add undo

README.md

@@ -3,16 +3,19 @@
 ## Run
 
 Linux and Windows:
+
 ```sh
 zig build run
 ```
 
 Web:
+
 ```sh
 zig build -Dtarget=wasm32-emscripten run
 ```
 
 Cross-compile for Windows from Linux:
+
 ```sh
 zig build -Dtarget=x86_64-windows
 ```

assets/tiled/map.tmx

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@@ -81,24 +441,36 @@
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   </data>
  </layer>
- <objectgroup id="5" name="Markers">
+ <objectgroup id="7" name="Level bounds" visible="0">
-  <object id="1" name="spawn" x="484" y="555">
+  <object id="15" x="93.3333" y="805.334" width="848" height="441.334">
-   <point/>
-  </object>
-  <object id="17" name="spawn" x="1381.33" y="497.333">
-   <point/>
-  </object>
- </objectgroup>
- <objectgroup id="7" name="Level bounds">
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     <property name="level" type="int" value="1"/>
    </properties>
   </object>
-  <object id="18" x="1196.67" y="206" width="633.333" height="566.667">
+  <object id="18" x="1118" y="811.333" width="829.333" height="434.667">
    <properties>
     <property name="level" type="int" value="2"/>
    </properties>
   </object>
+  <object id="19" x="2070.67" y="818.666" width="829.333" height="434.667">
+   <properties>
+    <property name="level" type="int" value="3"/>
+   </properties>
+  </object>
+  <object id="20" x="2988" y="813.333" width="829.333" height="434.667">
+   <properties>
+    <property name="level" type="int" value="4"/>
+   </properties>
+  </object>
+  <object id="21" x="3877.33" y="814.666" width="829.333" height="434.667">
+   <properties>
+    <property name="level" type="int" value="5"/>
+   </properties>
+  </object>
+  <object id="22" x="4772" y="812" width="829.333" height="434.667">
+   <properties>
+    <property name="level" type="int" value="6"/>
+   </properties>
+  </object>
  </objectgroup>
 </map>

assets/tiled/tileset.tsx

@@ -26,6 +26,11 @@
    <property name="type" value="box"/>
   </properties>
  </tile>
+ <tile id="11">
+  <properties>
+   <property name="type" value="box_hole"/>
+  </properties>
+ </tile>
  <tile id="25">
   <properties>
    <property name="type" value="goal_marker"/>
@@ -36,6 +41,36 @@
    <property name="type" value="goal_marker"/>
   </properties>
  </tile>
+ <tile id="39">
+  <properties>
+   <property name="type" value="box_goal"/>
+  </properties>
+ </tile>
+ <tile id="40">
+  <properties>
+   <property name="type" value="box_goal"/>
+  </properties>
+ </tile>
+ <tile id="41">
+  <properties>
+   <property name="type" value="box_goal"/>
+  </properties>
+ </tile>
+ <tile id="42">
+  <properties>
+   <property name="type" value="box_goal"/>
+  </properties>
+ </tile>
+ <tile id="43">
+  <properties>
+   <property name="type" value="box_goal"/>
+  </properties>
+ </tile>
+ <tile id="44">
+  <properties>
+   <property name="type" value="box_goal"/>
+  </properties>
+ </tile>
  <tile id="51">
   <properties>
    <property name="type" value="goal_marker"/>
@@ -46,6 +81,16 @@
    <property name="type" value="goal_marker"/>
   </properties>
  </tile>
+ <tile id="71">
+  <properties>
+   <property name="type" value="player"/>
+  </properties>
+ </tile>
+ <tile id="74">
+  <properties>
+   <property name="type" value="coin"/>
+  </properties>
+ </tile>
  <tile id="77">
   <properties>
    <property name="type" value="goal_marker"/>

src/app.zig

@@ -44,52 +44,19 @@ const PlayerSprites = struct {
     }
 };
 
