add entities

assets/impact-sounds/License.txt

@@ -0,0 +1,23 @@
+	
+
+	Impact Sounds (1.0)
+
+	Created/distributed by Kenney (www.kenney.nl)
+	Creation date: 19-12-2019
+
+			------------------------------
+
+	License: (Creative Commons Zero, CC0)
+	http://creativecommons.org/publicdomain/zero/1.0/
+
+	This content is free to use in personal, educational and commercial projects.
+	Support us by crediting Kenney or www.kenney.nl (this is not mandatory)
+
+			------------------------------
+
+	Donate:   http://support.kenney.nl
+	Request:  http://request.kenney.nl
+	Patreon:  http://patreon.com/kenney/
+
+	Follow on Twitter for updates:
+	http://twitter.com/KenneyNL

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="0" nextlayerid="5" nextobjectid="1">
+<map version="1.10" tiledversion="1.12.2" orientation="orthogonal" renderorder="right-down" width="30" height="20" tilewidth="64" tileheight="64" infinite="0" nextlayerid="6" nextobjectid="4">
  <tileset firstgid="1" source="tileset.tsx"/>
  <layer id="2" name="Ground" width="30" height="20">
   <data encoding="csv">
@@ -49,7 +49,7 @@
 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
 </data>
  </layer>
- <layer id="4" name="Pushable" width="30" height="20">
+ <layer id="4" name="Boxes" width="30" height="20">
   <data encoding="csv">
 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
@@ -73,4 +73,9 @@
 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
 </data>
  </layer>
+ <objectgroup id="5" name="Markers">
+  <object id="1" name="spawn" x="479" y="550">
+   <point/>
+  </object>
+ </objectgroup>
 </map>

assets/tiled/sokoban.tiled-session

@@ -1,17 +1,31 @@
 {
-    "activeFile": "",
+    "activeFile": "map.tmx",
     "expandedProjectPaths": [
     ],
+    "file.lastUsedOpenFilter": "All Files (*)",
     "fileStates": {
+        "map.tmx": {
+            "scale": 1,
+            "selectedLayer": 3,
+            "viewCenter": {
+                "x": 624.5,
+                "y": 421
+            }
+        },
+        "tileset.tsx": {
+            "scaleInDock": 1
+        }
     },
     "last.imagePath": "/home/rokas/code/games/sokol-template-v2/assets/sokoban",
     "map.lastUsedFormat": "tmx",
     "map.tileHeight": 64,
     "map.tileWidth": 64,
     "openFiles": [
+        "map.tmx"
     ],
     "project": "sokoban.tiled-project",
     "recentFiles": [
+        "map.tmx"
     ],
     "tileset.lastUsedFormat": "tsx",
     "tileset.tileSize": {

build.zig

@@ -10,7 +10,8 @@ pub fn build(b: *std.Build) !void {
         "sokoban/sokoban_tilesheet.png",
         "roboto-font/Roboto-Regular.ttf",
         "tiled/map.tmx",
-        "tiled/tileset.tsx"
+        "tiled/tileset.tsx",
+        "impact-sounds/footstep_concrete_000.ogg"
     };
 
     const asset_dir_realpath = try b.build_root.join(b.graph.arena, &.{ assets_dir });

libs/tiled/src/layer.zig

@@ -98,7 +98,16 @@ pub const ObjectVariant = struct {
 
     color: ?Color,
     draw_order: DrawOrder,
-    items: []Object
+    items: []Object,
+
+    pub fn getByName(self: *const ObjectVariant, name: []const u8) ?*const Object {
+        for (self.items) |*item| {
+            if (std.mem.eql(u8, item.name, name)) {
+                return item;
+            }
+        }
+        return null;
+    }
 };
 
 pub const GroupVariant = struct {

libs/tiled/src/tilemap.zig

@@ -77,6 +77,14 @@ pub const Tile = struct {
     pub fn getProperties(self: Tile) Property.List {
         return self.tileset.getTileProperties(self.id) orelse .empty;
     }
+
+    pub fn getPositionInImage(self: Tile) Position {
+        return self.tileset.getTilePositionInImage(self.id);
+    }
+
+    pub fn getPosition(self: Tile) Tileset.TilePosition {
+        return self.tileset.getTilePosition(self.id);
+    }
 };
 
 arena: std.heap.ArenaAllocator,
@@ -230,6 +238,72 @@ pub fn getTile(self: *const Tilemap, layer: *const Layer, tilesets: Tileset.List
     };
 }
 
+pub fn getLayer(self: *const Tilemap, name: []const u8) ?*const Layer {
+    for (self.layers) |*layer| {
+        if (std.mem.eql(u8, layer.name, name)) {
+            return layer;
+        }
+    }
+    return null;
+}
+
+pub const Bounds = struct {
+    min_x: usize,
+    min_y: usize,
+    max_x: usize,
+    max_y: usize,
+
+    const zero = Bounds{
+        .min_x = 0,
+        .min_y = 0,
+        .max_x = 0,
+        .max_y = 0,
+    };
+
+    pub fn width(self: Bounds) usize {
+        return self.max_x - self.min_x + 1;
+    }
+
+    pub fn height(self: Bounds) usize {
+        return self.max_y - self.min_y + 1;
+    }
+};
+
+pub fn getTileBounds(self: *const Tilemap) Bounds {
+    var result: ?Bounds = null;
+
+    for (self.layers) |*layer| {
+        if (layer.variant != .tile) {
+            continue;
+        }
+
+        for (0..self.height) |y| {
+            for (0..self.width) |x| {
+                const gid = layer.variant.tile.get(x, y).?;
+                if (gid != 0) {
+                    if (result) |bounds| {
+                        result = Bounds{
+                            .min_x = @min(x, bounds.min_x),
+                            .min_y = @min(y, bounds.min_y),
+                            .max_x = @max(x, bounds.max_x),
+                            .max_y = @max(y, bounds.max_y)
+                        };
+                    } else {
+                        result = Bounds{
+                            .min_x = x,
+                            .min_y = y,
+                            .max_x = x,
+                            .max_y = y
+                        };
+                    }
+                }
+            }
+        }
+    }
+
+    return result orelse Bounds.zero;
+}
+
 pub fn deinit(self: *const Tilemap) void {
     self.arena.deinit();
 }

libs/tiled/src/tileset.zig

@@ -1,5 +1,6 @@
 const std = @import("std");
 const Io = std.Io;
+const assert = std.debug.assert;
 const Allocator = std.mem.Allocator;
 
 const xml = @import("./xml.zig");
@@ -204,21 +205,32 @@ pub fn getTileProperties(self: *const Tileset, id: u32) ?Property.List {
     return null;
 }
 
-pub fn getTilePositionInImage(self: *const Tileset, id: u32) ?Position {
+pub const TilePosition = struct {
-    if (id >= self.tile_count) {
+    x: usize,
-        return null;
+    y: usize,
-    }
+};
+
+pub fn getTilePosition(self: *const Tileset, id: u32) TilePosition {
+    assert(id < self.tile_count);
 
     const tileset_width = @divExact(self.image.width, self.tile_width);
 
     const tile_x = @mod(id, tileset_width);
     const tile_y = @divFloor(id, tileset_width);
 
-    return Position{
+    return .{
-        .x = @floatFromInt(tile_x * self.tile_width),
+        .x = tile_x,
-        .y = @floatFromInt(tile_y * self.tile_height),
+        .y = tile_y,
     };
+}
 
+pub fn getTilePositionInImage(self: *const Tileset, id: u32) Position {
+    const pos = self.getTilePosition(id);
+
+    return Position{
+        .x = @floatFromInt(pos.x * self.tile_width),
+        .y = @floatFromInt(pos.y * self.tile_height),
+    };
 }
 
 pub fn deinit(self: *const Tileset) void {

src/app.zig

@@ -1,5 +1,6 @@
 const std = @import("std");
 const log = std.log.scoped(.app);
+const assert = std.debug.assert;
 const Allocator = std.mem.Allocator;
 
 const Math = @import("math");
@@ -40,20 +41,75 @@ const PlayerSprites = struct {
     }
 };
 
-show_first_window: bool,
+const Tilemap = struct {
-check: bool,
+    tiles: []Tile,
-player_pos: Vec2,
+    width: usize,
-wall_sprite: Gfx.Sprite.Id,
+    height: usize,
+
+    const Tile = struct {
+        ground_sprite: ?Gfx.Sprite.Id,
+        wall_sprite: ?Gfx.Sprite.Id,
+
+        const empty = Tile{
+            .ground_sprite = null,
+            .wall_sprite = null
+        };
+    };
+
+    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 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];
+    }
+};
+
+const Entity = struct {
+    type: Type,
+
+    pos_x: i32 = 0,
+    pos_y: i32 = 0,
+    sprite: ?Gfx.Sprite.Id = null,
+
+    player_direction: Direction = .down,
+    player_frame_index: u32 = 0,
+
+    const Type = enum {
+        player,
+        box
+    };
+
+    const SlotMap = Platform.SlotMapType(u8, u16, Entity);
+    const Id = SlotMap.Id;
+};
+
 roboto_font: Gfx.Font.Id,
+tilemap: Tilemap,
+entities: Entity.SlotMap,
 
 tilesheet: Tilesheet,
 
 player_sprites: PlayerSprites,
-player_direction: Direction,
-player_frame_index: u32,
 animation_timer: Platform.Nanoseconds,
 
-sound: Audio.Sound.Id,
+footstep_buffer: Audio.BufferId,
+footstep_sound: Audio.SoundId = .nil,
+
+sfx_bus: Audio.BusId,
 
 const Tilesheet = struct {
     image: Gfx.ImageData,
@@ -62,7 +118,9 @@ const Tilesheet = struct {
     width: u32,
     height: u32,
 
-    pub fn init(gpa: Allocator, image: Gfx.ImageData, width: u32, height: u32, tile_size: Vec2) !Tilesheet {
+    pub fn init(gpa: Allocator, image: Gfx.ImageData, tile_width: u32, tile_height: u32) !Tilesheet {
+        const width = image.width / tile_width;
+        const height = image.height / tile_height;
         const sprites = try gpa.alloc(Gfx.Sprite.Id, width * height);
         errdefer gpa.free(sprites);
         @memset(sprites, .nil);
@@ -72,7 +130,7 @@ const Tilesheet = struct {
             .image = image,
             .width = width,
             .height = height,
-            .tile_size = tile_size
+            .tile_size = .initFromInt(u32, tile_width, tile_height)
         };
     }
 
