to the map, adjusted for pixel zoom.</param>
-        /// <param name="scale">The UI scale applied to pixel coordinates.</param>
+        /// <param name="zoomMultiplier">The multiplier applied to pixel coordinates to adjust them for pixel zoom.</param>
-        private CursorPosition GetCursorPosition(MouseState mouseState, Vector2 absolutePixels, float scale)
+        private CursorPosition GetCursorPosition(MouseState mouseState, Vector2 absolutePixels, float zoomMultiplier)
         {
-            Vector2 screenPixels = new Vector2(mouseState.X / scale, mouseState.Y / scale);
+            Vector2 screenPixels = new Vector2(mouseState.X * zoomMultiplier, mouseState.Y * zoomMultiplier);
-            Vector2 tile = new Vector2((int)((Game1.uiViewport.X + screenPixels.X) / Game1.tileSize), (int)((Game1.uiViewport.Y + screenPixels.Y) / Game1.tileSize));
+            Vector2 tile = new Vector2((int)((Game1.viewport.X + screenPixels.X) / Game1.tileSize), (int)((Game1.viewport.Y + screenPixels.Y) / Game1.tileSize));
             Vector2 grabTile = (Game1.mouseCursorTransparency > 0 && Utility.tileWithinRadiusOfPlayer((int)tile.X, (int)tile.Y, 1, Game1.player)) // derived from Game1.pressActionButton
                 ? tile
                 : Game1.player.GetGrabTile();

src/SMAPI/ICursorPosition.cs

@@ -1,15 +1,19 @@
 using System;
 using Microsoft.Xna.Framework;
+using StardewValley;
 
 namespace StardewModdingAPI
 {
     /// <summary>Represents a cursor position in the different coordinate systems.</summary>
     public interface ICursorPosition : IEquatable<ICursorPosition>
     {
-        /// <summary>The pixel position relative to the top-left corner of the in-game map.</summary>
+        /*********
+        ** Accessors
+        *********/
+        /// <summary>The pixel position relative to the top-left corner of the in-game map, adjusted for zoom but not UI scaling. See also <see cref="GetScaledAbsolutePixels"/>.</summary>
         Vector2 AbsolutePixels { get; }
 
-        /// <summary>The pixel position relative to the top-left corner of the visible screen.</summary>
+        /// <summary>The pixel position relative to the top-left corner of the visible screen, adjusted for zoom but not UI scaling. See also <see cref="GetScaledScreenPixels"/>.</summary>
         Vector2 ScreenPixels { get; }
 
         /// <summary>The tile position under the cursor relative to the top-left corner of the map.</summary>
@@ -17,5 +21,15 @@ namespace StardewModdingAPI
 
         /// <summary>The tile position that the game considers under the cursor for purposes of clicking actions. This may be different than <see cref="Tile"/> if that's too far from the player.</summary>
         Vector2 GrabTile { get; }
+
+
+        /*********
+        ** Public methods
+        *********/
+        /// <summary>Get the <see cref="AbsolutePixels"/>, adjusted for UI scaling if needed. This is only different if <see cref="Game1.uiMode"/> is true.</summary>
+        Vector2 GetScaledAbsolutePixels();
+
+        /// <summary>Get the <see cref="ScreenPixels"/>, adjusted for UI scaling if needed. This is only different if <see cref="Game1.uiMode"/> is true.</summary>
+        Vector2 GetScaledScreenPixels();
     }
 }