add audio subsystem

README.md

@@ -20,6 +20,11 @@ zig build -Dtarget=x86_64-windows
 ## TODO
 
 * Use [Skribidi](https://github.com/memononen/Skribidi) instead of fontstash for text rendering
+* Support for audio formats (Might not need all of them, haven't decided):
+  * QOA, maybe [qoa.h](https://github.com/phoboslab/qoa/blob/master/qoa.h)?
+  * Flac, maybe [dr_flac.h](https://github.com/mackron/dr_libs/blob/master/dr_flac.h)?
+  * Wav, maybe [dr_wav.h](https://github.com/mackron/dr_libs/blob/master/dr_wav.h)?
+  * Mp3, maybe [dr_mp3.h](https://github.com/mackron/dr_libs/blob/master/dr_mp3.h)?
 * Gamepad support.
   * WASM Support. Currently a build config isn't provided for this target.
   * Update build config for other platforms to reduce binary size. All of the video and audio drivers aren't needed, only gamepads

build.zig

@@ -1,5 +1,4 @@
 const std = @import("std");
-const cimgui = @import("cimgui");
 const sokol = @import("sokol");
 const builtin = @import("builtin");
 
@@ -24,7 +23,6 @@ pub fn build(b: *std.Build) !void {
         .link_libc = true
     });
 
-    const cimgui_conf = cimgui.getConfig(false);
     const dep_sokol = b.dependency("sokol", .{
         .target = target,
         .optimize = optimize,
@@ -38,6 +36,8 @@ pub fn build(b: *std.Build) !void {
             .target = target,
             .optimize = optimize,
         })) |dep_cimgui| {
+            const cimgui = b.lazyImport(@This(), "cimgui").?;
+            const cimgui_conf = cimgui.getConfig(false);
             mod_main.addImport("cimgui", dep_cimgui.module(cimgui_conf.module_name));
             dep_sokol.artifact("sokol_clib").addIncludePath(dep_cimgui.path(cimgui_conf.include_dir));
         }
@@ -57,8 +57,9 @@ pub fn build(b: *std.Build) !void {
     const dep_tiled = b.dependency("tiled", .{});
     mod_main.addImport("tiled", dep_tiled.module("tiled"));
 
-    const dep_stb_image = b.dependency("stb_image", .{});
-    mod_main.addImport("stb_image", dep_stb_image.module("stb_image"));
+    const dep_stb = b.dependency("stb", .{});
+    mod_main.addImport("stb_image", dep_stb.module("stb_image"));
+    mod_main.addImport("stb_vorbis", dep_stb.module("stb_vorbis"));
 
     const dep_fontstash_c = b.dependency("fontstash_c", .{});
     mod_main.addIncludePath(dep_fontstash_c.path("src"));
@@ -106,7 +107,6 @@ pub fn build(b: *std.Build) !void {
             .name = "sokol_template",
             .mod_main = mod_main,
             .dep_sokol = dep_sokol,
-            .cimgui_clib_name = cimgui_conf.clib_name,
         });
     } else {
         try buildNative(b, "sokol_template", mod_main, has_console);
@@ -169,7 +169,6 @@ const BuildWasmOptions = struct {
     name: []const u8,
     mod_main: *std.Build.Module,
     dep_sokol: *std.Build.Dependency,
-    cimgui_clib_name: []const u8,
 };
 
 fn patchWasmIncludeDirs(

build.zig.zon

@@ -28,8 +28,8 @@
         .tiled = .{
             .path = "./libs/tiled",
         },
-        .stb_image = .{
-            .path = "./libs/stb_image",
+        .stb = .{
+            .path = "./libs/stb",
         },
         // .sdl = .{
         //     .url = "git+https://github.com/allyourcodebase/SDL3.git#f85824b0db782b7d01c60aaad8bcb537892394e8",