@@ -82,7 +140,7 @@ const Tilesheet = struct {
         }
     }
 
-    pub fn get(self: Tilesheet, x: u32, y: u32) Gfx.Sprite.Id {
+    pub fn get(self: Tilesheet, x: usize, y: usize) Gfx.Sprite.Id {
         if (x >= self.width or y >= self.height) {
             log.warn("Attempt to get tile which is out of bounds", .{});
             return .nil;
@@ -106,24 +164,6 @@ pub fn init(self: *App, plt: Platform.Init) !?u8 {
     const robot_font = Gfx.initFont();
     Gfx.setFont(robot_font, plt.assets.readFile("roboto-font/Roboto-Regular.ttf"));
 
-    var scratch = std.heap.ArenaAllocator.init(plt.gpa);
-    defer scratch.deinit();
-
-    var buffers = Tiled.xml.Lexer.Buffers.init(plt.gpa);
-    defer buffers.deinit();
-
-    const tilemap = try Tiled.Tilemap.initFromBuffer(plt.gpa, &scratch, &buffers, plt.assets.readFile("tiled/map.tmx"));
-    defer tilemap.deinit();
-
-    var tilesets: Tiled.Tileset.List = .empty;
-    defer tilesets.deinit(plt.gpa);
-
-    try tilesets.add(plt.gpa, "tiled/tilemap.tsx", try Tiled.Tileset.initFromBuffer(plt.gpa, &scratch, &buffers, plt.assets.readFile("tiled/tileset.tsx")));
-
-    for (tilemap.layers) |layer| {
-        std.debug.print("{s}\n", .{layer.name});
-    }
-
     const tilesheet_png = try STBImage.load(plt.assets.readFile("sokoban/sokoban_tilesheet.png"));
     const tilesheet = try Tilesheet.init(
         plt.arena,
@@ -132,13 +172,9 @@ pub fn init(self: *App, plt: Platform.Init) !?u8 {
             .height = tilesheet_png.height,
             .pixels = .{ .rgba8 = tilesheet_png.rgba8_pixels }
         },
-        13,
+        64, 64,
-        8,
-        .init(64, 64)
     );
 
-    const wall_sprite = tilesheet.get(1, 0);
-
     var player_sprites: PlayerSprites = undefined;
     inline for (.{
         .{
@@ -164,99 +200,203 @@ pub fn init(self: *App, plt: Platform.Init) !?u8 {
         }
     }
 
-    const sound = Audio.initSound(.{
+    const footstep_sound = Audio.addBuffer(.{
-        .cb = .{ .sample = sinSampleCallback },
+        .vorbis = plt.assets.readFile("impact-sounds/footstep_concrete_000.ogg")
-        .playing = false,
-        .frequency = 1
     });
 
     self.* = App{
-        .player_pos = .init(100, 100),
-        .show_first_window = true,
-        .check = false,
         .player_sprites = player_sprites,
-        .wall_sprite = wall_sprite,
         .roboto_font = robot_font,
-        .player_direction = .left,
-        .player_frame_index = 0,
         .animation_timer = 0,
         .tilesheet = tilesheet,
-        .sound = sound
+        .footstep_buffer = footstep_sound,
+        .sfx_bus = Audio.addBus(.{ .label = "sfx" }),
+        .tilemap = undefined,
+        .entities = try .initCapacity(plt.gpa, 256)
     };
 
+    var player_pos_x: i32 = 0;
+    var player_pos_y: i32 = 0;
+    {
+        var scratch = std.heap.ArenaAllocator.init(plt.gpa);
+        defer scratch.deinit();
+
+        var buffers = Tiled.xml.Lexer.Buffers.init(plt.gpa);
+        defer buffers.deinit();
+
+        const tilemap = try Tiled.Tilemap.initFromBuffer(plt.gpa, &scratch, &buffers, plt.assets.readFile("tiled/map.tmx"));
+        defer tilemap.deinit();
+
+        var tilesets: Tiled.Tileset.List = .empty;
+        defer tilesets.deinit(plt.gpa);
+
+        try tilesets.add(plt.gpa, "tileset.tsx", try Tiled.Tileset.initFromBuffer(plt.gpa, &scratch, &buffers, plt.assets.readFile("tiled/tileset.tsx")));
+
+        const bounds = tilemap.getTileBounds();
+
+        self.tilemap = try Tilemap.init(plt.gpa, bounds.width(), bounds.height());
+
+        const ground = tilemap.getLayer("Ground").?;
+        const walls = tilemap.getLayer("Walls").?;
+        for (0..bounds.height()) |oy| {
+            for (0..bounds.width()) |ox| {
+                const x = bounds.min_x + ox;
+                const y = bounds.min_y + oy;
+
+                const tile = self.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);
+                }
+
+                if (tilemap.getTile(walls, tilesets, x, y)) |tiled_tile| {
+                    const pos = tiled_tile.getPosition();
+                    tile.wall_sprite = tilesheet.get(pos.x, pos.y);
+                }
+            }
+        }
+
+        const markers = &tilemap.getLayer("Markers").?.variant.object;
+        const spawn = markers.getByName("spawn").?;
+        player_pos_x = @divFloor(@as(i32, @intFromFloat(spawn.shape.point.x)), @as(i32, @intCast(tilemap.tile_width)));
+        player_pos_x -= @intCast(bounds.min_x);
+        player_pos_y = @divFloor(@as(i32, @intFromFloat(spawn.shape.point.y)),@as(i32, @intCast(tilemap.tile_height)));
+        player_pos_y -= @intCast(bounds.min_y);
+
+        const boxes = tilemap.getLayer("Boxes").?;
+        for (0..bounds.height()) |oy| {
+            for (0..bounds.width()) |ox| {
+                const x = bounds.min_x + ox;
+                const y = bounds.min_y + oy;
+
+                if (tilemap.getTile(boxes, tilesets, x, y)) |tiled_tile| {
+                    const pos = tiled_tile.getPosition();
+                    _ = try self.spawnBox(@intCast(ox), @intCast(oy), tilesheet.get(pos.x, pos.y));
+                }
+            }
+        }
+    }
+
+    const player_id = try self.spawnPlayer();
+    const player = self.entities.getAssumeExists(player_id);
+    player.pos_x = player_pos_x;
+    player.pos_y = player_pos_y;
+
     return null;
 }
 
-fn sinSampleCallback(sound: *Audio.Sound) f32 {
+fn spawnPlayer(self: *App) !Entity.Id {
-    return @sin(440 * sound.phase);
+    return try self.entities.insert(Entity{
+        .type = .player,
+    });
+}
+
+fn spawnBox(self: *App, x: i32, y: i32, sprite: Gfx.Sprite.Id) !Entity.Id {
+    return try self.entities.insert(Entity{
+        .type = .box,
+        .pos_x = x,
+        .pos_y = y,
+        .sprite = sprite
+    });
 }
 
 pub fn frame(self: *App, plt: Platform.Frame) !void {
     const input = plt.input;
 
-    const dt = plt.deltaTime();
+    var dir_y: i32 = 0;
-
+    var dir_x: i32 = 0;
-    var dir: Vec2 = .init(0, 0);
+    if (input.isKeyPressedOrRepeat(.S)) {
-    if (input.isKeyDown(.S)) {
+        dir_y += 1;
-        dir.y += 1;
     }
-    if (input.isKeyDown(.W)) {
+    if (input.isKeyPressedOrRepeat(.W)) {
-        dir.y -= 1;
+        dir_y -= 1;
     }
-    if (input.isKeyDown(.D)) {
+    if (input.isKeyPressedOrRepeat(.D)) {
-        dir.x += 1;
+        dir_x += 1;
     }
-    if (input.isKeyDown(.A)) {
+    if (input.isKeyPressedOrRepeat(.A)) {
-        dir.x -= 1;
+        dir_x -= 1;
     }
-    dir = dir.normalized();
+    if (dir_x != 0) {
-    self.player_pos = self.player_pos.add(dir.multiplyScalar(50 * dt));
+        dir_y = 0;
-
-    if (input.isKeyPressed(.E)) {
-        Audio.setPlaying(self.sound, !Audio.getPlaying(self.sound));
     }
 
-    var new_direction = self.player_direction;
+    Gfx.setClearColor(.rgb(40, 40, 40));
-    if (dir.x < 0) {
+
+    const tile_size = Vec2.init(48, 48);
+    for (0..self.tilemap.height) |y| {
+        for (0..self.tilemap.width) |x| {
+            const tile = self.tilemap.get(x, y);
+
+            if (tile.ground_sprite) |sprite| {
+                Gfx.drawSprite(sprite, Vec2.initFromInt(usize, x, y).multiply(tile_size), tile_size, .white);
+            }
+
+            if (tile.wall_sprite) |sprite| {
+                Gfx.drawSprite(sprite, Vec2.initFromInt(usize, x, y).multiply(tile_size), tile_size, .white);
+            }
+        }
+    }
+
+    var entity_iter = self.entities.iterator();
+    while (entity_iter.next()) |entity_id| {
+        const entity = self.entities.getAssumeExists(entity_id);
+        if (entity.type == .player) {
+            entity.pos_x += dir_x;
+            entity.pos_y += dir_y;
+
+            var new_direction = entity.player_direction;
+            if (dir_x < 0) {
                 new_direction = .left;
-    } else if (dir.x > 0) {
+            } else if (dir_x > 0) {
                 new_direction = .right;
-    } else if (dir.y > 0) {
+            } else if (dir_y > 0) {
                 new_direction = .down;
-    } else if (dir.y < 0) {
+            } else if (dir_y < 0) {
                 new_direction = .up;
             }
 
-    if (self.player_direction != new_direction) {
+            if (entity.player_direction != new_direction) {
-        self.player_frame_index = 0;
+                entity.player_frame_index = 0;
-        self.player_direction = new_direction;
+                entity.player_direction = new_direction;
             }
 
-    const frames = self.player_sprites.getDirection(self.player_direction);
+            const frames = self.player_sprites.getDirection(entity.player_direction);
 
