From cc0c64a610efed72b6b48fa562900eaaf84c178e Mon Sep 17 00:00:00 2001
From: JitseB <Jitse@operamail.com>
Date: Mon, 7 May 2018 10:14:55 +0200
Subject: [PATCH] Work on issue #7 (skin rendering issue).

---
 .../main/java/net/jitse/npclib/api/NPC.java   | 21 +++++++++++++
 .../npclib/listeners/PlayerListener.java      | 10 +++---
 .../net/jitse/npclib/plugin/NPCLibPlugin.java | 31 ++++++++++++-------
 3 files changed, 46 insertions(+), 16 deletions(-)

diff --git a/commons/src/main/java/net/jitse/npclib/api/NPC.java b/commons/src/main/java/net/jitse/npclib/api/NPC.java
index 6c20b7e..2b3469d 100644
--- a/commons/src/main/java/net/jitse/npclib/api/NPC.java
+++ b/commons/src/main/java/net/jitse/npclib/api/NPC.java
@@ -15,6 +15,7 @@ import org.bukkit.Bukkit;
 import org.bukkit.Location;
 import org.bukkit.entity.Player;
 import org.bukkit.plugin.java.JavaPlugin;
+import org.bukkit.util.Vector;
 
 import java.util.*;
 
@@ -113,6 +114,17 @@ public abstract class NPC {
             return;
         }
 
+        if (!canSeeNPC(player)) {
+            if (!auto) {
+                shown.add(player.getUniqueId());
+            }
+
+            if (!autoHidden.contains(player.getUniqueId())) {
+                autoHidden.add(player.getUniqueId());
+            }
+            return;
+        }
+
         if (auto) {
             sendShowPackets(player);
         } else {
@@ -132,6 +144,15 @@ public abstract class NPC {
         }
     }
 
+    public boolean canSeeNPC(Player player) {
+        Vector dir = location.toVector().subtract(player.getEyeLocation().toVector()).normalize();
+        double dot = dir.dot(player.getLocation().getDirection());
+        Bukkit.broadcastMessage("dot: " + dot);
+        // 0.5 equals a FOV of 60 deg (but should be 0.55)
+        // We want to spawn the NPC *just* before the player can see it.
+        return dot >= 0.5;
+    }
+
     // Internal method.
     protected abstract void sendShowPackets(Player player);
 
diff --git a/commons/src/main/java/net/jitse/npclib/listeners/PlayerListener.java b/commons/src/main/java/net/jitse/npclib/listeners/PlayerListener.java
index 8b6f37e..3252315 100644
--- a/commons/src/main/java/net/jitse/npclib/listeners/PlayerListener.java
+++ b/commons/src/main/java/net/jitse/npclib/listeners/PlayerListener.java
@@ -58,9 +58,9 @@ public class PlayerListener implements Listener {
         Location from = event.getFrom();
         Location to = event.getTo();
 
-        if (from.getX() == to.getX() && from.getY() == to.getY() && from.getZ() == to.getZ()) {
-            return;
-        }
+//        if (from.getX() == to.getX() && from.getY() == to.getY() && from.getZ() == to.getZ()) {
+//            return;
+//        }
 
         handleMove(event.getPlayer());
     }
@@ -89,14 +89,14 @@ public class PlayerListener implements Listener {
             if (npc.getAutoHidden().contains(player.getUniqueId())) {
                 // Check if the player and NPC are within the range to sendShowPackets it again.
                 if (inRange) {
-                    npc.show(player, true);
                     npc.getAutoHidden().remove(player.getUniqueId());
+                    npc.show(player, true);
                 }
             } else {
                 // Check if the player and NPC are out of range to sendHidePackets it.
                 if (!inRange) {
-                    npc.hide(player, true, true);
                     npc.getAutoHidden().add(player.getUniqueId());
+                    npc.hide(player, true, true);
                 }
             }
         }
diff --git a/plugin/src/main/java/net/jitse/npclib/plugin/NPCLibPlugin.java b/plugin/src/main/java/net/jitse/npclib/plugin/NPCLibPlugin.java
index 2cd427d..b8a4e3d 100644
--- a/plugin/src/main/java/net/jitse/npclib/plugin/NPCLibPlugin.java
+++ b/plugin/src/main/java/net/jitse/npclib/plugin/NPCLibPlugin.java
@@ -23,6 +23,7 @@ import java.util.Arrays;
 public class NPCLibPlugin extends JavaPlugin implements Listener {
 
     private NPCLib npcLib;
+    private NPC npc;
 
     @Override
     public void onEnable() {
@@ -48,17 +49,25 @@ public class NPCLibPlugin extends JavaPlugin implements Listener {
             return;
         }
 
-        MineSkinFetcher.fetchSkinFromIdAsync(168841, skin -> {
-            NPC npc = npcLib.createNPC(skin, Arrays.asList(
-                    ChatColor.BOLD + "NPC Library", "",
-                    "Create your own", "non-player characters",
-                    "with the simplistic", "API of NPCLib!"
-            ));
-            npc.create(event.getPlayer().getLocation());
-
-            for (Player player : getServer().getOnlinePlayers()) {
-                npc.show(player);
+        if (npc != null) {
+            if (npc.isActuallyShown(event.getPlayer())) {
+                npc.hide(event.getPlayer());
+            } else {
+                npc.show(event.getPlayer());
             }
-        });
+        } else {
+            MineSkinFetcher.fetchSkinFromIdAsync(168841, skin -> {
+                npc = npcLib.createNPC(skin, Arrays.asList(
+                        ChatColor.BOLD + "NPC Library", "",
+                        "Create your own", "non-player characters",
+                        "with the simplistic", "API of NPCLib!"
+                ));
+                npc.create(event.getPlayer().getLocation());
+
+                for (Player player : getServer().getOnlinePlayers()) {
+                    npc.show(player);
+                }
+            });
+        }
     }
 }