libs/stb/build.zig

@@ -0,0 +1,38 @@
+const std = @import("std");
+
+pub fn build(b: *std.Build) void {
+    const target = b.standardTargetOptions(.{});
+    const optimize = b.standardOptimizeOption(.{});
+
+    const stb_dependency = b.dependency("stb", .{});
+
+    {
+        const mod_stb_image = b.addModule("stb_image", .{
+            .target = target,
+            .optimize = optimize,
+            .root_source_file = b.path("src/stb_image.zig"),
+            .link_libc = true,
+        });
+
+        mod_stb_image.addIncludePath(stb_dependency.path("."));
+        mod_stb_image.addCSourceFile(.{
+            .file = b.path("src/stb_image_impl.c"),
+            .flags = &.{}
+        });
+    }
+
+    {
+        const mod_stb_image = b.addModule("stb_vorbis", .{
+            .target = target,
+            .optimize = optimize,
+            .root_source_file = b.path("src/stb_vorbis.zig"),
+            .link_libc = true,
+        });
+
+        mod_stb_image.addIncludePath(stb_dependency.path("."));
+        mod_stb_image.addCSourceFile(.{
+            .file = b.path("src/stb_vorbis_impl.c"),
+            .flags = &.{}
+        });
+    }
+}

libs/stb/src/stb_vorbis.zig

@@ -0,0 +1,170 @@
+const std = @import("std");
+const assert = std.debug.assert;
+const log = std.log.scoped(.stb_vorbis);
+
+const c = @cImport({
+    @cDefine("STB_VORBIS_NO_INTEGER_CONVERSION", {});
+    @cDefine("STB_VORBIS_NO_STDIO", {});
+    @cDefine("STB_VORBIS_HEADER_ONLY", {});
+    @cInclude("stb_vorbis.c");
+});
+
+const STBVorbis = @This();
+
+pub const Error = error {
+    NeedMoreData,
+    InvalidApiMixing,
+    OutOfMemory,
+    FeatureNotSupported,
+    TooManyChannels,
+    FileOpenFailure,
+    SeekWithoutLength,
+    UnexpectedEof,
+    SeekInvalid,
+    InvalidSetup,
+    InvalidStream,
+    MissingCapturePattern,
+    InvalidStreamStructureVersion,
+    ContinuedPacketFlagInvalid,
+    IncorrectStreamSerialNumber,
+    InvalidFirstPage,
+    BadPacketType,
+    CantFindLastPage,
+    SeekFailed,
+    OggSkeletonNotSupported,
+
+    Unknown
+};
+
+fn errorFromInt(err: c_int) ?Error {
+    return switch (err) {
+        c.VORBIS__no_error => null,
+        c.VORBIS_need_more_data => Error.NeedMoreData,
+        c.VORBIS_invalid_api_mixing => Error.InvalidApiMixing,
+        c.VORBIS_outofmem => Error.OutOfMemory,
+        c.VORBIS_feature_not_supported => Error.FeatureNotSupported,
+        c.VORBIS_too_many_channels => Error.TooManyChannels,
+        c.VORBIS_file_open_failure => Error.FileOpenFailure,
+        c.VORBIS_seek_without_length => Error.SeekWithoutLength,
+        c.VORBIS_unexpected_eof => Error.UnexpectedEof,
+        c.VORBIS_seek_invalid => Error.SeekInvalid,
+        c.VORBIS_invalid_setup => Error.InvalidSetup,
+        c.VORBIS_invalid_stream => Error.InvalidStream,
+        c.VORBIS_missing_capture_pattern => Error.MissingCapturePattern,
+        c.VORBIS_invalid_stream_structure_version => Error.InvalidStreamStructureVersion,
+        c.VORBIS_continued_packet_flag_invalid => Error.ContinuedPacketFlagInvalid,
+        c.VORBIS_incorrect_stream_serial_number => Error.IncorrectStreamSerialNumber,
+        c.VORBIS_invalid_first_page => Error.InvalidFirstPage,
+        c.VORBIS_bad_packet_type => Error.BadPacketType,
+        c.VORBIS_cant_find_last_page => Error.CantFindLastPage,
+        c.VORBIS_seek_failed => Error.SeekFailed,
+        c.VORBIS_ogg_skeleton_not_supported => Error.OggSkeletonNotSupported,
+        else => Error.Unknown
+    };
+}
+
+handle: *c.stb_vorbis,
+
+pub fn init(data: []const u8, alloc_buffer: []u8) Error!STBVorbis {
+    const stb_vorbis_alloc: c.stb_vorbis_alloc = .{
+        .alloc_buffer = alloc_buffer.ptr,
+        .alloc_buffer_length_in_bytes = @intCast(alloc_buffer.len)
+    };
+    var error_code: c_int = -1;
+    const handle = c.stb_vorbis_open_memory(
+        data.ptr,
+        @intCast(data.len),
+        &error_code,
+        &stb_vorbis_alloc
+    );
+    if (handle == null) {
+        return errorFromInt(error_code) orelse Error.Unknown;
+    }
+
+    return STBVorbis{
+        .handle = handle.?
+    };
+}
+
+pub fn getMinimumAllocBufferSize(self: STBVorbis) u32 {
+    const info = self.getInfo();
+    return info.setup_memory_required + @max(info.setup_temp_memory_required, info.temp_memory_required);
+}
+
+fn getLastError(self: STBVorbis) ?Error {
+    const error_code = c.stb_vorbis_get_error(self.handle);
+    return errorFromInt(error_code);
+}
+
+pub fn seek(self: STBVorbis, sample_number: u32) !void {
+    const success = c.stb_vorbis_seek(self.handle, sample_number);
+    if (success != 1) {
+        return self.getLastError() orelse Error.Unknown;
+    }
+}
+
+pub fn getStreamLengthInSamples(self: STBVorbis) u32 {
+    return c.stb_vorbis_stream_length_in_samples(self.handle);
+}
+
+pub fn getStreamLengthInSeconds(self: STBVorbis) f32 {
+    return c.stb_vorbis_stream_length_in_seconds(self.handle);
+}
+
+pub fn getSamples(
+    self: STBVorbis,
+    channels: []const [*]f32,
+    max_samples_per_channel: u32
+) u32 {
+    const samples_per_channel = c.stb_vorbis_get_samples_float(
+        self.handle,
+        @intCast(channels.len),
+        @constCast(@ptrCast(channels.ptr)),
+        @intCast(max_samples_per_channel)
+    );
+    return @intCast(samples_per_channel);
+}
+
+const Frame = struct {
+    channels: []const [*c]const f32,
+    samples_per_channel: u32
+};
+
+pub fn getFrame(self: STBVorbis) Frame {
+    var output: [*c][*c]f32 = null;
+    var channels: c_int = undefined;
+    const samples_per_channel = c.stb_vorbis_get_frame_float(
+        self.handle,
+        &channels,
+        &output
+    );
+    return Frame{
+        .channels = output[0..@intCast(channels)],
+        .samples_per_channel = @intCast(samples_per_channel)
+    };
+}
+
+pub const Info = struct {
+    sample_rate: u32,
+    channels: u32,
+
+    setup_memory_required: u32,
+    setup_temp_memory_required: u32,
+    temp_memory_required: u32,
+
+    max_frame_size: u32
+};
+
+pub fn getInfo(self: STBVorbis) Info {
+    const info = c.stb_vorbis_get_info(self.handle);
+    return Info{
+        .sample_rate = info.sample_rate,
+        .channels = @intCast(info.channels),
+
+        .setup_memory_required = info.setup_memory_required,
+        .setup_temp_memory_required = info.setup_temp_memory_required,
+        .temp_memory_required = info.temp_memory_required,
+
+        .max_frame_size = @intCast(info.max_frame_size),
+    };
+}

