world saving and loading integrated into the game

.gitignore

@@ -7,6 +7,9 @@
 # BlueJ files
 *.ctxt
 
+# run
+saves/
+
 # Mobile Tools for Java (J2ME)
 .mtj.tmp/
 

src/main/java/com/github/halotroop/litecraft/Litecraft.java

@@ -4,9 +4,11 @@ import java.util.Random;
 
 import org.lwjgl.glfw.GLFW;
 
+import com.github.halotroop.litecraft.save.LitecraftSave;
 import com.github.halotroop.litecraft.screens.TitleScreen;
+import com.github.halotroop.litecraft.types.block.*;
 import com.github.halotroop.litecraft.world.World;
-import com.github.halotroop.litecraft.world.gen.Dimension;
+import com.github.halotroop.litecraft.world.gen.*;
 import com.github.hydos.ginger.engine.api.*;
 import com.github.hydos.ginger.engine.api.game.*;
 import com.github.hydos.ginger.engine.cameras.*;
@@ -26,6 +28,7 @@ import tk.valoeghese.gateways.client.io.*;
 public class Litecraft extends Game
 {
 	private World world;
+	private LitecraftSave save;
 	private Ginger ginger3D;
 	private static Litecraft INSTANCE;
 
@@ -51,6 +54,8 @@ public class Litecraft extends Game
 
 		setupKeybinds();
 
+		Block b = Blocks.AIR; // make sure blocks are initialised
+
 		GingerUtils.init();
 		Window.setBackgroundColour(0.2f, 0.2f, 0.6f);
 		TexturedModel dirtModel = ModelLoader.loadGenericCube("block/cubes/stone/brick/stonebrick.png");
@@ -89,6 +94,7 @@ public class Litecraft extends Game
 	@Override
 	public void exit()
 	{
+		this.world.unloadAllChunks();
 		ginger3D.cleanup(); 
 		System.exit(0);
 	}
@@ -146,7 +152,8 @@ public class Litecraft extends Game
 	public void onPlayButtonClick() {
 		if (world == null)
 		{
-			world = new World(new Random().nextLong(), 2, Dimension.OVERWORLD);
+			this.save = new LitecraftSave("test", false);
+			this.world = this.save.getWorldOrCreate(Dimensions.OVERWORLD);
 		}		
 	}
 }

src/main/java/com/github/halotroop/litecraft/save/LitecraftSave.java

@@ -1,59 +1,67 @@
 package com.github.halotroop.litecraft.save;
 
 import java.io.*;
+import java.util.Random;
 
-import com.github.halotroop.litecraft.world.Chunk;
+import com.github.halotroop.litecraft.world.*;
+import com.github.halotroop.litecraft.world.gen.*;
 
-import tk.valoeghese.sod.BinaryData;
+import tk.valoeghese.sod.*;
 
 public final class LitecraftSave
 {
 	public LitecraftSave(String name, boolean mustCreateNew)
 	{
 		StringBuilder sb = new StringBuilder(SAVE_DIR).append(name);
-		File saveFile = new File(sb.toString());
+		File saveDir = new File(sb.toString());
 
 		if (mustCreateNew)
 		{
-			while (saveFile.exists())
+			while (saveDir.exists())
 			{
-				sb.append('_');
-				saveFile = new File(sb.toString());
+				sb.append('_'); // append "_" to the save name until we get a unique save, if we must create a new save
+				saveDir = new File(sb.toString());
 			}
 		}
 
-		this.file = saveFile;
+		this.file = saveDir;
 		this.file.mkdirs();
 	}
 
 	private final File file;
 
-	public void saveChunk(Chunk chunk)
+	public boolean saveChunk(Chunk chunk)
 	{
 		StringBuilder fileLocBuilder = new StringBuilder(this.file.getPath())
+				.append('/').append(chunk.dimension)
 				.append('/').append(chunk.chunkX)
 				.append('/').append(chunk.chunkZ);
 		File chunkDir = new File(fileLocBuilder.toString());
-		chunkDir.mkdirs();
+		chunkDir.mkdirs(); // create directory for file if it does not exist
+
+		// format: <save dir>/<dim>/<chunkX>/<chunkZ>/<chunkY>.sod
 		File chunkFile = new File(fileLocBuilder.append('/').append(chunk.chunkY).append(".sod").toString());
 
 		try
 		{
 			chunkFile.createNewFile();
 
-			BinaryData data = new BinaryData();
-			chunk.write(data);
-			data.write(chunkFile);
+			BinaryData data = new BinaryData(); // create new empty binary data
+			chunk.write(data); // write the chunk info to the binary data
+			return data.write(chunkFile); // write the data to the file, return whether an io exception occurred
 		}
 		catch (IOException e)
 		{
 			e.printStackTrace();
+			return false; // io exception = chunk writing failed at some point
 		}
 	}
 
