Merge pull request #62 from Querz/iterators

Iterators

src/main/java/net/querz/mca/Chunk.java

@@ -12,9 +12,13 @@
 import java.io.IOException;
 import java.io.RandomAccessFile;
 import java.util.Arrays;
+import java.util.Iterator;
+import java.util.Map;
+import java.util.TreeMap;
+
 import static net.querz.mca.LoadFlags.*;
 
-public class Chunk {
+public class Chunk implements Iterable<Section> {
 
 	public static final int DEFAULT_DATA_VERSION = 2567;
 
@@ -31,7 +35,7 @@ public class Chunk {
 	private int[] biomes;
 	private CompoundTag heightMaps;
 	private CompoundTag carvingMasks;
-	private Section[] sections = new Section[16]; //always initialized with size = 16 for fast access
+	private Map<Integer, Section> sections = new TreeMap<>();
 	private ListTag<CompoundTag> entities;
 	private ListTag<CompoundTag> tileEntities;
 	private ListTag<CompoundTag> tileTicks;
@@ -112,15 +116,9 @@ private void initReferences(long loadFlags) {
 		}
 		if ((loadFlags & (BLOCK_LIGHTS|BLOCK_STATES|SKY_LIGHT)) != 0 && level.containsKey("Sections")) {
 			for (CompoundTag section : level.getListTag("Sections").asCompoundTagList()) {
-				int sectionIndex = section.getByte("Y");
-				if (sectionIndex > 15 || sectionIndex < 0) {
-					continue;
-				}
+				int sectionIndex = section.getNumber("Y").byteValue();
 				Section newSection = new Section(section, dataVersion, loadFlags);
-				if (newSection.isEmpty()) {
-					continue;
-				}
-				sections[sectionIndex] = newSection;
+				sections.put(sectionIndex, newSection);
 			}
 		}
 
@@ -285,7 +283,7 @@ int getBiomeIndex(int biomeX, int biomeY, int biomeZ) {
 	}
 
 	public CompoundTag getBlockStateAt(int blockX, int blockY, int blockZ) {
-		Section section = sections[MCAUtil.blockToChunk(blockY)];
+		Section section = sections.get(MCAUtil.blockToChunk(blockY));
 		if (section == null) {
 			return null;
 		}
@@ -306,9 +304,9 @@ public CompoundTag getBlockStateAt(int blockX, int blockY, int blockZ) {
 	public void setBlockStateAt(int blockX, int blockY, int blockZ, CompoundTag state, boolean cleanup) {
 		checkRaw();
 		int sectionIndex = MCAUtil.blockToChunk(blockY);
-		Section section = sections[sectionIndex];
+		Section section = sections.get(sectionIndex);
 		if (section == null) {
-			section = sections[sectionIndex] = Section.newSection();
+			sections.put(sectionIndex, section = Section.newSection());
 		}
 		section.setBlockStateAt(blockX, blockY, blockZ, state, cleanup);
 	}
@@ -328,7 +326,7 @@ public int getDataVersion() {
 	public void setDataVersion(int dataVersion) {
 		checkRaw();
 		this.dataVersion = dataVersion;
-		for (Section section : sections) {
+		for (Section section : sections.values()) {
 			if (section != null) {
 				section.dataVersion = dataVersion;
 			}
@@ -373,7 +371,7 @@ public void setStatus(String status) {
 	 * @return The Section.
 	 */
 	public Section getSection(int sectionY) {
-		return sections[sectionY];
+		return sections.get(sectionY);
 	}
 
 	/**
@@ -383,7 +381,7 @@ public Section getSection(int sectionY) {
 	 */
 	public void setSection(int sectionY, Section section) {
 		checkRaw();
-		sections[sectionY] = section;
+		sections.put(sectionY, section);
 	}
 
 	/**
@@ -623,7 +621,7 @@ int getBlockIndex(int blockX, int blockZ) {
 
 	public void cleanupPalettesAndBlockStates() {
 		checkRaw();
-		for (Section section : sections) {
+		for (Section section : sections.values()) {
 			if (section != null) {
 				section.cleanupPaletteAndBlockStates();
 			}
@@ -712,12 +710,17 @@ public CompoundTag updateHandle(int xPos, int zPos) {
 			level.put("Structures", structures);
 		}
 		ListTag<CompoundTag> sections = new ListTag<>(CompoundTag.class);
-		for (int i = 0; i < this.sections.length; i++) {
-			if (this.sections[i] != null) {
-				sections.add(this.sections[i].updateHandle(i));
+		for (Section section : this.sections.values()) {
+			if (section != null) {
+				sections.add(section.updateHandle());
 			}
 		}
 		level.put("Sections", sections);
 		return data;
 	}
+
+	@Override
+	public Iterator<Section> iterator() {
+		return sections.values().iterator();
+	}
 }

src/main/java/net/querz/mca/MCAFile.java

@@ -1,10 +1,15 @@
 package net.querz.mca;
 
 import net.querz.nbt.tag.CompoundTag;
+import net.querz.nbt.tag.Tag;
+
 import java.io.IOException;
 import java.io.RandomAccessFile;
+import java.util.Arrays;
+import java.util.Iterator;
+import java.util.Map;
 
