From 59e10a782b93c35db0309adfd1b6aed96ed561c8 Mon Sep 17 00:00:00 2001
From: WayofTime <wtime@live.ca>
Date: Sun, 16 Oct 2016 19:33:14 -0400
Subject: [PATCH] Modified the Sigil of the Phantom Bridge so it better
 performs with speed modifications

---
 changelog.txt                                 |  1 +
 .../item/sigil/ItemSigilPhantomBridge.java    | 70 ++++++++++++++++---
 2 files changed, 62 insertions(+), 9 deletions(-)

diff --git a/changelog.txt b/changelog.txt
index e6547b15..32dec725 100644
--- a/changelog.txt
+++ b/changelog.txt
@@ -13,6 +13,7 @@ Version 2.1.0-66
 - Changed most of the BlockString blocks to a BlockEnum in order to solve a loading issue with schematics.
 - Added the entries for the Skeleton Turret Array and the Updraft Array
 - Added the Bounce Array
+- Modified the Sigil of the Phantom Bridge so it better performs with speed modifications
 
 ------------------------------------------------------
 Version 2.1.0-65
diff --git a/src/main/java/WayofTime/bloodmagic/item/sigil/ItemSigilPhantomBridge.java b/src/main/java/WayofTime/bloodmagic/item/sigil/ItemSigilPhantomBridge.java
index f6745251..8a8846a0 100644
--- a/src/main/java/WayofTime/bloodmagic/item/sigil/ItemSigilPhantomBridge.java
+++ b/src/main/java/WayofTime/bloodmagic/item/sigil/ItemSigilPhantomBridge.java
@@ -1,13 +1,23 @@
 package WayofTime.bloodmagic.item.sigil;
 
+import java.util.HashMap;
+import java.util.Map;
+
 import net.minecraft.entity.player.EntityPlayer;
 import net.minecraft.item.ItemStack;
 import net.minecraft.util.math.BlockPos;
 import net.minecraft.world.World;
+
+import org.apache.commons.lang3.tuple.Pair;
+
 import WayofTime.bloodmagic.registry.ModBlocks;
 
 public class ItemSigilPhantomBridge extends ItemSigilToggleableBase
 {
+    private Map<EntityPlayer, Pair<Double, Double>> prevPositionMap = new HashMap<EntityPlayer, Pair<Double, Double>>();
+    private double expansionFactor = 2;
+    private int range = 3;
+
     public ItemSigilPhantomBridge()
     {
         super("phantomBridge", 100);
@@ -16,28 +26,70 @@ public class ItemSigilPhantomBridge extends ItemSigilToggleableBase
     @Override
     public void onSigilUpdate(ItemStack stack, World world, EntityPlayer player, int itemSlot, boolean isSelected)
     {
-        if ((!player.onGround && !player.isRiding()) && !player.isSneaking())
-            return;
+        if (!prevPositionMap.containsKey(player))
+        {
+            prevPositionMap.put(player, Pair.of(player.posX, player.posZ));
+        }
+
+        if ((!player.onGround && !player.isRiding()) && !player.isSneaking())
+        {
+            prevPositionMap.put(player, Pair.of(player.posX, player.posZ));
+            return;
+        }
 
-        int range = 2;
         int verticalOffset = -1;
 
         if (player.isSneaking())
             verticalOffset--;
 
-        int posX = (int) Math.round(player.posX - 0.5f);
-        int posY = (int) player.posY;
-        int posZ = (int) Math.round(player.posZ - 0.5f);
+        Pair<Double, Double> prevPosition = prevPositionMap.get(player);
 
-        for (int ix = posX - range; ix <= posX + range; ix++)
+        double playerVelX = player.posX - prevPosition.getLeft();
+        double playerVelZ = player.posZ - prevPosition.getRight();
+
+        double totalVel = Math.sqrt(playerVelX * playerVelX + playerVelZ * playerVelZ);
+        if (totalVel > 2)
         {
-            for (int iz = posZ - range; iz <= posZ + range; iz++)
+            //I am SURE you are teleporting!
+            playerVelX = 0;
+            playerVelZ = 0;
+        }
+
+        BlockPos playerPos = player.getPosition();
+        int posX = playerPos.getX();
+        int posY = playerPos.getY();
+        int posZ = playerPos.getZ();
+
+        double offsetPosX = posX + expansionFactor * playerVelX;
+        double offsetPosZ = posZ + expansionFactor * playerVelZ;
+        double avgX = (posX + offsetPosX) / 2;
+        double avgZ = (posZ + offsetPosZ) / 2;
+
+        double C = 2 * (range + expansionFactor * totalVel) + 1;
+        int truncC = (int) C;
+
+        //TODO: Make this for-loop better.
+        for (int ix = -truncC; ix <= truncC; ix++)
+        {
+            for (int iz = -truncC; iz <= truncC; iz++)
             {
-                BlockPos blockPos = new BlockPos(ix, posY + verticalOffset, iz);
+                if (computeEllipse(ix + avgX, iz + avgZ, posX, posZ, offsetPosX, offsetPosZ) > C)
+                {
+                    continue;
+                }
+
+                BlockPos blockPos = new BlockPos(ix + posX, posY + verticalOffset, iz + posZ);
 
                 if (world.isAirBlock(blockPos))
                     world.setBlockState(blockPos, ModBlocks.PHANTOM_BLOCK.getDefaultState());
             }
         }
+
+        prevPositionMap.put(player, Pair.of(player.posX, player.posZ));
+    }
+
+    public static double computeEllipse(double x, double z, double focusX1, double focusZ1, double focusX2, double focusZ2)
+    {
+        return Math.sqrt((x - focusX1) * (x - focusX1) + (z - focusZ1) * (z - focusZ1)) + Math.sqrt((x - focusX2) * (x - focusX2) + (z - focusZ2) * (z - focusZ2));
     }
 }