From d3dd879dd523db03ff8c398e85329df88eae6632 Mon Sep 17 00:00:00 2001
From: Song Minjae <alswo9628@gmail.com>
Date: Tue, 20 Dec 2016 21:01:22 +0900
Subject: [PATCH] seamlessly looped terrain generation WIP (resolving issue #4)

Former-commit-id: cb2110fc1574ddfbff9ea6bd21596945c5895e13
Former-commit-id: 4f17d4d0bb1b1ed1ee61872651abfeb046de8b9c
---
 src/net/torvald/terrarum/Terrarum.kt           |  4 ++--
 .../terrarum/mapgenerator/WorldGenerator.kt    | 18 ++++++++++++++++--
 2 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/src/net/torvald/terrarum/Terrarum.kt b/src/net/torvald/terrarum/Terrarum.kt
index 651008b1f..e40af8051 100644
--- a/src/net/torvald/terrarum/Terrarum.kt
+++ b/src/net/torvald/terrarum/Terrarum.kt
@@ -234,11 +234,11 @@ constructor(gamename: String) : StateBasedGame(gamename) {
          * 0xAA_BB_XXXX
          * AA: Major version
          * BB: Minor version
-         * XXXX: Revision
+         * XXXX: Revision (Repository commits)
          *
          * e.g. 0x02010034 can be translated as 2.1.52
          */
-        const val VERSION_RAW = 0x0002006D
+        const val VERSION_RAW = 0x000200E1
         const val VERSION_STRING: String =
                 "${VERSION_RAW.ushr(24)}.${VERSION_RAW.and(0xFF0000).ushr(16)}.${VERSION_RAW.and(0xFFFF)}"
         const val NAME = "Terrarum"
diff --git a/src/net/torvald/terrarum/mapgenerator/WorldGenerator.kt b/src/net/torvald/terrarum/mapgenerator/WorldGenerator.kt
index 60930fb34..967a3db85 100644
--- a/src/net/torvald/terrarum/mapgenerator/WorldGenerator.kt
+++ b/src/net/torvald/terrarum/mapgenerator/WorldGenerator.kt
@@ -256,6 +256,8 @@ object WorldGenerator {
         return noiseArrayLocal
     }
 
+    private val TWO_PI = Math.PI * 2.0
+
     /**
      * http://accidentalnoise.sourceforge.net/minecraftworlds.html
      *
@@ -405,11 +407,23 @@ object WorldGenerator {
         println("[mapgenerator] Raising and eroding terrain...")
         for (y in 0..(TERRAIN_UNDULATION - 1)) {
             for (x in 0..WIDTH) {
-                val map: Boolean = (
+                // straight-line sampling
+                /*val map: Boolean = (
                         joise.get(
                                 x / SCALE_X,
                                 y / SCALE_Y
-                        ) == 1.0)
+                        ) == 1.0)*/
+                // circular sampling
+                // Mapping function:
+                //      World(x, y) -> Joise(sin x, y, cos x)
+                val sampleTheta = (x.toDouble() / WIDTH) * TWO_PI
+                val sampleOffset = (WIDTH / SCALE_X) / 4.0
+                val sampleX = Math.sin(sampleTheta) * sampleOffset + sampleOffset // plus sampleOffset to make only
+                val sampleZ = Math.cos(sampleTheta) * sampleOffset + sampleOffset // positive points are to be sampled
+                val sampleY = y / SCALE_Y
+                val map: Boolean = (
+                        joise.get(sampleX, sampleY, sampleZ) == 1.0
+                                   )
                 noiseMap[y + TERRAIN_AVERAGE_HEIGHT - (TERRAIN_UNDULATION / 2)].set(x, map)
             }
         }