implement parsing multiple levels from map file

assets/tiled/map.tmx

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<map version="1.10" tiledversion="1.12.2" orientation="orthogonal" renderorder="right-down" width="30" height="20" tilewidth="64" tileheight="64" infinite="1" nextlayerid="8" nextobjectid="17">
+<map version="1.10" tiledversion="1.12.2" orientation="orthogonal" renderorder="right-down" width="30" height="20" tilewidth="64" tileheight="64" infinite="1" nextlayerid="8" nextobjectid="19">
  <tileset firstgid="1" source="tileset.tsx"/>
  <layer id="2" name="Ground" width="30" height="20">
   <data encoding="csv">
@@ -85,14 +85,17 @@
   <object id="1" name="spawn" x="484" y="555">
    <point/>
   </object>
+  <object id="17" name="spawn" x="1381.33" y="497.333">
+   <point/>
+  </object>
  </objectgroup>
  <objectgroup id="7" name="Level bounds">
-  <object id="15" x="345.333" y="218.667" width="633.333" height="566.667">
+  <object id="15" x="324" y="214.667" width="633.333" height="566.667">
    <properties>
     <property name="level" type="int" value="1"/>
    </properties>
   </object>
-  <object id="16" x="1228" y="172" width="565.333" height="593.333">
+  <object id="18" x="1196.67" y="206" width="633.333" height="566.667">
    <properties>
     <property name="level" type="int" value="2"/>
    </properties>

libs/tiled/src/object.zig

@@ -3,6 +3,7 @@ const std = @import("std");
 const xml = @import("./xml.zig");
 const Position = @import("./position.zig");
 const Color = @import("./color.zig");
+const Property = @import("./property.zig");
 
 const Object = @This();
 
@@ -113,6 +114,7 @@ class: []const u8,
 rotation: f32, // TODO: maybe this field should be moved to Shape struct
 visible: bool,
 shape: Shape,
+properties: Property.List,
 
 pub fn initFromXml(
     arena: std.mem.Allocator,
@@ -255,13 +257,16 @@ pub fn initFromXml(
         }
     }
 
+    const properties = try Property.List.initFromXmlContainer(arena, doc, element_id);
+
     return Object{
         .id = id,
         .name = name,
         .class = class,
         .rotation = rotation,
         .visible = visible,
-        .shape = shape orelse return error.UnknownShapeType
+        .shape = shape orelse return error.UnknownShapeType,
+        .properties = properties
     };
 }
 

libs/tiled/src/property.zig

@@ -57,6 +57,24 @@ pub const List = struct {
         };
     }
 
+    pub fn initFromXmlContainer(
+        arena: std.mem.Allocator,
+        doc: xml.Document,
+        element_id: xml.Element.Id
+    ) !Property.List {
+        var iter = doc.iterChildren(element_id);
+        while (iter.next()) |child_id| {
+            const child = doc.getTag(child_id) orelse continue;
+            const child_name = child.variant.tag.name;
+
+            if (std.mem.eql(u8, child_name, "properties")) {
+                return try Property.List.initFromXml(arena, doc, child_id);
+            }
+        }
+
+        return .empty;
+    }
+
     pub fn get(self: List, name: []const u8) ?Value {
         for (self.items) |item| {
             if (std.mem.eql(u8, item.name, name)) {
@@ -68,8 +86,19 @@ pub const List = struct {
 
     pub fn getString(self: List, name: []const u8) ?[]const u8 {
         if (self.get(name)) |value| {
+            if (value == .string) {
                 return value.string;
             }
+        }
+        return null;
+    }
+
+    pub fn getInt(self: List, name: []const u8) ?i32 {
+        if (self.get(name)) |value| {
+            if (value == .int) {
+                return value.int;
+            }
+        }
         return null;
     }
 };

libs/tiled/src/tilemap.zig

@@ -263,6 +263,10 @@ pub const Bounds = struct {
     pub fn height(self: Bounds) u32 {
         return @intCast(self.max_y - self.min_y + 1);
     }
+
+    pub fn isInside(self: Bounds, x: i32, y: i32) bool {
+        return (self.min_x <= x and x <= self.max_x) and (self.min_y <= y and y <= self.max_y);
+    }
 };
 
 pub fn getTileBounds(self: *const Tilemap) Bounds {
@@ -274,29 +278,21 @@ pub fn getTileBounds(self: *const Tilemap) Bounds {
         }
 
