Workaround OF breaking spectator hand mixin

src/main/java/com/replaymod/core/ReplayModMixinConfigPlugin.java

@@ -0,0 +1,75 @@
+package com.replaymod.core;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.objectweb.asm.tree.ClassNode;
+import org.spongepowered.asm.mixin.extensibility.IMixinConfigPlugin;
+import org.spongepowered.asm.mixin.extensibility.IMixinInfo;
+
+import java.io.IOException;
+import java.util.List;
+import java.util.Set;
+
+//#if MC>=11400
+import java.io.InputStream;
+//#else
+//$$ import net.minecraft.launchwrapper.Launch;
+//#endif
+
+public class ReplayModMixinConfigPlugin implements IMixinConfigPlugin {
+    static boolean hasClass(String name) throws IOException {
+        //#if MC>=11400
+        InputStream stream = Thread.currentThread().getContextClassLoader().getResourceAsStream(name.replace('.', '/') + ".class");
+        if (stream != null) stream.close();
+        return stream != null;
+        //#else
+        //$$ return Launch.classLoader.getClassBytes(name) != null;
+        //#endif
+    }
+
+    private final Logger logger = LogManager.getLogger("replaymod/mixin");
+    private final boolean hasOF = hasClass("optifine.OptiFineForgeTweaker") || hasClass("me.modmuss50.optifabric.mod.Optifabric");
+
+    {
+        logger.error("hasOF: " + hasOF);
+    }
+
+    @Override
+    public boolean shouldApplyMixin(String targetClassName, String mixinClassName) {
+        if (mixinClassName.endsWith("_OF")) return hasOF;
+        if (mixinClassName.endsWith("_NoOF")) return !hasOF;
+        return true;
+    }
+
+    @Override
+    public void onLoad(String mixinPackage) {
+    }
+
+    @Override
+    public String getRefMapperConfig() {
+        return null;
+    }
+
+    @Override
+    public void acceptTargets(Set<String> myTargets, Set<String> otherTargets) {
+
+    }
+
+    @Override
+    public List<String> getMixins() {
+        return null;
+    }
+
+    @Override
+    public void preApply(String targetClassName, ClassNode targetClass, String mixinClassName, IMixinInfo mixinInfo) {
+
+    }
+
+    @Override
+    public void postApply(String targetClassName, ClassNode targetClass, String mixinClassName, IMixinInfo mixinInfo) {
+
+    }
+
+    public ReplayModMixinConfigPlugin() throws IOException {
+    }
+}

src/main/java/com/replaymod/replay/mixin/Mixin_ShowSpectatedHand_NoOF.java

@@ -13,7 +13,7 @@ import org.spongepowered.asm.mixin.injection.Redirect;
 import static com.replaymod.core.versions.MCVer.getMinecraft;
 
 @Mixin(GameRenderer.class)
-public abstract class MixinGameRenderer {
+public abstract class Mixin_ShowSpectatedHand_NoOF {
     @Redirect(
             method = "renderHand",
             at = @At(

src/main/java/com/replaymod/replay/mixin/Mixin_ShowSpectatedHand_OF.java

@@ -0,0 +1,42 @@
+//#if MC>=11400
+package com.replaymod.replay.mixin;
+
+import com.replaymod.replay.camera.CameraEntity;
+import net.minecraft.client.network.ClientPlayerEntity;
+import net.minecraft.client.network.ClientPlayerInteractionManager;
+import net.minecraft.world.GameMode;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Pseudo;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import static com.replaymod.core.versions.MCVer.getMinecraft;
+
+@Pseudo
+@Mixin(targets = "net.optifine.shaders.Shaders", remap = false)
+public abstract class Mixin_ShowSpectatedHand_OF {
+    // OptiFine redirects renderHand to a new method with the same name but with more arguments
+    // since that method is only added by Optifabric, we can't inject our redirect in there (Mixin won't see it).
+    // So instead we fake the getCurrentGameMode for an entire section of the new renderHand method by injecting
+    // into `Shaders.setRenderingFirstPersonHand` which OF calls before and after our original target.
+    // We could also just inject into HEAD and RETURN of the original renderHand method but then we'd miss any calls
+    // which OF manually does to its method (and given it has extra parameters, I'd assume that it'll do some).
+
+    @Inject(method = "setRenderingFirstPersonHand", at = @At("HEAD"), remap = false)
+    private static void fakePlayerGameMode(boolean renderingHand, CallbackInfo ci) {
+        ClientPlayerEntity camera = getMinecraft().player;
+        if (camera instanceof CameraEntity) {
+            ClientPlayerInteractionManager interactionManager = getMinecraft().interactionManager;
+            assert interactionManager != null;
+            if (renderingHand) {
+                // alternative doesn't really matter, the caller only checks for equality to SPECTATOR
+                interactionManager.setGameMode(camera.isSpectator() ? GameMode.SPECTATOR : GameMode.SURVIVAL);
+            } else {
+                // reset back to spectator (we're always in spectator during a replay)
+                interactionManager.setGameMode(GameMode.SPECTATOR);
+            }
+        }
+    }
+}
+//#endif

src/main/resources/mixins.replay.replaymod.json

@@ -1,6 +1,7 @@
 {
   "required": true,
   "package": "com.replaymod.replay.mixin",
+  "plugin": "com.replaymod.core.ReplayModMixinConfigPlugin",
   "mixins": [],
   "server": [],
   "client": [
@@ -10,7 +11,8 @@
     //#endif
     "EntityLivingBaseAccessor",
     //#if MC>=11400
-    "MixinGameRenderer",
+    "Mixin_ShowSpectatedHand_NoOF",
+    "Mixin_ShowSpectatedHand_OF",
     //#else
     //$$ "EntityOtherPlayerMPAccessor",
     //#endif