From 7893ff412bbaf7ff2bed32b1a4d047bda23c0783 Mon Sep 17 00:00:00 2001
From: Dejvino <dejvino@gmail.com>
Date: Sat, 21 Jan 2017 16:10:04 +0100
Subject: [PATCH] Map: added base classes for consistent procedural generation.
 To be used for maps.

---
 .../model/AbstractProceduralBlock.java        | 50 +++++++++++++++++++
 src/roadtrip/model/ProceduralBlock.java       | 39 +++++++++++++++
 2 files changed, 89 insertions(+)
 create mode 100644 src/roadtrip/model/AbstractProceduralBlock.java
 create mode 100644 src/roadtrip/model/ProceduralBlock.java

diff --git a/src/roadtrip/model/AbstractProceduralBlock.java b/src/roadtrip/model/AbstractProceduralBlock.java
new file mode 100644
index 0000000..909cf9b
--- /dev/null
+++ b/src/roadtrip/model/AbstractProceduralBlock.java
@@ -0,0 +1,50 @@
+package roadtrip.model;
+
+import java.lang.reflect.Constructor;
+import java.lang.reflect.InvocationTargetException;
+import java.util.Random;
+
+/**
+ * Created by dejvino on 21.01.2017.
+ */
+public abstract class AbstractProceduralBlock implements ProceduralBlock
+{
+	private long seed;
+
+	public AbstractProceduralBlock(long seed)
+	{
+		this.seed = seed;
+	}
+
+	@Override
+	public long getBlockSeed()
+	{
+		return seed;
+	}
+
+	@Override
+	public Random getBlockRandom()
+	{
+		return new Random(seed);
+	}
+
+	@Override
+	public long getSubBlockSeed(String subBlockKey)
+	{
+		return (String.valueOf(seed) + "::" + subBlockKey).hashCode();
+	}
+
+	@Override
+	public <T extends ProceduralBlock> T getSubBlock(String subBlockKey, Class<T> subBlockClass)
+	{
+		if (subBlockClass == null) throw new NullPointerException("subBlockClass");
+		try {
+			Constructor<T> constructor = subBlockClass.getConstructor(Long.class);
+			return constructor.newInstance(getSubBlockSeed(subBlockKey));
+		} catch (NoSuchMethodException e) {
+			throw new IllegalArgumentException("Class " + subBlockClass + " does not have the default constructor with a single 'long' parameter.", e);
+		} catch (IllegalAccessException | InstantiationException | InvocationTargetException e) {
+			throw new IllegalArgumentException("Unable to instantiate sub-block.", e);
+		}
+	}
+}
diff --git a/src/roadtrip/model/ProceduralBlock.java b/src/roadtrip/model/ProceduralBlock.java
new file mode 100644
index 0000000..a2e0720
--- /dev/null
+++ b/src/roadtrip/model/ProceduralBlock.java
@@ -0,0 +1,39 @@
+package roadtrip.model;
+
+import java.util.Random;
+
+/**
+ * Created by dejvino on 21.01.2017.
+ */
+public interface ProceduralBlock
+{
+	/**
+	 * The main PRNG seed defining this block's content.
+	 * @return Seed value.
+	 */
+	long getBlockSeed();
+
+	/**
+	 * Random generator initialized with the block's seed.
+	 *
+	 * @return fresh PRNG.
+	 */
+	Random getBlockRandom();
+
+	/**
+	 * Provides a seed to be used with a sub-block with a given key (identifier).
+	 *
+	 * @param subBlockKey
+	 * @return Sub-block seed.
+	 */
+	long getSubBlockSeed(String subBlockKey);
+
+	/**
+	 * Provides a sub-block of the given class. The sub-block's seed is based on this block's seed.
+	 *
+	 * @param subBlockClass
+	 * @param <T>
+	 * @return Newly added sub-block.
+	 */
+	<T extends ProceduralBlock> T getSubBlock(String subBlockKey, Class<T> subBlockClass);
+}