Merge pull request #22 from rune-js/item-swapping

Adding the ability to swap inventory items.

src/net/rs-buffer.ts

@@ -116,10 +116,14 @@ export class RsBuffer {
         return this.buffer.readInt8(this.readerIndex++);
     }
 
-    public readNegativeOffsetByte(): number {
+    public readPreNegativeOffsetByte(): number {
         return 128 - (this.readByte() & 0xff);
     }
 
+    public readPostNegativeOffsetByte(): number {
+        return (this.readByte() & 0xff) - 128;
+    }
+
     public readShortBE(): number {
         const value = this.buffer.readInt16BE(this.readerIndex);
         this.readerIndex += 2;

src/world/entity/mob/items/item-container.ts

@@ -77,6 +77,14 @@ export class ItemContainer {
         return slots;
     }
 
+    public swap(fromSlot: number, toSlot: number): void {
+        const fromItem = this._items[fromSlot];
+        const toItem = this._items[toSlot];
+
+        this._items[toSlot] = fromItem;
+        this._items[fromSlot] = toItem;
+    }
+
     public weight(): number {
         let weight = 0;
 

src/world/entity/mob/player/action/swap-item-action.ts

@@ -0,0 +1,14 @@
+import { Player } from '../player';
+import { interfaceIds } from '../game-interface';
+
+export const swapItemAction = (player: Player, fromSlot: number, toSlot: number, interfaceId: number) => {
+    if(interfaceId === interfaceIds.inventory) {
+        const inventory = player.inventory;
+
+        if(toSlot > inventory.size - 1 || fromSlot > inventory.size - 1) {
+            return;
+        }
+
+        inventory.swap(fromSlot, toSlot);
+    }
+};

src/world/entity/mob/player/packet/impl/item-swap-packet.ts

@@ -0,0 +1,22 @@
+import { incomingPacket } from '../incoming-packet';
+import { Player } from '../../player';
+import { RsBuffer } from '../../../../../../net/rs-buffer';
+import { swapItemAction } from '../../action/swap-item-action';
+
+export const itemSwapPacket: incomingPacket = (player: Player, packetId: number, packetSize: number, packet: RsBuffer): void => {
+    const toSlot = packet.readNegativeOffsetShortLE();
+    const swapType = packet.readPostNegativeOffsetByte();
+    const interfaceId = packet.readNegativeOffsetShortBE();
+    const fromSlot = packet.readShortLE();
+
+    if(toSlot < 0 || fromSlot < 0) {
+        return;
+    }
+
+    if(swapType === 0) {
+        // Swap
+        swapItemAction(player, fromSlot, toSlot, interfaceId);
+    } else if(swapType === 1) {
+        // @TODO insert
+    }
+};

src/world/entity/mob/player/packet/impl/walk-packet.ts

@@ -23,7 +23,7 @@ export const walkPacket: incomingPacket = (player: Player, packetId: number, pac
 
     for(let i = 0; i < totalSteps; i++) {
         const x = packet.readByte();
-        const y = packet.readNegativeOffsetByte();
+        const y = packet.readPreNegativeOffsetByte();
         walkingQueue.add(x + firstX, y + firstY);
     }
 };

src/world/entity/mob/player/packet/incoming-packet-directory.ts

@@ -11,6 +11,7 @@ import { buttonClickPacket } from './impl/button-click-packet';
 import { walkPacket } from './impl/walk-packet';
 import { itemOption1Packet } from './impl/item-option-1-packet';
 import { commandPacket } from './impl/command-packet';
+import { itemSwapPacket } from './impl/item-swap-packet';
 
 const packets: { [key: number]: incomingPacket } = {
     19:  interfaceClickPacket,
@@ -24,8 +25,9 @@ const packets: { [key: number]: incomingPacket } = {
 
     163: characterDesignPacket,
 
-    24: itemEquipPacket,
-    3:  itemOption1Packet,
+    24:  itemEquipPacket,
+    3:   itemOption1Packet,
+    123: itemSwapPacket,
 
     56: commandPacket
 };