diff --git a/patterns/gmd.hexpat b/patterns/gmd.hexpat
new file mode 100644
index 00000000..bacf45fc
--- /dev/null
+++ b/patterns/gmd.hexpat
@@ -0,0 +1,963 @@
+#pragma author DmitriLeon2000
+#pragma description Game Maker 4.0-6.1A data (GMD/GMR/GM6)
+#pragma endian little
+#pragma magic [ 91 D5 12 00 ] @ 0x00;
+
+import std.mem;
+import std.io;
+
+enum ColorDepth : u32 {
+    HighColor = 0,
+    TrueColor = 1
+};
+
+enum ColorDepthV2 : u32 {
+    Native = 0,
+    HighColor = 1,
+    TrueColor = 2
+};
+
+enum Resolution : u32 {
+    SixFortyByFourEighty = 0,
+    EightHundredBySixHundred = 1,
+    TenTwentyFourBySevenSixtyEight = 2,
+    TwelveEightyByTenTwentyFour = 3,
+    Native = 4,
+    ThreeTwentyByTwoForty = 5,
+    SixteenHundredByTwelveHundred = 6
+};
+
+enum ResolutionV2 : u32 {
+    Native = 0,
+    ThreeTwentyByTwoForty = 1,
+    SixFortyByFourEighty = 2,
+    EightHundredBySixHundred = 3,
+    TenTwentyFourBySevenSixtyEight = 4,
+    TwelveEightyByTenTwentyFour = 5,
+    ThreeTwentyByTwoForty = 6,
+    SixteenHundredByTwelveHundred = 7
+};
+
+enum RefreshRate : u32 {
+    SixtyHertz = 0,
+    SeventyHertz = 1,
+    EightyFiveHertz = 2,
+    HundredHertz = 3,
+    Native = 4
+};
+
+enum RefreshRateV2 : u32 {
+    Native = 0,
+    SixtyHertz = 1,
+    SeventyHertz = 2,
+    EightyFiveHertz = 3,
+    HundredHertz = 4,
+    HundredTwentyHertz = 5
+};
+
+enum ShowLoadingBar : u8 {
+    False = 0,
+    True = 1,
+    Custom = 2
+};
+
+struct RGBA8 {
+    u8 red, green, blue; padding[1];
+} [[color(std::format("{:02X}{:02X}{:02X}", red, green, blue)),
+    hex::inline_visualize("color", red, green, blue, 255)]];
+
+struct BGR8 {
+    u8 blue, green, red;
+} [[color(std::format("{:02X}{:02X}{:02X}", red, green, blue)),
+    hex::inline_visualize("color", red, green, blue, 255)]];
+
+struct RLEImageDataRow {
+    u32 segment_count;
+    u8 lengths[segment_count];
+    BGR8 colors[segment_count];
+};
+
+struct RLEImage {
+    u32 width, height;
+    RLEImageDataRow rle[height];
+};
+
+struct RLEImageColorTabledDataRow {
+    u32 segment_count;
+    u8 lengths[segment_count];
+    u8 color_ids[segment_count];
+};
+
+struct RLEImageColorTabled {
+    u32 color_count;
+    BGR8 colors[color_count];
+    u32 width, height;
+    RLEImageColorTabledDataRow rle[height];
+};
+
+struct PascalString {
+    u32 length;
+    char data[length];
+} [[format_read("PascalStringDisplay")]];
+
+fn PascalStringDisplay(PascalString myString) {
+    return myString.data;
+};
+
+struct BitmapData {
+    s32 bmType;
+    match (bmType) {
+        (0): {
+            u8 bfType[2];
+            u32 bfSize;
+            u8 bfData[bfSize-6] [[sealed, static]];}
+        (1): RLEImage bfData [[sealed, static]];
+        (2): RLEImageColorTabled bfData [[sealed, static]];
+        (10): {u32 bmSize; u8 bmData[bmSize] [[sealed, static]];}
+    }
+};
+
+enum Transition : u32 {
+    None = 0,
+    CreateFromLeft = 1,
+    CreateFromRight = 2,
+    CreateFromTop = 3,
+    CreateFromBottom = 4,
+    CreateFromCenter = 5,
+    ShiftFromLeft = 6,
+    ShiftFromRight = 7,
+    ShiftFromTop = 8,
+    ShiftFromBottom = 9,
+    PushFromLeft = 10,
+    PushFromRight = 11,
+    PushFromTop = 12,
+    PushFromBottom = 13
+};
+
+enum SoundKind : u32 {
+    WAVE = 0,
