Gradient hair compat

Source/VariedBodySizes/GradientHairCompatibilityPatches.cs

@@ -0,0 +1,62 @@
+using System.Reflection.Emit;
+using AccessTools = HarmonyLib.AccessTools;
+
+namespace VariedBodySizes;
+
+public static partial class HarmonyPatches
+{
+    [HarmonyPatch]
+    public static class GradientHairCompatibilityPatches
+    {
+        private static readonly MethodBase maskInit =
+            AccessTools.Method("GradientHair.Graphic_MultiMask:Init");
+
+        public static bool Prepare()
+        {
+            return ModsConfig.IsActive("automatic.gradienthair") && NotNull(maskInit);
+        }
+
+        public static MethodBase TargetMethod()
+        {
+            return maskInit;
+        }
+
+        // The input path in the originating function is processed as path.Split('\0') where [1] is the mask path, if present
+        // Otherwise the graphic should fall back to req.maskPath
+        // ReSharper disable once SuggestBaseTypeForParameter -- we want to match the signature as closely as possible
+        private static string ProcessMaskPath(string[] paths, GraphicRequest req)
+        {
+            return paths.Length > 1 ? paths[1] : req.maskPath;
+        }
+
+        // This patch is basically implementing https://github.com/AUTOMATIC1111/GradientHair/pull/3/files from our side
+        public static CodeInstructions Transpiler(CodeInstructions instructions)
+        {
+            var editor = new CodeMatcher(instructions);
+            // Replace the local that holds the mask path with `self.maskPath = args.Length > 1 ? args[1] : req.maskPath;`
+            var pattern = InstructionMatchSignature((Graphic self, GraphicRequest req) =>
+            {
+                var args = req.path.Split('\0');
+                var mask = args[1];
+            });
+            var replacement = InstructionSignature((Graphic self, GraphicRequest req) =>
+            {
+                var args = req.path.Split('\0');
+                self.maskPath = ProcessMaskPath(args, req);
+            });
+            editor.Replace(pattern, replacement);
+
+            // Replace lookups for the local with the field reference
+            // e.g. `array2[0] = ContentFinder<Texture2D>.Get(mask, false);` -> `array2[0] = ContentFinder<Texture2D>.Get(maskPath, false);`
+            var lookupPattern = new[] { new CodeMatch(OpCodes.Ldloc_1) };
+            var lookupReplacement = InstructionSignature((Graphic self) => self.maskPath).ToArray();
+            while (editor.IsValid)
+            {
+                editor.Replace(lookupPattern, lookupReplacement, suppress:true);
+            }
+
+            // Done!
+            return editor.InstructionEnumeration();
+        }
+    }
+}