libs/stb/src/stb_vorbis_impl.c

@@ -0,0 +1,3 @@
+#define STB_VORBIS_NO_INTEGER_CONVERSION
+#define STB_VORBIS_NO_STDIO
+#include "stb_vorbis.c"

libs/stb_image/build.zig

@@ -1,31 +0,0 @@
-const std = @import("std");
-
-pub fn build(b: *std.Build) void {
-    const target = b.standardTargetOptions(.{});
-    const optimize = b.standardOptimizeOption(.{});
-
-    const mod = b.addModule("stb_image", .{
-        .target = target,
-        .optimize = optimize,
-        .root_source_file = b.path("src/root.zig"),
-        .link_libc = true,
-    });
-
-    const stb_dependency = b.dependency("stb", .{});
-    mod.addIncludePath(stb_dependency.path("."));
-    mod.addCSourceFile(.{
-        .file = b.path("src/stb_image_impl.c"),
-        .flags = &.{}
-    });
-
-    {
-        const tests = b.addTest(.{
-            .root_module = mod
-        });
-
-        const run_tests = b.addRunArtifact(tests);
-
-        const test_step = b.step("test", "Run tests");
-        test_step.dependOn(&run_tests.step);
-    }
-}

src/assets.zig

@@ -1,5 +1,9 @@
 const std = @import("std");
-const Gfx = @import("./engine/graphics.zig");
+
+const Math =  @import("./engine/math.zig");
+const Engine = @import("./engine/root.zig");
+const Gfx = Engine.Graphics;
+const Audio = Engine.Audio;
 
 const Assets = @This();
 