-const Tile = struct {
+const Point = struct {
-    ground_sprite: ?Gfx.Sprite.Id,
+    x: i32,
+    y: i32,
 
-    entities_by_layer: std.EnumArray(Entity.Layer, Entity.Id),
+    pub fn add(lhs: Point, rhs: Point) Point {
-
+        return Point{
-    const empty = Tile{
+            .x = lhs.x + rhs.x,
-        .ground_sprite = null,
+            .y = lhs.y + rhs.y,
-        .entities_by_layer = .initFill(.nil)
-    };
-};
-
-const Tilemap = struct {
-    tiles: []Tile,
-    width: usize,
-    height: usize,
-
-    pub fn init(gpa: Allocator, width: usize, height: usize) !Tilemap {
-        const tiles = try gpa.alloc(Tile, width * height);
-        @memset(tiles, .empty);
-
-        return Tilemap{
-            .width = width,
-            .height = height,
-            .tiles = tiles
         };
     }
 
-    pub fn clone(self: Tilemap, gpa: Allocator) !Tilemap {
+    pub fn eql(lhs: Point, rhs: Point) bool {
-        const tiles = try gpa.dupe(Tile, self.tiles);
+        return lhs.x == rhs.x and lhs.y == rhs.y;
-        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);
-    }
-
-    pub fn get(self: *Tilemap, x: usize, y: usize) *Tile {
-        assert(x < self.width);
-        assert(y < self.height);
-        return &self.tiles[y * self.width + x];
     }
 };
 
@@ -97,8 +64,7 @@ const Entity = struct {
     type: Type,
     layer: Layer,
 
-    pos_x: i32 = -1,
+    pos: Point = .{ .x = -1, .y = -1 },
-    pos_y: i32 = -1,
     visual_pos: Vec2 = .init(0, 0),
     sprite: ?Gfx.Sprite.Id = null,
 
@@ -106,14 +72,19 @@ const Entity = struct {
     player_frame_index: u32 = 0,
 
     const Type = enum {
+        nil,
+
         player,
         box,
-        goal_marker,
+        wall,
-        wall
+        coin,
+        box_hole,
+        box_goal,
     };
 
     const Layer = enum {
         ground,
+        on_ground,
         surface,
     };
 
@@ -121,14 +92,47 @@ const Entity = struct {
     const Id = SlotMap.Id;
 };
 
+const UndoFrame = struct {
+    const EntityState = struct {
+        id: Entity.Id,
+        pos: Point,
+        player_direction: Direction,
+    };
+
+    entities_buffer: [8]EntityState,
+    entities_len: usize,
+
+    pub const empty = UndoFrame{
+        .entities_buffer = undefined,
+        .entities_len = 0
+    };
+
+    pub fn entities(self: *const UndoFrame) []const EntityState {
+        return self.entities_buffer[0..self.entities_len];
+    }
+
+    pub fn pushEntity(self: *UndoFrame, e: EntityState) bool {
+        if (self.entities_len < self.entities_buffer.len) {
+            self.entities_buffer[self.entities_len] = e;
+            self.entities_len += 1;
+
+            return true;
+        }
+
+        return false;
+    }
+
+    pub fn isEmpty(self: UndoFrame) bool {
+        return self.entities_len == 0;
+    }
+};
+
 const World = struct {
-    tilemap: Tilemap,
     entities: Entity.SlotMap,
+    width: u32,
+    height: u32,
 
     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);
 
@@ -136,85 +140,86 @@ const World = struct {
         entities.slots = entity_slots;
 
         return World{
-            .tilemap = tilemap,
+            .width = self.width,
-            .entities = entities
+            .height = self.height,
+            .entities = entities,
         };
     }
 
     pub fn deinit(self: *World, gpa: Allocator) void {
-        self.tilemap.deinit(gpa);
         self.entities.deinit(gpa);
     }
 
     fn spawnEntity(self: *World, opts: Entity) Entity.Id {
-        var e = opts; 
+        return self.entities.insert(opts) catch |err| {
-        e.pos_x = -1;
-        e.pos_y = -1;
-        const entity_id = self.entities.insert(e) catch |err| {
             log.err("Failed to spawn entity: {}", .{err});
             return .nil;
         };
+    }
 
