feat(modloader): pdb mapping, dynamic invoke, mixins

ExampleMod/ExampleMod.cs

@@ -9,6 +9,8 @@ namespace ExampleMod;
      Description = "A sample mod demonstrating the WeaveLoader API")]
 public class ExampleMod : IMod
 {
+    private static nint s_currentLevel;
+    private static bool s_hasLevel;
     public static RegisteredBlock? RubyOre;
     public static RegisteredBlock? RubyStone;
     public static RegisteredBlock? RubyWoodPlanks;
@@ -189,6 +191,17 @@ public class ExampleMod : IMod
 
     public void OnInitialize()
     {
+        GameEvents.OnWorldLoaded += (_, e) =>
+        {
+            s_currentLevel = e.NativeLevelPointer;
+            s_hasLevel = s_currentLevel != 0;
+        };
+        GameEvents.OnWorldUnloaded += (_, __) =>
+        {
+            s_currentLevel = 0;
+            s_hasLevel = false;
+        };
+
         RubyOre = Registry.Block.Register("examplemod:ruby_ore",
             new BlockProperties()
                 .Material(MaterialType.Stone)
@@ -391,4 +404,10 @@ public class ExampleMod : IMod
     {
         Logger.Info("Example Mod shutting down.");
     }
+
+    internal static bool TryGetCurrentLevel(out nint levelPtr)
+    {
+        levelPtr = s_currentLevel;
+        return s_hasLevel && levelPtr != 0;
+    }
 }

ExampleMod/ExampleMod.csproj

@@ -22,6 +22,7 @@
 
   <ItemGroup>
     <Content Include="assets\**\*" CopyToOutputDirectory="PreserveNewest" />
+    <Content Include="weave.mixins.json" CopyToOutputDirectory="PreserveNewest" />
   </ItemGroup>
 
 </Project>

ExampleMod/Mixins/CreeperExplosionMixin.cs

@@ -0,0 +1,127 @@
+using System;
+using System.Collections.Generic;
+using WeaveLoader.API;
+using WeaveLoader.API.Mixins;
+using WeaveLoader.API.Native;
+
+namespace ExampleMod.Mixins;
+
+[Mixin("Creeper")]
+public static class CreeperExplosionMixin
+{
+    private const int Radius = 6;
+
+    private static readonly HashSet<nint> s_processed = new();
+    private static int s_triggerLogCount;
+    private static bool s_offsetsReady;
+    private static bool s_offsetsWarned;
+    private static int s_swellOffset;
+    private static int s_maxSwellOffset;
+    private static int s_isClientSideOffset;
+
+    [Inject("tick", At.Tail)]
+    private static void OnTick(MixinContext ctx)
+    {
+        nint thisPtr = ctx.ThisPtr;
+        if (thisPtr == 0 || ExampleMod.RubySand == null)
+            return;
+
+        nint levelPtr = 0;
+        if (NativeOffsets.TryGet("Entity", "level", out var levelOffset))
+            levelPtr = NativeMemory.ReadPtr(thisPtr, levelOffset);
+
+        if (levelPtr == 0 && !ExampleMod.TryGetCurrentLevel(out levelPtr))
+            return;
+
+        if (!EnsureOffsets())
+            return;
+
+        if (s_isClientSideOffset != 0 && NativeMemory.ReadBool(levelPtr, s_isClientSideOffset))
+            return;
+
+        int swell = NativeMemory.ReadInt32(thisPtr, s_swellOffset);
+        int maxSwell = NativeMemory.ReadInt32(thisPtr, s_maxSwellOffset);
+        if (swell < maxSwell)
+            return;
+
+        if (!NativeMemory.ReadBool(thisPtr, NativeOffsets.Entity.Removed))
+            return;
+
+        if (!s_processed.Add(thisPtr))
+            return;
+        if (s_processed.Count > 256)
+            s_processed.Clear();
+
+        if (s_triggerLogCount < 1)
+        {
+            Logger.Info($"CreeperExplosionMixin triggered at ({NativeMemory.ReadDouble(thisPtr, NativeOffsets.Entity.X):F2}, {NativeMemory.ReadDouble(thisPtr, NativeOffsets.Entity.Y):F2}, {NativeMemory.ReadDouble(thisPtr, NativeOffsets.Entity.Z):F2})");
+            s_triggerLogCount++;
+        }
+
+        int x = (int)Math.Floor(NativeMemory.ReadDouble(thisPtr, NativeOffsets.Entity.X));
+        int y = (int)Math.Floor(NativeMemory.ReadDouble(thisPtr, NativeOffsets.Entity.Y));
+        int z = (int)Math.Floor(NativeMemory.ReadDouble(thisPtr, NativeOffsets.Entity.Z));
+        PaintSphereTop(levelPtr, x, y, z);
+    }
+
+    private static bool EnsureOffsets()
+    {
+        if (s_offsetsReady)
+            return true;
+
+        bool ok = true;
+        ok &= NativeOffsets.TryGet("Creeper", "swell", out s_swellOffset);
+        ok &= NativeOffsets.TryGet("Creeper", "maxSwell", out s_maxSwellOffset);
+        NativeOffsets.TryGet("Level", "isClientSide", out s_isClientSideOffset);
+
+        s_offsetsReady = ok;
+        if (!s_offsetsReady && !s_offsetsWarned)
+        {
+            Logger.Warning("CreeperExplosionMixin: missing offsets for Creeper swell/maxSwell.");
+            s_offsetsWarned = true;
+        }
+        return s_offsetsReady;
+    }
+
+    private static void PaintSphereTop(nint levelPtr, int centerX, int centerY, int centerZ)
+    {
+        int minY = Math.Max(0, centerY - Radius);
+        int maxY = Math.Min(255, centerY + Radius);
+        int radiusSq = Radius * Radius;
+        var targets = new List<(int X, int Y, int Z)>();
+
+        for (int dx = -Radius; dx <= Radius; dx++)
+        {
+            int dxSq = dx * dx;
+            for (int dz = -Radius; dz <= Radius; dz++)
+            {
+                int distSq = dxSq + dz * dz;
+                if (distSq > radiusSq)
+                    continue;
+
+                int worldX = centerX + dx;
+                int worldZ = centerZ + dz;
+                int verticalRadius = (int)Math.Floor(Math.Sqrt(radiusSq - distSq));
+                int startY = Math.Min(maxY, centerY + verticalRadius);
+                int endY = Math.Max(minY, centerY - verticalRadius);
+
+                int topY = -1;
+                for (int y = startY; y >= endY; --y)
+                {
+                    int id = NativeLevel.GetTile(levelPtr, worldX, y, worldZ);
+                    if (id != 0)
+                    {
+                        topY = y;
+                        break;
+                    }
+                }
+
+                if (topY >= 0)
+                    targets.Add((worldX, topY, worldZ));
+            }
+        }
+
+        foreach (var (tx, ty, tz) in targets)
+            NativeLevel.SetTile(levelPtr, tx, ty, tz, ExampleMod.RubySand!.NumericId, 0, 2);
+    }
+}

ExampleMod/weave.mixins.json

@@ -0,0 +1,13 @@
+{
+  "required": false,
+  "minVersion": "0.1",
+  "package": "ExampleMod.Mixins",
+  "mixins": [],
+  "client": [
+    "CreeperExplosionMixin"
+  ],
+  "server": [],
+  "injectors": {
+    "defaultRequire": 1
+  }
+}