From dc7289a04817a2f25160f193ab0308c2e1cc7234 Mon Sep 17 00:00:00 2001
From: SenseiKiwi <senseikiwi@server.fake>
Date: Thu, 15 Aug 2013 07:29:37 -0400
Subject: [PATCH] Dungeon Selection Fix and Chain Config Change

Changed how Random is initialized in SchematicLoader to prevent issues
with dim doors in the same chunks leading to the same dungeon. The
selection seems much more varied now. Also changed the hardcoded config
for the default dungeon chains to the one we'll be using later (from a
file). For testing purposes.
---
 .../mod_pocketDim/SchematicLoader.java        | 51 +++++++++++++++----
 .../mod_pocketDim/helpers/DungeonHelper.java  | 15 ++++--
 2 files changed, 53 insertions(+), 13 deletions(-)

diff --git a/StevenDimDoors/mod_pocketDim/SchematicLoader.java b/StevenDimDoors/mod_pocketDim/SchematicLoader.java
index b1c796a..f5006f4 100644
--- a/StevenDimDoors/mod_pocketDim/SchematicLoader.java
+++ b/StevenDimDoors/mod_pocketDim/SchematicLoader.java
@@ -42,16 +42,9 @@ public class SchematicLoader
 				
 				if (dimList.get(destDimID).dungeonGenerator == null)
 				{
-					//The following initialization code is based on code from ChunkProviderGenerate.
-					//It makes our generation depend on the world seed. We have an additional seed here
-					//to prevent correlations between the selected dungeons and the locations of gateways.
 					//TODO: We should centralize RNG initialization and world-seed modifiers for each specific application.
-					
-					final long localSeed = world.getSeed() ^ 0x2F50DB9B4A8057E4L;
-					final Random random = new Random();
-					final long factorA = random.nextLong() / 2L * 2L + 1L;
-					final long factorB = random.nextLong() / 2L * 2L + 1L;
-					random.setSeed((link.destXCoord >> 4) * factorA + (link.destZCoord >> 4) * factorB ^ localSeed);
+					final long localSeed = world.getSeed() ^ 0x2F50DB9B4A8057E4L ^ computeDestinationHash(link);
+					final Random random = new Random(localSeed);
 					
 					dungeonHelper.generateDungeonLink(link, dungeonHelper.RuinsPack, random);
 				}
@@ -160,4 +153,44 @@ public class SchematicLoader
 		}
 		return dungeon;
 	}
+	
+	private static long computeDestinationHash(LinkData link)
+	{
+		//Time for some witchcraft.
+		//The code here is inspired by a discussion on Stack Overflow regarding hash codes for 3D.
+		//Source: http://stackoverflow.com/questions/9858376/hashcode-for-3d-integer-coordinates-with-high-spatial-coherence
+		
+		//Use 8 bits from Y and 24 bits from X and Z. Mix in 8 bits from the destination dim ID too - that means
+		//even if you aligned two doors perfectly between two pockets, it's unlikely they would lead to the same dungeon.
+		
+		int bit;
+		int index;
+		long hash;
+		int w = link.destDimID;
+		int x = link.destXCoord;
+		int y = link.destYCoord;
+		int z = link.destZCoord;
+		
+		hash = 0;
+		index = 0;
+		for (bit = 0; bit < 8; bit++)
+		{
+			hash |= ((w >> bit) & 1) << index;
+			index++;
+			hash |= ((x >> bit) & 1) << index;
+			index++;
+			hash |= ((y >> bit) & 1) << index;
+			index++;
+			hash |= ((z >> bit) & 1) << index;
+			index++;
+		}
+		for (; bit < 24; bit++)
+		{
+			hash |= ((x >> bit) & 1) << index;
+			index++;
+			hash |= ((z >> bit) & 1) << index;
+			index++;
+		}
+		return hash;
+	}
 }
\ No newline at end of file
diff --git a/StevenDimDoors/mod_pocketDim/helpers/DungeonHelper.java b/StevenDimDoors/mod_pocketDim/helpers/DungeonHelper.java
index 372979d..ae5e6c1 100644
--- a/StevenDimDoors/mod_pocketDim/helpers/DungeonHelper.java
+++ b/StevenDimDoors/mod_pocketDim/helpers/DungeonHelper.java
@@ -114,10 +114,17 @@ public class DungeonHelper
 		//It'll be removed later when we read dungeon configurations from files.
 
 		ArrayList<DungeonChainRuleDefinition> rules = new ArrayList<DungeonChainRuleDefinition>();
-		rules.add(parseDefinitionUnsafe("? ? ?  -> DeadEnd Exit"));
-		rules.add(parseDefinitionUnsafe("Trap -> ?"));
-		rules.add(parseDefinitionUnsafe("Hub -> Trap"));
-		rules.add(parseDefinitionUnsafe("? -> Hub"));
+
+		rules.add(parseDefinitionUnsafe("? ? ? ? ? ? ? ? -> Trap#20 SimpleHall#40 ComplexHall#10 Exit#20 DeadEnd#10"));
+
+		rules.add(parseDefinitionUnsafe("? ? ? ? -> Trap#18 SimpleHall#40 ComplexHall#10 Exit#18 DeadEnd#10 Hub#4"));
+
+		rules.add(parseDefinitionUnsafe("? ? ? -> ComplexHall Hub Trap SimpleHall Maze"));
+
+		rules.add(parseDefinitionUnsafe("? ? -> ComplexHall Hub Trap SimpleHall Maze"));
+
+		rules.add(parseDefinitionUnsafe("? -> ComplexHall#40 Hub#30 Trap#10 SimpleHall#10 Maze#10"));
+
 		rules.add(parseDefinitionUnsafe("-> ComplexHall#40 Hub#30 Trap#10 SimpleHall#10 Maze#10"));
 		
 		String[] typeNames = "Hub Trap Maze Exit DeadEnd SimpleHall ComplexHall".toUpperCase().split(" ");