-    if (dir.x != 0 or dir.y != 0) {
+            if (dir_x != 0 or dir_y != 0) {
-        self.animation_timer += plt.dt;
+                self.animation_timer += plt.input.delta_time;
                 const animatin_time = std.time.ns_per_s / 5;
                 while (self.animation_timer >= animatin_time) {
-            self.player_frame_index = (self.player_frame_index + 1) % @as(u32, @intCast(frames.len));
+                    entity.player_frame_index = (entity.player_frame_index + 1) % @as(u32, @intCast(frames.len));
                     self.animation_timer -= animatin_time;
                 }
             } else {
                 self.animation_timer = 0;
-        self.player_frame_index = 0;
+                entity.player_frame_index = 0;
+            }
+
+            if (dir_x != 0 or dir_y != 0) {
+                self.footstep_sound = Audio.play(.{ .buffer = self.footstep_buffer, .bus = self.sfx_bus });
+            }
+
+            entity.sprite = frames[entity.player_frame_index];
+        }
+
+
+        if (entity.sprite) |sprite| {
+            Gfx.drawSprite(
+                sprite,
+                Vec2.initFromInt(i32, entity.pos_x, entity.pos_y).multiply(tile_size),
+                tile_size,
+                .white
+            );
+        }
     }
 
-    Gfx.setClearColor(.rgb(40, 40, 40));
-    Gfx.drawSprite(frames[self.player_frame_index], self.player_pos, .init(64, 64), .white);
-    Gfx.drawSprite(self.tilesheet.get(11, 6), self.player_pos.add(.init(0, 200)), .init(64, 64), .white);
-    Gfx.drawText(self.roboto_font, .{
-        .pos = .init(300, 100),
-        .text = "Hello, World!",
-        .height = 64,
-    });
 }
 
 pub fn deinit(self: *App, plt: Platform.Deinit) void {
-    _ = plt; // autofix
+    self.tilemap.deinit(plt.gpa);
-    _ = self; // autofix
+    self.entities.slots.deinit(plt.gpa);
 }

src/platform/audio.zig

@@ -1,47 +1,66 @@
 const std = @import("std");
 const log = std.log.scoped(.audio);
 const Io = std.Io;
+const Allocator = std.mem.Allocator;
 const assert = std.debug.assert;
+const build_options = @import("build_options");
 
 const sokol = @import("sokol");
 const sapp = sokol.app;
 const saudio = sokol.audio;
 
+const ImGUI = @import("imgui.zig");
 const tracy = @import("tracy");
+const STBVorbis = @import("stb_vorbis");
+const Math = @import("math");
 
 const SlotMapType = @import("./slot_map.zig").SlotMapType;
 
-const State = struct {
+const Bus = struct {
-    io: Io,
+    label: ?[]const u8 = null,
-    mutex: std.Io.Mutex,
+    volume: f32 = 1,
-    sounds: Sound.SlotMap,
+    parent_id: ?Bus.Id = null,
-    volume: f32 = 0.1,
-    running: std.atomic.Value(bool) = .init(false),
 
-    temp_buffer: []f32
+    pub const Id = packed struct {
+        index: u16,
+
+        pub const nil = Id{ .index = std.math.maxInt(u16) };
+    };
+};
+pub const BusId = Bus.Id;
+
+const Buffer = struct {
+    samples: Samples,
+
+    const Samples = struct {
+        len: usize,
+        left: [*]const f32,
+
+        // If `right` is is null, then this is mono
+        right: ?[*]const f32,
+
+        pub fn deinit(self: Samples, gpa: Allocator) void {
+            gpa.free(self.left[0..self.len]);
+            if (self.right) |right| {
+                gpa.free(right[0..self.len]);
+            }
+        }
     };
 
-var g_state: State = undefined;
+    pub const Id = packed struct {
+        index: u16,
 
-pub const InitOptions = struct {
+        pub const nil = Id{ .index = std.math.maxInt(u16) };
-    logger: saudio.Logger = .{},
-    buffer_frames: u32 = 512,
-    max_sounds: usize = 128,
     };
+};
+pub const BufferId = Buffer.Id;
 
-pub const Sound = struct {
+const Sound = struct {
-    cb: Callback,
+    cursor: usize,
-    userdata: ?*anyopaque,
+    buffer: BufferId,
-    volume: f32,
+    volume: f32 = 1,
-    looping: bool,
+    loop: bool = false,
-    adsr: ADSR,
+    bus: BusId,
-    playing: bool,
-
-    phase_increment: f32 = 0,
-    duration_frames: u32 = 0,
-
-    frame_index: u32 = 0,
-    phase: f32 = 0,
 
     pub const ADSR = struct {
         attack: f32,
@@ -49,7 +68,7 @@ pub const Sound = struct {
         sustain: f32,
         release: f32,
 
-        pub const default = ADSR{
+        pub const identity = ADSR{
             .attack = 0,
             .decay = 0,
             .sustain = 1,
@@ -57,195 +76,544 @@ pub const Sound = struct {
         };
     };
 
-    pub const Callback = union(enum) {
+    const SlotMap = SlotMapType(u16, u8, Sound);
-        sample: *const fn(sound: *Sound) f32,
+    const Id = SlotMap.Id;
-        block: *const fn(sound: *Sound, samples: *std.ArrayList(f32)) void,
+};
+pub const SoundId = Sound.Id;
+
+const ThreadState = struct {
+    // When modifying any fields in this struct, you must first acquire the mutex.
+    mutex: std.Io.Mutex,
+
+    sounds: Sound.SlotMap,
+    bus_volumes: []f32,
+
+    elapsed_time_ms: ?[]f32 = null,
+    budget_reached_counter: u32 = 0
 };
 
-    const SlotMap = SlotMapType(u8, u16, Sound);
+const State = struct {
-    pub const Id = SlotMap.Id;
+    io: Io,
+    gpa: Allocator,
+    running: std.atomic.Value(bool) = .init(false),
+
+    vorbis_alloc_buffer: []u8,
+
+    buses: std.ArrayList(Bus),
+    buffers: std.ArrayList(Buffer),
+
+    thread_state: ThreadState
+};
+
+var g_state: State = undefined;
+pub var main_bus: BusId = .nil;
+const g_sample_rate = 44100;
+
+pub const InitOptions = struct {
+    logger: saudio.Logger = .{},
+    buffer_frames: u32 = 512,
+
+    max_buffers: usize = 128,
+    max_sounds: usize = 256,
+    max_buses: usize = 16,
+    max_vorbis_alloc_buffer_size: u32 = 1 * Math.bytes_per_mib,
+
+    track_elapsed_time: bool = build_options.has_imgui
 };
 
 pub fn init(io: Io, gpa: std.mem.Allocator, opts: InitOptions) !void {
-    const channels = 1; // TODO: Stereo audio
     const self = &g_state;
 
-    const sounds_buffer = try gpa.alloc(Sound.SlotMap.Slot, opts.max_sounds);
+    var buses = try std.ArrayList(Bus).initCapacity(gpa, opts.max_buses);
-    errdefer gpa.free(sounds_buffer);
+    errdefer buses.deinit(gpa);
 
-    const temp_buffer = try gpa.alloc(f32, opts.buffer_frames);
+    const bus_volumes = try gpa.alloc(f32, opts.max_buses);
-    errdefer gpa.free(temp_buffer);
+    errdefer gpa.free(bus_volumes);
+
+    var buffers = try std.ArrayList(Buffer).initCapacity(gpa, opts.max_buffers);
+    errdefer buffers.deinit(gpa);
+
+    const sounds = try gpa.alloc(Sound.SlotMap.Slot, opts.max_sounds);
+    errdefer gpa.free(sounds);
+
+    const vorbis_alloc_buffer = try gpa.alloc(u8, opts.max_vorbis_alloc_buffer_size);
+    errdefer gpa.free(vorbis_alloc_buffer);
 
     self.* = State{
         .io = io,
+        .gpa = gpa,
+        .buffers = buffers,
+        .buses = buses,
+        .vorbis_alloc_buffer = vorbis_alloc_buffer,
+        .thread_state = .{
             .mutex = .init,
-        .sounds = .init(sounds_buffer),
+            .sounds = .initBuffer(sounds),
-        .temp_buffer = temp_buffer,
+            .bus_volumes = bus_volumes,
+        }
     };
-    self.running.store(true, .seq_cst);
 
+    main_bus = addBus(.{
+        .label = "main"
+    });
+
+    const channels = 2;
     saudio.setup(.{
         .stream_cb = sokolStreamCallback,
         .logger = opts.logger,
         .num_channels = channels,
         .buffer_frames = @intCast(opts.buffer_frames),
+        .sample_rate = g_sample_rate
     });
 
-    log.debug("Init:", .{});
+    if (opts.track_elapsed_time) {
-    log.debug("- sample_rate: {}", .{saudio.sampleRate()});
+        const measurements_per_second: usize = @intCast(@divFloor(std.time.ns_per_s, getMaxAudioThreadDuration().nanoseconds));
-    log.debug("- channels: {}", .{saudio.channels()});
+        self.thread_state.elapsed_time_ms = try gpa.alloc(f32, 3*measurements_per_second);
-    log.debug("- buffer_frames: {}", .{saudio.bufferFrames()});
+        @memset(self.thread_state.elapsed_time_ms.?, 0);
+    }
+
+    self.running.store(true, .seq_cst);
 }
 
 pub fn deinit(gpa: std.mem.Allocator) void {
     var self = &g_state;
 
+    {
+        self.thread_state.mutex.lock(self.io) catch @panic("Failed to lock audio mutex");
+        defer self.thread_state.mutex.unlock(self.io);
+
         self.running.store(false, .seq_cst);
+    }
 
     saudio.shutdown();
 
-    gpa.free(self.sounds.slots.allocatedSlice());
+    for (self.buffers.items) |buffer| {
-    gpa.free(self.temp_buffer);
+        buffer.samples.deinit(gpa);
+    }
+    self.buffers.deinit(gpa);
+
+    self.buses.deinit(gpa);
+    gpa.free(self.thread_state.sounds.slots.allocatedSlice());
+    gpa.free(self.thread_state.bus_volumes);
+    if (self.thread_state.elapsed_time_ms) |elapsed_time_ms| {
+        gpa.free(elapsed_time_ms);
+    }
+    gpa.free(self.vorbis_alloc_buffer);
 }
 
-pub fn getSampleRate() f32 {
+const BufferData = union(enum) {
-    return @floatFromInt(saudio.sampleRate());
+    raw: struct {
-}
+        samples_mono: []f32,
-
+        sample_rate: u32
-pub const SoundOptions = struct {
+    },
-    cb: Sound.Callback,
+    vorbis: []const u8
-    userdata: ?*anyopaque = null,
-    adsr: Sound.ADSR = .default,
-    volume: f32 = 1,
-    playing: bool = true,
-    looping: bool = false,
-
-    frequency: ?f32 = null,
-    duration_ns: ?u64 = null
 };
 