+    MIDI = 1,
+    MP3 = 2,
+    None = 0xFFFFFFFF
+};
+
+enum SoundKindV2 : u32 {
+    WAVE = 0,
+    MIDI = 1,
+    ThreeDimensional = 2,
+    MP3 = 3
+};
+
+struct BoundingBox {
+    u32 left, right, bottom, top;
+};
+
+struct RectRegion {
+    s32 left, top, width, height;
+};
+
+enum BoundingBoxType : u32 {
+    Automatic = 0,
+    FullImage = 1,
+    Manual = 2
+};
+
+enum ActionGroupID : s32 { //Introduced in 5.0 beta
+    None = 0,
+    Move = 1
+};   
+
+enum ActionID : s32 {
+    None = 0,
+    Move = 1,
+    ReverseX = 2,
+    ReverseY = 3,
+    MoveTo = 4,
+    MoveRandom = 5,
+    Bounce = 6,
+    SetSpeedHorizontal = 7,
+    SetSpeedVertical = 8,
+    SetGravity = 9,
+    SetFriction = 10,
+    SetMotion = 11,
+    SetAlarm = 12,
+    InstanceCreate = 13,
+    InstanceDestroy = 14,
+    InstanceChange = 15,
+    PositionDestroy = 16,
+    SoundPlay = 17,
+    ShowMessage = 18,
+    SetScore = 19,
+    DisplayHighscore = 20,
+    RoomAnother = 21,
+    EndGame = 22,
+    Sleep = 23,
+    ExitEvent = 24,
+    CheckPlaceFree = 25,
+    CheckInstanceNumber = 26,
+    CheckPlaceObject = 27,
+    CheckPlaceCollision = 28,
+    CheckQuestion = 29,
+    CheckExpression = 30,
+    Else = 31,
+    BlockStart = 32,
+    BlockEnd = 33,
+    ExecuteCode = 34,
+    SetVariable = 35,
+    DrawSprite = 36,
+    DrawText = 37,
+    SetFont = 38,
+    SoundStop = 39,
+    SnapToGrid = 40,
+    RoomPrevious = 41,
+    RoomNext = 42,
+    ExecuteScript = 43,
+    DrawRectangle = 44,
+    DrawEllipse = 45,
+    DrawLine = 46,
+    SetBrushColor = 47,
+    SetPenColor = 48,
+    MoveStart = 49,
+    MovePoint = 50,
+    SetSprite = 51,
+    SetLives = 52,
+    RoomCurrent = 53,
+    DrawBackground = 54,
+    CheckRandom = 55,
+    CheckSound = 56,
+    SaveGame = 57,
+    LoadGame = 58,
+    Repeat = 59,
+    RestartGame = 60,
+    ShowInfo = 61,
+    SwitchFullscreen = 62,
+    CheckMouseButton = 63,
+    CheckGridAlign = 64,
+    Inherited = 65,
+    Comment = 66,
+    SetPath = 67, // Paths introduced in version 4.2
+    TestVariable = 68, // Introduced in 4.3
+    DrawVariable = 69 // Introduced in 4.3
+};
+
+enum ActionID2 : s32 {
+    None = 0,
+    Move = 101,
+    SetMotion = 102,
+    SetSpeedHorizontal = 103,
+    SetSpeedVertical = 104,
+    MovePoint = 105,
+    SetGravity = 107,
+    SetFriction = 108,
+    JumpPosition = 109,
+    JumpStartPosition = 110,
+    JumpRandom = 111,
+    Wrap = 112,
+    ReverseHorizontal = 113,
+    ReverseVertical = 114,
+    Bounce = 115,
+    MoveContact = 116,
+    SnapToGrid = 117,
+    SetPathOld = 118,
+    SetPath = 119,
+    StepLinear = 120,
+    StepPotential = 121,
+    PathPosition = 122,
+    PathSpeed = 123,
+    PathEnd = 124,
+    InstanceCreate = 201,
+    InstanceChange = 202,
+    InstanceDestroy = 203,
+    PositionDestroy = 204,
+    SetSpriteOld = 205,
+    InstanceCreateMoving = 206,
+    InstanceCreateRandom = 207,
+    SoundPlay = 211,
+    SoundStop = 212,
+    CheckSound = 213,
+    RoomPrevious = 221,
+    RoomNext = 222,
+    RoomCurrent = 223,
+    RoomAnother = 224,
+    CheckRoomPrevious = 225,
+    CheckRoomNext = 226,
+    SetAlarm = 301,
+    Sleep = 302,
+    SetTimeline = 303,
+    SetTimelinePosition = 304,
+    ShowMessage = 321,
+    ShowInfo = 322,