-public class MCAFile {
+public class MCAFile implements Iterable<Chunk> {
 
 	/**
 	 * The default chunk data version used when no custom version is supplied.
@@ -292,4 +297,9 @@ public void cleanupPalettesAndBlockStates() {
 			}
 		}
 	}
+
+	@Override
+	public Iterator<Chunk> iterator() {
+		return Arrays.stream(chunks).iterator();
+	}
 }

src/main/java/net/querz/mca/Section.java

@@ -7,17 +7,19 @@
 import net.querz.nbt.tag.LongArrayTag;
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 
-public class Section {
+public class Section implements Comparable<Section> {
 
 	private CompoundTag data;
 	private Map<String, List<PaletteIndex>> valueIndexedPalette = new HashMap<>();
 	private ListTag<CompoundTag> palette;
 	private byte[] blockLight;
 	private long[] blockStates;
 	private byte[] skyLight;
+	private int height;
 	int dataVersion;
 
 	public Section(CompoundTag sectionRoot, int dataVersion) {
@@ -27,6 +29,8 @@ public Section(CompoundTag sectionRoot, int dataVersion) {
 	public Section(CompoundTag sectionRoot, int dataVersion, long loadFlags) {
 		data = sectionRoot;
 		this.dataVersion = dataVersion;
+		height = sectionRoot.getNumber("Y").byteValue();
+
 		ListTag<?> rawPalette = sectionRoot.getListTag("Palette");
 		if (rawPalette == null) {
 			return;
@@ -85,6 +89,14 @@ PaletteIndex getValueIndexedPalette(CompoundTag data) {
 		return null;
 	}
 
+	@Override
+	public int compareTo(Section o) {
+		if (o == null) {
+			return -1;
+		}
+		return Integer.compare(height, o.height);
+	}
+
 	private static class PaletteIndex {
 
 		CompoundTag data;
@@ -104,6 +116,17 @@ public boolean isEmpty() {
 		return data == null;
 	}
 
+	/**
+	* @return the Y value of this section.
+	* */
+	public int getHeight() {
+		return height;
+	}
+
+	public void setHeight(int height) {
+		this.height = height;
+	}
+
 	/**
 	 * Fetches a block state based on a block location from this section.
 	 * The coordinates represent the location of the block inside of this Section.
@@ -113,7 +136,10 @@ public boolean isEmpty() {
 	 * @return The block state data of this block.
 	 */
 	public CompoundTag getBlockStateAt(int blockX, int blockY, int blockZ) {
-		int index = getBlockIndex(blockX, blockY, blockZ);
+		return getBlockStateAt(getBlockIndex(blockX, blockY, blockZ));
+	}
+
+	private CompoundTag getBlockStateAt(int index) {
 		int paletteIndex = getPaletteIndex(index);
 		return palette.get(paletteIndex);
 	}
@@ -239,8 +265,10 @@ static long bitRange(long value, int from, int to) {
 	 * Recalculating the Palette should only be executed once right before saving the Section to file.
 	 */
 	public void cleanupPaletteAndBlockStates() {
-		Map<Integer, Integer> oldToNewMapping = cleanupPalette();
-		adjustBlockStateBits(oldToNewMapping, blockStates);
+		if (blockStates != null) {
+			Map<Integer, Integer> oldToNewMapping = cleanupPalette();
+			adjustBlockStateBits(oldToNewMapping, blockStates);
+		}
 	}
 
 	private Map<Integer, Integer> cleanupPalette() {
@@ -395,4 +423,51 @@ public CompoundTag updateHandle(int y) {
 		}
 		return data;
 	}
+
+	public CompoundTag updateHandle() {
+		return updateHandle(height);
+	}
+
+	/**
+	 * Creates an iterable that iterates over all blocks in this section, in order of their indices.
+	 * An index can be calculated using the following formula:
+	 * <pre>
+	 * {@code
+	 * index = (blockY & 0xF) * 256 + (blockZ & 0xF) * 16 + (blockX & 0xF);
+	 * }
+	 * </pre>
+	 * The CompoundTags are references to this Section's Palette and should only be modified if the intention is to
+	 * modify ALL blocks of the same type in this Section at the same time.
+	 * */
+	public Iterable<CompoundTag> blocksStates() {
+		return new BlockIterator(this);
+	}
+
+	private static class BlockIterator implements Iterable<CompoundTag>, Iterator<CompoundTag> {
+
+		private Section section;
+		private int currentIndex;
+
+		public BlockIterator(Section section) {
+			this.section = section;
+			currentIndex = 0;
+		}
+
+		@Override
+		public boolean hasNext() {
+			return currentIndex < 4096;
+		}
+
+		@Override
+		public CompoundTag next() {
+			CompoundTag blockState = section.getBlockStateAt(currentIndex);
+			currentIndex++;
+			return blockState;
+		}
+
+		@Override
+		public Iterator<CompoundTag> iterator() {
+			return this;
+		}
+	}
 }