From 36d417d3db0c7dd41036172abfc2b95c65dbf760 Mon Sep 17 00:00:00 2001
From: dfsek <dfsek@protonmail.com>
Date: Tue, 28 Dec 2021 17:46:40 -0700
Subject: [PATCH] implement padded grid distributor

---
 .../feature/distributor/DistributorAddon.java |  2 +
 .../config/PaddedGridDistributorTemplate.java | 25 +++++++++++++
 .../distributors/PaddedGridDistributor.java   | 37 +++++++++++++++++++
 3 files changed, 64 insertions(+)
 create mode 100644 common/addons/config-distributors/src/main/java/com/dfsek/terra/addons/feature/distributor/config/PaddedGridDistributorTemplate.java
 create mode 100644 common/addons/config-distributors/src/main/java/com/dfsek/terra/addons/feature/distributor/distributors/PaddedGridDistributor.java

diff --git a/common/addons/config-distributors/src/main/java/com/dfsek/terra/addons/feature/distributor/DistributorAddon.java b/common/addons/config-distributors/src/main/java/com/dfsek/terra/addons/feature/distributor/DistributorAddon.java
index 182cc935c..f28e5b02d 100644
--- a/common/addons/config-distributors/src/main/java/com/dfsek/terra/addons/feature/distributor/DistributorAddon.java
+++ b/common/addons/config-distributors/src/main/java/com/dfsek/terra/addons/feature/distributor/DistributorAddon.java
@@ -13,6 +13,7 @@ import java.util.function.Supplier;
 
 import com.dfsek.terra.addons.feature.distributor.config.AndDistributorTemplate;
 import com.dfsek.terra.addons.feature.distributor.config.NoDistributorTemplate;
+import com.dfsek.terra.addons.feature.distributor.config.PaddedGridDistributorTemplate;
 import com.dfsek.terra.addons.feature.distributor.config.SamplerDistributorTemplate;
 import com.dfsek.terra.addons.feature.distributor.config.OrDistributorTemplate;
 import com.dfsek.terra.addons.feature.distributor.config.PointSetDistributorTemplate;
@@ -49,6 +50,7 @@ public class DistributorAddon implements AddonInitializer {
                             DISTRIBUTOR_TOKEN);
                     distributorRegistry.register(addon.key("SAMPLER"), SamplerDistributorTemplate::new);
                     distributorRegistry.register(addon.key("POINTS"), PointSetDistributorTemplate::new);
+                    distributorRegistry.register(addon.key("PADDED_GRID"), PaddedGridDistributorTemplate::new);
                     distributorRegistry.register(addon.key("AND"), AndDistributorTemplate::new);
                     distributorRegistry.register(addon.key("OR"), OrDistributorTemplate::new);
                     distributorRegistry.register(addon.key("YES"), YesDistributorTemplate::new);
diff --git a/common/addons/config-distributors/src/main/java/com/dfsek/terra/addons/feature/distributor/config/PaddedGridDistributorTemplate.java b/common/addons/config-distributors/src/main/java/com/dfsek/terra/addons/feature/distributor/config/PaddedGridDistributorTemplate.java
new file mode 100644
index 000000000..ff77d18be
--- /dev/null
+++ b/common/addons/config-distributors/src/main/java/com/dfsek/terra/addons/feature/distributor/config/PaddedGridDistributorTemplate.java
@@ -0,0 +1,25 @@
+package com.dfsek.terra.addons.feature.distributor.config;
+
+import com.dfsek.tectonic.api.config.template.annotations.Value;
+import com.dfsek.tectonic.api.config.template.object.ObjectTemplate;
+
+import com.dfsek.terra.addons.feature.distributor.distributors.PaddedGridDistributor;
+import com.dfsek.terra.api.config.meta.Meta;
+import com.dfsek.terra.api.structure.feature.Distributor;
+
+
+public class PaddedGridDistributorTemplate implements ObjectTemplate<Distributor> {
+    @Value("width")
+    private @Meta int width;
+    
+    @Value("padding")
+    private @Meta int padding;
+    
+    @Value("salt")
+    private @Meta int salt;
+    
+    @Override
+    public Distributor get() {
+        return new PaddedGridDistributor(width, padding, salt);
+    }
+}
diff --git a/common/addons/config-distributors/src/main/java/com/dfsek/terra/addons/feature/distributor/distributors/PaddedGridDistributor.java b/common/addons/config-distributors/src/main/java/com/dfsek/terra/addons/feature/distributor/distributors/PaddedGridDistributor.java
new file mode 100644
index 000000000..1be75d3e5
--- /dev/null
+++ b/common/addons/config-distributors/src/main/java/com/dfsek/terra/addons/feature/distributor/distributors/PaddedGridDistributor.java
@@ -0,0 +1,37 @@
+package com.dfsek.terra.addons.feature.distributor.distributors;
+
+import com.dfsek.terra.api.structure.feature.Distributor;
+
+import com.dfsek.terra.api.util.MathUtil;
+
+import net.jafama.FastMath;
+
+import java.util.Random;
+
+
+public class PaddedGridDistributor implements Distributor {
+    private final int width;
+    
+    private final int cellWidth;
+    
+    private final int salt;
+    
+    public PaddedGridDistributor(int width, int padding, int salt) {
+        this.width = width;
+        this.salt = salt;
+        this.cellWidth = width + padding;
+    }
+    
+    @Override
+    public boolean matches(int x, int z, long seed) {
+        int cellX = FastMath.floorDiv(x, cellWidth);
+        int cellZ = FastMath.floorDiv(z, cellWidth);
+    
+        Random random = new Random(MathUtil.squash(cellX, cellZ) + salt);
+        
+        int pointX = random.nextInt(width) + cellX * cellWidth;
+        int pointZ = random.nextInt(width) + cellZ * cellWidth;
+        
+        return x == pointX && z == pointZ;
+    }
+}