X-Git-Url: http://git.localhorst.tv/?a=blobdiff_plain;f=src%2Fchunk.cpp;h=2a764f31c1c637435feb7738161a42f576f997b9;hb=4485397da18a25dfd1a51e864814887b66ba0f2e;hp=14930863ed1c38063fc2e919563dae0f5c7d1a6b;hpb=b4995967309bf5570161db2287e27b84ca94ab9a;p=blank.git

diff --git a/src/chunk.cpp b/src/chunk.cpp
index 1493086..2a764f3 100644
--- a/src/chunk.cpp
+++ b/src/chunk.cpp
@@ -2,21 +2,19 @@
 
 #include "generator.hpp"
 
+#include <algorithm>
 #include <limits>
+#include <queue>
 #include <glm/gtx/transform.hpp>
 
 
-namespace {
-
-blank::Model::Buffer buf;
-
-}
-
 namespace blank {
 
 Chunk::Chunk(const BlockTypeRegistry &types)
 : types(&types)
-, blocks()
+, neighbor{0}
+, blocks{}
+, light{0}
 , model()
 , position(0, 0, 0)
 , dirty(false) {
@@ -25,23 +23,344 @@ Chunk::Chunk(const BlockTypeRegistry &types)
 
 Chunk::Chunk(Chunk &&other)
 : types(other.types)
-, blocks(std::move(other.blocks))
 , model(std::move(other.model))
+, position(other.position)
 , dirty(other.dirty) {
-
+	std::copy(other.neighbor, other.neighbor + sizeof(neighbor), neighbor);
+	std::copy(other.blocks, other.blocks + sizeof(blocks), blocks);
+	std::copy(other.light, other.light + sizeof(light), light);
 }
 
 Chunk &Chunk::operator =(Chunk &&other) {
 	types = other.types;
-	blocks = std::move(other.blocks);
+	std::copy(other.neighbor, other.neighbor + sizeof(neighbor), neighbor);
+	std::copy(other.blocks, other.blocks + sizeof(blocks), blocks);
+	std::copy(other.light, other.light + sizeof(light), light);
 	model = std::move(other.model);
+	position = other.position;
 	dirty = other.dirty;
 	return *this;
 }
 
