get light from edge chunks

ReadMe.md

@@ -12,7 +12,7 @@ Minosoft is an open source minecraft client, written from scratch in kotlin (and
 ## Feature overview
 
 - Rendering
-- Connect with any version to any server  (1.7 - latest)
+- Connect with any version to any server  (1.7 - 1.19)
 - ~~Modding~~
 - Bleeding edge performance (e.g. incredible start time)
 - Free (as far as we consider original minecraft as free) and open source
@@ -125,11 +125,11 @@ Support for macOS is a delicate topic. Let's say it works for now, but it is not
 
 ## Building
 
-1. Install Maven and java 11+ (On Ubuntu based distributions: `sudo apt install maven openjdk-11-jdk`). For Windows users, download and install java from oracle or openjdk. Also download maven and follow along
+1. Install Maven and java 11+ (e.g. `sudo apt install maven openjdk-11-jdk`). For Windows users, download and install java from oracle or openjdk. Also download maven and follow along
 2. Clone this repository (`git clone https://gitlab.bixilon.de/bixilon/minosoft.git`)
 3. Change directory (`cd minosoft`)
 4. Optional: Checkout a current feature branch (Warning: might be unstable; might not even build) (`git checkout <branch>`)
-5. Build and run Minosoft with `mvn clean verify exec:java`. If any errors occur, feel free to open an issue. In this early stage it might be helpful to delete the config file
+5. Build and run Minosoft with `mvn clean verify exec:java`. If any errors occur, feel free to open an issue. In this early stage it might be helpful to delete its configuration files
 6. (Optional) Build a fat jar with `mvn package`. You'll find the jar with all dependencies in `target/`. Then you don't need to recompile everytime
 
 ## Code mirrors

src/main/java/de/bixilon/minosoft/data/world/World.kt

@@ -376,24 +376,27 @@ class World(
         val neighboursPositions = getChunkNeighbourPositions(chunkPosition)
         val neighbours = getChunkNeighbours(neighboursPositions)
 
-        if (neighbours.received) {
+        val neighboursReceived = neighbours.received
+        if (neighboursReceived) {
             chunk.neighbours = neighbours.cast()
 
             if (!chunk.biomesInitialized && cacheBiomeAccessor != null && chunk.biomeSource != null && neighbours.canBuildBiomeCache) {
                 chunk.buildBiomeCache()
             }
+        }
+
+
+        if (checkNeighbours) {
+            for (index in 0 until 8) {
+                val neighbour = neighbours[index] ?: continue
+                onChunkUpdate(neighboursPositions[index], neighbour, false)
+            }
+        }
+
+        if (neighboursReceived) {
+            chunk.recalculateLight()
             connection.fireEvent(ChunkDataChangeEvent(connection, EventInitiators.UNKNOWN, chunkPosition, chunk))
         }
-
-
-        if (!checkNeighbours) {
-            return
-        }
-
-        for (index in 0 until 8) {
-            val neighbour = neighbours[index] ?: continue
-            onChunkUpdate(neighboursPositions[index], neighbour, false)
-        }
     }
 
     fun getBrightness(position: Vec3i): Float {

src/main/java/de/bixilon/minosoft/data/world/chunk/Chunk.kt

@@ -59,14 +59,13 @@ class Chunk(
     val heightmap = IntArray(ProtocolDefinition.SECTION_WIDTH_X * ProtocolDefinition.SECTION_WIDTH_Z)
 
     var neighbours: Array<Chunk>? = null
-        set(value) {
+        @Synchronized set(value) {
             if (field.contentEquals(value)) {
                 return
             }
             field = value
             if (value != null) {
                 updateSectionNeighbours(value)
-                recalculateLight()
             }
         }
 
@@ -104,6 +103,7 @@ class Chunk(
         if (blockEntity == null) {
             getOrPutBlockEntity(x, y, z)
         }
+        // ToDo: Remove section if isEmpty
 
         val neighbours = this.neighbours ?: return
 
@@ -250,12 +250,16 @@ class Chunk(
                 if (cacheBiomeAccessor != null && biomesInitialized) {
                     section.buildBiomeCache(chunkPosition, sectionHeight, this, neighbours, cacheBiomeAccessor)
                 }
+                section.neighbours = ChunkUtil.getDirectNeighbours(neighbours, this, sectionHeight)
                 for (neighbour in neighbours) {
                     val neighbourNeighbours = neighbour.neighbours ?: continue
                     neighbour.updateNeighbours(neighbourNeighbours, sectionHeight)
                 }
             }
             sections[sectionIndex] = section
+
+            // check light of neighbours to check if their light needs to be traced into our own chunk
+            section.light.propagateFromNeighbours()
         }
         return section
     }

src/main/java/de/bixilon/minosoft/data/world/chunk/light/SectionLight.kt

@@ -42,7 +42,7 @@ class SectionLight(
 
     private fun startDecreaseTrace(x: Int, y: Int, z: Int) {
         // that is kind of hacky, but far easier and kind of faster
-        val light = this.light[getIndex(x, y, z)].toInt() and 0x0F
+        val light = this.light[getIndex(x, y, z)].toInt() and BLOCK_LIGHT_MASK
 
         decreaseLight(x, y, z, light, true) // just clear the light
         decreaseLight(x, y, z, light, false) // increase the light in all sections
@@ -96,7 +96,7 @@ class SectionLight(
         }
 
