Sprite runtime unification to Skia (#2552)

Author: vchelaru

.claude/skills/gum-cross-platform-unification/SKILL.md

@@ -72,3 +72,19 @@ This ensures changes remain reviewable, TDD stays manageable, and build errors (
 ## What This Skill Is Not
 
 Not a general refactoring guide. Not a pattern for unifying non-runtime files. Specifically: the runtime unification pattern (shared source + `#if` + csproj linking) is appropriate because the Raylib and Skia runtime projects are small wrappers around the MonoGame-style API. Do not apply this pattern to tool code, to GumCommon code (which already lives in one place and is shared differently), or to Forms controls (which are linked as a directory glob).
+
+## Runtime Refactor Status
+
+This table tracks the unification progress across platforms. **✅ Unified** means the project links to the shared source in `MonoGameGum\GueDeriving\`.
+
+| Runtime | MonoGame | Raylib | Skia | Sokol |
+| :--- | :---: | :---: | :---: | :---: |
+| **SpriteRuntime** | ✅ Unified | ✅ Unified | ✅ Unified | ❌ Local |
+| **TextRuntime** | ✅ Unified | ✅ Unified | ✅ Unified | ❌ Local |
+| **ContainerRuntime** | ✅ Unified | ✅ Unified | ✅ Unified | ✅ Unified |
+| **ColoredRectangleRuntime** | ✅ Unified | ✅ Unified | ✅ Unified | ✅ Unified |
+| **NineSliceRuntime** | ✅ Unified | ❌ Local | ❌ Local | ❌ Local |
+| **CircleRuntime** | ✅ Unified | ❌ Local | ❌ Local | ❌ Local |
+| **PolygonRuntime** | ✅ Unified | ❌ Local | ❌ Local | ❌ Local |
+| **RectangleRuntime** | ✅ Unified | ❌ Local | ❌ Local | ❌ Local |
+

GEMINI.md

@@ -1,3 +1,5 @@
+Never ever write to this file unless explicitly told to do so. This file just redirects to shared skill or CLAUDE.md files.
+
 # Gum Repository Guidelines (Gemini)
 
 ## Foundational Mandate
@@ -8,7 +10,4 @@ Before proceeding with any request, you **MUST** read and adhere to the guidelin
 
 1.  **Project Overview & Build/Test Rules**: Read **`CLAUDE.md`**. Use the solution-based building and testing workflows defined there.
 2.  **Code Style & Architecture**: Read **`.claude/code-style.md`**.
-3.  **Task-Specific Logic (Skills)**: Search the **`.claude/skills/`** directory. If a skill exists for the current task (e.g., `gum-cross-platform-unification`), you MUST load its `SKILL.md` and follow its specific "Always-Ask" checklists and mechanical steps.
-
-## Communication Rule
-If a referenced skill or document (like the unification skill) mandates a "Research and Confirm" phase, you must present your findings and wait for user approval before modifying any files.
+3.  **Task-Specific Logic (Skills)**: Search the **`.claude/skills/`** directory. If a skill exists for the current task (e.g., `gum-cross-platform-unification`), you MUST load its `SKILL.md` and follow its specific checklists and status tracking.

MonoGameGum/GueDeriving/SpriteRuntime.cs

@@ -20,6 +20,13 @@
 using Texture2D = Raylib_cs.Texture2D;
 using ContainedSpriteType = Gum.Renderables.Sprite;
 namespace Gum.GueDeriving;
+#elif SKIA
+using SkiaGum.Renderables;
+using Color = SkiaSharp.SKColor;
+using Rectangle = SkiaSharp.SKRect;
+using Texture2D = SkiaSharp.SKBitmap;
+using ContainedSpriteType = SkiaGum.Renderables.Sprite;
+namespace SkiaGum.GueDeriving;
 #else
 using RenderingLibrary.Graphics;
 using Color = Microsoft.Xna.Framework.Color;
@@ -115,15 +122,15 @@ public Color Color
     {
         get
         {
-#if RAYLIB
+#if RAYLIB || SKIA
             return ContainedSprite.Color;
 #else
             return RenderingLibrary.Graphics.XNAExtensions.ToXNA(ContainedSprite.Color);
 #endif
         }
         set
         {
-#if RAYLIB
+#if RAYLIB || SKIA
             ContainedSprite.Color = value;
 #else
             ContainedSprite.Color = RenderingLibrary.Graphics.XNAExtensions.ToSystemDrawing(value);
@@ -181,6 +188,7 @@ public bool FlipVertical
         }
     }
 
