Get world database working

src/game.zig

@@ -213,21 +213,9 @@ pub fn start() !void {
 
     map = Map.init(&map_buf, level_size);
 
-    var stream = std.io.FixedBufferStream([]const u8){
+    var db = try world.Database.init(alloc);
-        .pos = 0,
-        .buffer = world_data,
-    };
-    const world_reader = stream.reader();
 
-    var levels = try world.read(alloc, world_reader);
+    level = try db.levelLoad(alloc, 0);
-    var level_data_offset = try stream.getPos();
-
-    try stream.seekTo(level_data_offset + levels[0].offset);
-
-    level = try world.Level.read(world_reader);
-
-    level_buf = try alloc.alloc(world.TileData, level.size);
-    try level.readTiles(world_reader, level_buf);
 
     try extract.extractLevel(.{
         .alloc = frame_alloc,
@@ -241,9 +229,6 @@ pub fn start() !void {
         .switch_on = world.Tiles.SwitchesOn,
     });
 
-    var entity_buf = try alloc.alloc(world.Entity, level.entity_count);
-    try level.readEntities(world_reader, entity_buf);
-
     const spawnArr = level.getSpawn() orelse return error.NoPlayerSpawn;
     const spawn = Vec2{ spawnArr[0], spawnArr[1] };
 

src/world.zig

@@ -457,6 +457,54 @@ pub fn read(alloc: std.mem.Allocator, reader: anytype) ![]LevelHeader {
     return level_headers;
 }
 
+const Cursor = std.io.FixedBufferStream([]const u8);
+pub const Database = struct {
+    cursor: Cursor,
+    level_info: []LevelHeader,
+    level_data_begin: usize,
+
+    const world_data = @embedFile(@import("world_data").path);
+
+    pub fn init(alloc: std.mem.Allocator) !Database {
+        var cursor = Cursor{
+            .pos = 0,
+            .buffer = world_data,
+        };
+
+        var reader = cursor.reader();
+
+        var levels = try read(alloc, reader);
+        var level_data_begin = @intCast(usize, try cursor.getPos());
+
+        return Database{
+            .cursor = cursor,
+            .level_info = levels,
+            .level_data_begin = level_data_begin,
+        };
+    }
+
+    pub fn levelInfo(db: *Database, level: usize) !Level {
+        try db.cursor.seekTo(db.level_data_begin + db.level_info[level].offset);
+        const reader = db.cursor.reader();
+
+        return try Level.read(reader);
+    }
+
+    pub fn levelLoad(db: *Database, alloc: std.mem.Allocator, level: usize) !Level {
+        var level_info = try db.levelInfo(level);
+
+        const reader = db.cursor.reader();
+
+        var level_buf = try alloc.alloc(TileData, level_info.size);
+        try level_info.readTiles(reader, level_buf);
+
+        var entity_buf = try alloc.alloc(Entity, level_info.entity_count);
+        try level_info.readEntities(reader, entity_buf);
+
+        return level_info;
+    }
+};
+
 // All levels in the game. If two rooms are next to each other, they
 // are assumed to be neighbors. Leaving the screen will load in the next
 // level in that direction. The player is placed at the same position