         for (layer.variant.tile.chunks) |chunk| {
-            for (0..chunk.height) |oy| {
+            const chunk_bounds = Bounds{
-                for (0..chunk.width) |ox| {
+                .min_x = chunk.x,
-                    const x = chunk.x + @as(i32, @intCast(ox));
+                .min_y = chunk.y,
-                    const y = chunk.y + @as(i32, @intCast(oy));
+                .max_x = chunk.x + @as(i32, @intCast(chunk.width)),
-                    const gid = layer.variant.tile.get(x, y).?;
+                .max_y = chunk.y + @as(i32, @intCast(chunk.height))
-                    if (gid != 0) {
+            };
             if (result) |bounds| {
                 result = Bounds{
-                                .min_x = @min(x, bounds.min_x),
+                    .min_x = @min(chunk_bounds.min_x, bounds.min_x),
-                                .min_y = @min(y, bounds.min_y),
+                    .min_y = @min(chunk_bounds.min_y, bounds.min_y),
-                                .max_x = @max(x, bounds.max_x),
+                    .max_x = @max(chunk_bounds.max_x, bounds.max_x),
-                                .max_y = @max(y, bounds.max_y)
+                    .max_y = @max(chunk_bounds.max_y, bounds.max_y)
                 };
             } else {
-                            result = Bounds{
+                result = chunk_bounds;
-                                .min_x = x,
-                                .min_y = y,
-                                .max_x = x,
-                                .max_y = y
-                            };
-                        }
-                    }
-                }
             }
         }
     }
@@ -304,6 +300,59 @@ pub fn getTileBounds(self: *const Tilemap) Bounds {
     return result orelse Bounds.zero;
 }
 
+fn isRowEmpty(tile_layer: Layer.TileVariant, x: i32, y: i32, length: u32) bool {
+    for (0..length) |i| {
+        const gid = tile_layer.get(x + @as(i32, @intCast(i)), y) orelse continue;
+        if (gid != 0) {
+            return false;
+        }
+    }
+    return true;
+}
+
+fn isColumnEmpty(tile_layer: Layer.TileVariant, x: i32, y: i32, length: u32) bool {
+    for (0..length) |i| {
+        const gid = tile_layer.get(x, y + @as(i32, @intCast(i))) orelse continue;
+        if (gid != 0) {
+            return false;
+        }
+    }
+    return true;
+}
+
+pub fn trimBoundsByEmptyTiles(self: *const Tilemap, bounds: Bounds) Bounds {
+    var result: Bounds = bounds;
+
+    for (self.layers) |*layer| {
+        if (layer.variant != .tile) {
+            continue;
+        }
+        const tile_layer = layer.variant.tile;
+
+        // Trim left
+        while (result.min_x < result.max_x and isColumnEmpty(tile_layer, result.min_x, result.min_y, result.height())) {
+            result.min_x += 1;
+        }
+
+        // Trim right
+        while (result.min_x < result.max_x and isColumnEmpty(tile_layer, result.max_x, result.min_y, result.height())) {
+            result.max_x -= 1;
+        }
+
+        // Trim top
+        while (result.min_y < result.max_y and isRowEmpty(tile_layer, result.min_x, result.min_y, result.width())) {
+            result.min_y += 1;
+        }
+
+        // Trim bottom
+        while (result.min_y < result.max_y and isRowEmpty(tile_layer, result.min_x, result.max_y, result.width())) {
+            result.max_y -= 1;
+        }
+    }
+
+    return result;
+}
+
 pub fn deinit(self: *const Tilemap) void {
     self.arena.deinit();
 }

libs/tiled/src/tileset.zig

@@ -43,18 +43,7 @@ pub const Tile = struct {
         const tile_attrs = tag.variant.tag.attributes;
 
         const id = try tile_attrs.getNumber(u32, "id") orelse return error.MissingId;
-
+        const properties = try Property.List.initFromXmlContainer(arena, doc, element_id);
-        var properties: Property.List = .empty;
-
-        var iter = doc.iterChildren(element_id);
-        while (iter.next()) |child_id| {
-            const child = doc.getTag(child_id) orelse continue;
-            const child_name = child.variant.tag.name;
-
-            if (std.mem.eql(u8, child_name, "properties")) {
-                properties = try Property.List.initFromXml(arena, doc, child_id);
-            }
-        }
 
         return Tile{
             .id = id,

src/app.zig

@@ -71,6 +71,17 @@ const Tilemap = struct {
         };
     }
 
+    pub fn clone(self: Tilemap, gpa: Allocator) !Tilemap {
+        const tiles = try gpa.dupe(Tile, self.tiles);
+        errdefer gpa.free(tiles);
+
+        return Tilemap{
+            .tiles = tiles,
+            .width = self.width,
+            .height = self.height,
+        };
+    }
+
     pub fn deinit(self: *Tilemap, gpa: Allocator) void {
         gpa.free(self.tiles);
     }
@@ -114,6 +125,22 @@ const World = struct {
     tilemap: Tilemap,
     entities: Entity.SlotMap,
 