         // get block or next luminance level
-        val currentLight = light[index].toInt() and 0x0F // we just care about block light
+        val currentLight = light[index].toInt() and BLOCK_LIGHT_MASK // we just care about block light
         if (currentLight >= nextLuminance) {
             // light is already higher, no need to trace
             return
@@ -202,4 +202,30 @@ class SectionLight(
     override operator fun get(index: Int): Byte {
         return light[index]
     }
+
+    fun propagateFromNeighbours() {
+        val neighbours = section.neighbours ?: return
+        // ToDo(p): this::traceIncrease checks als the block light level, not needed
+        for (x in 0 until ProtocolDefinition.SECTION_WIDTH_X) {
+            for (z in 0 until ProtocolDefinition.SECTION_WIDTH_Z) {
+                neighbours[Directions.O_DOWN]?.let { traceIncrease(x, 0, z, it.light[x, ProtocolDefinition.SECTION_MAX_Y, z].toInt() and BLOCK_LIGHT_MASK) }
+                neighbours[Directions.O_UP]?.let { traceIncrease(x, ProtocolDefinition.SECTION_MAX_Y, z, it.light[x, 0, z].toInt() and BLOCK_LIGHT_MASK) }
+            }
+            for (y in 0 until ProtocolDefinition.SECTION_HEIGHT_Y) {
+                neighbours[Directions.O_NORTH]?.let { traceIncrease(x, y, 0, it.light[x, y, ProtocolDefinition.SECTION_MAX_Z].toInt() and BLOCK_LIGHT_MASK) }
+                neighbours[Directions.O_SOUTH]?.let { traceIncrease(x, y, ProtocolDefinition.SECTION_MAX_Z, it.light[x, y, 0].toInt() and BLOCK_LIGHT_MASK) }
+            }
+        }
+        for (z in 0 until ProtocolDefinition.SECTION_WIDTH_Z) {
+            for (y in 0 until ProtocolDefinition.SECTION_HEIGHT_Y) {
+                neighbours[Directions.O_WEST]?.let { traceIncrease(0, y, z, it.light[ProtocolDefinition.SECTION_MAX_Z, y, z].toInt() and BLOCK_LIGHT_MASK) }
+                neighbours[Directions.O_UP]?.let { traceIncrease(ProtocolDefinition.SECTION_MAX_X, y, z, it.light[0, y, z].toInt() and BLOCK_LIGHT_MASK) }
+            }
+        }
+    }
+
+    companion object {
+        const val BLOCK_LIGHT_MASK = 0x0F
+        const val SKY_LIGHT_MASK = 0xF0
+    }
 }

src/main/java/de/bixilon/minosoft/protocol/protocol/ProtocolDefinition.java

@@ -51,11 +51,12 @@ public final class ProtocolDefinition {
 
     public static final Pattern MINECRAFT_NAME_VALIDATOR = Pattern.compile("\\w{3,16}");
 
-    public static final int SECTION_WIDTH_X = 16;
+    public static final int SECTION_LENGTH = 16;
+    public static final int SECTION_WIDTH_X = SECTION_LENGTH;
     public static final int SECTION_MAX_X = SECTION_WIDTH_X - 1;
-    public static final int SECTION_WIDTH_Z = 16;
+    public static final int SECTION_WIDTH_Z = SECTION_LENGTH;
     public static final int SECTION_MAX_Z = SECTION_WIDTH_Z - 1;
-    public static final int SECTION_HEIGHT_Y = 16;
+    public static final int SECTION_HEIGHT_Y = SECTION_LENGTH;
     public static final int SECTION_MAX_Y = SECTION_HEIGHT_Y - 1;
     public static final int BLOCKS_PER_SECTION = SECTION_WIDTH_X * SECTION_HEIGHT_Y * SECTION_WIDTH_X;
     public static final Vec3i CHUNK_SECTION_SIZE = new Vec3i(ProtocolDefinition.SECTION_WIDTH_X, ProtocolDefinition.SECTION_HEIGHT_Y, ProtocolDefinition.SECTION_WIDTH_Z);