Add Structure Building Blocks based Generator (#1227)

* Revert "Remove SBBGen"

This reverts commit b49048412f21c57d5638144da7f039753a94cafc.

* Revert "Remove example SBB"

This reverts commit afc5d6fed0ba92b558ccda91893fdb3fc63f69ec.

* Revert "Remove blueprint code"

This reverts commit 2553950adbdcef9c1c68afe4109f9247b74abb92.

* Fix compilation errors

* Fix compilation errors #2

* Fix test errors

* Fix rotateZ

* Resolve structure reference while instantiating SBBGen

* Fix formatting issues

* Add new trees to forest

* Add new trees to grassland

* Decrease forest density so you can find new trees

* Add degradable paste mode

* Remove substitutions

* Apply review suggestions

* Use lookup table for alignment

* Apply suggestions from code review

* Update src/server/terrain/simple_structures/_list.zig

Co-authored-by: IntegratedQuantum <43880493+IntegratedQuantum@users.noreply.github.com>

* Fix inital SBB offset

* Never place air in placeInGeneration

* Integrate void block with paste

* Revert "Move hashInt and hashCombine to utils"

This reverts commit 9bb276f69f60ad60f1170d07ec30ebd02307a36a.

* Make PasteMode comptime

* Fix remaining issues with void block integration

* Fix formatting

* Apply review change requests

* Remove origin and child blocks while resolving sbbs

* Apply review change requests

* I hate indexing

* Fix example tree models

* Use single index for chunk and blueprint in pasteInGeneration

* Fix formatting

* Extract blueprintOffset

* Fix formatting

* Apply suggestions from code review

Co-authored-by: IntegratedQuantum <43880493+IntegratedQuantum@users.noreply.github.com>

* Apply Quantums suggestion for Y and Z

* No cast

* Use pos instead of chunkOffset

* Remove test tree

* Apply suggestions from code review

---------

Co-authored-by: IntegratedQuantum <43880493+IntegratedQuantum@users.noreply.github.com>

src/blueprint.zig

@@ -108,9 +108,46 @@ pub const Blueprint = struct {
 		}
 		return .{.success = self};
 	}
+
+	pub const PasteMode = enum {all, degradable};
+
+	pub fn pasteInGeneration(self: Blueprint, pos: Vec3i, chunk: *ServerChunk, mode: PasteMode) void {
+		switch(mode) {
+			inline else => |comptimeMode| _pasteInGeneration(self, pos, chunk, comptimeMode),
+		}
+	}
+
+	fn _pasteInGeneration(self: Blueprint, pos: Vec3i, chunk: *ServerChunk, comptime mode: PasteMode) void {
+		const indexEndX: i32 = @min(@as(i32, chunk.super.width) - pos[0], @as(i32, @intCast(self.blocks.width)));
+		const indexEndY: i32 = @min(@as(i32, chunk.super.width) - pos[1], @as(i32, @intCast(self.blocks.depth)));
+		const indexEndZ: i32 = @min(@as(i32, chunk.super.width) - pos[2], @as(i32, @intCast(self.blocks.height)));
+
+		var indexX: u31 = @max(0, -pos[0]);
+		while(indexX < indexEndX) : (indexX += chunk.super.pos.voxelSize) {
+			var indexY: u31 = @max(0, -pos[1]);
+			while(indexY < indexEndY) : (indexY += chunk.super.pos.voxelSize) {
+				var indexZ: u31 = @max(0, -pos[2]);
+				while(indexZ < indexEndZ) : (indexZ += chunk.super.pos.voxelSize) {
+					const block = self.blocks.get(indexX, indexY, indexZ);
+
+					if(block.typ == voidType) continue;
+
+					const chunkX = indexX + pos[0];
+					const chunkY = indexY + pos[1];
+					const chunkZ = indexZ + pos[2];
+					switch(mode) {
+						.all => chunk.updateBlockInGeneration(chunkX, chunkY, chunkZ, block),
+						.degradable => chunk.updateBlockIfDegradable(chunkX, chunkY, chunkZ, block),
+					}
+				}
+			}
+		}
+	}
+
 	pub const PasteFlags = struct {
 		preserveVoid: bool = false,
 	};
+
 	pub fn paste(self: Blueprint, pos: Vec3i, flags: PasteFlags) void {
 		const startX = pos[0];
 		const startY = pos[1];
@@ -339,3 +376,7 @@ pub fn registerVoidBlock(block: Block) void {
 	voidType = block.typ;
 	std.debug.assert(voidType != 0);
 }
+
+pub fn getVoidBlock() Block {
+	return Block{.typ = voidType.?, .data = 0};
+}