@@ -13,18 +17,28 @@ const FontName = enum {
 
 font_id: FontName.EnumArray,
 
-pub fn init() !Assets {
+wood01: Audio.Data.Id,
+
+pub fn init(gpa: std.mem.Allocator) !Assets {
+    _ = gpa; // autofix
     const font_id_array: FontName.EnumArray = .init(.{
         .regular = try Gfx.addFont("regular", @embedFile("assets/roboto-font/Roboto-Regular.ttf")),
         .bold = try Gfx.addFont("bold", @embedFile("assets/roboto-font/Roboto-Bold.ttf")),
         .italic = try Gfx.addFont("italic", @embedFile("assets/roboto-font/Roboto-Italic.ttf")),
     });
 
+    const wood01 = try Audio.load(.{
+        .format = .vorbis,
+        .data = @embedFile("assets/wood01.ogg"),
+    });
+
     return Assets{
-        .font_id = font_id_array
+        .font_id = font_id_array,
+        .wood01 = wood01
     };
 }
 
-pub fn deinit(self: *Assets) void {
+pub fn deinit(self: *Assets, gpa: std.mem.Allocator) void {
     _ = self; // autofix
+    _ = gpa; // autofix
 }

src/engine/audio/data.zig

@@ -0,0 +1,64 @@
+const std = @import("std");
+const assert = std.debug.assert;
+
+const STBVorbis = @import("stb_vorbis");
+
+pub const Data = union(enum) {
+    raw: struct {
+        channels: [][*]f32,
+        sample_count: u32,
+        sample_rate: u32
+    },
+    vorbis: struct {
+        alloc_buffer: []u8,
+        stb_vorbis: STBVorbis,
+    },
+
+    pub fn streamChannel(
+        self: Data,
+        buffer: []f32,
+        cursor: u32,
+        channel_index: u32,
+        sample_rate: u32
+    ) []f32 {
+        // var result: std.ArrayList(f32) = .initBuffer(buffer);
+        switch (self) {
+            .raw => |opts| {
+                if (opts.sample_rate == sample_rate) {
+                    assert(channel_index < opts.channels.len); // TODO:
+                    const channel = opts.channels[channel_index];
+
+                    var memcpy_len: usize = 0;
+                    if (cursor + buffer.len <= opts.sample_count) {
+                        memcpy_len = buffer.len;
+                    } else if (cursor < opts.sample_count) {
+                        memcpy_len = opts.sample_count - cursor;
+                    }
+
+                    @memcpy(buffer[0..memcpy_len], channel[cursor..][0..memcpy_len]);
+                    return buffer[0..memcpy_len];
+                } else {
+                    // const in_sample_rate: f32 = @floatFromInt(opts.sample_rate);
+                    // const out_sample_rate: f32 = @floatFromInt(sample_rate);
+                    // const increment = in_sample_rate / out_sample_rate;
+                    // _ = increment; // autofix
+                    unreachable;
+                }
+            },
+            .vorbis => |opts| {
+                _ = opts; // autofix
+                unreachable;
+            },
+        }
+        // return result.items;
+    }
+
+    pub fn getSampleCount(self: Data) u32 {
+        return switch (self) {
+            .raw => |opts| opts.sample_count,
+            .vorbis => |opts| opts.stb_vorbis.getStreamLengthInSamples()
+        };
+    }
+
+    pub const Id = enum (u16) { _ };
+};