-pub fn initSound(opts: SoundOptions) Sound.Id {
+// Source: https://amini-allight.org/post/game-audio-programming-tutorial-part-6
-    var self = &g_state;
+fn hermiteResample(input: []f32, output: []f32) void {
+    for (0..output.len) |i| {
+        const elapsed = @as(f32, @floatFromInt(i)) / @as(f32, @floatFromInt(output.len));
 
-    self.mutex.lock(self.io) catch return .nil;
+        const b_index: isize = @intFromFloat(elapsed * @as(f32, @floatFromInt(input.len)));
-    defer self.mutex.unlock(self.io);
+        const a_index = b_index - 1;
+        const c_index = b_index + 1;
+        const d_index = b_index + 2;
 
-    const id = self.sounds.insertUndefined() catch {
+        const a = if (a_index >= 0 and a_index < input.len) input[@intCast(a_index)] else input[@intCast(b_index)];
-        log.warn("Sound limit reached! limit: {}", .{self.sounds.slots.capacity});
+        const b = input[@intCast(b_index)];
+        const c = if (c_index >= 0 and c_index < input.len) input[@intCast(c_index)] else input[@intCast(b_index)];
+        const d = if (d_index >= 0 and d_index < input.len) input[@intCast(d_index)] else input[@intCast(b_index)];
+
+        const t = (elapsed * @as(f32, @floatFromInt(input.len))) - @as(f32, @floatFromInt(b_index));
+
+        const c0 = b;
+        const c1 = (c - a) * 0.5;
+        const c2 = a - (b * 2.5) + (c * 2.0) - (d * 0.5);
+        const c3 = ((b - c) * 1.5) + ((d - a) * 0.5);
+        output[i] = (((((c3 * t) + c2) * t) + c1) * t) + c0;
+    }
+}
+
+fn resampleIfNeeded(gpa: Allocator, samples: *[]f32, sample_rate: u32) !void {
+    const new_sample_count = samples.len * g_sample_rate / sample_rate;
+    if (new_sample_count != samples.len) {
+        const new_samples = try gpa.alloc(f32, new_sample_count);
+        hermiteResample(samples.*, new_samples);
+        gpa.free(samples.*);
+        samples.* = new_samples;
+    }
+}
+
+fn bufferDataToSamples(data: BufferData) !Buffer.Samples {
+    const self = &g_state;
+    return switch (data) {
+        .raw => |raw| {
+            var samples = try self.gpa.dupe(f32, raw.samples_mono);
+            errdefer self.gpa.free(samples);
+
+            try resampleIfNeeded(self.gpa, &samples, raw.sample_rate);
+
+            return Buffer.Samples{
+                .len = samples.len,
+                .left = samples.ptr,
+                .right = null
+            };
+        },
+        .vorbis => |vorbis_data| {
+            const vorbis = try STBVorbis.init(vorbis_data, self.vorbis_alloc_buffer);
+            const sample_count = vorbis.getStreamLengthInSamples();
+
+            const info = vorbis.getInfo();
+            if (info.channels == 1) {
+                var samples = try self.gpa.alloc(f32, sample_count);
+                errdefer self.gpa.free(samples);
+
+                const result = vorbis.getSamples(&.{ samples.ptr }, sample_count);
+                assert(result == sample_count);
+
+                try resampleIfNeeded(self.gpa, &samples, info.sample_rate);
+
+                return .{
+                    .len = samples.len,
+                    .left = samples.ptr,
+                    .right = null
+                };
+            } else if (info.channels >= 2) {
+                var left_samples = try self.gpa.alloc(f32, sample_count);
+                errdefer self.gpa.free(left_samples);
+
+                var right_samples = try self.gpa.alloc(f32, sample_count);
+                errdefer self.gpa.free(right_samples);
+
+                const result = vorbis.getSamples(&.{ left_samples.ptr, right_samples.ptr }, sample_count);
+                assert(result == sample_count);
+
+                try resampleIfNeeded(self.gpa, &left_samples, info.sample_rate);
+                try resampleIfNeeded(self.gpa, &right_samples, info.sample_rate);
+
+                return Buffer.Samples{
+                    .len = left_samples.len,
+                    .left = left_samples.ptr,
+                    .right = right_samples.ptr
+                };
+            } else {
+                return Buffer.Samples{
+                    .len = 0,
+                    .left = &.{},
+                    .right = null
+                };
+            }
+        }
+    };
+}
+
+pub fn addBuffer(data: BufferData) BufferId {
+    const self = &g_state;
+
+    if (self.buffers.items.len == self.buffers.capacity) {
+        log.warn("Max audio buffers reached, limit: {}", .{self.buffers.capacity});
+        return .nil;
+    }
+
+    const samples = bufferDataToSamples(data) catch |e| {
+        log.err("Failed to add buffer: {}", .{e});
         return .nil;
     };
 
-    var phase_increment: f32 = 0;
+    const buffer_id = BufferId{ .index = @intCast(self.buffers.items.len) };
-    if (opts.frequency) |frequency| {
+    const buffer = self.buffers.addOneAssumeCapacity();
-        phase_increment = frequency * 2 * std.math.pi / getSampleRate();
+    buffer.* = Buffer{
-    }
+        .samples = samples
-
-    var duration_frames: u32 = 0;
-    if (opts.duration_ns) |duration_ns| {
-        duration_frames = @intCast(duration_ns * @as(u64, @intCast(saudio.sampleRate())) / std.time.ns_per_s);
-    }
-
-    const sound = self.sounds.getAssumeExists(id);
-    sound.* = Sound{
-        .cb = opts.cb,
-        .userdata = opts.userdata,
-        .adsr = opts.adsr,
-        .looping = opts.looping,
-        .volume = opts.volume,
-        .playing = opts.playing,
-        .duration_frames = duration_frames,
-        .phase_increment = phase_increment
     };
 
-    return id;
+    assert(buffer_id != BufferId.nil);
+
+    return buffer_id;
 }
 
-pub fn deinitSound(id: Sound.Id) void {
+pub fn addBus(opts: Bus) BusId {
-    var self = &g_state;
-
-    if (self.sounds.get(id)) |sound| {
-        self.mutex.lock(self.io) catch return;
-        defer self.mutex.unlock(self.io);
-
-        _ = sound; // autofix
-        self.sounds.removeAssumeExists(id);
-    }
-}
-
-pub fn setPlaying(id: Sound.Id, playing: bool) void {
-    var self = &g_state;
-
-    if (self.sounds.get(id)) |sound| {
-        self.mutex.lock(self.io) catch return;
-        defer self.mutex.unlock(self.io);
-
-        sound.playing = playing;
-    }
-}
-
-pub fn getPlaying(id: Sound.Id) bool {
-    var self = &g_state;
-
-    if (self.sounds.get(id)) |sound| {
-        return sound.playing;
-    } else {
-        return false;
-    }
-}
-
-fn bumpSoundCursor(sound: *Sound, count: u32) void {
-    if (sound.duration_frames > 0) {
-        sound.frame_index += count;
-        sound.frame_index = @mod(sound.frame_index, sound.duration_frames);
-    }
-
-    if (sound.phase_increment > 0) {
-        sound.phase += sound.phase_increment * @as(f32, @floatFromInt(count));
-        sound.phase = @mod(sound.phase, 2 * std.math.pi);
-    }
-}
-
-fn sokolStream(buffer: [*c]f32, num_frames: u32, num_channels: u32) !void {
     const self = &g_state;
 
