Added event to allow modification of player visibility to mobs/AI (#3382)

(cherry picked from commit 0a5ef64d6ea96fe85d7c62107081ced649e6a3e9)

patches/minecraft/net/minecraft/world/World.java.patch

@@ -692,7 +692,16 @@
      }
  
      public boolean func_175640_z(BlockPos p_175640_1_)
-@@ -3240,7 +3427,7 @@
+@@ -3179,6 +3366,8 @@
+                     d2 *= ((Double)Objects.firstNonNull(p_184150_11_.apply(entityplayer1), Double.valueOf(1.0D))).doubleValue();
+                 }
+ 
++                d2 = net.minecraftforge.common.ForgeHooks.getPlayerVisibilityDistance(entityplayer1, d2, p_184150_9_);
++
+                 if ((p_184150_9_ < 0.0D || Math.abs(entityplayer1.field_70163_u - p_184150_3_) < p_184150_9_ * p_184150_9_) && (p_184150_7_ < 0.0D || d1 < d2 * d2) && (d0 == -1.0D || d1 < d0))
+                 {
+                     d0 = d1;
+@@ -3240,7 +3429,7 @@
  
      public long func_72905_C()
      {
@@ -701,7 +710,7 @@
      }
  
      public long func_82737_E()
-@@ -3250,17 +3437,17 @@
+@@ -3250,17 +3439,17 @@
  
      public long func_72820_D()
      {
@@ -722,7 +731,7 @@
  
          if (!this.func_175723_af().func_177746_a(blockpos))
          {
-@@ -3272,7 +3459,7 @@
+@@ -3272,7 +3461,7 @@
  
      public void func_175652_B(BlockPos p_175652_1_)
      {
@@ -731,7 +740,7 @@
      }
  
      @SideOnly(Side.CLIENT)
-@@ -3292,12 +3479,18 @@
+@@ -3292,12 +3481,18 @@
  
          if (!this.field_72996_f.contains(p_72897_1_))
          {
@@ -750,7 +759,7 @@
          return true;
      }
  
-@@ -3391,8 +3584,7 @@
+@@ -3391,8 +3586,7 @@
  
      public boolean func_180502_D(BlockPos p_180502_1_)
      {
@@ -760,7 +769,7 @@
      }
  
      @Nullable
-@@ -3453,12 +3645,12 @@
+@@ -3453,12 +3647,12 @@
  
      public int func_72800_K()
      {
@@ -775,7 +784,7 @@
      }
  
      public Random func_72843_D(int p_72843_1_, int p_72843_2_, int p_72843_3_)
-@@ -3502,7 +3694,7 @@
+@@ -3502,7 +3696,7 @@
      @SideOnly(Side.CLIENT)
      public double func_72919_O()
      {
@@ -784,7 +793,7 @@
      }
  
      public void func_175715_c(int p_175715_1_, BlockPos p_175715_2_, int p_175715_3_)
-@@ -3536,7 +3728,7 @@
+@@ -3536,7 +3730,7 @@
  
      public void func_175666_e(BlockPos p_175666_1_, Block p_175666_2_)
      {
@@ -793,7 +802,7 @@
          {
              BlockPos blockpos = p_175666_1_.func_177972_a(enumfacing);
  
-@@ -3621,6 +3813,112 @@
+@@ -3621,6 +3815,112 @@
          return i >= -128 && i <= 128 && j >= -128 && j <= 128;
      }
  

src/main/java/net/minecraftforge/common/ForgeHooks.java

@@ -116,6 +116,7 @@ import net.minecraftforge.event.entity.living.LivingSetAttackTargetEvent;
 import net.minecraftforge.event.entity.living.LootingLevelEvent;
 import net.minecraftforge.event.entity.player.AnvilRepairEvent;
 import net.minecraftforge.event.entity.player.AttackEntityEvent;
+import net.minecraftforge.event.entity.player.PlayerEvent;
 import net.minecraftforge.event.entity.player.PlayerInteractEvent;
 import net.minecraftforge.event.world.BlockEvent;
 import net.minecraftforge.event.world.NoteBlockEvent;
@@ -586,6 +587,14 @@ public class ForgeHooks
         return event.getLootingLevel();
     }
 
+    public static double getPlayerVisibilityDistance(EntityPlayer player, double xzDistance, double maxXZDistance)
+    {
+        PlayerEvent.Visibility event = new PlayerEvent.Visibility(player);
+        MinecraftForge.EVENT_BUS.post(event);
+        double value = event.getVisibilityModifier() * xzDistance;
+        return value >= maxXZDistance ? maxXZDistance : value;
+    }
+
     public static boolean isLivingOnLadder(IBlockState state, World world, BlockPos pos, EntityLivingBase entity)
     {
         boolean isSpectator = (entity instanceof EntityPlayer && ((EntityPlayer)entity).isSpectator());

src/main/java/net/minecraftforge/event/entity/player/PlayerEvent.java

@@ -351,4 +351,36 @@ public class PlayerEvent extends LivingEvent
             return playerUUID;
         }
     }
+
+    /**
+     * Fired when the world checks if a player is near enough to be attacked by an entity.
+     * The resulting visibility modifier is multiplied by the one calculated by Minecraft (based on sneaking and more) and used to calculate the radius a player has to be in (targetDistance*modifier).
+     * This can also be used to increase the visibility of a player, if it was decreased by Minecraft or other mods. But the resulting value cannot be higher than the standard target distance.
+     */
+    public static class Visibility extends PlayerEvent
+    {
+
+        private double visibilityModifier = 1D;
+
+        public Visibility(EntityPlayer player)
+        {
+            super(player);
+        }
+
+        /**
+         * @param mod Is multiplied with the current modifier
+         */
+        public void modifyVisibility(double mod)
+        {
+            visibilityModifier *= mod;
+        }
+
+        /**
+         * @return The current modifier
+         */
+        public double getVisibilityModifier()
+        {
+            return visibilityModifier;
+        }
+    }
 }