+    ShowSplashVideo = 323,
+    RestartGame = 331,
+    EndGame = 332,
+    SaveGame = 333,
+    LoadGame = 334,
+    CheckPlaceFree = 401,
+    CheckPlaceCollision = 402,
+    CheckPlaceObject = 403,
+    CheckInstanceNumber = 404,
+    CheckRandom = 405,
+    CheckQuestion = 407,
+    CheckExpression = 408,
+    CheckMouseButton = 409,
+    CheckGridAlign = 410,
+    Else = 421,
+    BlockStart = 422,
+    Repeat = 423,
+    BlockEnd = 424,
+    ExitEvent = 425,
+    DrawSprite = 501,
+    DrawBackground = 502,
+    DrawRectangle = 511,
+    DrawEllipse = 512,
+    DrawLine = 513,
+    DrawText = 514,
+    DrawArrow = 515,
+    DrawGradientHorizontal = 516,
+    DrawGradientVertical = 517,
+    DrawGradientEllipse = 517,
+    DrawTextTransformed = 519,
+    SetBrushColor = 521,
+    SetPenColor = 522,
+    SetFontOld = 523,
+    SetColors = 524,
+    SetFontOld2 = 525,
+    SetFont = 526,
+    SwitchFullscreen = 531,
+    CreateEffect = 532,
+    SetSprite = 541,
+    TransformSprite = 542,
+    ColorBlendSprite = 543,
+    ExecuteScript = 601,
+    ExecuteCode = 603,
+    Inherited = 604,
+    Comment = 605,
+    SetVariable = 611,
+    CheckVariable = 612,
+    DrawVariable = 613,
+    SetScore = 701,
+    CheckScore = 702,
+    DrawScore = 703,
+    DisplayHighscoreOld = 706,
+    ClearHighscore = 707,
+    DisplayHighscore = 709,
+    SetLives = 711,
+    CheckLives = 712,
+    DrawLives = 713,
+    DrawLivesSprite = 714,
+    SetHealth = 721,
+    CheckHealth = 722,
+    DrawHealth = 723,
+    SetCaption = 731,
+    SetMouse = 801,
+    ScreenSnapshot = 802,
+    ReplaceSprite = 803,
+    ReplaceSound = 804,
+    ReplaceBackground = 805,
+    GradientBackground = 806,
+    OpenWebpage = 807,
+    CDPlay = 808,
+    CDStop = 809,
+    CDPause = 810,
+    CDResume = 811,
+    CheckCD = 812,
+    CheckCDPlaying = 813,
+    ParticleSystemCreate = 820,
+    ParticleSystemDestroy = 821,
+    ParticlesClear = 822,
+    ParticleTypeCreate = 823,
+    ParticleTypeColor = 824,
+    ParticleTypeCreateOld = 825,
+    ParticleTypeLife = 826,
+    ParticleTypeSpeed = 827,
+    ParticleTypeGravity = 828,
+    ParticleTypeSecondary = 829,
+    ParticleEmitterCreate = 831,
+    ParticleEmitterDestroy = 832,
+    ParticleEmitterBurst = 833,
+    ParticleEmitterStream = 834
+};
+
+enum ActionParamWidgetType : u32 {
+    Input = 0,
+    InputString = 1,
+    InputMemo = 2,
+    DropDownBoolean = 3,
+    DropDownNumber = 4,
+    DropDownSprite = 5,
+    DropDownSound = 6,
+    DropDownBackground = 7,
+    DropDownPath = 8,
+    DropDownScript = 9,
+    DropDownObject = 10,
+    DropDownRoom = 11,
+    DropDownColor = 13,
+    DropDownTimeline = 14,
+    DropDownFontCustom = 15
+};
+
+bitfield ActionFlags {
+    has_name:   1;
+    expression: 1;
+};
+
+struct GameObjectAction {
+    s32 version_verify;
+    if (version_verify >= 440) {
+        u32 reserved;
+        ActionID2 action_id;
+    }
+    else ActionID action_id;
+    if (version_verify >= 440) {
+        u32 code_id; /* 1 - start, 2 - end, 3 - else, 4 - exit, 5 - repeat, 6 - var, 7 - code chunks */
+        bool has_relative; padding[3];
+        bool conditional; padding[3];
+        bool can_target_objects; padding[3];
+        ActionFlags flags; padding[3];
+        PascalString action_name;