-	public Chunk readChunk(int chunkX, int chunkY, int chunkZ)
+	public Chunk readChunk(int chunkX, int chunkY, int chunkZ, int dimension)
 	{
+		// format: <save dir>/<dim>/<chunkX>/<chunkZ>/<chunkY>.sod
 		File chunkFile = new File(new StringBuilder(this.file.getPath())
+				.append('/').append(dimension)
 				.append('/').append(chunkX)
 				.append('/').append(chunkZ)
 				.append('/').append(chunkY).append(".sod").toString());
@@ -62,12 +70,60 @@ public final class LitecraftSave
 		{
 			BinaryData data = BinaryData.read(chunkFile);
 
-			Chunk result = new Chunk(chunkX, chunkY, chunkZ);
-			result.read(data);
+			Chunk result = new Chunk(chunkX, chunkY, chunkZ, dimension); // create chunk
+			result.read(data); // load the chunk data we have just read into the chunk
 			return result;
 		}
 		else return null;
 	}
 
+	public World getWorldOrCreate(Dimension<?> dim)
+	{
+		File worldFile = new File(this.file.getPath() + "/global_data.sod");
+
+		if (worldFile.isFile()) // load world
+		{
+			BinaryData data = BinaryData.read(worldFile); // read data from the world file
+			DataSection properties = data.get("properties"); // get the properties data section from the data that we have just read
+			long seed = 0; // default seed if we cannot read it is 0
+
+			try // try read the seed from the file
+			{
+				seed = properties.readLong(0); // seed is at index 0
+			}
+			catch (Throwable e)
+			{
+				e.printStackTrace();
+			}
+
+			World world = new World(seed, 2, dim, this); // create new world with seed read from file or 0, if it could not be read
+			world.spawnPlayer(); // spawn player in world
+			return world;
+		}
+		else // create world
+		{
+			long seed = new Random().nextLong();
+
+			try
+			{
+				worldFile.createNewFile(); // create world file
+				BinaryData data = new BinaryData(); // create empty binary data
+				DataSection properties = new DataSection(); // create empty data section for properties
+				properties.writeLong(seed); // write seed at index 0
+				data.put("properties", properties); // add properties section
+				data.write(worldFile); // write to file
+			}
+			catch (IOException e)
+			{
+				// If this fails the world seed will not be consistent across saves
+				e.printStackTrace();
+			}
+
+			World world = new World(seed, 2, dim, this); // create new world with generated seed
+			world.spawnPlayer(); // spawn player in world
+			return world;
+		}
+	}
+
 	private static final String SAVE_DIR = "./saves/";
 }

src/main/java/com/github/halotroop/litecraft/types/block/Block.java

@@ -7,10 +7,6 @@ import com.github.hydos.ginger.engine.render.models.TexturedModel;
 
 public class Block
 {
-	public static final Block AIR = new Block(new Properties("air").visible(false));
-	public static final Block DIRT = new Block("block/cubes/soil/dirt.png", new Properties("dirt"));
-	public static final Block STONE = new Block("block/cubes/stone/basic/gneiss.png", new Properties("stone"));
-
 	public static class Properties
 	{ // add properties to this builder!
 		private boolean visible = true;

src/main/java/com/github/halotroop/litecraft/types/block/Blocks.java

@@ -0,0 +1,10 @@
+package com.github.halotroop.litecraft.types.block;
+
+import com.github.halotroop.litecraft.types.block.Block.Properties;
+
+public final class Blocks
+{
+	public static final Block AIR = new Block(new Properties("air").visible(false));
+	public static final Block DIRT = new Block("block/cubes/soil/dirt.png", new Properties("dirt"));
+	public static final Block STONE = new Block("block/cubes/stone/basic/gneiss.png", new Properties("stone"));
+}

src/main/java/com/github/halotroop/litecraft/world/Chunk.java

@@ -30,8 +30,9 @@ public class Chunk implements BlockAccess, WorldGenConstants, DataStorage
 	public final int chunkX, chunkY, chunkZ;
 	public final int chunkStartX, chunkStartY, chunkStartZ;
 	private boolean fullyGenerated = false;
+	public final int dimension;
 