src/engine/audio/mixer.zig

@@ -0,0 +1,131 @@
+const std = @import("std");
+const log = std.log.scoped(.audio);
+const assert = std.debug.assert;
+const Allocator = std.mem.Allocator;
+
+const sokol = @import("sokol");
+const saudio = sokol.audio;
+
+const AudioData = @import("./data.zig").Data;
+pub const Store = @import("./store.zig");
+
+const Mixer = @This();
+
+pub const Instance = struct {
+    data_id: AudioData.Id,
+    cursor: u32 = 0,
+};
+
+pub const Command = union(enum) {
+    play: struct {
+        data_id: AudioData.Id,
+    },
+
+    pub const RingBuffer = struct {
+        // TODO: This ring buffer will work in a single producer single consumer configuration
+        // For my game this will be good enough
+
+        items: []Command,
+        head: std.atomic.Value(usize) = .init(0),
+        tail: std.atomic.Value(usize) = .init(0),
+
+        pub fn push(self: *RingBuffer, command: Command) error{OutOfMemory}!void {
+            const head = self.head.load(.monotonic);
+            const tail = self.tail.load(.monotonic);
+            const next_head = @mod(head + 1, self.items.len);
+
+            // A single slot in the .items array will always not be used.
+            if (next_head == tail) {
+                return error.OutOfMemory;
+            }
+
+            self.items[head] = command;
+            self.head.store(next_head, .monotonic);
+        }
+
+        pub fn pop(self: *RingBuffer) ?Command {
+            const head = self.head.load(.monotonic);
+            const tail = self.tail.load(.monotonic);
+
+            if (head == tail) {
+                return null;
+            }
+
+            const result = self.items[tail];
+            self.tail.store(@mod(tail + 1, self.items.len), .monotonic);
+            return result;
+        }
+    };
+};
+
+// TODO: Tracks
+
+instances: std.ArrayList(Instance),
+commands: Command.RingBuffer,
+
+pub fn init(
+    gpa: Allocator,
+    max_instances: u32,
+    max_commands: u32
+) !Mixer {
+    var instances = try std.ArrayList(Instance).initCapacity(gpa, max_instances);
+    errdefer instances.deinit(gpa);
+
+    const commands = try gpa.alloc(Command, max_commands);
+    errdefer gpa.free(commands);
+
+    return Mixer{
+        .instances = instances,
+        .commands = .{
+            .items = commands
+        }
+    };
+}
+
+pub fn deinit(self: *Mixer, gpa: Allocator) void {
+    self.instances.deinit(gpa);
+    gpa.free(self.commands.items);
+}
+
+pub fn queue(self: *Mixer, command: Command) void {
+    self.commands.push(command) catch log.warn("Maximum number of audio commands reached!", .{});
+}
+
+pub fn stream(self: *Mixer, store: Store, buffer: []f32, num_frames: u32, num_channels: u32) !void {
+    while (self.commands.pop()) |command| {
+        switch (command) {
+            .play => |opts| {
+                self.instances.appendBounded(.{
+                    .data_id = opts.data_id
+                }) catch log.warn("Maximum number of audio instances reached!", .{});
+            }
+        }
+    }
+
+    assert(num_channels == 1); // TODO:
+    const sample_rate: u32 = @intCast(saudio.sampleRate());
+
+    @memset(buffer, 0);
+
+    // var written: u32 = 0;
+    for (self.instances.items) |*instance| {
+        const audio_data = store.get(instance.data_id);
+        const samples = audio_data.streamChannel(buffer[0..num_frames], instance.cursor, 0, sample_rate);
+        instance.cursor += @intCast(samples.len);
+    }
+
+    {
+        var i: usize = 0;
+        while (i < self.instances.items.len) {
+            const instance = self.instances.items[i];
+            const audio_data = store.get(instance.data_id);
+            const is_complete = instance.cursor == audio_data.getSampleCount();
+
+            if (is_complete) {
+                _ = self.instances.swapRemove(i);
+            } else {
+                i += 1;
+            }
+        }
+    }
+}

