Allow teleporting to a biome with /tp.

src/server/command/tp.zig

@@ -4,9 +4,68 @@ const main = @import("root");
 const User = main.server.User;
 
 pub const description = "Teleport to location.";
-pub const usage = "/tp <x> <y>\n/tp <x> <y> <z>";
+pub const usage = "/tp <x> <y>\n/tp <x> <y> <z>\n/tp <biome>";
 
 pub fn execute(args: []const u8, source: *User) void {
+	if(std.mem.containsAtLeast(u8, args, 1, ":")) {
+		const biome = main.server.terrain.biomes.getById(args);
+		if(!std.mem.eql(u8, biome.id, args)) {
+			const msg = std.fmt.allocPrint(main.stackAllocator.allocator, "#ff0000Couldn't find biome with id \"{s}\"", .{args}) catch unreachable;
+			defer main.stackAllocator.free(msg);
+			source.sendMessage(msg);
+			return;
+		}
+		if(biome.isCave) {
+			source.sendMessage("#ff0000Teleport to biome is only available for surface biomes.");
+			return;
+		}
+		const radius = 16384;
+		const mapSize: i32 = main.server.terrain.ClimateMap.ClimateMapFragment.mapSize;
+		// Explore chunks in a spiral from the center:
+		const spiralLen = 2*radius/mapSize*2*radius/mapSize;
+		var wx = source.lastPos[0] & ~(mapSize - 1);
+		var wy = source.lastPos[1] & ~(mapSize - 1);
+		var dirChanges: usize = 1;
+		var dir: main.chunk.Neighbor = .dirNegX;
+		var stepsRemaining: usize = 1;
+		for(0..spiralLen) |_| {
+			const map = main.server.terrain.ClimateMap.getOrGenerateFragmentAndIncreaseRefCount(wx, wy);
+			defer map.decreaseRefCount();
+			for(0..map.map.len) |_| {
+				const x = main.random.nextIntBounded(u31, &main.seed, map.map.len);
+				const y = main.random.nextIntBounded(u31, &main.seed, map.map.len);
+				const sample = map.map[x][y];
+				if(sample.biome == biome) {
+					const z = sample.height + sample.hills + sample.mountains + sample.roughness;
+					const biomeSize = main.server.terrain.SurfaceMap.MapFragment.biomeSize;
+					main.network.Protocols.genericUpdate.sendTPCoordinates(source.conn, .{@floatFromInt(wx + x*biomeSize + biomeSize/2), @floatFromInt(wy + y*biomeSize + biomeSize/2), @floatCast(z + biomeSize/2)});
+					return;
+				}
+			}
+			switch (dir) {
+				.dirNegX => wx -%= mapSize,
+				.dirPosX => wx +%= mapSize,
+				.dirNegY => wy -%= mapSize,
+				.dirPosY => wy +%= mapSize,
+				else => unreachable,
+			}
+			stepsRemaining -= 1;
+			if(stepsRemaining == 0) {
+				switch (dir) {
+					.dirNegX => dir = .dirNegY,
+					.dirPosX => dir = .dirPosY,
+					.dirNegY => dir = .dirPosX,
+					.dirPosY => dir = .dirNegX,
+					else => unreachable,
+				}
+				dirChanges += 1;
+				// Every second turn the number of steps needed doubles.
+				stepsRemaining = dirChanges/2;
+			}
+		}
+		source.sendMessage("#ff0000Couldn't find biome. Searched in a radius of 16384 blocks.");
+		return;
+	}
 	var x: ?f64 = null;
 	var y: ?f64 = null;
 	var z: ?f64 = null;

src/server/terrain/ClimateMap.zig

@@ -137,7 +137,7 @@ pub fn deinit() void {
 	cache.clear();
 }
 
-fn getOrGenerateFragmentAndIncreaseRefCount(wx: i32, wy: i32) *ClimateMapFragment {
+pub fn getOrGenerateFragmentAndIncreaseRefCount(wx: i32, wy: i32) *ClimateMapFragment {
 	const compare = ClimateMapFragmentPosition{.wx = wx, .wy = wy};
 	const result = cache.findOrCreate(compare, cacheInit, ClimateMapFragment.increaseRefCount);
 	return result;