-	public Chunk(int chunkX, int chunkY, int chunkZ)
+	public Chunk(int chunkX, int chunkY, int chunkZ, int dimension)
 	{
 		renderList = new ArrayList<BlockEntity>();
 		this.chunkX = chunkX;
@@ -40,6 +41,7 @@ public class Chunk implements BlockAccess, WorldGenConstants, DataStorage
 		this.chunkStartX = chunkX << POS_SHIFT;
 		this.chunkStartY = chunkY << POS_SHIFT;
 		this.chunkStartZ = chunkZ << POS_SHIFT;
+		this.dimension = dimension;
 	}
 
 	public boolean doRender()

src/main/java/com/github/halotroop/litecraft/world/World.java

@@ -1,7 +1,9 @@
 package com.github.halotroop.litecraft.world;
 
 import java.util.Random;
+import java.util.function.LongConsumer;
 
+import com.github.halotroop.litecraft.save.LitecraftSave;
 import com.github.halotroop.litecraft.types.block.Block;
 import com.github.halotroop.litecraft.world.block.BlockRenderer;
 import com.github.halotroop.litecraft.world.gen.*;
@@ -18,31 +20,48 @@ public class World implements BlockAccess, WorldGenConstants
 	private final WorldModifier[] worldModifiers;
 	private final ChunkGenerator chunkGenerator;
 	private final BlockAccess genBlockAccess;
+	private final LitecraftSave save;
 
 	private final long seed;
+	private final int dimension;
 
 	public Player player;
 
-	public World(long seed, int size, Dimension<?> dim)
+	// This will likely become the main public constructor after we add dynamic chunkloading
+	private World(long seed, Dimension<?> dim, LitecraftSave save)
 	{
 		this.chunks = new Long2ObjectArrayMap<>();
 		this.seed = seed;
 		this.chunkGenerator = dim.createChunkGenerator(seed);
 		this.worldModifiers = dim.getWorldModifierArray();
 		this.genBlockAccess = new GenWorld(this);
+		this.save = save;
+		this.dimension = dim.id;
+	}
+
+	public void spawnPlayer()
+	{
+		TexturedModel dirtModel = ModelLoader.loadGenericCube("block/cubes/soil/dirt.png");
+		this.player = new Player(dirtModel, new Vector3f(0, 0, -3), 0, 180f, 0, new Vector3f(0.2f, 0.2f, 0.2f));
+	}
+
+	// this constructor will likely not be neccesary when we have dynamic chunkloading
+	public World(long seed, int size, Dimension<?> dim, LitecraftSave save)
+	{
+		this(seed, dim, save);
 
 		for (int i = (0 - (size/2)); i < (size/2); i++)
 			for (int k = (0 - (size/2)); k < (size/2); k++)
 				for (int y = -2; y < 0; ++y)
 					this.getChunk(i, y, k).setRender(true);
-
-		TexturedModel dirtModel = ModelLoader.loadGenericCube("block/cubes/soil/dirt.png");
-		this.player = new Player(dirtModel, new Vector3f(0, 0, -3), 0, 180f, 0, new Vector3f(0.2f, 0.2f, 0.2f));
 	}
 
 	public Chunk getChunk(int chunkX, int chunkY, int chunkZ)
 	{
-		Chunk chunk = this.chunks.computeIfAbsent(posHash(chunkX, chunkY, chunkZ), pos -> this.chunkGenerator.generateChunk(chunkX, chunkY, chunkZ));
+		Chunk chunk = this.chunks.computeIfAbsent(posHash(chunkX, chunkY, chunkZ), pos -> {
+			Chunk readChunk = save.readChunk(chunkX, chunkY, chunkZ, this.dimension);
+			return readChunk == null ? this.chunkGenerator.generateChunk(chunkX, chunkY, chunkZ) : readChunk;
+		});
 
 		if (chunk.isFullyGenerated()) return chunk;
 
@@ -51,6 +70,23 @@ public class World implements BlockAccess, WorldGenConstants
 		return chunk;
 	}
 
+	/**
+	 * @return whether the chunk was unloaded without errors. Will often, but not always, be equal to whether the chunk was already in memory.
+	 */
+	public boolean unloadChunk(int chunkX, int chunkY, int chunkZ)
+	{
+		long posHash = posHash(chunkX, chunkY, chunkZ);
+		Chunk chunk = this.chunks.get(posHash);
+
+		// If the chunk is not in memory, it does not need to be unloaded
+		if (chunk == null) return false;
+
+		// Otherwise save the chunk
+		boolean result = this.save.saveChunk(chunk);
+		this.chunks.remove(posHash);
+		return result;
+	}
+
 	private void populateChunk(int chunkX, int chunkY, int chunkZ, int chunkStartX, int chunkStartY, int chunkStartZ)
 	{
 		Random rand = new Random(this.seed + 5828671L * (long) chunkX + -47245139L * (long) chunkY + 8972357 * (long) chunkZ);
@@ -90,4 +126,16 @@ public class World implements BlockAccess, WorldGenConstants
 