src/engine/audio/root.zig

@@ -0,0 +1,100 @@
+const std = @import("std");
+const log = std.log.scoped(.audio);
+const assert = std.debug.assert;
+
+const tracy = @import("tracy");
+
+const Math = @import("../math.zig");
+const STBVorbis = @import("stb_vorbis");
+
+pub const Data = @import("./data.zig").Data;
+pub const Store = @import("./store.zig");
+pub const Mixer = @import("./mixer.zig");
+
+const sokol = @import("sokol");
+const saudio = sokol.audio;
+
+var stopped: bool = true;
+var gpa: std.mem.Allocator = undefined;
+var store: Store = undefined;
+pub var mixer: Mixer = undefined;
+
+const Options = struct {
+    allocator: std.mem.Allocator,
+    logger: saudio.Logger = .{},
+    channels: u32 = 1,
+    max_vorbis_alloc_buffer_size: u32 = 1 * Math.bytes_per_mib,
+    buffer_frames: u32 = 2048,
+    max_instances: u32 = 64
+};
+
+pub fn init(opts: Options) !void {
+    gpa = opts.allocator;
+
+    store = try Store.init(.{
+        .allocator = opts.allocator,
+        .max_vorbis_alloc_buffer_size = opts.max_vorbis_alloc_buffer_size,
+    });
+
+    mixer = try Mixer.init(gpa, opts.max_instances, opts.max_instances);
+
+    saudio.setup(.{
+        .logger = opts.logger,
+        .stream_cb = sokolStreamCallback,
+        .num_channels = @intCast(opts.channels),
+        .buffer_frames = @intCast(opts.buffer_frames)
+    });
+    stopped = false;
+
+    const sample_rate: f32 = @floatFromInt(saudio.sampleRate());
+    const audio_latency: f32 = @as(f32, @floatFromInt(opts.buffer_frames)) / sample_rate;
+    log.debug("Audio latency = {D}", .{@as(u64, @intFromFloat(audio_latency * std.time.ns_per_s))});
+}
+
+pub fn deinit() void {
+    stopped = true;
+    saudio.shutdown();
+    mixer.deinit(gpa);
+    store.deinit();
+}
+
+pub fn load(opts: Store.LoadOptions) !Data.Id {
+    return try store.load(opts);
+}
+
+pub const PlayOptions = struct {
+    id: Data.Id,
+    delay: f32 = 0
+};
+
+pub fn play(opts: PlayOptions) void {
+    mixer.queue(.{
+        .play = .{
+            .data_id = opts.id
+        }
+    });
+}
+
+fn sokolStreamCallback(buffer: [*c]f32, num_frames: i32, num_channels: i32) callconv(.c) void {
+    if (stopped) {
+        return;
+    }
+
+    const zone = tracy.initZone(@src(), .{ });
+    defer zone.deinit();
+
+    const num_frames_u32: u32 = @intCast(num_frames);
+    const num_channels_u32: u32 = @intCast(num_channels);
+
+    mixer.stream(
+        store,
+        buffer[0..(num_frames_u32 * num_channels_u32)],
+        num_frames_u32,
+        num_channels_u32
+    ) catch |e| {
+        log.err("mixer.stream() failed: {}", .{e});
+        if (@errorReturnTrace()) |trace| {
+            std.debug.dumpStackTrace(trace.*);
+        }
+    };
+}