 
-void Chunk::Allocate() {
-	blocks.resize(Size());
+namespace {
+
+struct SetNode {
+
+	Chunk *chunk;
+	Chunk::Pos pos;
+
+	SetNode(Chunk *chunk, Chunk::Pos pos)
+	: chunk(chunk), pos(pos) { }
+
+	int Get() const { return chunk->GetLight(pos); }
+	void Set(int level) { chunk->SetLight(pos, level); }
+
+	bool HasNext(Block::Face face) {
+		const BlockLookup next(chunk, pos, face);
+		return next && !next.GetType().block_light;
+	}
+	SetNode GetNext(Block::Face face) {
+		const BlockLookup next(chunk, pos, face);
+		return SetNode(&next.GetChunk(), next.GetBlockPos());
+	}
+
+};
+
+struct UnsetNode
+: public SetNode {
+
+	int level;
+
+	UnsetNode(Chunk *chunk, Chunk::Pos pos)
+	: SetNode(chunk, pos), level(Get()) { }
+
+	UnsetNode(const SetNode &set)
+	: SetNode(set), level(Get()) { }
+
+
+	bool HasNext(Block::Face face) {
+		const BlockLookup next(chunk, pos, face);
+		return next;
+	}
+	UnsetNode GetNext(Block::Face face) { return UnsetNode(SetNode::GetNext(face)); }
+
+};
+
+std::queue<SetNode> light_queue;
+std::queue<UnsetNode> dark_queue;
+
+void work_light() {
+	while (!light_queue.empty()) {
+		SetNode node = light_queue.front();
+		light_queue.pop();
+
+		int level = node.Get() - 1;
+		for (int face = 0; face < Block::FACE_COUNT; ++face) {
+			if (node.HasNext(Block::Face(face))) {
+				SetNode other = node.GetNext(Block::Face(face));
+				if (other.Get() < level) {
+					other.Set(level);
+					light_queue.emplace(other);
+				}
+			}
+		}
+	}
+}
+
+void work_dark() {
+	while (!dark_queue.empty()) {
+		UnsetNode node = dark_queue.front();
+		dark_queue.pop();
+
+		for (int face = 0; face < Block::FACE_COUNT; ++face) {
+			if (node.HasNext(Block::Face(face))) {
+				UnsetNode other = node.GetNext(Block::Face(face));
+				// TODO: if there a light source here with the same level this will err
+				if (other.Get() != 0 && other.Get() < node.level) {
+					other.Set(0);
+					dark_queue.emplace(other);
+				} else {
+					light_queue.emplace(other);
+				}
+			}
+		}
+	}
+}
+
+}
+
+void Chunk::SetBlock(int index, const Block &block) {
+	const BlockType &old_type = Type(blocks[index]);
+	const BlockType &new_type = Type(block);
+
+	blocks[index] = block;
+
+	if (&old_type == &new_type) return;
+
+	if (new_type.luminosity > old_type.luminosity) {
+		// light added
+		SetLight(index, new_type.luminosity);
+		light_queue.emplace(this, ToPos(index));
+		work_light();
+	} else if (new_type.luminosity < old_type.luminosity) {
+		// light removed
+		dark_queue.emplace(this, ToPos(index));
+		SetLight(index, 0);
+		work_dark();
+		SetLight(index, new_type.luminosity);
+		light_queue.emplace(this, ToPos(index));
+		work_light();
+	} else if (new_type.block_light && !old_type.block_light) {
+		// obstacle added
+		if (GetLight(index) > 0) {
+			dark_queue.emplace(this, ToPos(index));
+			SetLight(index, 0);
+			work_dark();
+			work_light();
+		}
+	} else if (!new_type.block_light && old_type.block_light) {
+		// obstacle removed
+		int level = 0;
+		for (int face = 0; face < Block::FACE_COUNT; ++face) {
+			BlockLookup next_block(this, ToPos(index), Block::Face(face));
+			if (next_block) {
+				level = std::min(level, next_block.GetLight());
+			}
+		}
+		if (level > 1) {
+			SetLight(index, level - 1);
+			light_queue.emplace(this, ToPos(index));
+			work_light();
+		}
+	}
+}
+
+void Chunk::SetNeighbor(Chunk &other) {
+	if (other.position == position + Pos(-1, 0, 0)) {
+		if (neighbor[Block::FACE_LEFT] != &other) {
+			neighbor[Block::FACE_LEFT] = &other;
+			other.neighbor[Block::FACE_RIGHT] = this;
+			for (int z = 0; z < Depth(); ++z) {
+				for (int y = 0; y < Height(); ++y) {
+					Pos my_pos(0, y, z);
+					Pos other_pos(Width() - 1, y, z);
+					if (GetLight(my_pos) > 0) {
+						light_queue.emplace(this, my_pos);
+					}
+					if (other.GetLight(other_pos) > 0) {
+						light_queue.emplace(&other, other_pos);
+					}
+				}
+			}
+			work_light();
+		}
+	} else if (other.position == position + Pos(1, 0, 0)) {
+		if (neighbor[Block::FACE_RIGHT] != &other) {
+			neighbor[Block::FACE_RIGHT] = &other;
+			other.neighbor[Block::FACE_LEFT] = this;
+			for (int z = 0; z < Depth(); ++z) {
+				for (int y = 0; y < Height(); ++y) {
+					Pos my_pos(Width() - 1, y, z);
+					Pos other_pos(0, y, z);
+					if (GetLight(my_pos) > 0) {
+						light_queue.emplace(this, my_pos);
+					}
+					if (other.GetLight(other_pos) > 0) {
+						light_queue.emplace(&other, other_pos);
+					}
+				}
+			}
+			work_light();
+		}
+	} else if (other.position == position + Pos(0, -1, 0)) {
+		if (neighbor[Block::FACE_DOWN] != &other) {
+			neighbor[Block::FACE_DOWN] = &other;
+			other.neighbor[Block::FACE_UP] = this;
+			for (int z = 0; z < Depth(); ++z) {
+				for (int x = 0; x < Width(); ++x) {
+					Pos my_pos(x, 0, z);
+					Pos other_pos(x, Height() - 1, z);
+					if (GetLight(my_pos) > 0) {
+						light_queue.emplace(this, my_pos);
+					}
+					if (other.GetLight(other_pos) > 0) {
+						light_queue.emplace(&other, other_pos);
+					}
+				}
+			}
+			work_light();
+		}
+	} else if (other.position == position + Pos(0, 1, 0)) {
+		if (neighbor[Block::FACE_UP] != &other) {
+			neighbor[Block::FACE_UP] = &other;
+			other.neighbor[Block::FACE_DOWN] = this;
+			for (int z = 0; z < Depth(); ++z) {
+				for (int x = 0; x < Width(); ++x) {
+					Pos my_pos(x, Height() - 1, z);
+					Pos other_pos(x, 0, z);
+					if (GetLight(my_pos) > 0) {
+						light_queue.emplace(this, my_pos);
+					}
+					if (other.GetLight(other_pos) > 0) {
+						light_queue.emplace(&other, other_pos);
+					}
+				}
+			}
+			work_light();
+		}
+	} else if (other.position == position + Pos(0, 0, -1)) {
+		if (neighbor[Block::FACE_BACK] != &other) {
+			neighbor[Block::FACE_BACK] = &other;
+			other.neighbor[Block::FACE_FRONT] = this;
+			for (int y = 0; y < Height(); ++y) {
+				for (int x = 0; x < Width(); ++x) {
+					Pos my_pos(x, y, 0);
+					Pos other_pos(x, y, Depth() - 1);
+					if (GetLight(my_pos) > 0) {
+						light_queue.emplace(this, my_pos);
+					}
+					if (other.GetLight(other_pos) > 0) {
+						light_queue.emplace(&other, other_pos);
+					}
+				}
+			}
+			work_light();
+		}
+	} else if (other.position == position + Pos(0, 0, 1)) {
+		if (neighbor[Block::FACE_FRONT] != &other) {
+			neighbor[Block::FACE_FRONT] = &other;
+			other.neighbor[Block::FACE_BACK] = this;
+			for (int y = 0; y < Height(); ++y) {
+				for (int x = 0; x < Width(); ++x) {
+					Pos my_pos(x, y, Depth() - 1);
+					Pos other_pos(x, y, 0);
+					if (GetLight(my_pos) > 0) {
+						light_queue.emplace(this, my_pos);
+					}
+					if (other.GetLight(other_pos) > 0) {
+						light_queue.emplace(&other, other_pos);
+					}
+				}
+			}
+			work_light();
+		}
+	}
+}
+
+void Chunk::ClearNeighbors() {
+	for (int i = 0; i < Block::FACE_COUNT; ++i) {
+		neighbor[i] = nullptr;
+	}
+}
+
+void Chunk::Unlink() {
+	for (int face = 0; face < Block::FACE_COUNT; ++face) {
+		if (neighbor[face]) {
+			neighbor[face]->neighbor[Block::Opposite(Block::Face(face))] = nullptr;
+		}
+	}
+}
+
+void Chunk::Relink() {
+	for (int face = 0; face < Block::FACE_COUNT; ++face) {
+		if (neighbor[face]) {
+			neighbor[face]->neighbor[Block::Opposite(Block::Face(face))] = this;
+		}
+	}
+}
+
+
+void Chunk::SetLight(int index, int level) {
+	if (light[index] != level) {
+		light[index] = level;
+		Invalidate();
+	}
+}
+
+int Chunk::GetLight(int index) const {
+	return light[index];
+}
+
+float Chunk::GetVertexLight(int index, const BlockModel::Position &vtx, const BlockModel::Normal &norm) const {
+	float light = GetLight(index);
+	Chunk::Pos pos(ToPos(index));
+
+	Block::Face direct_face(Block::NormalFace(norm));
+	// tis okay
+	BlockLookup direct(const_cast<Chunk *>(this), pos, Block::NormalFace(norm));
+	if (direct) {
+		float direct_light = direct.GetLight();
+		if (direct_light > light) {
+			light = direct_light;
+		}
+	}
+
+	// cheap alternative until AO etc are implemented
+	// to tell the faces apart
+
+	if (direct_face == Block::FACE_LEFT || direct_face == Block::FACE_RIGHT) {
+		light -= 0.2;
+	} else if (direct_face == Block::FACE_FRONT || direct_face == Block::FACE_BACK) {
+		light -= 0.4;
+	}
+
+	return light;
+}
+
+
+bool Chunk::IsSurface(const Pos &pos) const {
+	const Block &block = BlockAt(pos);
+	if (!Type(block).visible) {
+		return false;
+	}
+	for (int face = 0; face < Block::FACE_COUNT; ++face) {
+		BlockLookup next = BlockLookup(const_cast<Chunk *>(this), pos, Block::Face(face));
+		if (!next || !next.GetType().visible) {
+			return true;
+		}
+	}
+	return false;
 }
 