+        PascalString action_value;
+        u32 widget_count_active;
+        u32 widget_count_total;
+        ActionParamWidgetType widget_types[widget_count_active];
+        padding[(widget_count_total-widget_count_active)*4];
+    }
+    s32 apply_to [[format_read("GetApplyToObjectNameByIndex")]];
+    bool relative; padding[3];
+    u32 param_count;
+    PascalString params[param_count];
+    if (version_verify >= 440) {bool inverted_condition; padding[3];}
+};
+
+struct GameObjectSubEvent {
+    s32 subevent_number;
+    s32 version_verify;
+    u32 action_count;
+    GameObjectAction actions[action_count];
+};
+
+struct GameObjectEvent {
+    GameObjectSubEvent subevents[while(std::mem::read_unsigned($, 4) != 0xFFFFFFFF)];
+    padding[4];
+};
+
+struct Sprite {
+    bool data_present [[hidden]]; padding[3];
+    if (data_present) {
+        PascalString name;
+        s32 version_verify;
+        u32 width, height;
+        BoundingBox bounding_box;
+        bool transparent; padding[3];
+        if (version_verify >= 540) {
+            bool smooth_edges; padding[3];
+            bool preload; padding[3];
+        }
+        BoundingBoxType bounding_box_mode;
+        bool precise_collider; padding[3];
+        if (version_verify <= 530) {
+            bool video_memory; padding[3];
+            bool load_only_on_use; padding[3];
+        }
+        s32 origin_x, origin_y;
+        u32 image_count;
+        BitmapData images[image_count];
+    }
+} [[name(data_present ? name.data : "<dead data>")]];
+
+struct Background {
+    bool data_present [[hidden]]; padding[3];
+    if (data_present) {
+        PascalString name;
+        s32 version_verify;
+        u32 width, height;
+        bool transparent; padding[3];
+        if (version_verify >= 540) {
+        bool smooth_edges; padding[3];
+        bool preload; padding[3];
+        bool is_a_tileset; padding[3];
+        u32 tile_width, tile_height, tile_x_offset, tile_y_offset, tile_x_seperation, tile_y_seperation;
+        } else {
+            bool video_memory; padding[3];
+            bool load_only_on_use; padding[3];
+        }
+        u32 image_count;
+        BitmapData images[image_count];
+    }
+} [[name(data_present ? name.data : "<dead data>")]];
+
+enum PathEndAction : u32 {
+    Stop = 0,
+    JumpToStart = 1,
+    MoveToStart = 2,
+    Reverse = 3,
+    Continue = 4
+};
+
+struct PathPoint {
+    double x, y, speed;
+};
+
+struct Path {
+    bool data_present [[hidden]]; padding[3];
+    if (data_present) {
+        PascalString name;
+        s32 version_verify;
+        bool curved; padding[3];
+        if (version_verify >= 530) {
+            bool closed; padding[3];
+            u32 precision;
+            s32 background_room [[format_read("GetRoomNameByIndex")]];
+            s32 grid_width, grid_height;
+        } else {
+            PathEndAction end_action;
+            padding[4];
+        }
+        u32 point_count;
+        PathPoint points[point_count];
+    }
+} [[name(data_present ? name.data : "<dead data>")]];
+
+struct Script {
+    bool data_present [[hidden]]; padding[3];
+    if (data_present) {
+        PascalString name;
+        s32 version_verify;
+        PascalString code;
+    }
+} [[name(data_present ? name.data : "<dead data>")]];