 	public void render(BlockRenderer blockRenderer)
 	{ this.chunks.forEach((pos, chunk) -> chunk.render(blockRenderer)); }
+
+	public void unloadAllChunks()
+	{
+		LongList chunkPositions = new LongArrayList();
+
+		this.chunks.forEach((pos, chunk) -> { // for every chunk in memory
+			chunkPositions.add((long) pos); // add pos to chunk positions list for removal later
+			this.save.saveChunk(chunk); // save chunk
+		});
+
+		chunkPositions.forEach((LongConsumer) (pos -> this.chunks.remove(pos))); // remove all chunks
+	}
 }

src/main/java/com/github/halotroop/litecraft/world/gen/Dimension.java

@@ -2,13 +2,20 @@ package com.github.halotroop.litecraft.world.gen;
 
 import java.util.*;
 
-import com.github.halotroop.litecraft.world.Chunk;
+import it.unimi.dsi.fastutil.ints.*;
 
 public abstract class Dimension<T extends ChunkGenerator>
 {
 	public List<WorldModifier> worldModifiers = new ArrayList<>();
+	public final int id;
 
-	public Dimension addWorldModifier(WorldModifier modifier)
+	public Dimension(int id)
+	{
+		this.id = id;
+		ID_TO_DIMENSION.put(id, this);
+	}
+
+	public Dimension<T> addWorldModifier(WorldModifier modifier)
 	{
 		this.worldModifiers.add(modifier);
 		return this;
@@ -20,5 +27,5 @@ public abstract class Dimension<T extends ChunkGenerator>
 
 	public abstract T createChunkGenerator(long seed);
 
-	public static final Dimension OVERWORLD = new OverworldDimension();
+	private static final Int2ObjectMap<Dimension<?>> ID_TO_DIMENSION = new Int2ObjectArrayMap<>();
 }

src/main/java/com/github/halotroop/litecraft/world/gen/Dimensions.java

@@ -0,0 +1,6 @@
+package com.github.halotroop.litecraft.world.gen;
+
+public final class Dimensions
+{
+	public static final Dimension<OverworldChunkGenerator> OVERWORLD = new OverworldDimension(0);
+}

src/main/java/com/github/halotroop/litecraft/world/gen/OverworldChunkGenerator.java

@@ -2,23 +2,25 @@ package com.github.halotroop.litecraft.world.gen;
 
 import java.util.Random;
 
-import com.github.halotroop.litecraft.types.block.Block;
+import com.github.halotroop.litecraft.types.block.*;
 import com.github.halotroop.litecraft.util.noise.OctaveSimplexNoise;
 import com.github.halotroop.litecraft.world.Chunk;
 
 public class OverworldChunkGenerator implements ChunkGenerator, WorldGenConstants
 {
-	public OverworldChunkGenerator(long seed)
+	public OverworldChunkGenerator(long seed, int dimension)
 	{
 		this.noise = new OctaveSimplexNoise(new Random(seed), 3, 250.0, 35.0, 10.0);
+		this.dimension = dimension;
 	}
 
 	private final OctaveSimplexNoise noise;
+	private final int dimension;
 
 	@Override
 	public Chunk generateChunk(int chunkX, int chunkY, int chunkZ)
 	{
-		Chunk chunk = new Chunk(chunkX, chunkY, chunkZ);
+		Chunk chunk = new Chunk(chunkX, chunkY, chunkZ, this.dimension);
 
 		for (int x = 0; x < CHUNK_SIZE; ++x) {
 			double totalX = x + chunk.chunkStartX;
@@ -28,15 +30,15 @@ public class OverworldChunkGenerator implements ChunkGenerator, WorldGenConstant
 
 				for (int y = 0; y < CHUNK_SIZE; ++y) {
 					int totalY = chunk.chunkStartY + y;
-					Block block = Block.AIR;
+					Block block = Blocks.AIR;
 
 					if (totalY < height - 3)
 					{
-						block = Block.DIRT;
+						block = Blocks.DIRT;
 					}
 					else if (totalY < height)
 					{
-						block = Block.STONE;
+						block = Blocks.STONE;
 					}
 
 					chunk.setBlock(x, y, z, block);

src/main/java/com/github/halotroop/litecraft/world/gen/OverworldDimension.java

@@ -2,9 +2,14 @@ package com.github.halotroop.litecraft.world.gen;
 
 public class OverworldDimension extends Dimension<OverworldChunkGenerator>
 {
+	public OverworldDimension(int id)
+	{
+		super(id);
+	}
+
 	@Override
 	public OverworldChunkGenerator createChunkGenerator(long seed)
 	{
-		return new OverworldChunkGenerator(seed);
+		return new OverworldChunkGenerator(seed, this.id);
 	}
 }