 
@@ -56,24 +375,14 @@ void Chunk::Draw() {
 bool Chunk::Intersection(
 	const Ray &ray,
 	const glm::mat4 &M,
-	int *blkid,
-	float *dist,
-	glm::vec3 *normal) const {
-	{ // rough check
-		if (!blank::Intersection(ray, Bounds(), M)) {
-			return false;
-		}
-	}
-
-	if (!blkid && !dist && !normal) {
-		return true;
-	}
-
+	int &blkid,
+	float &dist,
+	glm::vec3 &normal
+) const {
 	// TODO: should be possible to heavily optimize this
 	int id = 0;
-	int closest_id = -1;
-	float closest_dist = std::numeric_limits<float>::infinity();
-	glm::vec3 closest_normal(0, 1, 0);
+	blkid = -1;
+	dist = std::numeric_limits<float>::infinity();
 	for (int z = 0; z < Depth(); ++z) {
 		for (int y = 0; y < Height(); ++y) {
 			for (int x = 0; x < Width(); ++x, ++id) {
@@ -83,30 +392,22 @@ bool Chunk::Intersection(
 				float cur_dist;
 				glm::vec3 cur_norm;
 				if (Type(blocks[id]).shape->Intersects(ray, M * ToTransform(id), cur_dist, cur_norm)) {
-					if (cur_dist < closest_dist) {
-						closest_id = id;
-						closest_dist = cur_dist;
-						closest_normal = cur_norm;
+					if (cur_dist < dist) {
+						blkid = id;
+						dist = cur_dist;
+						normal = cur_norm;
 					}
 				}
 			}
 		}
 	}
 