+
+enum DataFileExportMode : u32 {
+    None = 0,
+    TempDirectory = 1,
+    WorkingDirectory = 2,
+    Font = 3
+};
+
+struct DataFile {
+    bool data_present [[hidden]]; padding[3];
+    if (data_present) {
+        PascalString name;
+        s32 version_verify;
+        PascalString file_name;
+        u32 size;
+        u8 file[size] [[sealed, static]];
+        DataFileExportMode export_mode;
+        bool overwrite; padding[3];
+        bool free_data_memory; padding[3];
+        bool remove_at_game_end; padding[3];
+    }
+} [[name(data_present ? name.data : "<dead data>")]];
+
+struct Font {
+    bool data_present [[hidden]]; padding[3];
+    if (data_present) {
+        PascalString name;
+        s32 version_verify;
+        PascalString font_name;
+        u32 size;
+        bool bold; padding[3];
+        bool italic; padding[3];
+        u32 char_min, char_max;
+    }
+} [[name(data_present ? name.data : "<dead data>")]];
+
+struct Timeline {
+    bool data_present [[hidden]]; padding[3];
+    if (data_present) {
+        PascalString name;
+        s32 version_verify;
+        u32 moment_count;
+        GameObjectSubEvent moments[moment_count];
+        // PascalString code;
+    }
+} [[name(data_present ? name.data : "<dead data>")]];
+
+struct GameObject {
+    bool data_present [[hidden]]; padding[3];
+    if (data_present) {
+        PascalString name;
+        s32 version_verify;
+        s32 sprite_index [[format_read("GetSpriteNameByIndex")]];
+        bool solid; padding[3];
+        bool visible; padding[3];
+        s32 depth;
+        bool persistent; padding[3];
+        s32 parent_index [[format_read("GetObjectNameByIndex")]];
+        s32 mask_index [[format_read("GetMaskSpriteNameByIndex")]];
+        if (version_verify >= 430) {
+            u32 event_count;
+            GameObjectEvent events[event_count+1];
+        } else GameObjectEvent events[9];
+        // Events: 0 - Create, 1 - Destroy, 2 - Alarm, 3 - Step, 4 - Collision,
+        // 5 - Mouse, 6 - Keyboard, 7 - Other, 8 - Drawing
+    }
+} [[name(data_present ? name.data : "<dead data>")]];
+
+struct RoomView {
+    bool enabled; padding[3];
+    s32 x, y;
+    u32 width, height;
+    if (parent.version_verify < 541)
+        s32 x_screen, y_screen;
+    else s32 x_port, y_port, width_port, height_port;
+    u32 border_horiz, border_vert;
+    s32 hspeed, vspeed;
+    s32 object_to_follow [[format_read("GetObjectNameByIndex")]];
+};
+
+struct RoomBackground {
+    bool enabled; padding[3];
+    bool foreground; padding[3];
+    s32 background_index [[format_read("GetBackgroundNameByIndex")]];
+    s32 x, y;
+    bool tile_horiz; padding[3];
+    bool tile_vert; padding[3];
+    s32 hspeed, vspeed;
+    if (parent.version_verify >= 520) {bool stretch; padding[3];}
+};
+
+struct RoomInstance {
+    s32 x, y;
+    s32 object_index [[format_read("GetObjectNameByIndex")]];
+    s32 id;
+    if ((parent.version_verify >= 440) && (parent.version_verify < 520)) {
+        padding[8];
+    } else if (parent.version_verify >= 520) {
+        PascalString creation_code;
+        bool locked; padding[3];
+    }
+};
+
+struct RoomTile {
+    s32 x, y;
+    s32 tileset_index [[format_read("GetBackgroundNameByIndex")]];