+    if (self.buses.items.len == self.buses.capacity) {
+        log.warn("Max audio buses reached, limit: {}", .{self.buses.capacity});
+        return .nil;
+    }
+
+    const bus_id = BusId{ .index = @intCast(self.buses.items.len) };
+    const bus = self.buses.addOneAssumeCapacity();
+    bus.* = opts;
+
+    if (bus.parent_id != null and bus.parent_id == BusId.nil) {
+        bus.parent_id = null;
+    }
+
+    if (bus.parent_id == null and main_bus != BusId.nil) {
+        bus.parent_id = main_bus;
+    }
+
+    assert(bus_id != BusId.nil);
+
+    return bus_id;
+}
+
+fn busMultipliedVolume(id: BusId) f32 {
+    const self = &g_state;
+
+    var result: f32 = 1;
+    var iter: ?BusId = id;
+    while (iter) |current| {
+        const bus = &self.buses.items[current.index];
+        result *= bus.volume;
+        iter = bus.parent_id;
+    }
+    return result;
+}
+
+const PlayOptions = struct {
+    buffer: BufferId,
+    // TODO: adsr: ?Sound.ADSR = null,
+    volume: f32 = 1,
+    loop: bool = false,
+    bus: ?BusId = null
+};
+
+pub fn play(opts: PlayOptions) SoundId {
+    const self = &g_state;
+
+    var mutex = &self.thread_state.mutex;
+    var sounds = &self.thread_state.sounds;
+
+    mutex.lock(self.io) catch |e| {
+        log.warn("Failed to lock mutex: {}", .{e});
+        return .nil;
+    };
+    defer mutex.unlock(self.io);
+
+    const bus = opts.bus orelse main_bus;
+    if (bus == BusId.nil) {
+        return .nil;
+    }
+
+    if (opts.buffer == BufferId.nil) {
+        return .nil;
+    }
+
+    if (sounds.unusedCapacity() == 0) {
+        log.warn("Max sounds reached, limit: {}", .{sounds.slots.capacity});
+        return .nil;
+    }
+
+    const sound_id = sounds.insertAssumeCapacity();
+    const sound = sounds.getAssumeExists(sound_id);
+    sound.* = Sound{
+        .cursor = 0,
+        .volume = opts.volume,
+        .loop = opts.loop,
+        .buffer = opts.buffer,
+        .bus = bus,
+    };
+
+    return sound_id;
+}
+
+pub fn stop(id: SoundId) void {
+    const self = &g_state;
+
+    var mutex = &self.thread_state.mutex;
+    var sounds = &self.thread_state.sounds;
+
+    mutex.lock(self.io) catch |e| {
+        log.warn("Failed to lock mutex: {}", .{e});
+        return;
+    };
+    defer mutex.unlock(self.io);
+
+    _ = sounds.remove(id);
+}
+
+pub fn getBus(id: BusId) ?*Bus {
+    const self = &g_state;
+
+    if (id == .nil) {
+        return null;
+    }
+    return &self.buses.items[id.index];
+}
+
+pub fn showDebug() void {
+    const self = &g_state;
+
+    const sounds = &self.thread_state.sounds;
+    const buses = &self.buses;
+    const buffers = &self.buffers;
+
+    _ = ImGUI.beginTabBar("audio tab bar");
+    defer ImGUI.endTabBar();
+
+    if (ImGUI.beginTabItem("General")) {
+        defer ImGUI.endTabItem();
+
+        ImGUI.text("Sample rate: {}Hz", .{saudio.sampleRate()});
+        ImGUI.text("Buffer frames: {}", .{saudio.bufferFrames()});
+        ImGUI.text("Max callback duration: {f}", .{getMaxAudioThreadDuration()});
+
+        ImGUI.separator();
+        ImGUI.text("Buffers: {}/{}", .{buffers.items.len, buffers.capacity});
+        ImGUI.text("Buses: {}/{}", .{buses.items.len, buses.capacity});
+        ImGUI.text("Sounds: {}/{}", .{sounds.count(), sounds.slots.capacity});
+
+        if (self.thread_state.elapsed_time_ms) |elapsed_time_ms| {
+            ImGUI.separator();
+
+            ImGUI.plotLines(.{
+                .label = "Elapsed (ms)",
+                .values = elapsed_time_ms,
+                .ex = .{
+                    .scale_max = getMaxAudioThreadDurationMs()
+                }
+            });
+
+            var min_elapsed = elapsed_time_ms[0];
+            var max_elapsed = elapsed_time_ms[0];
+            var sum_elapsed = elapsed_time_ms[0];
+            for (elapsed_time_ms[1..]) |duration_ms| {
+                min_elapsed = @min(min_elapsed, duration_ms);
+                max_elapsed = @max(max_elapsed, duration_ms);
+                sum_elapsed += duration_ms;
+            }
+            const avg_elapsed = sum_elapsed / @as(f32, @floatFromInt(elapsed_time_ms.len));
+            ImGUI.text("Min/Max/Avg: {:.3}ms/{:.3}ms/{:.3}ms{s}", .{
+                min_elapsed, max_elapsed, avg_elapsed,
+                if (max_elapsed > getMaxAudioThreadDurationMs()) " !!!" else ""
+            });
+        }
+
+        ImGUI.separator();
+        ImGUI.text("Budget reached counter: {}", .{self.thread_state.budget_reached_counter});
+    }
+    if (ImGUI.beginTabItem("Buses")) {
+        defer ImGUI.endTabItem();
+        if(ImGUI.beginTable("buses", 3, 0)) {
+            defer ImGUI.endTable();
+
+            ImGUI.tableSetupColumn("ID (Label)", 0);
+            ImGUI.tableSetupColumn("Volume", 0);
+            ImGUI.tableSetupColumn("Multiplied volume", 0);
+            ImGUI.tableHeadersRow();
+
+            for (0.., buses.items) |i, *bus| {
+                ImGUI.pushID(.{ .int = @intCast(i) });
+                defer ImGUI.popID();
+
+                ImGUI.tableNextRow();
+
+                ImGUI.tableNextColumn();
+                ImGUI.text("{} ({s})", .{i, bus.label orelse "-"});
+
+                ImGUI.tableNextColumn();
+                _ = ImGUI.inputF32Drag(.{
+                    .label = "",
+                    .value = &bus.volume,
+                    .ex = .{
+                        .min = 0,
+                        .max = 1,
+                        .speed = 0.01
+                    }
+                });
+
+                ImGUI.tableNextColumn();
+                ImGUI.text("{}", .{busMultipliedVolume(.{ .index = @intCast(i) })});
+            }
+        }
+    }
+}
+
+fn getMaxAudioThreadDuration() Io.Duration {
+    const margin = 0.05;
+    return Io.Duration{
+        .nanoseconds = @divFloor((@as(i64, @intFromFloat(@as(f64, @floatFromInt(std.time.ns_per_s)) * (1 - margin)))) * @as(i64, saudio.bufferFrames()), saudio.sampleRate())
+    };
+}
+
+fn getMaxAudioThreadDurationMs() f32 {
+    return @floatCast(@as(f64, @floatFromInt(getMaxAudioThreadDuration().nanoseconds)) / std.time.ns_per_ms);
+}
+
+fn sokolStream(output_buffer: [*c]f32, num_frames: u32, num_channels: u32) !void {
+    const self = &g_state;
+
+    const started_at = Io.Clock.awake.now(self.io);
+
+    var zone = tracy.initZone(@src(), .{});
+    defer zone.deinit();
+
+    const mutex = &self.thread_state.mutex;
+    const sounds = &self.thread_state.sounds;
+    const buses = self.buses.items;
+    const bus_volumes = self.thread_state.bus_volumes;
+
+    try mutex.lock(self.io);
+    defer mutex.unlock(self.io);
+
     if (!self.running.load(.seq_cst)) {
         return;
     }
 
-    try self.mutex.lock(self.io);
+    assert(num_channels == 2);
-    defer self.mutex.unlock(self.io);
+    @memset(output_buffer[0..(num_frames*2)], 0);
 
-    assert(num_channels == 1);
+    for (0..buses.len) |i| {
-    assert(self.temp_buffer.len >= num_frames);
+        bus_volumes[i] = busMultipliedVolume(.{ .index = @intCast(i) });
-
-    @memset(buffer[0..num_frames], 0);
-
-    var iter = self.sounds.iterator();
-    while (iter.next()) |id| {
-        const sound = self.sounds.getAssumeExists(id);
-        if (!sound.playing) {
-            continue;
     }
 
-        var samples = std.ArrayList(f32).initBuffer(self.temp_buffer[0..num_frames]);
+    var sound_iter = sounds.iterator();
-        switch (sound.cb) {
+    while (sound_iter.next()) |sound_id| {
-            .block => |cb| {
+        const sound = sounds.getAssumeExists(sound_id);
-                cb(sound, &samples);
+        const buffer = &self.buffers.items[sound.buffer.index];
-                bumpSoundCursor(sound, @intCast(samples.items.len));
+
-            },
+        const bus_id = sound.bus;
-            .sample => |cb| {
+        const bus = buses[bus_id.index];
-                samples.expandToCapacity();
+        _ = bus; // autofix
-                for (samples.items) |*sample| {
+
-                    sample.* = cb(sound);
+        const volume = sound.volume * bus_volumes[bus_id.index];
-                    bumpSoundCursor(sound, 1);
+
+        const left_channel = buffer.samples.left;
+        const right_channel = buffer.samples.right orelse buffer.samples.left;
+
+        var output_index: usize = 0;
+        while (output_index < num_frames) {
+            while (sound.cursor < buffer.samples.len and output_index < num_frames) {
+                const left = left_channel[sound.cursor];
+                const right = right_channel[sound.cursor];
+                sound.cursor += 1;
+
+                output_buffer[2*output_index+0] += left * volume;
+                output_buffer[2*output_index+1] += right * volume;
+                output_index += 1;
+            }
+
+            if (!sound.loop) {
+                break;
+            } else {
+                if (sound.cursor == buffer.samples.len) {
+                    sound.cursor = 0;
                 }
             }
         }
 
-        for (0..samples.items.len) |i| {
+        if (!sound.loop and sound.cursor == buffer.samples.len) {
-            buffer[i] += samples.items[i] * sound.volume * self.volume;
+            sounds.removeAssumeExists(sound_id);
         }
     }
+
+    const duration = started_at.durationTo(Io.Clock.awake.now(self.io));
+    if (self.thread_state.elapsed_time_ms) |elapsed_time_ms| {
+        @memmove(elapsed_time_ms[1..elapsed_time_ms.len], elapsed_time_ms[0..(elapsed_time_ms.len-1)]);
+        elapsed_time_ms[0] = @floatCast(@as(f64, @floatFromInt(duration.nanoseconds)) / std.time.ns_per_ms);
+    }
+
+    if (duration.nanoseconds > getMaxAudioThreadDuration().nanoseconds) {
+        self.thread_state.budget_reached_counter += 1;
+    }
 }
 
 fn sokolStreamCallback(buffer: [*c]f32, num_frames_i32: i32, num_channels: i32) callconv(.c) void {

src/platform/file_watcher.zig

@@ -288,7 +288,7 @@ fn nextEvents(self: *FileWatcher) !?*File {
 }
 
 pub fn next(self: *FileWatcher, io: Io) !?[]const u8 {
-    const now = Io.Clock.real.now(io);
+    const now = Io.Clock.awake.now(io);
 
     var queue_overflow = false;
     while (true) {

src/platform/graphics.zig

@@ -168,16 +168,16 @@ pub fn init(gpa: std.mem.Allocator, logger: sg.Logger) !void {
         .transforms = .initBuffer(&self.transforms_buffer),
 
         .textures_buffer = undefined,
-        .textures = .init(&self.textures_buffer),
+        .textures = .initBuffer(&self.textures_buffer),
 
         .sprites_buffer = undefined,
-        .sprites = .init(&self.sprites_buffer),
+        .sprites = .initBuffer(&self.sprites_buffer),
 
         .spritesheets_buffer = undefined,
-        .spritesheets = .init(&self.spritesheets_buffer),
+        .spritesheets = .initBuffer(&self.spritesheets_buffer),
 
         .fonts_buffer = undefined,
-        .fonts = .init(&self.fonts_buffer),
+        .fonts = .initBuffer(&self.fonts_buffer),
     };
 
     self.default_spritesheet = initSpritesheet(.{});
@@ -233,9 +233,6 @@ pub fn init(gpa: std.mem.Allocator, logger: sg.Logger) !void {
             }
         });
     }
-
-    repackSpritesheetIfNeeded(self.default_spritesheet);
-    rebuildSpritesheetTextureIfNeeded(self.default_spritesheet);
 }
 
 pub fn deinit() void {
@@ -347,45 +344,75 @@ pub fn beginFrame() void {
         .swapchain = sglue.swapchain()
     });
 
-    const default_spritesheet = self.spritesheets.getAssumeExists(self.default_spritesheet);
+    self.bindings.views[shd.VIEW_tex].id = sg.invalid_id;
-    const spritesheet_texture = self.textures.getAssumeExists(default_spritesheet.texture);
-    self.bindings.views[shd.VIEW_tex] = spritesheet_texture.view;
     self.bindings.samplers[shd.SMP_smp] = self.linear_sampler;
 }
 
 pub fn showDebug() void {
     const self = &g_state;
-    _ = self; // autofix
 
-    // TODO: Improve this by using tables or somekind of filtering
+    _ = ImGUI.beginTabBar("graphics tab bar");
+    defer ImGUI.endTabBar();
 