-	if (closest_id < 0) {
+	if (blkid < 0) {
 		return false;
+	} else {
+		normal = glm::vec3(BlockAt(blkid).Transform() * glm::vec4(normal, 0.0f));
+		return true;
 	}
-
-	if (blkid) {
-		*blkid = closest_id;
-	}
-	if (dist) {
-		*dist = closest_dist;
-	}
-	if (normal) {
-		*normal = closest_normal;
-	}
-	return true;
 }
 
 void Chunk::Position(const Pos &pos) {
@@ -118,6 +419,12 @@ glm::mat4 Chunk::Transform(const Pos &offset) const {
 }
 
 
+namespace {
+
+BlockModel::Buffer buf;
+
+}
+
 void Chunk::CheckUpdate() {
 	if (dirty) {
 		Update();
@@ -134,13 +441,19 @@ void Chunk::Update() {
 	buf.Clear();
 	buf.Reserve(vtx_count, idx_count);
 
-	Model::Index vtx_counter = 0;
+	BlockModel::Index vtx_counter = 0;
 	for (size_t i = 0; i < Size(); ++i) {
-		if (Obstructed(i)) continue;
-
 		const BlockType &type = Type(blocks[i]);
-		type.FillModel(buf, ToTransform(i), vtx_counter);
+
+		if (!type.visible || Obstructed(i)) continue;
+
+		type.FillBlockModel(buf, ToTransform(i), vtx_counter);
+		size_t vtx_begin = vtx_counter;
 		vtx_counter += type.shape->VertexCount();
+
+		for (size_t vtx = vtx_begin; vtx < vtx_counter; ++vtx) {
+			buf.lights.emplace_back(GetVertexLight(i, buf.vertices[vtx], buf.normals[vtx]));
+		}
 	}
 
