Apply offsets to the logical plot grid

src/test/java/com/majinnaibu/bukkitplugins/metropolis/PlotGridLayoutTest.java

@@ -0,0 +1,55 @@
+/*
+This file is part of Metropolis.
+
+Metropolis is free software: you can redistribute it and/or modify
+it under the terms of the GNU Affero General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+Metropolis is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU Affero General Public License for more details.
+
+You should have received a copy of the GNU Affero General Public License
+along with Metropolis. If not, see <https://www.gnu.org/licenses/agpl-3.0.txt>.
+*/
+
+package com.majinnaibu.bukkitplugins.metropolis;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import com.sk89q.worldedit.math.BlockVector3;
+
+import org.junit.jupiter.api.Test;
+
+class PlotGridLayoutTest {
+  @Test
+  void zeroOffsetsPreserveTheExistingPlotGrid() {
+    PlotGridLayout grid = new PlotGridLayout(32, 10, 32, 4, 4, 0, 0, 0, 62);
+
+    assertEquals(BlockVector3.at(0, 62, 0), grid.gridMin(0, 0, 0));
+    assertEquals(BlockVector3.at(35, 71, 35), grid.gridMax(0, 0, 1, 1, 0));
+    assertEquals(BlockVector3.at(2, 62, 2), grid.plotMin(0, 0, 0));
+    assertEquals(BlockVector3.at(33, 71, 33), grid.plotMax(0, 0, 1, 1, 0));
+  }
+
+  @Test
+  void offsetsShiftGridAndPlotsOnAllAxesIncludingHigherLevels() {
+    PlotGridLayout grid = new PlotGridLayout(32, 10, 32, 2, 6, -7, 3, 11, 62);
+
+    assertEquals(BlockVector3.at(-45, 97, -23), grid.gridMin(-1, -1, 2));
+    assertEquals(BlockVector3.at(30, 106, 44), grid.gridMax(-1, -1, 2, 2, 2));
+    assertEquals(BlockVector3.at(-42, 97, -22), grid.plotMin(-1, -1, 2));
+    assertEquals(BlockVector3.at(27, 106, 43), grid.plotMax(-1, -1, 2, 2, 2));
+  }
+
+  @Test
+  void mapsNegativePlotBoundsBackToTheirLogicalIndices() {
+    PlotGridLayout grid = new PlotGridLayout(32, 10, 32, 2, 6, -7, 3, 11, 62);
+    Cuboid plot = new Cuboid(grid.plotMin(-1, -1, 0), grid.plotMax(-1, -1, 2, 2, 0));
+
+    assertEquals(-1, grid.plotXIndexFromMin(plot));
+    assertEquals(-1, grid.plotZIndexFromMin(plot));
+  }
+}

src/test/java/com/majinnaibu/bukkitplugins/metropolis/SpawnLayoutTest.java

@@ -26,21 +26,21 @@ import org.junit.jupiter.api.Test;
 class SpawnLayoutTest {
   @Test
   void defaultMultipliersPreserveTheOnePlotSpawnBounds() {
-    Cuboid spawn = SpawnLayout.bounds(1, 1, 1, 32, 10, 32, 4, 4, 62);
+    Cuboid spawn = SpawnLayout.bounds(1, 1, 1, 32, 10, 32, 4, 4, 62, 0, 0, 0);
 
     assertEqualsBounds(spawn, 2, 62, 2, 33, 71, 33);
   }
 
   @Test
   void appliesEachMultiplierToItsOwnAlignedGridDimension() {
-    Cuboid spawn = SpawnLayout.bounds(2, 3, 4, 32, 10, 32, 4, 4, 62);
+    Cuboid spawn = SpawnLayout.bounds(2, 3, 4, 32, 10, 32, 4, 4, 62, 0, 0, 0);
 
     assertEqualsBounds(spawn, 2, 62, 2, 69, 91, 141);
   }
 
   @Test
   void validatesTheEntireSpawnHeightAgainstWorldBounds() {
-    Cuboid spawn = SpawnLayout.bounds(1, 3, 1, 32, 10, 32, 4, 4, 62);
+    Cuboid spawn = SpawnLayout.bounds(1, 3, 1, 32, 10, 32, 4, 4, 62, 0, 0, 0);
 
     assertTrue(SpawnLayout.withinBuildHeight(spawn, -64, 320));
     assertFalse(SpawnLayout.withinBuildHeight(spawn, -64, 91));
@@ -48,15 +48,23 @@ class SpawnLayoutTest {
 
   @Test
   void alignsSpawnAxesToTheirIndependentRoadWidths() {
-    Cuboid spawn = SpawnLayout.bounds(2, 1, 3, 32, 10, 32, 6, 2, 62);
+    Cuboid spawn = SpawnLayout.bounds(2, 1, 3, 32, 10, 32, 6, 2, 62, 0, 0, 0);
 
     assertEqualsBounds(spawn, 3, 62, 1, 72, 71, 100);
   }
 
+  @Test
+  void alignsSpawnBoundsWithAllGridOffsets() {
+    Cuboid spawn = SpawnLayout.bounds(2, 2, 3, 32, 10, 32, 6, 2, 62, -7, 3, 11);
+
+    assertEqualsBounds(spawn, -4, 65, 12, 65, 84, 111);
+  }
+
   @Test
   void rejectsNonPositiveSpawnMultipliers() {
     assertThrows(
-        IllegalArgumentException.class, () -> SpawnLayout.bounds(0, 1, 1, 32, 10, 32, 4, 4, 62));
+        IllegalArgumentException.class,
+        () -> SpawnLayout.bounds(0, 1, 1, 32, 10, 32, 4, 4, 62, 0, 0, 0));
   }
 
   private static void assertEqualsBounds(