-        if (opts.pos_x != -1 or opts.pos_y != -1) {
+    fn findEntity(self: *World, pos: Point, layer: Entity.Layer) Entity.Id {
-            assert(opts.pos_x != -1 and opts.pos_y != -1);
+        var entity_iter = self.entities.iterator();
-            if (!self.setEntityPosition(entity_id, opts.pos_x, opts.pos_y)) {
+        while (entity_iter.next()) |entity_id| {
-                log.err("Entity position: {}, {}", .{opts.pos_x, opts.pos_y});
+            const entity = self.entities.getAssumeExists(entity_id);
-                @panic("Failed to set initial entity position");
+            if (entity.layer == layer and entity.pos.eql(pos)) {
+                return entity_id;
             }
         }
 
-        return entity_id;
+        return .nil;
     }
+};
 
-    fn getTile(self: *World, x: i32, y: i32) ?*Tile {
+const TickContext = struct {
-        const width: i32 = @intCast(self.tilemap.width);
+    world: *World,
-        const height: i32 = @intCast(self.tilemap.height);
+    undo_frame: UndoFrame = .empty,
-        if (0 <= x and x < width and 0 <= y and y < height) {
-            return &self.tilemap.tiles[@intCast(x + y * width)];
-        }
-        return null;
-    }
 
-    fn setEntityPosition(self: *World, id: Entity.Id, x: i32, y: i32) bool {
+    fn moveEntity(self: *TickContext, id: Entity.Id, dir: Point) bool {
-        const e = self.entities.get(id) orelse return false;
+        if (dir.x == 0 and dir.y == 0) {
-        const destination_tile = self.getTile(x, y) orelse return false;
-
-        if (self.entities.exists(destination_tile.entities_by_layer.get(e.layer))) {
-            // Cant't overwrite entity
             return false;
         }
-        destination_tile.entities_by_layer.set(e.layer, id);
 
-        if (self.getTile(e.pos_x, e.pos_y)) |tile| {
+        const e = self.world.entities.get(id) orelse return false;
-            tile.entities_by_layer.set(e.layer, .nil);
-        }
 
-        e.pos_x = x;
+        const next_pos = e.pos.add(dir);
-        e.pos_y = y;
-
-        return true;
-    }
-
-    fn moveEntity(self: *World, id: Entity.Id, dx: i32, dy: i32) bool {
-        const e = self.entities.get(id) orelse return false;
-
-        const next_x = e.pos_x+dx;
-        const next_y = e.pos_y+dy;
-
-        const destination_tile = self.getTile(next_x, next_y) orelse return false;
 
         if (e.type == .player or e.type == .box) {
-            const destination_entity_id = destination_tile.entities_by_layer.get(e.layer);
+            const destination_entity_id = self.world.findEntity(next_pos, e.layer);
-            if (self.entities.get(destination_entity_id)) |destination_entity| {
+            if (self.world.entities.get(destination_entity_id)) |destination_entity| {
                 if (destination_entity.type == .box) {
-                    if (!self.moveEntity(destination_entity_id, dx, dy)) {
+                    if (!self.moveEntity(destination_entity_id, dir)) {
                         return false;
                     }
                 }
+                else if (destination_entity.type == .wall) {
+                    return false;
+                }
             }
         }
 