+    pub fn clone(self: World, gpa: Allocator) !World {
+        var tilemap = try self.tilemap.clone(gpa);
+        errdefer tilemap.deinit(gpa);
+
+        var entity_slots = try self.entities.slots.clone(gpa);
+        errdefer entity_slots.deinit(gpa);
+
+        var entities = self.entities;
+        entities.slots = entity_slots;
+
+        return World{
+            .tilemap = tilemap,
+            .entities = entities
+        };
+    }
+
     fn spawnEntity(self: *World, opts: Entity) Entity.Id {
         var e = opts; 
         e.pos_x = -1;
@@ -186,7 +213,13 @@ const World = struct {
     }
 };
 
+const Level = struct {
+    number: i32,
     world: World,
+};
+
+world: World,
+levels: std.ArrayList(Level),
 
 roboto_font: Font,
 tilesheet: Tilesheet,
@@ -263,35 +296,94 @@ pub fn init(self: *App, plt: Platform.Init) !?u8 {
         .tilesheet = tilesheet,
         .footstep_buffer = footstep_sound,
         .sfx_bus = Audio.addBus(.{ .label = "sfx" }),
-        .world = .{
+        .world = undefined,
-            .tilemap = undefined,
+        .levels = .empty,
-            .entities = try .initCapacity(plt.gpa, 256)
-        }
     };
 
-    {
+    self.levels = try self.loadLevels(plt.gpa, plt.assets);
-        var xml_parser = try Tiled.xml.Parser.initCapacity(plt.gpa, .{});
+    self.world = try self.levels.items[0].world.clone(plt.gpa);
-        defer xml_parser.deinit(plt.gpa);
+
+    return null;
+}
+
+pub fn loadLevels(self: *App, gpa: Allocator, assets: *Platform.Assets) !std.ArrayList(Level) {
+    var xml_parser = try Tiled.xml.Parser.initCapacity(gpa, .{});
+    defer xml_parser.deinit(gpa);
 
     const tilemap = try Tiled.Tilemap.initFromXml(
-            plt.gpa,
+        gpa,
-            try xml_parser.parse(plt.assets.readFile("tiled/map.tmx")),
+        try xml_parser.parse(assets.readFile("tiled/map.tmx")),
         .root
     );
     defer tilemap.deinit();
 
     var tilesets: Tiled.Tileset.List = .empty;
-        defer tilesets.deinit(plt.gpa);
+    defer tilesets.deinit(gpa);
 
-        try tilesets.add(plt.gpa, "tileset.tsx", try Tiled.Tileset.initFromXml(
+    try tilesets.add(gpa, "tileset.tsx", try Tiled.Tileset.initFromXml(
-            plt.gpa,
+        gpa,
-            try xml_parser.parse(plt.assets.readFile("tiled/tileset.tsx")),
+        try xml_parser.parse(assets.readFile("tiled/tileset.tsx")),
         .root
     ));
 
-        const bounds = tilemap.getTileBounds();
+    var levels: std.ArrayList(Level) = .empty;
 
-        self.world.tilemap = try Tilemap.init(plt.gpa, bounds.width(), bounds.height());
+    const level_bounds = tilemap.getLayer("Level bounds").?;
+    for (level_bounds.variant.object.items) |obj| {
+        if (obj.shape != .rectangle) {
+            continue;
+        }
+
+        const level_index = obj.properties.getInt("level") orelse {
+            log.warn("Level bounds doesn't have index", .{});
+            continue;
+        };
+
+        var rect = obj.shape.rectangle;
+        rect.x /= @floatFromInt(tilemap.tile_width);
+        rect.y /= @floatFromInt(tilemap.tile_height);
+        rect.width /= @floatFromInt(tilemap.tile_width);
+        rect.height /= @floatFromInt(tilemap.tile_height);
+
+        var level_bound = Tiled.Tilemap.Bounds{
+            .min_x = @intFromFloat(@floor(rect.x)),
+            .min_y = @intFromFloat(@floor(rect.y)),
+            .max_x = @intFromFloat(@ceil(rect.x + rect.width)),
+            .max_y = @intFromFloat(@ceil(rect.y + rect.height)),
+        };
+        level_bound = tilemap.trimBoundsByEmptyTiles(level_bound);
+
+        var level = try self.loadLevel(gpa, tilemap, tilesets, level_bound);
+        level.number = level_index;
+        try levels.append(gpa, level);
+    }
+
+    const Context = struct {
+        fn lessThan(_: @This(), lhs: Level, rhs: Level) bool {
+            return lhs.number < rhs.number;
+        }
+    };
+
+    std.mem.sort(Level, levels.items, Context{}, Context.lessThan);
+
+
+    return levels;
+}
+
+pub fn loadLevel(
+    self: *App,
+    gpa: Allocator,
+    tilemap: Tiled.Tilemap,
+    tilesets: Tiled.Tileset.List,
+    bounds: Tiled.Tilemap.Bounds
+) !Level {
+    var level = Level{
+        .number = 0,
+        .world = .{
+            .tilemap = try .init(gpa, bounds.width(), bounds.height()),
+            .entities = try .initCapacity(gpa, 256)
+        }
+    };
 