src/server/terrain/simple_structures/SbbGen.zig

@@ -0,0 +1,90 @@
+const std = @import("std");
+
+const main = @import("main");
+const terrain = main.server.terrain;
+const Vec3i = main.vec.Vec3i;
+const GenerationMode = terrain.biomes.SimpleStructureModel.GenerationMode;
+const CaveMapView = terrain.CaveMap.CaveMapView;
+const CaveBiomeMapView = terrain.CaveBiomeMap.CaveBiomeMapView;
+const sbb = terrain.structure_building_blocks;
+const Blueprint = main.blueprint.Blueprint;
+const ZonElement = main.ZonElement;
+const Neighbor = main.chunk.Neighbor;
+const ServerChunk = main.chunk.ServerChunk;
+const NeverFailingAllocator = main.heap.NeverFailingAllocator;
+
+pub const id = "cubyz:sbb";
+pub const generationMode = .floor;
+
+const SbbGen = @This();
+
+structureRef: *const sbb.StructureBuildingBlock,
+placeMode: Blueprint.PasteMode,
+
+pub fn getHash(self: SbbGen) u64 {
+	return std.hash.Wyhash.hash(@intFromEnum(self.placeMode), self.structureRef.id);
+}
+
+pub fn loadModel(arenaAllocator: NeverFailingAllocator, parameters: ZonElement) *SbbGen {
+	const structureId = parameters.get(?[]const u8, "structure", null) orelse unreachable;
+	const structureRef = sbb.getByStringId(structureId) orelse {
+		std.log.err("Could not find structure building block with id '{s}'", .{structureId});
+		unreachable;
+	};
+	const self = arenaAllocator.create(SbbGen);
+	self.* = .{
+		.structureRef = structureRef,
+		.placeMode = std.meta.stringToEnum(Blueprint.PasteMode, parameters.get([]const u8, "placeMode", "degradable")) orelse Blueprint.PasteMode.degradable,
+	};
+	return self;
+}
+
+pub fn generate(self: *SbbGen, _: GenerationMode, x: i32, y: i32, z: i32, chunk: *ServerChunk, _: CaveMapView, _: CaveBiomeMapView, seed: *u64, _: bool) void {
+	placeSbb(self, self.structureRef, Vec3i{x, y, z}, Neighbor.dirUp, chunk, seed);
+}
+
+fn placeSbb(self: *SbbGen, structure: *const sbb.StructureBuildingBlock, placementPosition: Vec3i, placementDirection: Neighbor, chunk: *ServerChunk, seed: *u64) void {
+	const origin = structure.blueprints[0].originBlock;
+	const rotationCount = alignDirections(origin.direction(), placementDirection) catch |err| {
+		std.log.err("Could not align directions for structure '{s}' for directions '{s}'' and '{s}', error: {s}", .{structure.id, @tagName(origin.direction()), @tagName(placementDirection), @errorName(err)});
+		return;
+	};
+	const rotated = &structure.blueprints[rotationCount];
+	const rotatedOrigin = rotated.originBlock.pos();
+	const pastePosition = placementPosition - rotatedOrigin - placementDirection.relPos();
+
+	rotated.blueprint.pasteInGeneration(pastePosition, chunk, self.placeMode);
+
+	for(rotated.childBlocks) |childBlock| {
+		const child = structure.pickChild(childBlock, seed);
+		placeSbb(self, child, pastePosition + childBlock.pos(), childBlock.direction(), chunk, seed);
+	}
+}
+
+fn alignDirections(input: Neighbor, desired: Neighbor) !usize {
+	const Rotation = enum(u3) {
+		@"0" = 0,
+		@"90" = 1,
+		@"180" = 2,
+		@"270" = 3,
+		NotPossibleToAlign = 4,
+	};
+	comptime var alignTable: [6][6]Rotation = undefined;
+	comptime for(Neighbor.iterable) |in| {
+		for(Neighbor.iterable) |out| blk: {
+			var current = in;
+			for(0..4) |i| {
+				if(current == out) {
+					alignTable[in.toInt()][out.toInt()] = @enumFromInt(i);
+					break :blk;
+				}
+				current = current.rotateZ();
+			}
+			alignTable[in.toInt()][out.toInt()] = Rotation.NotPossibleToAlign;
+		}
+	};
+	switch(alignTable[input.toInt()][desired.toInt()]) {
+		.NotPossibleToAlign => return error.NotPossibleToAlign,
+		else => |v| return @intFromEnum(v),
+	}
+}

src/server/terrain/simple_structures/_list.zig

@@ -2,6 +2,7 @@ pub const Boulder = @import("Boulder.zig");
 pub const FallenTree = @import("FallenTree.zig");
 pub const FlowerPatch = @import("FlowerPatch.zig");
 pub const GroundPatch = @import("GroundPatch.zig");
+pub const SbbGen = @import("SbbGen.zig");
 pub const SimpleTreeModel = @import("SimpleTreeModel.zig");
 pub const SimpleVegetation = @import("SimpleVegetation.zig");
 pub const Stalagmite = @import("Stalagmite.zig");

