Landtrain!!!!

2026-02-06 16:04:34 -05:00
parent 9194c5e96d
commit fc14fe2b57
9 changed files with 750 additions and 1 deletions
--- a/tools/java/BaseVehicleConstraintPatch.java
+++ b/tools/java/BaseVehicleConstraintPatch.java
@@ -0,0 +1,105 @@
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import org.objectweb.asm.ClassReader;
+import org.objectweb.asm.ClassWriter;
+import org.objectweb.asm.tree.AbstractInsnNode;
+import org.objectweb.asm.tree.ClassNode;
+import org.objectweb.asm.tree.InsnNode;
+import org.objectweb.asm.tree.InsnList;
+import org.objectweb.asm.tree.MethodInsnNode;
+import org.objectweb.asm.tree.MethodNode;
+import org.objectweb.asm.Opcodes;
+
+/**
+ * Patches zombie.vehicles.BaseVehicle so addPointConstraint() no longer force-breaks
+ * both vehicles before creating a new constraint.
+ */
+public final class BaseVehicleConstraintPatch {
+    private static final String TARGET_NAME = "addPointConstraint";
+    private static final String BREAK_DESC_OBJECT_BOOL = "(ZLjava/lang/Boolean;)V";
+    private static final String BREAK_DESC_PRIMITIVE_BOOL = "(ZZ)V";
+    private static final String BASE_VEHICLE_OWNER = "zombie/vehicles/BaseVehicle";
+
+    private BaseVehicleConstraintPatch() {
+    }
+
+    public static void main(String[] args) throws Exception {
+        if (args.length != 2) {
+            System.err.println("Usage: BaseVehicleConstraintPatch <input BaseVehicle.class> <output BaseVehicle.class>");
+            System.exit(2);
+        }
+
+        Path input = Paths.get(args[0]);
+        Path output = Paths.get(args[1]);
+        byte[] original = Files.readAllBytes(input);
+
+        ClassNode classNode = new ClassNode();
+        new ClassReader(original).accept(classNode, 0);
+
+        int removedCalls = 0;
+        int inspectedAddPointMethods = 0;
+        for (MethodNode method : classNode.methods) {
+            if (!TARGET_NAME.equals(method.name) || !isTargetAddPointConstraint(method.desc)) {
+                continue;
+            }
+            inspectedAddPointMethods++;
+            removedCalls += patchAddPointConstraint(method);
+        }
+
+        if (removedCalls < 2) {
+            throw new IllegalStateException(
+                    "Expected to remove 2 breakConstraint calls, removed "
+                            + removedCalls
+                            + " (inspected addPoint methods: "
+                            + inspectedAddPointMethods
+                            + ")");
+        }
+
+        ClassWriter writer = new ClassWriter(0);
+        classNode.accept(writer);
+
+        Files.createDirectories(output.getParent());
+        Files.write(output, writer.toByteArray());
+        System.out.println("Patched BaseVehicle.class; removed breakConstraint calls: " + removedCalls);
+    }
+
+    private static boolean isTargetAddPointConstraint(String methodDesc) {
+        // We only want the 5-arg overload:
+        // (IsoPlayer, BaseVehicle, String, String, boolean|Boolean) -> void
+        return "(Lzombie/characters/IsoPlayer;Lzombie/vehicles/BaseVehicle;Ljava/lang/String;Ljava/lang/String;Z)V"
+                        .equals(methodDesc)
+                || "(Lzombie/characters/IsoPlayer;Lzombie/vehicles/BaseVehicle;Ljava/lang/String;Ljava/lang/String;Ljava/lang/Boolean;)V"
+                        .equals(methodDesc);
+    }
+
+    private static int patchAddPointConstraint(MethodNode method) {
+        int patched = 0;
+        InsnList insns = method.instructions;
+
+        for (AbstractInsnNode node = insns.getFirst(); node != null; ) {
+            AbstractInsnNode next = node.getNext();
+            if (node instanceof MethodInsnNode call
+                    && BASE_VEHICLE_OWNER.equals(call.owner)
+                    && "breakConstraint".equals(call.name)) {
+                if (!(BREAK_DESC_OBJECT_BOOL.equals(call.desc)
+                        || BREAK_DESC_PRIMITIVE_BOOL.equals(call.desc))) {
+                    node = next;
+                    continue;
+                }
+                // Keep stack-map frames valid by preserving stack effect:
+                // breakConstraint(...) consumes objectref + 2 args and returns void.
+                // Replace invoke with POP2 + POP (consume 3 category-1 stack slots).
+                InsnList replacement = new InsnList();
+                replacement.add(new InsnNode(Opcodes.POP2));
+                replacement.add(new InsnNode(Opcodes.POP));
+                insns.insert(node, replacement);
+                insns.remove(node);
+                patched++;
+            }
+            node = next;
+        }
+
+        return patched;
+    }
+}