+    RectRegion region;
+    s32 depth;
+    s32 id;
+    if (parent.version_verify >= 520)
+        bool locked; padding[3];
+};
+
+struct Room {
+    bool data_present [[hidden]]; padding[3];
+    if (data_present) {
+        PascalString name;
+        s32 version_verify;
+        PascalString caption;
+        s32 width, height, grid_width, grid_height;
+        if (version_verify >= 520) {bool grid_isometric; padding[3];}
+        s32 speed;
+        bool persistent; padding[3];
+        RGBA8 back_color;
+        bool draw_back_color; padding[3];
+        if (version_verify >= 411) PascalString creation_code;
+        u32 background_count;
+        RoomBackground backgrounds[background_count];
+        bool enabled_views; padding[3];
+        u32 view_count;
+        RoomView views[view_count];
+        u32 instance_count;
+        RoomInstance instances[instance_count];
+        if (version_verify >= 420) {
+            u32 tile_count;
+            RoomTile tiles[tile_count];
+        }
+        if ((version_verify >= 440) && (version_verify <= 530)) padding[80];
+        if (version_verify >= 541) padding[56];
+    }
+} [[name(data_present ? name.data : "<dead data>")]];
+
+bitfield SoundAudioEffects {
+    chorus:  1;
+    echo:    1;
+    flanger: 1;
+    gargle:  1;
+    reverb:  1;
+};
+
+struct Sound {
+    bool data_present [[hidden]]; padding[3];
+    if (data_present) {
+        PascalString name;
+        s32 version_verify;
+        if (version_verify >= 600) SoundKindV2 data_kind;
+        else SoundKind data_kind;
+        if (data_kind != SoundKind::None) {
+            PascalString file_type;
+        }
+        if (version_verify >= 600) {
+            PascalString file_name;
+            padding[4];
+        }
+        u32 data_size;
+        u8 data[data_size] [[sealed, static]];
+        if (version_verify >= 600) {
+            SoundAudioEffects effects; padding[3];
+            double volume;
+            double panning;
+            bool preload; padding[3];
+        } else {
+            bool allow_for_sfx; padding[3];
+            u32 buffer_count;
+            bool load_only_on_use; padding[3];
+        }
+    }
+} [[name(data_present ? name.data : "<dead data>")]];
+
+struct GameConstant {
+    PascalString name, value;
+};
+
+struct GameOptions {
+    s32 version_verify;
+    // Graphics
+    bool fullscreen_startup; padding[3];
+    if (version_verify >= 600) {bool antialiased; padding[3];}
+    if (version_verify >= 411) {bool no_border_windowed; padding[3];}
+    bool display_cursor; padding[3];
+    if (version_verify >= 420) {
+        s32 scale_percentage_windowed;
+        if (version_verify >= 600) {
+            bool allow_resizing; padding[3];
+            bool always_on_top; padding[3];
+            RGBA8 outside_color;
+        } else {
+            s32 scale_percentage_fullscreen;
+            bool scale_hardware_only; padding[3];
+        }
+        bool set_resolution; padding[3];
+    } else {bool fullscreen_scale; padding[3];}
+    if (version_verify < 600) {bool exclusive_gfx_mode; padding[3];}
+    if (version_verify >= 600) ColorDepthV2 color_depth;
+    else ColorDepth color_depth;
+    if (version_verify >= 600) ResolutionV2 resolution;
+    else Resolution resolution;