 	model.Update(buf);
@@ -148,29 +461,15 @@ void Chunk::Update() {
 }
 
 bool Chunk::Obstructed(int idx) const {
-	if (IsBorder(idx)) return false;
-
-	// not checking neighbor visibility here, so all
-	// invisible blocks must have their fill set to 6x false
-	// (the default, so should be okay)
-
-	const BlockType &right = Type(blocks[idx + 1]);
-	if (!right.fill.left) return false;
-
-	const BlockType &left = Type(blocks[idx - 1]);
-	if (!left.fill.right) return false;
-
-	const BlockType &top = Type(blocks[idx + Width()]);
-	if (!top.fill.bottom) return false;
+	Chunk::Pos pos(ToPos(idx));
 
-	const BlockType &bottom = Type(blocks[idx - Width()]);
-	if (!bottom.fill.top) return false;
-
-	const BlockType &front = Type(blocks[idx + Width() * Height()]);
-	if (!front.fill.back) return false;
-
-	const BlockType &back = Type(blocks[idx - Width() * Height()]);
-	if (!back.fill.front) return false;
+	for (int f = 0; f < Block::FACE_COUNT; ++f) {
+		Block::Face face = Block::Face(f);
+		BlockLookup next(const_cast<Chunk *>(this), pos, face);
+		if (!next || !next.GetType().FaceFilled(next.GetBlock(), Block::Opposite(face))) {
+			return false;
+		}
+	}
 
 	return true;
 }
@@ -180,15 +479,83 @@ glm::mat4 Chunk::ToTransform(int idx) const {
 }
 
 
-ChunkLoader::ChunkLoader(const BlockTypeRegistry &reg, const Generator &gen)
+BlockLookup::BlockLookup(Chunk *c, const Chunk::Pos &p)
+: chunk(c), pos(p) {
+	while (pos.x >= Chunk::Width()) {
+		if (chunk->HasNeighbor(Block::FACE_RIGHT)) {
+			chunk = &chunk->GetNeighbor(Block::FACE_RIGHT);
+			pos.x -= Chunk::Width();
+		} else {
+			chunk = nullptr;
+			return;
+		}
+	}
+	while (pos.x < 0) {
+		if (chunk->HasNeighbor(Block::FACE_LEFT)) {
+			chunk = &chunk->GetNeighbor(Block::FACE_LEFT);
+			pos.x += Chunk::Width();
+		} else {
+			chunk = nullptr;
+			return;
+		}
+	}
+	while (pos.y >= Chunk::Height()) {
+		if (chunk->HasNeighbor(Block::FACE_UP)) {
+			chunk = &chunk->GetNeighbor(Block::FACE_UP);
+			pos.y -= Chunk::Height();
+		} else {
+			chunk = nullptr;
+			return;
+		}
+	}
+	while (pos.y < 0) {
+		if (chunk->HasNeighbor(Block::FACE_DOWN)) {
+			chunk = &chunk->GetNeighbor(Block::FACE_DOWN);
+			pos.y += Chunk::Height();
+		} else {
+			chunk = nullptr;
+			return;
+		}
+	}
+	while (pos.z >= Chunk::Depth()) {
+		if (chunk->HasNeighbor(Block::FACE_FRONT)) {
+			chunk = &chunk->GetNeighbor(Block::FACE_FRONT);
+			pos.z -= Chunk::Depth();
+		} else {
+			chunk = nullptr;
+			return;
+		}
+	}
+	while (pos.z < 0) {
+		if (chunk->HasNeighbor(Block::FACE_BACK)) {
+			chunk = &chunk->GetNeighbor(Block::FACE_BACK);
+			pos.z += Chunk::Depth();
+		} else {
+			chunk = nullptr;
+			return;
+		}
+	}
+}
+
+BlockLookup::BlockLookup(Chunk *c, const Chunk::Pos &p, Block::Face face)
+: chunk(c), pos(p) {
+	pos += Block::FaceNormal(face);
+	if (!Chunk::InBounds(pos)) {
+		pos -= Block::FaceNormal(face) * Chunk::Extent();
+		chunk = &chunk->GetNeighbor(face);
+	}
+}
+
+
+ChunkLoader::ChunkLoader(const Config &config, const BlockTypeRegistry &reg, const Generator &gen)
 : base(0, 0, 0)
 , reg(reg)
 , gen(gen)
 , loaded()
 , to_generate()
 , to_free()
-, load_dist(4)
-, unload_dist(5) {
+, load_dist(config.load_dist)
+, unload_dist(config.unload_dist) {
 