-        return self.setEntityPosition(id, next_x, next_y);
+        if (!self.undo_frame.pushEntity(.{
+            .id = id,
+            .pos = e.pos,
+            .player_direction = e.player_direction
+        })) {
+            log.warn("Failed to push entity undo", .{});
+        }
+
+        if (e.type == .player) {
+            if (dir.x < 0) {
+                e.player_direction = .left;
+            } else if (dir.x > 0) {
+                e.player_direction = .right;
+            } else if (dir.y > 0) {
+                e.player_direction = .down;
+            } else if (dir.y < 0) {
+                e.player_direction = .up;
+            }
+        }
+
+        e.pos = next_pos;
+
+        return true;
     }
 };
 
@@ -224,6 +229,7 @@ const Level = struct {
 };
 
 world: World,
+undo_stack: std.ArrayList(UndoFrame) = .empty,
 current_level: u32 = 0,
 levels: std.ArrayList(Level),
 
@@ -372,7 +378,6 @@ fn loadLevels(self: *App, gpa: Allocator, assets: *Platform.Assets) !std.ArrayLi
 
     std.mem.sort(Level, levels.items, Context{}, Context.lessThan);
 
-
     return levels;
 }
 
@@ -386,7 +391,8 @@ fn loadLevel(
     var level = Level{
         .number = 0,
         .world = .{
-            .tilemap = try .init(gpa, bounds.width(), bounds.height()),
+            .width = bounds.width(),
+            .height = bounds.height(),
             .entities = try .initCapacity(gpa, 256)
         }
     };
@@ -398,11 +404,18 @@ fn loadLevel(
             const x = bounds.min_x + @as(i32, @intCast(ox));
             const y = bounds.min_y + @as(i32, @intCast(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 = self.tilesheet.get(pos.x, pos.y);
+
+                _ = level.world.spawnEntity(Entity{
+                    .type = .nil,
+                    .layer = .ground,
+                    .pos = .{
+                        .x = @intCast(ox),
+                        .y = @intCast(oy),
+                    },
+                    .sprite = self.tilesheet.get(pos.x, pos.y)
+                });
             }
 
             if (tilemap.getTile(foreground, tilesets, x, y)) |tiled_tile| {
@@ -416,19 +429,27 @@ fn loadLevel(
                     entity_type = .wall;
                 } else if (std.mem.eql(u8, props_type, "box")) {
                     entity_type = .box;
-                } else if (std.mem.eql(u8, props_type, "goal_marker")) {
+                } else if (std.mem.eql(u8, props_type, "player")) {
-                    entity_type = .goal_marker;
+                    entity_type = .player;
-                    layer = .ground;
+                } else if (std.mem.eql(u8, props_type, "coin")) {
+                    entity_type = .coin;
+                } else if (std.mem.eql(u8, props_type, "box_hole")) {
+                    entity_type = .box_hole;
+                } else if (std.mem.eql(u8, props_type, "box_goal")) {
+                    entity_type = .box_goal;
+                    layer = .on_ground;
                 } else {
-                    log.warn("Unknown tile type: '{s}'", .{props_type});
+                    log.warn("Unknown tile type: '{s}' at {} {}", .{props_type, x, y});
                 }
 
                 if (entity_type != null) {
                     _ = level.world.spawnEntity(Entity{
                         .type = entity_type.?,
                         .layer = layer,
-                        .pos_x = @intCast(ox),
+                        .pos = .{
-                        .pos_y = @intCast(oy),
+                            .x = @intCast(ox),
+                            .y = @intCast(oy),
+                        },
                         .sprite = self.tilesheet.get(pos.x, pos.y)
                     });
                 }
@@ -436,58 +457,43 @@ fn loadLevel(
         }
     }
 
-    for (tilemap.getLayer("Markers").?.variant.object.items) |obj| {
-        if (obj.shape != .point) {
-            continue;
-        }
-        if (!std.mem.eql(u8, obj.name, "spawn")) {
-            continue;
-        }
-
-        var position = obj.shape.point;
-        position.x /= @floatFromInt(tilemap.tile_width);
-        position.y /= @floatFromInt(tilemap.tile_height);
-
-        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 = pos_x - bounds.min_x,
-                .pos_y = pos_y - bounds.min_y
-            });
-        }
-    }
-
     return level;
 }
 
