From ac4a18a428d32fe4af9606672f66d713c0965de1 Mon Sep 17 00:00:00 2001
From: alemi <me@alemi.dev>
Date: Sun, 19 Feb 2023 20:20:47 +0100
Subject: [PATCH] chore: some boilerplate for boat patch

---
 .../java/ftbsc/bscv/events/BoatEvent.java     | 12 ++++
 .../java/ftbsc/bscv/patches/BoatPatch.java    | 59 +++++++++++++++++++
 2 files changed, 71 insertions(+)
 create mode 100644 src/main/java/ftbsc/bscv/events/BoatEvent.java
 create mode 100644 src/main/java/ftbsc/bscv/patches/BoatPatch.java

diff --git a/src/main/java/ftbsc/bscv/events/BoatEvent.java b/src/main/java/ftbsc/bscv/events/BoatEvent.java
new file mode 100644
index 0000000..32eeb37
--- /dev/null
+++ b/src/main/java/ftbsc/bscv/events/BoatEvent.java
@@ -0,0 +1,12 @@
+package ftbsc.bscv.events;
+
+import net.minecraftforge.eventbus.api.Cancelable;
+import net.minecraftforge.eventbus.api.Event;
+
+public class BoatEvent {
+
+	@Cancelable
+	public class Control extends Event {
+		public Control() {}
+	}
+}
diff --git a/src/main/java/ftbsc/bscv/patches/BoatPatch.java b/src/main/java/ftbsc/bscv/patches/BoatPatch.java
new file mode 100644
index 0000000..3d7f13d
--- /dev/null
+++ b/src/main/java/ftbsc/bscv/patches/BoatPatch.java
@@ -0,0 +1,59 @@
+package ftbsc.bscv.patches;
+
+import net.minecraft.network.IPacket;
+import net.minecraftforge.common.MinecraftForge;
+
+import org.objectweb.asm.Opcodes;
+import org.objectweb.asm.tree.AbstractInsnNode;
+import org.objectweb.asm.tree.ClassNode;
+import org.objectweb.asm.tree.InsnNode;
+import org.objectweb.asm.tree.JumpInsnNode;
+import org.objectweb.asm.tree.LabelNode;
+import org.objectweb.asm.tree.MethodInsnNode;
+import org.objectweb.asm.tree.MethodNode;
+import org.objectweb.asm.tree.VarInsnNode;
+
+import ftbsc.bscv.events.BoatEvent;
+import ftbsc.bscv.events.PacketEvent;
+import ftbsc.lll.IInjector;
+import ftbsc.lll.tools.InsnSequence;
+import ftbsc.lll.tools.PatternMatcher;
+
+public class BoatPatch {
+
+	public static class BoatHook {
+		public static boolean boatControl(IPacket<?> pkt) {
+			return MinecraftForge.EVENT_BUS.post(new BoatEvent.Control());
+		}
+
+		public static boolean pktOut(IPacket<?> pkt) {
+			return MinecraftForge.EVENT_BUS.post(new PacketEvent(pkt, true));
+		}
+	}
+
+	public static class BoatControlOverride implements IInjector, Opcodes {
+		public String name()        { return "BoatControlOverride"; }
+		public String reason()      { return "add hook to cancel vanilla boat controls"; }
+		public String targetClass() { return "net.minecraft.entity.item.BoatEntity"; }
+		public String methodName()  { return "func_184443_x"; } // void controlBoat()
+		public String methodDesc()  { return "()V"; } 
+	
+		public void inject(ClassNode clazz, MethodNode main) {
+			// Hook at method start
+			LabelNode skip = new LabelNode();
+			InsnSequence is = new InsnSequence();
+			is.add(new VarInsnNode(ALOAD, 2));
+			is.add(new MethodInsnNode(
+				INVOKESTATIC,
+				"ftbsc/bscv/patches/BoatPatch$BoatHook",
+				"boatControl",
+				"(Lnet/minecraft/network/IPacket;)Z"
+			));
+			is.add(new JumpInsnNode(IFEQ, skip));
+			is.add(new InsnNode(RETURN));
+			is.add(skip);
+
+			main.instructions.insert(is);
+		}
+	}
+}