Add dPlayer.spectate mech

Yay forced cameras!

src/main/java/net/aufdemrand/denizen/objects/dPlayer.java

@@ -11,10 +11,7 @@
 import net.aufdemrand.denizen.utilities.debugging.dB;
 import net.aufdemrand.denizen.utilities.depends.Depends;
 import net.aufdemrand.denizen.utilities.nbt.ImprovedOfflinePlayer;
-import net.aufdemrand.denizen.utilities.packets.BossHealthBar;
-import net.aufdemrand.denizen.utilities.packets.EntityEquipment;
-import net.aufdemrand.denizen.utilities.packets.ItemChangeMessage;
-import net.aufdemrand.denizen.utilities.packets.PlayerBars;
+import net.aufdemrand.denizen.utilities.packets.*;
 import net.citizensnpcs.api.CitizensAPI;
 import net.citizensnpcs.api.npc.NPC;
 import net.minecraft.server.v1_8_R1.PacketPlayOutGameStateChange;
@@ -2197,6 +2194,20 @@ else if (split.length > 1) {
                     .sendPacket(new PacketPlayOutGameStateChange(4, 0.0F));
         }
 
+        // <--[mechanism]
+        // @object dPlayer
+        // @name spectate
+        // @input dEntity
+        // @description
+        // Forces the player to spectate from the entity's point of view.
+        // Note: They cannot cancel the spectating without a re-log -- you
+        // must make them spectate themselves to cancel the effect.
+        // (i.e. - adjust <player> "spectate:<player>")
+        // -->
+        if (mechanism.matches("spectate") && mechanism.requireObject(dEntity.class)) {
+            PlayerSpectateEntity.setSpectating(getPlayerEntity(), value.asType(dEntity.class).getBukkitEntity());
+        }
+
         // Iterate through this object's properties' mechanisms
         for (Property property : PropertyParser.getProperties(this)) {
             property.adjust(mechanism);

src/main/java/net/aufdemrand/denizen/utilities/packets/PlayerSpectateEntity.java

@@ -0,0 +1,34 @@
+package net.aufdemrand.denizen.utilities.packets;
+
+import net.aufdemrand.denizen.utilities.debugging.dB;
+import net.minecraft.server.v1_8_R1.PacketPlayOutCamera;
+import org.bukkit.entity.Entity;
+import org.bukkit.entity.Player;
+
+import java.lang.reflect.Field;
+import java.util.Map;
+
+public class PlayerSpectateEntity {
+
+    private static final Field entity_id;
+
+    static {
+        Map<String, Field> fields = PacketHelper.registerFields(PacketPlayOutCamera.class);
+        entity_id = fields.get("a");
+    }
+
+    public static PacketPlayOutCamera getCameraPacket(Entity entity) {
+        PacketPlayOutCamera cameraPacket = new PacketPlayOutCamera();
+        try {
+            entity_id.set(cameraPacket, entity.getEntityId());
+        } catch (Exception e) {
+            dB.echoError(e);
+        }
+        return cameraPacket;
+    }
+
+    public static void setSpectating(Player player, Entity entity) {
+        PacketPlayOutCamera cameraPacket = getCameraPacket(entity);
+        PacketHelper.sendPacket(player, cameraPacket);
+    }
+}