src/server/terrain/structure_building_blocks.zig

@@ -1,6 +1,7 @@
 const std = @import("std");
 
 const main = @import("main");
+const Vec3i = main.vec.Vec3i;
 const ZonElement = main.ZonElement;
 const Blueprint = main.blueprint.Blueprint;
 const List = main.List;
@@ -40,6 +41,10 @@ const BlueprintEntry = struct {
 		pub inline fn direction(self: StructureBlock) Neighbor {
 			return @enumFromInt(self.data);
 		}
+
+		pub inline fn pos(self: StructureBlock) Vec3i {
+			return Vec3i{self.x, self.y, self.z};
+		}
 	};
 
 	fn init(blueprint: Blueprint, stringId: []const u8) !BlueprintEntry {
@@ -70,6 +75,7 @@ const BlueprintEntry = struct {
 								.data = block.data,
 							};
 							hasOrigin = true;
+							self.blueprint.blocks.set(x, y, z, main.blueprint.getVoidBlock());
 						}
 					} else if(isChildBlock(block)) {
 						const childBlockLocalId = childBlockNumericIdMap.get(block.typ) orelse return error.ChildBlockNotRecognized;
@@ -80,6 +86,7 @@ const BlueprintEntry = struct {
 							.index = childBlockLocalId,
 							.data = block.data,
 						});
+						self.blueprint.blocks.set(x, y, z, main.blueprint.getVoidBlock());
 					}
 				}
 			}
@@ -103,6 +110,7 @@ pub fn isOriginBlock(block: Block) bool {
 }
 
 pub const StructureBuildingBlock = struct {
+	id: []const u8,
 	children: []AliasTable(Child),
 	blueprints: *[4]BlueprintEntry,
 
@@ -116,6 +124,7 @@ pub const StructureBuildingBlock = struct {
 			return error.MissingBlueprint;
 		};
 		const self = StructureBuildingBlock{
+			.id = stringId,
 			.children = arenaAllocator.alloc(AliasTable(Child), childBlockStringId.items.len),
 			.blueprints = blueprints,
 		};
@@ -172,6 +181,7 @@ pub fn registerSBB(structures: *std.StringHashMap(ZonElement)) !void {
 	std.debug.assert(structureCache.capacity() == 0);
 	structureCache.ensureTotalCapacity(arenaAllocator.allocator, structures.count()) catch unreachable;
 	childrenToResolve = .init(main.stackAllocator);
+	defer childrenToResolve.deinit();
 	{
 		var iterator = structures.iterator();
 		while(iterator.next()) |entry| {
@@ -195,7 +205,6 @@ pub fn registerSBB(structures: *std.StringHashMap(ZonElement)) !void {
 			std.log.debug("Resolved child structure '{s}'->'{s}'->'{d}' to '{s}'", .{entry.parentId, entry.colorName, entry.childIndex, entry.structureId});
 			parent.children[entry.colorIndex].items[entry.childIndex].structure = child;
 		}
-		childrenToResolve.deinit();
 	}
 }
 
@@ -221,17 +230,22 @@ pub fn registerBlueprints(blueprints: *std.StringHashMap([]u8)) !void {
 	var iterator = blueprints.iterator();
 	while(iterator.next()) |entry| {
 		const stringId = entry.key_ptr.*;
+		// Rotated copies need to be made before initializing BlueprintEntry as it removes origin and child blocks.
 		const blueprint0 = Blueprint.load(arenaAllocator, entry.value_ptr.*) catch |err| {
 			std.log.err("Could not load blueprint '{s}' ({s})", .{stringId, @errorName(err)});
 			continue;
 		};
+		const blueprint90 = blueprint0.rotateZ(arenaAllocator, .@"90");
+		const blueprint180 = blueprint0.rotateZ(arenaAllocator, .@"180");
+		const blueprint270 = blueprint0.rotateZ(arenaAllocator, .@"270");
 
 		const rotatedBlueprints = arenaAllocator.create([4]BlueprintEntry);
+
 		rotatedBlueprints.* = .{
 			BlueprintEntry.init(blueprint0, stringId) catch continue,
-			BlueprintEntry.init(blueprint0.rotateZ(arenaAllocator, .@"90"), stringId) catch continue,
+			BlueprintEntry.init(blueprint90, stringId) catch continue,
-			BlueprintEntry.init(blueprint0.rotateZ(arenaAllocator, .@"180"), stringId) catch continue,
+			BlueprintEntry.init(blueprint180, stringId) catch continue,
-			BlueprintEntry.init(blueprint0.rotateZ(arenaAllocator, .@"270"), stringId) catch continue,
+			BlueprintEntry.init(blueprint270, stringId) catch continue,
 		};
 
 		blueprintCache.put(arenaAllocator.allocator, arenaAllocator.dupe(u8, stringId), rotatedBlueprints) catch unreachable;