+#if !SKIA
     /// <summary>
     /// The source rectangle in the texture to render, using platform-specific Rectangle type.
     /// Setting this also updates TextureLeft, TextureTop, TextureWidth, and TextureHeight.
@@ -202,6 +210,7 @@ public Rectangle SourceRectangle
             TextureHeight = (int)value.Height;
         }
     }
+#endif
 
     #region AnimationChain
 
@@ -344,6 +353,7 @@ public event Action AnimationChainCycled
 
     #region Source File/Texture
 
+#if !SKIA
     /// <summary>
     /// Obsolete. Use Texture instead.
     /// </summary>
@@ -353,6 +363,30 @@ public Texture2D? SourceFile
         get => this.Texture;
         set => this.Texture = value;
     }
+#else
+    /// <summary>
+    /// The file path to the texture. Setting this will load the texture via the LoaderManager.
+    /// </summary>
+    public string? SourceFile
+    {
+        // eventually we may want to store this off somehow
+        get => null;
+        set
+        {
+            if (string.IsNullOrEmpty(value))
+            {
+                Texture = null;
+            }
+            else
+            {
+                var loaderManager = global::RenderingLibrary.Content.LoaderManager.Self;
+                var contentLoader = loaderManager.ContentLoader;
+                var image = contentLoader.LoadContent<SkiaSharp.SKBitmap>(value);
+                Texture = image;
+            }
+        }
+    }
+#endif
 
     /// <summary>
     /// The underlying texture used by the sprite.
@@ -400,12 +434,23 @@ public Texture2D? Texture
                 }
             }
 
-#if RAYLIB
+#if RAYLIB || SKIA
             NotifyPropertyChanged();
 #endif
         }
     }
 
+#if SKIA
+    /// <summary>
+    /// The underlying SKImage used by the sprite.
+    /// </summary>
+    public SkiaSharp.SKImage? Image
+    {
+        get => ContainedSprite.Image;
+        set => ContainedSprite.Image = value;
+    }
+#endif
+
     /// <summary>
     /// Sets the texture via file name and updates animation frames if necessary.
     /// </summary>
@@ -461,7 +506,7 @@ public SpriteRuntime(bool fullInstantiation = true, bool tryCreateFormsObject =
     {
         if (fullInstantiation)
         {
-#if RAYLIB
+#if RAYLIB || SKIA
             mContainedSprite = new ContainedSpriteType();
 #else
             mContainedSprite = new RenderingLibrary.Graphics.Sprite(null);

Runtimes/SkiaGum/GueDeriving/SpriteRuntime.cs

@@ -8,8 +8,12 @@
 
 namespace SkiaGum.Renderables;
 
-public class Sprite : RenderableShapeBase, IAspectRatio, ITextureCoordinate, IAnimatable
+public class Sprite : RenderableShapeBase, IAspectRatio, ITextureCoordinate, IAnimatable, ICloneable
 {
+    public object Clone()
+    {
+        return this.MemberwiseClone();
+    }
     public SKBitmap? Texture 
     { 
         get => _texture;

Runtimes/SkiaGum/Renderables/Sprite.cs

@@ -49,6 +49,7 @@
 		<Compile Include="..\..\MonoGameGum\GueDeriving\ColoredRectangleRuntime.cs" Link="GueDeriving\ColoredRectangleRuntime.cs" />
 		<Compile Include="..\..\MonoGameGum\GueDeriving\ContainerRuntime.cs" Link="GueDeriving\ContainerRuntime.cs" />
 		<Compile Include="..\..\MonoGameGum\GueDeriving\TextRuntime.cs" Link="GueDeriving\TextRuntime.cs" />
+		<Compile Include="..\..\MonoGameGum\GueDeriving\SpriteRuntime.cs" Link="GueDeriving\SpriteRuntime.cs" />
 
 	</ItemGroup>