+    if ((version_verify >= 420) && (version_verify < 600))
+        RefreshRate refresh_rate;
+    if (version_verify >= 600) {
+        RefreshRateV2 refresh_rate;
+        bool no_system_menu; padding[3];
+    }
+    bool wait_for_Vblank; padding[3];
+    if (version_verify < 600) {bool fullscreen_caption; padding[3];}
+    if ((version_verify >= 440) && (version_verify < 600)) {bool no_system_menu; padding[3];}
+    // Keys
+    bool keys_f4_fullscreen; padding[3];
+    bool keys_f1_info; padding[3];
+    bool keys_esc_end; padding[3];
+    bool keys_f5f6_saveload; padding[3];
+    if (version_verify >= 520) {u8 game_process_priority; padding[3];}
+    // Score (until version 5.0)
+    if (version_verify < 500) {
+        bool score_display; padding[3];
+        bool score_background; padding[3];
+        if (score_background)
+            BitmapData score_background_image;
+        RGBA8 score_color_new;
+        RGBA8 score_color_other;
+        RGBA8 score_color_background;
+        PascalString score_text_font;
+        u32 score_text_size;
+        bool score_border; padding[3];
+    }
+    // Interaction
+    if (version_verify < 600) {
+        bool continuous_key_events; padding[3];
+        bool continuous_mouse_events; padding[3];
+    }
+    bool lose_focus_freeze; padding[3];
+    // Loading
+    if (version_verify >= 411) {
+        ShowLoadingBar loading_show_bar; padding[3];
+        if (loading_show_bar == ShowLoadingBar::Custom) {
+            BitmapData loading_bar_back_image;
+            BitmapData loading_bar_front_image;
+        }
+    } else {bool loading_show_bar; padding[3];}
+    bool loading_background; padding[3];
+    if (loading_background)
+        BitmapData loading_background_image;
+    if (version_verify >= 510) {
+        bool loading_transparency; padding[3];
+        u8 loading_alpha; padding[3];
+        bool loading_bar_stretch; padding[3];
+    }
+    if (version_verify >= 411) {
+        u32 icon_size;
+        u8 icon_data[icon_size] [[sealed, static]];
+    }
+    // Errors
+    if (version_verify >= 420) {
+        bool display_errors; padding[3];
+        bool write_to_game_errors_log; padding[3];
+        bool abort_on_all_error_messages; padding[3];
+        bool uninitialized_as_zeroes; padding[3];
+    }
+    // Info
+    if (version_verify >= 500) {
+        PascalString author;
+        s32 game_version;
+        u64 datetime_changed;
+        PascalString information;
+    }
+    if (version_verify >= 530) {
+        u32 constant_count;
+        GameConstant constants[constant_count];
+    }
+    if (version_verify >= 600) {
+        u32 includes_count;
+        PascalString includes[includes_count];
+        bool includes_to_temp; padding[3];
+        bool includes_overwrite; padding[3];
+        bool includes_remove_on_exit; padding[3];
+    }
+};
+
+struct GameInformation {
+    s32 version_verify;
+    RGBA8 back_color;
+    if (version_verify >= 430) {
+        bool mimic_main_form; padding[3];
+    }
+    if (version_verify >= 600) {
+        PascalString caption;
+        s32 x,y, width, height;
+        bool show_border; padding[3];
+        bool allow_resizing; padding[3];
+        bool always_on_top; padding[3];
+        bool pause_game; padding[3];
+    }
+    PascalString info;