src/engine/audio/store.zig

@@ -0,0 +1,106 @@
+const std = @import("std");
+const assert = std.debug.assert;
+
+const Math = @import("../math.zig");
+const STBVorbis = @import("stb_vorbis");
+
+const AudioData = @import("./data.zig").Data;
+
+const Store = @This();
+
+arena: std.heap.ArenaAllocator,
+list: std.ArrayList(AudioData),
+temp_vorbis_alloc_buffer: []u8,
+
+const Options = struct {
+    allocator: std.mem.Allocator,
+    max_vorbis_alloc_buffer_size: u32,
+};
+
+pub fn init(opts: Options) !Store {
+    const gpa = opts.allocator;
+
+    const temp_vorbis_alloc_buffer = try gpa.alloc(u8, opts.max_vorbis_alloc_buffer_size);
+    errdefer gpa.free(temp_vorbis_alloc_buffer);
+
+    return Store{
+        .arena = std.heap.ArenaAllocator.init(gpa),
+        .list = .empty,
+        .temp_vorbis_alloc_buffer = temp_vorbis_alloc_buffer
+    };
+}
+
+pub fn deinit(self: *Store) void {
+    const gpa = self.arena.child_allocator;
+    gpa.free(self.temp_vorbis_alloc_buffer);
+    self.list.deinit(gpa);
+    self.arena.deinit();
+}
+
+pub const LoadOptions = struct {
+    const PlaybackStyle = enum {
+        stream,
+        decode_once,
+
+        // If the decoded size is less than `stream_threshold`, then .decode_once will by default be used.
+        const stream_threshold = 10 * Math.bytes_per_mib;
+    };
+
+    const Format = enum {
+        vorbis
+    };
+
+    format: Format,
+    data: []const u8,
+    playback_style: ?PlaybackStyle = null,
+};
+
+pub fn load(self: *Store, opts: LoadOptions) !AudioData.Id {
+    const gpa = self.arena.child_allocator;
+
+    const id = self.list.items.len;
+    try self.list.ensureUnusedCapacity(gpa, 1);
+
+    const PlaybackStyle = LoadOptions.PlaybackStyle;
+    const temp_stb_vorbis = try STBVorbis.init(opts.data, self.temp_vorbis_alloc_buffer);
+    const info = temp_stb_vorbis.getInfo();
+    const duration_in_samples = temp_stb_vorbis.getStreamLengthInSamples();
+    const decoded_size = info.channels * duration_in_samples * @sizeOf(f32);
+    const stream_threshold = PlaybackStyle.stream_threshold;
+    const default_playback_style: PlaybackStyle = if (decoded_size < stream_threshold) .decode_once else .stream;
+
+    const arena_allocator = self.arena.allocator();
+    const playback_style = opts.playback_style orelse default_playback_style;
+    if (playback_style == .decode_once) {
+        const channels = try arena_allocator.alloc([*]f32, info.channels);
+        for (channels) |*channel| {
+            channel.* = (try arena_allocator.alloc(f32, duration_in_samples)).ptr;
+        }
+        const samples_decoded = temp_stb_vorbis.getSamples(channels, duration_in_samples);
+        assert(samples_decoded == duration_in_samples);
+
+        self.list.appendAssumeCapacity(AudioData{
+            .raw = .{
+                .channels = channels,
+                .sample_count = duration_in_samples,
+                .sample_rate = info.sample_rate
+            }
+        });
+    } else {
+        const alloc_buffer = try arena_allocator.alloc(u8, temp_stb_vorbis.getMinimumAllocBufferSize());
+        const stb_vorbis = STBVorbis.init(opts.data, alloc_buffer) catch unreachable;
+
+        self.list.appendAssumeCapacity(AudioData{
+            .vorbis = .{
+                .alloc_buffer = alloc_buffer,
+                .stb_vorbis = stb_vorbis
+            }
+        });
+    }
+
+    return @enumFromInt(id);
+}
+
+pub fn get(self: Store, id: AudioData.Id) AudioData {
+    return self.list.items[@intFromEnum(id)];
+}

src/engine/root.zig

@@ -13,6 +13,7 @@ pub const Input = @import("./input.zig");
 const ScreenScalar = @import("./screen_scaler.zig");
 pub const imgui = @import("./imgui.zig");
 pub const Graphics = @import("./graphics.zig");
+pub const Audio = @import("./audio/root.zig");
 const tracy = @import("tracy");
 const builtin = @import("builtin");
 const STBImage = @import("stb_image");
@@ -148,7 +149,12 @@ fn sokolInit(self: *Engine) !void {
         }
     });
 
-    self.assets = try Assets.init();
+    try Audio.init(.{
+        .allocator = self.allocator,
+        .logger = .{ .func = sokolLogCallback },
+    });
+
+    self.assets = try Assets.init(self.allocator);
     self.game = try Game.init(self.allocator, &self.assets);
 }
 
@@ -156,8 +162,9 @@ fn sokolCleanup(self: *Engine) void {
     const zone = tracy.initZone(@src(), .{ });
     defer zone.deinit();
 
+    Audio.deinit();
     self.game.deinit();
-    self.assets.deinit();
+    self.assets.deinit(self.allocator);
     Gfx.deinit();
 }
 

src/game.zig

@@ -9,6 +9,7 @@ const imgui = Engine.imgui;
 const Vec2 = Engine.Vec2;
 const rgb = Engine.Math.rgb;
 const Gfx = Engine.Graphics;
+const Audio = Engine.Audio;
 
 const Game = @This();
 
@@ -48,6 +49,12 @@ pub fn tick(self: *Game, frame: Engine.Frame) !void {
     }
     dir = dir.normalized();
 
+    if (dir.x != 0 or dir.y != 0) {
+        Audio.play(.{
+            .id = self.assets.wood01
+        });
+    }
+
     self.player = self.player.add(dir.multiplyScalar(50 * frame.dt));
 
     const regular_font = self.assets.font_id.get(.regular);
@@ -77,4 +84,8 @@ pub fn debug(self: *Game) !void {
     defer imgui.endWindow();
 
     imgui.text("Hello World!\n");
+    imgui.textFmt("Audio: {}/{}\n", .{
+        Audio.mixer.instances.items.len,
+        Audio.mixer.instances.capacity
+    });
 }