-fn updateWorld(world: *World) void {
+const PlayerInput = struct {
-    _ = world; // autofix
+    move_dir: Point,
+    undo: bool
+};
+
+fn getPlayerInput(input: *Platform.Input) PlayerInput {
+    var result: PlayerInput = .{
+        .move_dir = .{ .x = 0, .y = 0 },
+        .undo = false
+    };
+
+    if (input.isKeyPressedOrRepeat(.S)) {
+        result.move_dir.y += 1;
+    }
+    if (input.isKeyPressedOrRepeat(.W)) {
+        result.move_dir.y -= 1;
+    }
+    if (input.isKeyPressedOrRepeat(.D)) {
+        result.move_dir.x += 1;
+    }
+    if (input.isKeyPressedOrRepeat(.A)) {
+        result.move_dir.x -= 1;
+    }
+    if (result.move_dir.x != 0) {
+        result.move_dir.y = 0;
+    }
+
+    result.undo = input.isKeyPressedOrRepeat(.Z);
+
+    return result;
 }
 
 pub fn frame(self: *App, plt: Platform.Frame) !void {
-    const input = plt.input;
+    const input = getPlayerInput(plt.input);
-
-    var dir_y: i32 = 0;
-    var dir_x: i32 = 0;
-    if (input.isKeyPressedOrRepeat(.S)) {
-        dir_y += 1;
-    }
-    if (input.isKeyPressedOrRepeat(.W)) {
-        dir_y -= 1;
-    }
-    if (input.isKeyPressedOrRepeat(.D)) {
-        dir_x += 1;
-    }
-    if (input.isKeyPressedOrRepeat(.A)) {
-        dir_x -= 1;
-    }
-    if (dir_x != 0) {
-        dir_y = 0;
-    }
 
     const clear_color = Color.rgb(40, 40, 40);
     Gfx.setClearColor(clear_color);
@@ -495,11 +501,25 @@ pub fn frame(self: *App, plt: Platform.Frame) !void {
 
     const tile_size = Vec2.init(48, 48);
     var canvas = CanvasScaler{
-        .size = Vec2.initFromInt(usize, self.world.tilemap.width, self.world.tilemap.height).multiply(tile_size)
+        .size = Vec2.initFromInt(usize, self.world.width, self.world.height).multiply(tile_size)
     };
     canvas.push();
     defer canvas.pop(clear_color);
 
+    if (input.undo) {
+        if (self.undo_stack.pop()) |undo_frame| {
+            for (undo_frame.entities()) |e_state| {
+                var e = self.world.entities.getAssumeExists(e_state.id);
+                e.pos = e_state.pos;
+                e.player_direction = e_state.player_direction;
+            }
+        }
+    }
+
+    var tick_context: TickContext = .{
+        .world = &self.world
+    };
+
     var goal_count: u32 = 0;
     var box_at_goal_count: u32 = 0;
     {
@@ -507,21 +527,10 @@ pub fn frame(self: *App, plt: Platform.Frame) !void {
         while (entity_iter.next()) |entity_id| {
             const entity = self.world.entities.getAssumeExists(entity_id);
             if (entity.type == .player) {
-                if ((dir_x != 0 or dir_y != 0) and self.world.moveEntity(entity_id, dir_x, dir_y)) {
+                const prev_player_direction = entity.player_direction;
-                    var new_direction = entity.player_direction;
+                if (tick_context.moveEntity(entity_id, input.move_dir)) {
-                    if (dir_x < 0) {
+                    if (entity.player_direction != prev_player_direction) {
-                        new_direction = .left;
-                    } else if (dir_x > 0) {
-                        new_direction = .right;
-                    } else if (dir_y > 0) {
-                        new_direction = .down;
-                    } else if (dir_y < 0) {
-                        new_direction = .up;
-                    }
-
-                    if (entity.player_direction != new_direction) {
                         entity.player_frame_index = 0;
-                        entity.player_direction = new_direction;
                     }
 
                     self.footstep_sound = Audio.play(.{ .buffer = self.footstep_buffer, .bus = self.sfx_bus });
@@ -529,7 +538,7 @@ pub fn frame(self: *App, plt: Platform.Frame) !void {
 
                 const frames = self.player_sprites.getDirection(entity.player_direction);
 
