private final String ITEM_STACK = isObfuscated() ? "add" : "net/minecraft/item/ItemStack";
private final String STACK_SIZE_NAME = isObfuscated() ? "b" : "stackSize";
private final String STACK_SIZE_DESC = "I";
private final String IS_REMOTE_NAME = isObfuscated() ? "E" : "isRemote";
private final String IS_REMOTE_DESC = "Z";
private final String INVENTORY_PLAYER = isObfuscated() ? "yx" : "net/minecraft/entity/player/InventoryPlayer";
private final String ENTITY_PLAYER = isObfuscated() ? "yz" : "net/minecraft/entity/player/EntityPlayer";
private final String ADD_ITEM_STACK_TO_INVENTORY_NAME = isObfuscated() ? "a" : "addItemStackToInventory";
private final String ADD_ITEM_STACK_TO_INVENTORY_DESC = isObfuscated() ? "(Ladd;)Z" : "(Lnet/minecraft/item/ItemStack;)
private final String ON_ITEM_PICKUP_NAME = isObfuscated() ? "a" : "onItemPickup";
private final String ON_ITEM_PICKUP_DESC = isObfuscated() ? "(Lsa;I)V" : "(Lnet/minecraft/entity/Entity;I)V";
private final String ON_ITEM_PICKUP_HOOK_NAME = "onItemPickedUp";
private final String ON_ITEM_PICKUP_HOOK_DESC = isObfuscated() ? "(Lxk;Lyz;I)V" : "(Lnet/minecraft/entity/item/EntityItem;Lnet/minecraft/entity/player/EntityPlayer;I)V";
private final String ON_COLLIDE_WITH_PLAYER_NAME = isObfuscated() ? "b_" : "onCollideWithPlayer";
private final String ON_COLLIDE_WITH_PLAYER_DESC = isObfuscated() ? "(Lyz;)V" : "(Lnet/minecraft/entity/player/EntityPlayer;)V";
private byte[] patchEntityItem(byte[] bytes){
ClassNode classNode = new ClassNode();
ClassReader classReader = new ClassReader(bytes);
classReader.accept(classNode, 0);
MethodNode onCollideWithPlayer = findMethod(classNode, ON_COLLIDE_WITH_PLAYER_NAME, ON_COLLIDE_WITH_PLAYER_DESC).orElseThrow(() -> new RuntimeException("Can not find target method 'onCollideWithPlayer' in class 'net.minecraft.entity.item.EntityItem'"));
InsnList instructions = onCollideWithPlayer.instructions;
// Добавляем проверку в if
AbstractInsnNode hookAnchor = null;
ListIterator<AbstractInsnNode> iterator = instructions.iterator();
while(iterator.hasNext()){
AbstractInsnNode node = iterator.next();
if(node.getOpcode() == INVOKEVIRTUAL){
MethodInsnNode methodNode = (MethodInsnNode)node;
if(methodNode.owner.equals(INVENTORY_PLAYER) && methodNode.name.equals(ADD_ITEM_STACK_TO_INVENTORY_NAME) && methodNode.desc.equals(ADD_ITEM_STACK_TO_INVENTORY_DESC)){
JumpInsnNode ifLastNode = (JumpInsnNode)findInsnsWithOpcode(instructions.getFirst(), IFNE, false).stream().filter(insn -> {
if(insn.getPrevious().getOpcode() == GETFIELD){
FieldInsnNode field = (FieldInsnNode)insn.getPrevious();
return field.owner.equals(WORLD) && field.name.equals(IS_REMOTE_NAME) && field.desc.equals(IS_REMOTE_DESC);
}
return false;
}).findFirst().orElseThrow(() -> new RuntimeException("Can not find target label instructions"));
AbstractInsnNode ifNode = findInsnsWithOpcode(instructions.getFirst(), GETSTATIC, false).stream().filter(insn -> ((FieldInsnNode)insn).name.equals("ALLOW")).findFirst().orElseThrow(() -> new RuntimeException("Can not find target label instructions"));
JumpInsnNode ifAddItem = (JumpInsnNode)methodNode.getNext();
ifAddItem.setOpcode(IFNE);
ifAddItem.label = ((JumpInsnNode)ifNode.getNext()).label;
InsnList list = new InsnList();
list.add(new VarInsnNode(ILOAD, 4));
list.add(new VarInsnNode(ALOAD, 3));
list.add(new FieldInsnNode(GETFIELD, ITEM_STACK, STACK_SIZE_NAME, STACK_SIZE_DESC));
