Fixed crashes when using multiple chunks. FPS is still terrible though

src/main/java/ru/windcorp/progressia/client/graphics/world/LayerWorld.java

@@ -107,7 +107,7 @@ public class LayerWorld extends Layer {
 			tmp_testControls.applyPlayerControls();
 			
 			for (EntityData data : this.client.getWorld().getData().getEntities()) {
-				tmp_applyFriction(data);
+				tmp_applyFriction(data, tickLength);
 				tmp_applyGravity(data, tickLength);
 				tmp_renderCollisionModel(data);
 			}
@@ -177,9 +177,9 @@ public class LayerWorld extends Layer {
 		return new StaticModel(b);
 	}
 
-	private void tmp_applyFriction(EntityData entity) {
+	private void tmp_applyFriction(EntityData entity, float tickLength) {
-		final float frictionCoeff = 1 - 1e-5f;
+		final float frictionCoeff = Units.get(1e-5f, "kg/s");
-		entity.getVelocity().mul(frictionCoeff);
+		entity.getVelocity().mul((float) Math.exp(-frictionCoeff / entity.getCollisionMass() * tickLength));
 	}
 	
 	private static final float MC_g  = Units.get("32  m/s^2");

src/main/java/ru/windcorp/progressia/common/world/WorldData.java

@@ -55,7 +55,7 @@ public class WorldData {
 	}
 	
 	public void tmp_generate() {
-		final int size = 1;
+		final int size = 3;
 		Vec3i cursor = new Vec3i(0, 0, 0);
 		
 		for (cursor.x = -(size / 2); cursor.x <= (size / 2); ++cursor.x) {

src/main/java/ru/windcorp/progressia/server/world/TickContextMutable.java

@@ -133,6 +133,11 @@ public abstract class TickContextMutable implements BlockTickContext, TSTickCont
 		protected Role role = Role.NONE;
 		protected boolean isBeingBuilt = false;
 		
+		/**
+		 * Updated lazily
+		 */
+		protected final Vec3i blockInChunk = new Vec3i();
+		
 		/*
 		 * TickContextMutable
 		 */
@@ -275,6 +280,11 @@ public abstract class TickContextMutable implements BlockTickContext, TSTickCont
 		 * Optimization
 		 */
 		
+		@Override
+		public Vec3i getBlockInChunk() {
+			return Coordinates.convertInWorldToInChunk(getBlockInWorld(), this.blockInChunk);
+		}
+		
 		@Override
 		public void forEachBlock(Consumer<BlockTickContext> action) {
 			checkContextState(Role.CHUNK);

src/main/java/ru/windcorp/progressia/server/world/block/BlockTickContext.java

@@ -5,6 +5,7 @@ import java.util.function.Consumer;
 import java.util.function.Function;
 
 import glm.vec._3.i.Vec3i;
+import ru.windcorp.progressia.common.world.Coordinates;
 import ru.windcorp.progressia.common.world.block.BlockData;
 import ru.windcorp.progressia.common.world.block.BlockFace;
 import ru.windcorp.progressia.common.world.block.BlockRelation;
@@ -20,6 +21,10 @@ public interface BlockTickContext extends ChunkTickContext {
 	 */
 	Vec3i getBlockInWorld();
 	
+	default Vec3i getBlockInChunk() {
+		return Coordinates.convertInWorldToInChunk(getBlockInWorld(), null);
+	}
+	
 	default BlockLogic getBlock() {
 		return getWorld().getBlock(getBlockInWorld());
 	}

src/main/java/ru/windcorp/progressia/server/world/tile/TSTickContext.java

@@ -27,22 +27,22 @@ public interface TSTickContext extends BlockTickContext {
 		ChunkLogic chunkLogic = getChunkLogic();
 		if (chunkLogic == null) return null;
 		
-		return chunkLogic.getTilesOrNull(getBlockInWorld(), getFace());
+		return chunkLogic.getTilesOrNull(getBlockInChunk(), getFace());
 	}
 	
 	default TileLogicStack getTLS() {
-		return getChunkLogic().getTiles(getBlockInWorld(), getFace());
+		return getChunkLogic().getTiles(getBlockInChunk(), getFace());
 	}
 	
 	default TileDataStack getTDSOrNull() {
 		ChunkData chunkData = getChunkData();
 		if (chunkData == null) return null;
 		
-		return chunkData.getTilesOrNull(getBlockInWorld(), getFace());
+		return chunkData.getTilesOrNull(getBlockInChunk(), getFace());
 	}
 	
 	default TileDataStack getTDS() {
-		return getChunkData().getTiles(getBlockInWorld(), getFace());
+		return getChunkData().getTiles(getBlockInChunk(), getFace());
 	}
 	
 	/*

src/main/java/ru/windcorp/progressia/test/TestContent.java

@@ -252,7 +252,7 @@ public class TestContent {
 		TileData flowers = TileDataRegistry.getInstance().get("Test:YellowFlowers");
 		TileData sand = TileDataRegistry.getInstance().get("Test:Sand");
 	
-		Vec3i aPoint = new Vec3i(5, 0, bpc + bpc/2).sub(chunk.getPosition());
+		Vec3i aPoint = new Vec3i(5, 0, bpc + bpc/4).sub(chunk.getPosition().mul_(ChunkData.BLOCKS_PER_CHUNK));
 		Vec3i pos = new Vec3i();
 		
 		for (int x = 0; x < bpc; ++x) {
@@ -280,6 +280,7 @@ public class TestContent {
 				pos.set(x, y, 0);
 				
 				for (pos.z = bpc - 1; pos.z >= 0 && chunk.getBlock(pos) == air; --pos.z);
+				if (pos.z < 0) continue;
 				
 				chunk.getTiles(pos, BlockFace.TOP).add(grass);
 				for (BlockFace face : BlockFace.getFaces()) {