-    // if (ImGUI.beginWindow(.{
+    if (ImGUI.beginTabItem("Spritesheets")) {
-    //     .name = "graphics",
+        defer ImGUI.endTabItem();
-    //     .size = .init(200, 200)
+
-    // })) {
+        if(ImGUI.beginTable("spritesheets", 2, 0)) {
-    //     defer ImGUI.endWindow();
+            defer ImGUI.endTable();
-    //
+
-    //     {
+            ImGUI.tableSetupColumn("ID", 0);
-    //         ImGUI.text("Spritesheets:", .{});
+            ImGUI.tableSetupColumn("Size", 0);
-    //         var spritesheet_iter = self.spritesheets.iterator();
+            ImGUI.tableHeadersRow();
-    //         while (spritesheet_iter.next()) |spritesheet_id| {
+
-    //             const spritesheet = self.spritesheets.getAssumeExists(spritesheet_id);
+            var spritesheet_iter = self.spritesheets.iterator();
-    //             const texture = self.textures.get(spritesheet.texture);
+            while (spritesheet_iter.next()) |spritesheet_id| {
-    //             ImGUI.text("{f}:", .{spritesheet_id});
+                const spritesheet = self.spritesheets.getAssumeExists(spritesheet_id);
-    //             ImGUI.text("  -  needs_texture_rebuild:{}", .{spritesheet.needs_texture_rebuild});
+
-    //             ImGUI.text("  - texture:{?}", .{texture});
+                ImGUI.pushID(.{ .int = spritesheet_id.index });
-    //         }
+                defer ImGUI.popID();
-    //     }
+
-    //
+                ImGUI.tableNextRow();
-    //     {
+
-    //         ImGUI.text("Sprites:", .{});
+                ImGUI.tableNextColumn();
-    //         var sprite_iter = self.sprites.iterator();
+                ImGUI.text("{{ {}, {} }}", .{spritesheet_id.index, spritesheet_id.generation});
-    //         while (sprite_iter.next()) |sprite_id| {
+
-    //             const sprite = self.sprites.getAssumeExists(sprite_id);
+                ImGUI.tableNextColumn();
-    //             ImGUI.text("{f} - {?}", .{sprite_id, sprite.position});
+                ImGUI.text("{}x{}", .{spritesheet.size.x, spritesheet.size.x});
-    //         }
+            }
-    //     }
+        }
-    // }
+    }
+
+    if (ImGUI.beginTabItem("Sprites")) {
+        defer ImGUI.endTabItem();
+
+        if(ImGUI.beginTable("sprites", 2, 0)) {
+            defer ImGUI.endTable();
+
+            ImGUI.tableSetupColumn("ID", 0);
+            ImGUI.tableSetupColumn("Position", 0);
+            ImGUI.tableHeadersRow();
+
+            var sprite_iter = self.sprites.iterator();
+            while (sprite_iter.next()) |sprite_id| {
+                const sprite = self.sprites.getAssumeExists(sprite_id);
+
+                ImGUI.pushID(.{ .int = sprite_id.index });
+                defer ImGUI.popID();
+
+                ImGUI.tableNextRow();
+
+                ImGUI.tableNextColumn();
+                ImGUI.text("{{ {}, {} }}", .{sprite_id.index, sprite_id.generation});
+
+                ImGUI.tableNextColumn();
+                if (sprite.position) |position| {
+                    ImGUI.text("{:3}, {:3}", .{position.x, position.y});
+                } else {
+                    ImGUI.text("null", .{});
+                }
+            }
+        }
+    }
 }
 
 // TODO: This will always have a 1-frame delay.
@@ -396,11 +423,7 @@ pub fn setClearColor(color: Color) void {
     self.clear_color = color;
 }
 
-const FlushOptions = struct {
+pub fn flush() void {
-    rebuild_spritesheets: bool = true
-};
-
-pub fn flush(opts: FlushOptions) void {
     const self = &g_state;
 
     if (self.quads.items.len == 0) {
@@ -408,7 +431,6 @@ pub fn flush(opts: FlushOptions) void {
     }
     defer self.quads.clearRetainingCapacity();
 
-    if (opts.rebuild_spritesheets) {
     var spritesheet_iter = self.spritesheets.iterator();
     while (spritesheet_iter.next()) |spritesheet_id| {
         const spritesheet = self.spritesheets.getAssumeExists(spritesheet_id);
@@ -417,6 +439,10 @@ pub fn flush(opts: FlushOptions) void {
             rebuildSpritesheetTextureIfNeeded(spritesheet_id);
         }
     }
+
+    if (sg.queryViewState(getBoundView().*) != .VALID) {
+        log.warn("Attempt to use view which isn't valid", .{});
+        return;
     }
 
     const vertex_buffer = self.bindings.vertex_buffers[0];
@@ -442,7 +468,7 @@ pub fn flush(opts: FlushOptions) void {
     var fs_params: shd.FsParams = .{
         .texture_mode = 0,
     };
-    const image = sg.queryViewImage(self.bindings.views[shd.VIEW_tex]);
+    const image = sg.queryViewImage(getBoundView().*);
     if (sg.queryImagePixelformat(image) == .R8) {
         fs_params.texture_mode = 1;
     }
@@ -451,17 +477,17 @@ pub fn flush(opts: FlushOptions) void {
     sg.applyBindings(self.bindings);
     sg.applyUniforms(shd.UB_vs_params, sg.asRange(&vs_params));
     sg.applyUniforms(shd.UB_fs_params, sg.asRange(&fs_params));
+    assert(self.quads.items.len > 0);
     sg.draw(0, @intCast(self.quads.items.len * 6), 1);
 }
 
 pub fn endFrame() void {
     const self = &g_state;
 
-    flush(.{});
+    flush();
 
     sg.endPass();
     sg.commit();
-    self.frame_index += 1;
 
     var spritesheet_iter = self.spritesheets.iterator();
     while (spritesheet_iter.next()) |spritesheet_id| {
@@ -473,6 +499,8 @@ pub fn endFrame() void {
     } else if (self.transforms.items.len == 0) {
         log.warn("Too many calls to transformPop()", .{});
     }
+
+    self.frame_index += 1;
 }
 
 pub fn drawRectangle(pos: Vec2, size: Vec2, color: Color) void {
@@ -577,33 +605,28 @@ pub fn initTexture(opts: TextureOptions) Texture.Id {
     return id;
 }
 
+fn getBoundView() *sg.View {
+    const self = &g_state;
+    return &self.bindings.views[shd.VIEW_tex];
+}
+
 fn isViewBound(view: sg.View) bool {
-    const self = &g_state;
+    return getBoundView().id == view.id;
-    const bound_view = &self.bindings.views[shd.VIEW_tex];
-    return bound_view.id == view.id;
-}
-
-fn deinitTextureResources(texture: *Texture) void {
-    const self = &g_state;
-
-    if (isViewBound(texture.view)) {
-        const default_sprite = self.sprites.getAssumeExists(self.default_sprite);
-        const default_spritesheet = self.spritesheets.getAssumeExists(default_sprite.spritesheet);
-        const default_texture = self.textures.getAssumeExists(default_spritesheet.texture);
-        bindView(default_texture.view, .{ .rebuild_spritesheets = false });
-    }
-
-    sg.destroyImage(texture.image);
 }
 
 pub fn deinitTexture(id: Texture.Id) void {
     const self = &g_state;
-    if (id == self.nil_texture) {
+    if (id == .nil) {
         return;
     }
 
     if (self.textures.get(id)) |texture| {
-        deinitTextureResources(texture);
+        const bound_view = getBoundView();
+        if (bound_view.id ==  texture.view.id) {
+            bound_view.id = sg.invalid_id;
+        }
+
+        sg.destroyImage(texture.image);
         sg.destroyView(texture.view);
         self.textures.removeAssumeExists(id);
     }
@@ -649,7 +672,6 @@ pub fn setTexture(id: Texture.Id, texture_data: ImageData) void {
 
     var texture_updated: bool = false;
     if (sg.queryImageState(texture.image) == .VALID) {
-        // sg.queryImageInfo
         const image_desc = sg.queryImageDesc(texture.image);
         if (image_desc.width == new_image_desc.width and
             image_desc.height == new_image_desc.height and
@@ -659,19 +681,19 @@ pub fn setTexture(id: Texture.Id, texture_data: ImageData) void {
             image_desc.usage.immutable == new_image_desc.usage.immutable and
             image_desc.usage.dynamic_update
         ) {
-            log.debug("Update texture '{f}'", .{id});
+            log.debug("[{}] Update texture '{f}'", .{self.frame_index, id});
             if (texture.updated_at == null or texture.updated_at.? != self.frame_index) {
                 sg.updateImage(texture.image, image_data);
                 texture_updated = true;
                 texture.updated_at = self.frame_index;
             } else {
-                log.warn("Attempt to update the same texture multiple times per frame", .{});
+                log.warn("Attempt to update the same texture multiple times per frame, texture: {f}", .{id});
             }
         }
     }
 
     if (!texture_updated) {
-        log.debug("Create image-view, texture={f}", .{id});
+        log.debug("[{}] Create image-view, texture={f}", .{self.frame_index, id});
         const new_image = sg.makeImage(new_image_desc);
         if (sg.queryImageState(new_image) != .VALID) {
             log.warn("makeImage() failed", .{});
@@ -689,11 +711,13 @@ pub fn setTexture(id: Texture.Id, texture_data: ImageData) void {
             return;
         }
 
-        deinitTextureResources(texture);
+        sg.destroyImage(texture.image);
         texture.image = new_image;
         texture.updated_at = null;
 
+        log.debug("is dynamic {f}, {}", .{id, texture.dynamic});
         if (texture.dynamic) {
+            log.debug("update texture {f}", .{id});
             sg.updateImage(new_image, image_data);
             texture.updated_at = self.frame_index;
         }
@@ -712,20 +736,11 @@ pub fn drawTexture(id: Texture.Id, pos: Vec2, size: Vec2, color: Color) void {
     });
 }
 
-fn bindView(view: sg.View, opts: FlushOptions) void {
+fn bindView(view: sg.View) void {
+    _ = view; // autofix
     const self = &g_state;
+    _ = self; // autofix
 
-    const view_state = sg.queryViewState(view);
-    if (view_state != .VALID and view_state != .ALLOC) {
-        log.warn("Attempt to bind non-valid view: state={}", .{view_state});
-        return;
-    }
-
-    const bound_view = &self.bindings.views[shd.VIEW_tex];
-    if (bound_view.id != view.id) {
-        flush(opts);
-        bound_view.* = view;
-    }
 }
 
 pub fn setDefaultSampler(sampler: Sampler) void {
@@ -773,7 +788,17 @@ pub fn draw(opts: DrawOptions) void {
         return;
     }
 