 }
 
@@ -220,10 +587,53 @@ void ChunkLoader::Generate(const Chunk::Pos &from, const Chunk::Pos &to) {
 				Chunk::Pos pos(x, y, z);
 				if (Known(pos)) {
 					continue;
-				} else if (x == 0 && y == 0 && z == 0) {
-					loaded.emplace_back(reg);
-					loaded.back().Position(pos);
-					gen(loaded.back());
+				} else if (pos == base) {
+					Generate(pos);
+
+				//	light testing
+				//	for (int i = 0; i < 16; ++i) {
+				//		for (int j = 0; j < 16; ++j) {
+				//			loaded.back().SetBlock(Chunk::Pos{  i, j,  0 }, Block(1));
+				//			loaded.back().SetBlock(Chunk::Pos{  i, j, 15 }, Block(1));
+				//			loaded.back().SetBlock(Chunk::Pos{  0, j,  i }, Block(1));
+				//			loaded.back().SetBlock(Chunk::Pos{ 15, j,  i }, Block(1));
+				//		}
+				//	}
+				//	loaded.back().SetBlock(Chunk::Pos{  1,  0,  1 }, Block(13));
+				//	loaded.back().SetBlock(Chunk::Pos{ 14,  0,  1 }, Block(13));
+				//	loaded.back().SetBlock(Chunk::Pos{  1,  0, 14 }, Block(13));
+				//	loaded.back().SetBlock(Chunk::Pos{ 14,  0, 14 }, Block(13));
+				//	loaded.back().SetBlock(Chunk::Pos{  1, 15,  1 }, Block(13));
+				//	loaded.back().SetBlock(Chunk::Pos{ 14, 15,  1 }, Block(13));
+				//	loaded.back().SetBlock(Chunk::Pos{  1, 15, 14 }, Block(13));
+				//	loaded.back().SetBlock(Chunk::Pos{ 14, 15, 14 }, Block(13));
+				//	loaded.back().SetBlock(Chunk::Pos{  7,  7,  0 }, Block(13));
+				//	loaded.back().SetBlock(Chunk::Pos{  8,  7,  0 }, Block(13));
+				//	loaded.back().SetBlock(Chunk::Pos{  7,  8,  0 }, Block(13));
+				//	loaded.back().SetBlock(Chunk::Pos{  8,  8,  0 }, Block(13));
+				//	loaded.back().SetBlock(Chunk::Pos{  7,  7, 15 }, Block(13));
+				//	loaded.back().SetBlock(Chunk::Pos{  8,  7, 15 }, Block(13));
+				//	loaded.back().SetBlock(Chunk::Pos{  7,  8, 15 }, Block(13));
+				//	loaded.back().SetBlock(Chunk::Pos{  8,  8, 15 }, Block(13));
+				//	loaded.back().SetBlock(Chunk::Pos{  0,  7,  7 }, Block(13));
+				//	loaded.back().SetBlock(Chunk::Pos{  0,  7,  8 }, Block(13));
+				//	loaded.back().SetBlock(Chunk::Pos{  0,  8,  7 }, Block(13));
+				//	loaded.back().SetBlock(Chunk::Pos{  0,  8,  8 }, Block(13));
+				//	loaded.back().SetBlock(Chunk::Pos{ 15,  7,  7 }, Block(13));
+				//	loaded.back().SetBlock(Chunk::Pos{ 15,  7,  8 }, Block(13));
+				//	loaded.back().SetBlock(Chunk::Pos{ 15,  8,  7 }, Block(13));
+				//	loaded.back().SetBlock(Chunk::Pos{ 15,  8,  8 }, Block(13));
+				//	loaded.back().Invalidate();
+				//	loaded.back().CheckUpdate();
+
+				//	orientation testing
+				//	for (int i = 0; i < Block::FACE_COUNT; ++i) {
+				//		for (int j = 0; j < Block::TURN_COUNT; ++j) {
+				//			loaded.back().BlockAt(512 * j + 2 * i) = Block(3 * (j + 1), Block::Face(i), Block::Turn(j));
+				//		}
+				//	}
+				//	loaded.back().Invalidate();
+				//	loaded.back().CheckUpdate();
 				} else {
 					to_generate.emplace_back(pos);
 				}
@@ -233,6 +643,25 @@ void ChunkLoader::Generate(const Chunk::Pos &from, const Chunk::Pos &to) {
 	to_generate.sort(ChunkLess(base));
 }
 
