Add spiral algorithm test cases

Author: robotgryphon

src/main/java/com/robotgryphon/compactmachines/util/MathUtil.java

@@ -1,5 +1,6 @@
 package com.robotgryphon.compactmachines.util;
 
+import net.minecraft.util.math.BlockPos;
 import net.minecraft.util.math.vector.Vector3i;
 
 public class MathUtil {
@@ -40,4 +41,11 @@ public static Vector3i getRegionPositionByIndex(int i) {
 
         return new Vector3i(x, 0, y);
     }
+
+    public static BlockPos getCenterWithY(Vector3i regionIndex, int y) {
+        return new BlockPos(
+                (regionIndex.getX() * 1024) + 8,
+                y,
+                (regionIndex.getZ() * 1024) + 8);
+    }
 }

src/main/java/com/robotgryphon/compactmachines/util/PlayerUtil.java

@@ -82,10 +82,7 @@ public static void teleportPlayerIntoMachine(ServerPlayerEntity serverPlayer, Bl
             Vector3i location = MathUtil.getRegionPositionByIndex(nextId);
 
             int centerY = ServerConfig.MACHINE_FLOOR_Y.get() + (size.getInternalSize() / 2);
-            BlockPos newCenter = new BlockPos(
-                    (location.getX() * 1024) + 8,
-                    centerY,
-                    (location.getZ() * 1024) + 8);
+            BlockPos newCenter = MathUtil.getCenterWithY(location, centerY);
 
             // Generate a new machine inside and update the tile
             CompactStructureGenerator.generateCompactStructure(compactWorld, size, newCenter);

src/test/java/com/robotgryphon/compactmachines/tests/MathTests.java

@@ -0,0 +1,44 @@
+package com.robotgryphon.compactmachines.tests;
+
+import com.robotgryphon.compactmachines.util.MathUtil;
+import net.minecraft.util.math.BlockPos;
+import net.minecraft.util.math.ChunkPos;
+import net.minecraft.util.math.vector.Vector3i;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+import java.util.HashMap;
+
+public class MathTests {
+
+    @Test
+    void positionGeneratorWorksCorrectly() {
+        // Our generation works in a counter-clockwise spiral, starting at 0,0
+        /*
+         *    6  5  4
+         *    7  0  3
+         *    8  1  2
+         */
+
+        HashMap<Integer, ChunkPos> tests = new HashMap<>();
+        tests.put(0, new ChunkPos(0, 0));
+        tests.put(1, new ChunkPos(0, -64));
+        tests.put(2, new ChunkPos(64, -64));
+        tests.put(3, new ChunkPos(64, 0));
+        tests.put(4, new ChunkPos(64, 64));
+        tests.put(5, new ChunkPos(0, 64));
+        tests.put(6, new ChunkPos(-64, 64));
+        tests.put(7, new ChunkPos(-64, 0));
+        tests.put(8, new ChunkPos(-64, -64));
+
+        tests.forEach((id, expectedChunk) -> {
+            Vector3i byIndex = MathUtil.getRegionPositionByIndex(id);
+            BlockPos finalPos = MathUtil.getCenterWithY(byIndex, 0);
+
+            ChunkPos calculatedChunk = new ChunkPos(finalPos);
+
+            String error = String.format("Generation did not match for %s.", id);
+            Assertions.assertEquals(expectedChunk, calculatedChunk, error);
+        });
+    }
+}