-    bindView(view, .{});
+    const view_state = sg.queryViewState(view);
+    if (view_state == .VALID or view_state == .ALLOC) {
+        const bound_view = getBoundView();
+        if (bound_view.id != view.id) {
+            flush();
+            bound_view.* = view;
+        }
+    } else {
+        log.warn("Attempt to bind non-valid view: state={}", .{view_state});
+        return;
+    }
 
     const sampler = switch (opts.sampler orelse self.default_sampler) {
         .linear => self.linear_sampler,
@@ -781,12 +806,12 @@ pub fn draw(opts: DrawOptions) void {
     };
     const bound_sampler = &self.bindings.samplers[shd.SMP_smp];
     if (bound_sampler.id != sampler.id) {
-        flush(.{});
+        flush();
         bound_sampler.* = sampler;
     }
 
     if (self.quads.items.len == self.quads.capacity) {
-        flush(.{});
+        flush();
     }
 
     if (getTransformPtr()) |transform| {
@@ -843,6 +868,7 @@ const SetSpriteOptions = struct {
 
 pub fn setSprite(id: Sprite.Id, opts: SetSpriteOptions) void {
     const self = &g_state;
+
     const sprite = self.sprites.get(id) orelse {
         log.warn("Attempt to set sprite that doesn't exist: {}", .{id});
         return;
@@ -897,12 +923,14 @@ pub fn setSprite(id: Sprite.Id, opts: SetSpriteOptions) void {
 
     const new_size = Vec2.initFromInt(u32, sprite_data.width, sprite_data.height); 
 
-    if (old_size != null and old_size.?.eql(new_size) and sprite.position != null) {
+    log.debug("set sprite on {f}", .{sprite.spritesheet});
-        spritesheet.needs_texture_rebuild = true;
+
-    } else {
+    if (old_size == null or !old_size.?.eql(new_size) or sprite.position == null) {
         sprite.position = null;
         spritesheet.needs_repack = true;
     }
+
+    spritesheet.needs_texture_rebuild = true;
 }
 
 // WARNING: This will change the UV coordinates of all sprites.
@@ -915,7 +943,7 @@ fn repackSpritesheet(id: Spritesheet.Id) void {
         return;
     };
 
-    log.debug("Repack spritesheet: {f}", .{id});
+    log.debug("[{}] Repack spritesheet: {f}", .{self.frame_index, id});
 
     // TODO: Add a smarter startegy for picking the initial texture size.
     // One idea is to calculate the sum area of all sprites and pick a atlas size based on that.
@@ -994,7 +1022,7 @@ fn rebuildSpritesheetTextureIfNeeded(id: Spritesheet.Id) void {
         return;
     }
 
-    log.debug("Rebuild spritesheet texture: {f}", .{id});
+    log.debug("[{}] Rebuild spritesheet texture: {f}", .{self.frame_index, id});
 
     const image_data = ImageData.init(
         self.gpa,
@@ -1265,12 +1293,12 @@ pub fn getGlyph(id: Font.Id, index: GlyphIndex, scale_x: f32, scale_y: f32) ?*Fo
         };
         glyph = font.cache.get(glyph_id);
         glyph.box = stb_font.getGlyphBitmapBox(glyph_key.index, glyph_key.scale_x, glyph_key.scale_y);
+        glyph.sprite = null;
 
         const box_width: u32 = @intCast(glyph.box.x1 - glyph.box.x0);
         const box_height: u32 = @intCast(glyph.box.y1 - glyph.box.y0);
         if (box_width > 0 and box_height > 0) {
-            assert(glyph.sprite == Sprite.Id.nil);
+            const sprite = initSprite(.{ .spritesheet = font.spritesheet, .padding = 1 });
-            glyph.sprite = initSprite(.{ .spritesheet = font.spritesheet, .padding = 1 });
 
             assert(box_width < Font.Glyph.max_width);
             assert(box_height < Font.Glyph.max_height);
@@ -1288,9 +1316,10 @@ pub fn getGlyph(id: Font.Id, index: GlyphIndex, scale_x: f32, scale_y: f32) ?*Fo
                 glyph_key.scale_x, glyph_key.scale_y,
                 glyph_key.index
             );
-            setSprite(glyph.sprite, .{ .image = bitmap });
+            setSprite(sprite, .{ .image = bitmap });
-        } else {
+
-            glyph.sprite = .nil;
+            assert(glyph.sprite == null);
+            glyph.sprite = sprite;
         }
     }
     glyph.used_this_frame = true;
@@ -1308,7 +1337,7 @@ pub const TextRunLayout = struct {
 
     const GlyphRect = struct {
         rect: Rect,
-        sprite: Sprite.Id,
+        sprite: ?Sprite.Id,
     };
 
     pub fn init(font: Font.Id, height: f32) TextRunLayout {
@@ -1406,9 +1435,10 @@ pub fn drawText(id: Font.Id, opts: DrawTextOptions) void {
     while (iter.nextCodepoint()) |codepoint| {
         const glyph_index = getGlyphIndex(id, codepoint) orelse continue;
         const glyph_layout = layout.next(glyph_index) orelse continue;
+        const glyph_sprite = glyph_layout.sprite orelse continue;
 
         drawSprite(
-            glyph_layout.sprite,
+            glyph_sprite,
             glyph_layout.rect.pos.add(pos),
             glyph_layout.rect.size,
             opts.color
@@ -2133,7 +2163,7 @@ pub const Font = struct {
         key: Key,
 
         box: STBTrueType.Box,
-        sprite: Sprite.Id,
+        sprite: ?Sprite.Id,
         used_this_frame: bool,
 
         const max_width: u32 = 512;
@@ -2169,7 +2199,9 @@ pub const Font = struct {
         }
 
         fn deinit(self: Glyph) void {
-            deinitSprite(self.sprite);
+            if (self.sprite) |sprite| {
+                deinitSprite(sprite);
+            }
         }
     };
 };

src/platform/imgui.zig

@@ -503,3 +503,92 @@ pub fn collapsingHeader(label: []const u8) bool {
         ig.ImGuiTreeNodeFlags_None
     );
 }
+
+pub fn beginTable(id: [*c]const u8, columns: u32, flags: ig.ImGuiTableFlags) bool {
+    if (isDisabled()) {
+        return false;
+    }
+
+    return ig.igBeginTable(id, @intCast(columns), flags);
+}
+
+pub fn endTable() void {
+    if (isDisabled()) {
+        return;
+    }
+
+    ig.igEndTable();
+}
+
+pub fn tableNextColumn() void {
+    if (isDisabled()) {
+        return;
+    }
+
+    _ = ig.igTableNextColumn();
+}
+
+pub fn tableNextRow() void {
+    if (isDisabled()) {
+        return;
+    }
+
+    _ = ig.igTableNextRow();
+}
+
+pub fn tableSetColumnIndex(index: usize) void {
+    if (isDisabled()) {
+        return;
+    }
+
+    _ = ig.igTableSetColumnIndex(@intCast(index));
+}
+
+pub fn tableSetupColumn(label: [*c]const u8, flags: ig.ImGuiTableColumnFlags) void {
+    if (isDisabled()) {
+        return;
+    }
+
+    ig.igTableSetupColumn(label, flags);
+}
+
+pub fn tableHeadersRow() void {
+    if (isDisabled()) {
+        return;
+    }
+
+    ig.igTableHeadersRow();
+}
+
+const PlotLinesOptions = struct {
+    label: [*c]const u8,
+    values: []f32,
+    ex: ?struct {
+        graph_width: f32 = 0,
+        graph_height: f32 = 0,
+        scale_min: f32 = 0,
+        scale_max: f32 = 1,
+        stride: u32 = 4,
+    } = null
+};
+
+pub fn plotLines(opts: PlotLinesOptions) void {
+    if (isDisabled()) {
+        return;
+    }
+
+    if (opts.ex) |ex| {
+        ig.igPlotLinesEx(
+            opts.label,
+            opts.values.ptr, @intCast(opts.values.len),
+            0,
+            null,
+            ex.scale_min,
+            ex.scale_max,
+            .{ .x = ex.graph_width, .y = ex.graph_height },
+            @intCast(ex.stride)
+        );
+    } else {
+        ig.igPlotLines(opts.label, opts.values.ptr, @intCast(opts.values.len));
+    }
+}

src/platform/input.zig

@@ -6,9 +6,16 @@ const sokol = @import("sokol");
 const Math = @import("math");
 const Vec2 = Math.Vec2;
 
+const Nanoseconds = @import("./root.zig").Nanoseconds;
+
 const Input = @This();
 
-key_code_mapping: std.EnumMap(KeyCode, u21),
+// TODO: Make this configurable from the app
+const key_repeat_first: Nanoseconds = 0.4 * std.time.ns_per_s;
+const key_repeat_delay: Nanoseconds = 0.2 * std.time.ns_per_s;
+
+now: Nanoseconds,
+delta_time: Nanoseconds,
 
 window_size: Vec2,
 focused: bool,
@@ -18,8 +25,13 @@ mouse_position: ?Vec2,
 mouse_delta: Vec2,
 mouse_scroll: Vec2,
 
+key_code_mapping: std.EnumMap(KeyCode, u21),
+last_key_repeat_at: std.EnumMap(KeyCode, Nanoseconds),
+
 pub fn init(window_size: Vec2) Input {
     return Input{
+        .now = 0,
+        .delta_time = 0,
         .key_code_mapping = .{},
         .focused = false,
         .keyboard = .empty,
@@ -27,7 +39,8 @@ pub fn init(window_size: Vec2) Input {
         .mouse_position = null,
         .mouse_delta = .init(0, 0),
         .mouse_scroll = .init(0, 0),
-        .window_size = window_size
+        .window_size = window_size,
+        .last_key_repeat_at = .{}
     };
 }
 