+Chunk &ChunkLoader::Generate(const Chunk::Pos &pos) {
+	loaded.emplace_back(reg);
+	Chunk &chunk = loaded.back();
+	chunk.Position(pos);
+	gen(chunk);
+	Insert(chunk);
+	return chunk;
+}
+
+void ChunkLoader::Insert(Chunk &chunk) {
+	for (Chunk &other : loaded) {
+		chunk.SetNeighbor(other);
+	}
+}
+
+void ChunkLoader::Remove(Chunk &chunk) {
+	chunk.Unlink();
+}
+
 Chunk *ChunkLoader::Loaded(const Chunk::Pos &pos) {
 	for (Chunk &chunk : loaded) {
 		if (chunk.Position() == pos) {
@@ -269,10 +698,7 @@ Chunk &ChunkLoader::ForceLoad(const Chunk::Pos &pos) {
 		}
 	}
 
-	loaded.emplace_back(reg);
-	loaded.back().Position(pos);
-	gen(loaded.back());
-	return loaded.back();
+	return Generate(pos);
 }
 
 void ChunkLoader::Rebase(const Chunk::Pos &new_base) {
@@ -287,6 +713,7 @@ void ChunkLoader::Rebase(const Chunk::Pos &new_base) {
 				|| std::abs(base.y - iter->Position().y) > unload_dist
 				|| std::abs(base.z - iter->Position().z) > unload_dist) {
 			auto saved = iter;
+			Remove(*saved);
 			++iter;
 			to_free.splice(to_free.end(), loaded, saved);
 		} else {
@@ -304,39 +731,40 @@ void ChunkLoader::Rebase(const Chunk::Pos &new_base) {
 		}
 	}
 	// add missing new chunks
+	GenerateSurrounding(base);
+}
+
+void ChunkLoader::GenerateSurrounding(const Chunk::Pos &pos) {
 	const Chunk::Pos offset(load_dist, load_dist, load_dist);
-	Generate(base - offset, base + offset);
+	Generate(pos - offset, pos + offset);
 }
 
 void ChunkLoader::Update() {
-	bool reused = false;
-	if (!to_generate.empty()) {
-		Chunk::Pos pos(to_generate.front());
-
-		for (auto iter(to_free.begin()), end(to_free.end()); iter != end; ++iter) {
-			if (iter->Position() == pos) {
-				loaded.splice(loaded.end(), to_free, iter);
-				reused = true;
-				break;
-			}
-		}
+	if (to_generate.empty()) {
+		return;
+	}
 
-		if (!reused) {
-			if (to_free.empty()) {
-				loaded.emplace_back(reg);
-			} else {
-				loaded.splice(loaded.end(), to_free, to_free.begin());
-				reused = true;
-			}
-			loaded.back().Position(pos);
-			gen(loaded.back());
+	Chunk::Pos pos(to_generate.front());
+	to_generate.pop_front();
+
+	for (auto iter(to_free.begin()), end(to_free.end()); iter != end; ++iter) {
+		if (iter->Position() == pos) {
+			iter->Relink();
+			loaded.splice(loaded.end(), to_free, iter);
+			return;
 		}
-		to_generate.pop_front();
 	}
 
-	if (!reused && !to_free.empty()) {
-		to_free.pop_front();
+	if (to_free.empty()) {
+		loaded.emplace_back(reg);
+	} else {
+		to_free.front().ClearNeighbors();
+		loaded.splice(loaded.end(), to_free, to_free.begin());
 	}
+	Chunk &chunk = loaded.back();
+	chunk.Position(pos);
+	gen(chunk);
+	Insert(chunk);
 }
 
 }