-                if (dir_x != 0 or dir_y != 0) {
+                if (input.move_dir.x != 0 or input.move_dir.y != 0) {
                     self.animation_timer += plt.input.delta_time;
                     const animatin_time = std.time.ns_per_s / 5;
                     while (self.animation_timer >= animatin_time) {
@@ -542,32 +551,25 @@ pub fn frame(self: *App, plt: Platform.Frame) !void {
                 }
 
                 entity.sprite = frames[entity.player_frame_index];
-            } else if (entity.type == .goal_marker) {
+            } else if (entity.type == .box_goal) {
                 goal_count += 1;
 
-                const tile = self.world.getTile(entity.pos_x, entity.pos_y).?;
+                if (self.world.entities.get(self.world.findEntity(entity.pos, .surface))) |above_entity| {
-                if (self.world.entities.get(tile.entities_by_layer.get(.surface))) |above_entity| {
                     if (above_entity.type == .box) {
                         box_at_goal_count += 1;
                     }
                 }
             }
 
-            entity.visual_pos = .initFromInt(i32, entity.pos_x, entity.pos_y);
+            entity.visual_pos = .initFromInt(i32, entity.pos.x, entity.pos.y);
         }
     }
 
-    for (0..self.world.tilemap.height) |y| {
+    if (!tick_context.undo_frame.isEmpty()) {
-        for (0..self.world.tilemap.width) |x| {
+        try self.undo_stack.append(plt.gpa, tick_context.undo_frame);
-            const tile = self.world.tilemap.get(x, y);
-
-            if (tile.ground_sprite) |sprite| {
-                Gfx.drawSprite(sprite, Vec2.initFromInt(usize, x, y).multiply(tile_size), tile_size, .white);
-            }
-        }
     }
 
-    inline for (.{ Entity.Layer.ground, Entity.Layer.surface }) |layer| {
+    inline for (.{ Entity.Layer.ground, Entity.Layer.on_ground, Entity.Layer.surface }) |layer| {
         var entity_iter = self.world.entities.iterator();
         while (entity_iter.next()) |entity_id| {
             const entity = self.world.entities.getAssumeExists(entity_id);
@@ -603,4 +605,5 @@ pub fn deinit(self: *App, plt: Platform.Deinit) void {
         level.world.deinit(plt.gpa);
     }
     self.levels.deinit(plt.gpa);
+    self.undo_stack.deinit(plt.gpa);
 }

src/platform/graphics.zig

@@ -90,6 +90,7 @@ pub fn init(gpa: std.mem.Allocator, logger: sg.Logger) !void {
     const pipeline = sg.makePipeline(.{
         .primitive_type = .TRIANGLES,
         .index_type = .UINT16,
+        .cull_mode = .BACK,
         .colors = init: {
             var s: [8]sg.ColorTargetState = @splat(.{});
             s[0] = .{

src/platform/root.zig

@@ -152,6 +152,7 @@ fn PlatformType(App: type) type {
                     if (ImGUI.beginTabItem("General")) {
                         defer ImGUI.endTabItem();
                         ImGUI.text("Embedded assets: {B}", .{self.assets.totalSize()});
+                        ImGUI.text("Graphics backend: {}", .{sg.queryBackend()});
                     }
 
                     if (ImGUI.beginTabItem("Graphics")) {