     const ground = tilemap.getLayer("Ground").?;
     const foreground = tilemap.getLayer("Foreground").?;
@@ -300,11 +392,11 @@ pub fn init(self: *App, plt: Platform.Init) !?u8 {
             const x = bounds.min_x + @as(i32, @intCast(ox));
             const y = bounds.min_y + @as(i32, @intCast(oy));
 
-                const tile = self.world.tilemap.get(ox, oy);
+            const tile = level.world.tilemap.get(ox, oy);
 
             if (tilemap.getTile(ground, tilesets, x, y)) |tiled_tile| {
                 const pos = tiled_tile.getPosition();
-                    tile.ground_sprite = tilesheet.get(pos.x, pos.y);
+                tile.ground_sprite = self.tilesheet.get(pos.x, pos.y);
             }
 
             if (tilemap.getTile(foreground, tilesets, x, y)) |tiled_tile| {
@@ -326,36 +418,44 @@ pub fn init(self: *App, plt: Platform.Init) !?u8 {
                 }
 
                 if (entity_type != null) {
-                        _ = self.world.spawnEntity(Entity{
+                    _ = level.world.spawnEntity(Entity{
                         .type = entity_type.?,
                         .layer = layer,
                         .pos_x = @intCast(ox),
                         .pos_y = @intCast(oy),
-                            .sprite = tilesheet.get(pos.x, pos.y)
+                        .sprite = self.tilesheet.get(pos.x, pos.y)
                     });
                 }
             }
         }
     }
 
-        const markers = &tilemap.getLayer("Markers").?.variant.object;
+    for (tilemap.getLayer("Markers").?.variant.object.items) |obj| {
-        const spawn = markers.getByName("spawn").?;
+        if (obj.shape != .point) {
+            continue;
+        }
+        if (!std.mem.eql(u8, obj.name, "spawn")) {
+            continue;
+        }
 
-        var player_pos: Vec2 = .zero;
+        var position = obj.shape.point;
-        player_pos.x = @divFloor(spawn.shape.point.x, @as(f32, @floatFromInt(tilemap.tile_width)));
+        position.x /= @floatFromInt(tilemap.tile_width);
-        player_pos.x -= @floatFromInt(bounds.min_x);
+        position.y /= @floatFromInt(tilemap.tile_height);
-        player_pos.y = @divFloor(spawn.shape.point.y, @as(f32, @floatFromInt(tilemap.tile_height)));
-        player_pos.y -= @floatFromInt(bounds.min_y);
 
-        _ = self.world.spawnEntity(Entity{
+        const pos_x: i32 = @intFromFloat(position.x);
+        const pos_y: i32 = @intFromFloat(position.y);
+
+        if (bounds.isInside(pos_x, pos_y)) {
+            _ = level.world.spawnEntity(Entity{
                 .type = .player,
                 .layer = .surface,
-            .pos_x = @intFromFloat(player_pos.x),
+                .pos_x = pos_x - bounds.min_x,
-            .pos_y = @intFromFloat(player_pos.y)
+                .pos_y = pos_y - bounds.min_y
             });
         }
+    }
 
-    return null;
+    return level;
 }
 
 pub fn frame(self: *App, plt: Platform.Frame) !void {
@@ -478,4 +578,10 @@ pub fn deinit(self: *App, plt: Platform.Deinit) void {
 
     self.world.tilemap.deinit(plt.gpa);
     self.world.entities.slots.deinit(plt.gpa);
+
+    for (self.levels.items) |*level| {
+        level.world.entities.deinit(plt.gpa);
+        level.world.tilemap.deinit(plt.gpa);
+    }
+    self.levels.deinit(plt.gpa);
 }