list.add(new JumpInsnNode(IF_ICMPLE, ifLastNode.label));
instructions.insert(methodNode.getNext(), list);
hookAnchor = methodNode;
break;
}
}
}
// Вызываем хук
AbstractInsnNode hookPos = findInsnsWith(hookAnchor, insn -> insn instanceof FrameNode && ((FrameNode)insn).type == F_SAME, false).stream().findFirst().orElseThrow(() -> new RuntimeException("Can not find target hook instructions"));
InsnList hookList = new InsnList();
hookList.add(new VarInsnNode(ALOAD, 0));
hookList.add(new VarInsnNode(ALOAD, 1));
hookList.add(new VarInsnNode(ILOAD, 4));
hookList.add(new VarInsnNode(ALOAD, 3));
hookList.add(new FieldInsnNode(GETFIELD, ITEM_STACK, STACK_SIZE_NAME, STACK_SIZE_DESC));
hookList.add(new InsnNode(ISUB));
hookList.add(new MethodInsnNode(INVOKESTATIC, HOOKS, ON_ITEM_PICKUP_HOOK_NAME, ON_ITEM_PICKUP_HOOK_DESC, false));
instructions.insert(hookPos, hookList);
// Перемещаем вызов EntityPlayer#onItemPickup в условие itemstack.stackSize <= 0 чтобы вызывался только когда весь предмет был подобран
AbstractInsnNode onItemPickupAnchor = findInsnsWith(instructions.getFirst(), insn -> {
if(insn.getOpcode() == INVOKEVIRTUAL){
MethodInsnNode methodNode = (MethodInsnNode)insn;
return methodNode.owner.equals(ENTITY_PLAYER) && methodNode.name.equals(ON_ITEM_PICKUP_NAME) && methodNode.desc.equals(ON_ITEM_PICKUP_DESC);
}
return false;
}, false).stream().findFirst().orElseThrow(() -> new RuntimeException("Can not find target onItemPickup call position"));
InsnList onItemPickupList = new InsnList();
onItemPickupList.add(new VarInsnNode(ALOAD, 1));
onItemPickupList.add(new VarInsnNode(ALOAD, 0));
onItemPickupList.add(new VarInsnNode(ILOAD, 4));
onItemPickupList.add(new MethodInsnNode(INVOKEVIRTUAL, ENTITY_PLAYER, ON_ITEM_PICKUP_NAME, ON_ITEM_PICKUP_DESC, false));
AbstractInsnNode onItemPickupNewCallPos = findInsnsWith(onItemPickupAnchor, insn -> {
if(insn.getOpcode() == GETFIELD){
FieldInsnNode field = (FieldInsnNode)insn;
return field.owner.equals(ITEM_STACK) && field.name.equals(STACK_SIZE_NAME) && field.desc.equals(STACK_SIZE_DESC);
}
return false;
}, false).stream().findFirst().orElseThrow(() -> new RuntimeException("Can not find target new onItemPickup call position"));
instructions.insert(onItemPickupNewCallPos.getNext(), onItemPickupList);
for(int i = 0; i < 3; i++){
instructions.remove(onItemPickupAnchor.getPrevious());
}
instructions.remove(onItemPickupAnchor);
ClassWriter classWriter = new SafeClassWriter(classMetadataReader, 0);
classNode.accept(classWriter);
return classWriter.toByteArray();
}
private static List<AbstractInsnNode> findInsnsWithOpcode(@NonNull AbstractInsnNode firstToCheck, int opcode, boolean reverseDirection){
return findInsnsWith(firstToCheck, insn -> insn.getOpcode() == opcode, reverseDirection);
}
private static List<AbstractInsnNode> findInsnsWith(@NonNull AbstractInsnNode firstToCheck, Predicate<AbstractInsnNode> predicate, boolean reverseDirection){
List<AbstractInsnNode> list = Lists.newArrayList();
AbstractInsnNode insn = firstToCheck;
while(insn != null){
if(predicate.test(insn)){
list.add(insn);
}
insn = reverseDirection ? insn.getPrevious() : insn.getNext();
}
return list;
}
private static Optional<MethodNode> findMethod(ClassNode classNode, String name, String desc){
return classNode.methods.stream().filter(method -> method.name.equals(name) && method.desc.equals(desc)).findFirst();
}