@@ -40,7 +53,33 @@ pub fn isKeyReleased(self: Input, key: KeyCode) bool {
 }
 
 pub fn isKeyDown(self: Input, key: KeyCode) bool {
-    return self.keyboard.down.contains(key);
+    return self.keyboard.pressed_at.contains(key);
+}
+
+pub fn getKeyDown(self: Input, key: KeyCode) ?Nanoseconds {
+    return self.keyboard.getDown(key, self.now);
+}
+
+pub fn isKeyRepeat(self: *Input, key: KeyCode) bool {
+    const pressed_at = self.keyboard.pressed_at.get(key) orelse return false;
+
+    var next_repeat_at: Nanoseconds = undefined;
+    if (self.last_key_repeat_at.get(key)) |last_repeat_at| {
+        next_repeat_at = last_repeat_at + key_repeat_delay;
+    } else {
+        next_repeat_at = pressed_at + key_repeat_first;
+    }
+
+    if (self.now >= next_repeat_at) {
+        self.last_key_repeat_at.put(key, next_repeat_at);
+        return true;
+    } else {
+        return false;
+    }
+}
+
+pub fn isKeyPressedOrRepeat(self: *Input, key: KeyCode) bool {
+    return self.isKeyPressed(key) or self.isKeyRepeat(key);
 }
 
 pub fn isMousePressed(self: Input, button: MouseButton) bool {
@@ -52,7 +91,11 @@ pub fn isMouseReleased(self: Input, button: MouseButton) bool {
 }
 
 pub fn isMouseDown(self: Input, button: MouseButton) bool {
-    return self.mouse_buttons.down.contains(button);
+    return self.mouse_buttons.pressed_at.contains(button);
+}
+
+pub fn getMouseDown(self: Input, button: MouseButton) ?Nanoseconds {
+    return self.mouse_buttons.getDown(button, self.now);
 }
 
 pub const KeyCode = enum(std.math.IntFittingRange(0, sokol.app.max_keycodes-1)) {
@@ -212,28 +255,35 @@ fn KeyStateType(T: type) type {
     return struct {
         pressed: std.EnumSet(T),
         released: std.EnumSet(T),
-        down: std.EnumSet(T),
+        pressed_at: std.EnumMap(T, Nanoseconds),
 
         pub const empty = @This(){
             .pressed = .empty,
             .released = .empty,
-            .down = .empty,
+            .pressed_at = .{},
         };
 
-        pub fn press(self: *@This(), key: T) void {
+        pub fn press(self: *@This(), key: T, now: Nanoseconds) void {
             self.pressed.insert(key);
-            self.down.insert(key);
+            self.pressed_at.put(key, now);
         }
 
         pub fn release(self: *@This(), key: T) void {
             self.released.insert(key);
-            self.down.remove(key);
+            self.pressed_at.remove(key);
+        }
+
+        pub fn getDown(self: @This(), key: T, now: Nanoseconds) ?Nanoseconds {
+            if (self.pressed_at.get(key)) |pressed_at| {
+                return now - pressed_at;
+            }
+            return null;
         }
 
         pub fn releaseAll(self: *@This()) void {
-            var iter = self.down.iterator();
+            var iter = self.pressed_at.iterator();
-            while (iter.next()) |key| {
+            while (iter.next()) |e| {
-                self.release(key);
+                self.release(e.key);
             }
         }
     };

src/platform/root.zig

@@ -27,6 +27,7 @@ pub const ImGUI = @import("./imgui.zig");
 pub const Gfx = @import("./graphics.zig");
 pub const Input = @import("./input.zig");
 pub const Audio = @import("./audio.zig");
+pub const SlotMapType = @import("./slot_map.zig").SlotMapType;
 
 const EmbeddedAssets = @import("embedded_assets");
 
@@ -105,10 +106,11 @@ fn PlatformType(App: type) type {
             _ = self.frame_arena.reset(.free_all); // TODO: make arena reset mode configurable
 
             const now = Io.Timestamp.now(self.io, .awake);
-            const t = self.started_at.durationTo(now);
-            const dt = self.last_frame_at.durationTo(now);
             self.last_frame_at = now;
 
+            self.input.now = @intCast(self.started_at.durationTo(now).nanoseconds);
+            self.input.delta_time = @intCast(self.last_frame_at.durationTo(now).nanoseconds);
+
             if (self.input.keyboard.pressed.contains(.F4)) {
                 self.show_imgui = !self.show_imgui;
             }
@@ -126,8 +128,6 @@ fn PlatformType(App: type) type {
 
                 if (@hasDecl(App, "frame")) {
                     const plt = Frame{
-                        .t = t.nanoseconds,
-                        .dt = dt.nanoseconds,
                         .gpa = self.gpa,
                         .arena = self.arena.allocator(),
                         .io = self.io,
@@ -139,8 +139,26 @@ fn PlatformType(App: type) type {
                     try self.app.frame(plt);
                 }
 
-                Gfx.flush(.{});
+                Gfx.flush();
+                if (ImGUI.beginWindow(.{
+                    .name = "Platform",
+                    .size = .init(300, 400)
+                })) {
+                    defer ImGUI.endWindow();
+
+                    _ = ImGUI.beginTabBar("platform tab bar");
+                    defer ImGUI.endTabBar();
+
+                    if (ImGUI.beginTabItem("Graphics")) {
+                        defer ImGUI.endTabItem();
                         Gfx.showDebug();
+                    }
+
+                    if (ImGUI.beginTabItem("Audio")) {
+                        defer ImGUI.endTabItem();
+                        Audio.showDebug();
+                    }
+                }
 
                 ImGUI.endFrame();
                 Gfx.endFrame();
@@ -177,7 +195,9 @@ fn PlatformType(App: type) type {
                         return false;
                     }
 
-                    input.keyboard.press(key);
+                    const now = self.started_at.durationTo(Io.Timestamp.now(self.io, .awake));
+
+                    input.keyboard.press(key, @intCast(now.nanoseconds));
                     self.last_key_pressed = key;
                 },
                 .key_released => |key| {
@@ -186,13 +206,16 @@ fn PlatformType(App: type) type {
                     }
 
                     input.keyboard.release(key);
+                    input.last_key_repeat_at.remove(key);
                 },
                 .mouse_pressed => |button| {
                     if (input.mouse_position == null or input.isMouseDown(button)) {
                         return false;
                     }
 
-                    input.mouse_buttons.press(button);
+                    const now = self.started_at.durationTo(Io.Timestamp.now(self.io, .awake));
+
+                    input.mouse_buttons.press(button, @intCast(now.nanoseconds));
                 },
                 .mouse_released => |button| {
                     if (input.mouse_position == null or !input.isMouseDown(button)) {
@@ -256,8 +279,8 @@ fn PlatformType(App: type) type {
                     }
 
                     assert(input.mouse_position == null);
-                    assert(input.keyboard.down.eql(.empty));
+                    assert(input.keyboard.pressed_at.count() == 0);
-                    assert(input.mouse_buttons.down.eql(.empty));
+                    assert(input.mouse_buttons.pressed_at.count() == 0);
                     input.focused = false;
                 }
             }
@@ -288,13 +311,13 @@ fn PlatformType(App: type) type {
                 }
 
                 if (e == .unfocused) {
-                    var key_iter = input.keyboard.down.iterator();
+                    var key_iter = input.keyboard.pressed_at.iterator();
-                    while (key_iter.next()) |key| {
+                    while (key_iter.next()) |key_pressed_at| {
-                        self.appendEvent(.{ .key_released = key });
+                        self.appendEvent(.{ .key_released = key_pressed_at.key });
                     }
-                    var mouse_buttons_iter = input.mouse_buttons.down.iterator();
+                    var mouse_buttons_iter = input.mouse_buttons.pressed_at.iterator();
-                    while (mouse_buttons_iter.next()) |button| {
+                    while (mouse_buttons_iter.next()) |key_pressed_at| {
-                        self.appendEvent(.{ .mouse_released = button });
+                        self.appendEvent(.{ .mouse_released = key_pressed_at.key });
                     }
                     self.appendEvent(.{ .mouse_leave = {} });
                 }
@@ -548,12 +571,9 @@ pub const Deinit = struct {
     io: Io,
 };
 
-pub const Nanoseconds = i96;
+pub const Nanoseconds = i64;
 
 pub const Frame = struct {
-    t: Nanoseconds,
-    dt: Nanoseconds,
-
     gpa: Allocator,
     arena: Allocator,
     frame: Allocator,
@@ -562,16 +582,16 @@ pub const Frame = struct {
     input: *Input,
     input_events: []Input.Event,
 
-    fn nanosecondsToSeconds(nanoseconds: i96) f32 {
+    fn nanosecondsToSeconds(nanoseconds: Nanoseconds) f32 {
         return @floatCast(@as(f64, @floatFromInt(nanoseconds)) / std.time.ns_per_s);
     }
 
     pub fn deltaTime(self: Frame) f32 {
-        return nanosecondsToSeconds(self.dt);
+        return nanosecondsToSeconds(self.input.delta_time);
     }
 
     pub fn time(self: Frame) f32 {
-        return nanosecondsToSeconds(self.t);
+        return nanosecondsToSeconds(self.input.now);
     }
 };
 
@@ -606,7 +626,7 @@ pub fn run(App: type, opts: RunOptions) void {
         .last_key_press_is_repeat = false,
         .last_key_pressed = null,
         .frame_arena = .init(gpa),
-        .show_imgui = builtin.mode == .Debug,
+        .show_imgui = false,
         .assets = .init(gpa, io, assets_dir),
         .last_mouse_position = null
     };

src/platform/slot_map.zig

@@ -87,7 +87,7 @@ pub fn SlotMapType(Index: type, Generation: type, Value: type) type {
         };
 
         pub fn clearRetainingCapacity(self: *Self) void {
-            self.* = .init(self.slots.items);
+            self.* = .initBuffer(self.slots.items);
         }
 
         fn insertHole(self: *Self, index: Index) void {
@@ -129,7 +129,11 @@ pub fn SlotMapType(Index: type, Generation: type, Value: type) type {
 
         pub fn unusedCapacity(self: *Self) usize {
             const capacity = @min(self.slots.capacity, std.math.maxInt(Index));
-            return capacity - self.slots.items.len + self.hole_count;
+            return capacity - self.count();
+        }
+
+        pub fn count(self: *Self) usize {
+            return self.slots.items.len - self.hole_count;
         }
 
         pub fn insertAssumeCapacity(self: *Self) Id {
@@ -215,11 +219,21 @@ pub fn SlotMapType(Index: type, Generation: type, Value: type) type {
             };
         }
 
-        pub fn init(slots: []Slot) Self {
+        pub fn initBuffer(slots: []Slot) Self {
             var self: Self = .empty;
             self.slots = .initBuffer(slots);
             return self;
         }
+
+        pub fn initCapacity(gpa: Allocator, capacity: usize) !Self {
+            var self: Self = .empty;
+            self.slots = try .initCapacity(gpa, capacity);
+            return self;
+        }
+
+        pub fn deinit(self: *Self, gpa: Allocator) void {
+            self.slots.deinit(gpa);
+        }
     };
 }