+};
+
+fn GetSpriteNameByIndex(s32 index) {
+    return (index == -1 ? "<no sprite>" : gmd.sprites[index].name.data);
+};
+
+fn GetMaskSpriteNameByIndex(s32 index) {
+    return (index == -1 ? "<same as sprite>" : gmd.sprites[index].name.data);
+};
+
+fn GetBackgroundNameByIndex(s32 index) {
+    return (index == -1 ? "<no image>" : gmd.backgrounds[index].name.data);
+};
+
+fn GetObjectNameByIndex(s32 index) {
+    match (index) {
+        (-100): return "<no parent>";
+        (-1):   return "<no object>";
+        (_):    return gmd.objects[index].name.data;
+    }
+};
+
+fn GetApplyToObjectNameByIndex(s32 index) {
+    match (index) {
+        (-2): return "<other>";
+        (-1):   return "<self>";
+        (_):    return gmd.objects[index].name.data;
+    }
+};
+
+fn GetRoomNameByIndex(s32 index) {
+    return (index == -1 ? "<no room>" : gmd.rooms[index].name.data);
+};
+
+enum TreeNodeType : u32 {
+    None = 0,
+    Folder = 1,
+    Subfolder = 2,
+    Data = 3
+};
+
+enum TreeNodeSubtype : u32 {
+    None = 0,
+    Object = 1,
+    Sprite = 2,
+    Sound = 3,
+    Room = 4,
+    Background = 6,
+    Script = 7,
+    Path = 8,
+    DataFile = 9, // Now Fonts in 6.x onward
+    GameInfo = 10,
+    GameOptions = 11,
+    TimeLine = 12
+};
+
+struct TreeNode {
+    TreeNodeType type;
+    TreeNodeSubtype subtype;
+    u32 uid;
+    PascalString node_name;
+    u32 child_count;
+    TreeNode child_nodes[child_count];
+} [[name(node_name)]];
+
+struct GMD {
+    s32 signature;
+    s32 ide_version;
+    if (ide_version < 600) u32 standalone_key; // 4.0 GMR only
+    s32 identifier;
+    if (ide_version >= 411)
+        u8 unique_id[16] [[sealed, static]];
+    GameOptions options;
+    s32 version_verify_sounds;
+    s32 sound_count;
+    if (ide_version < 600) Sound sounds[(standalone_key > 0 ? sound_count / standalone_key : sound_count)];
+    else Sound sounds[sound_count];
+    s32 version_verify_sprites;
+    s32 sprite_count;
+    if (ide_version < 600) Sprite sprites[(standalone_key > 0 ? sprite_count / standalone_key : sprite_count)];
+    else Sprite sprites[sprite_count];
+    s32 version_verify_backgrounds;
+    s32 background_count;
+    if (ide_version < 600) Background backgrounds[(standalone_key > 0 ? background_count / standalone_key : background_count)];
+    else Background backgrounds[background_count];
+    if (ide_version >= 420) {
+        s32 version_verify_paths;
+        s32 path_count;
+        Path paths[path_count];
+    }
+    s32 version_verify_scripts;
+    s32 script_count;
+    if (ide_version < 600) Script scripts[(standalone_key > 0 ? script_count / standalone_key : script_count)];
+    else Script scripts[script_count];
+    if ((ide_version >= 440) && (ide_version < 600)) {
+        s32 version_verify_datafiles [[hidden]];
+        s32 datafile_count;
+        DataFile datafiles[datafile_count];
+    }
+    if (ide_version >= 600) {
+        s32 version_verify_fonts;
+        s32 font_count;
+        Font fonts[font_count];
+    }
+    if (ide_version >= 500) {
+        s32 version_verify_timelines;
+        s32 timeline_count;
+        Timeline timelines[timeline_count];
+    }
+    s32 version_verify_objects;
+    s32 object_count;
+    if (ide_version < 600) GameObject objects[(standalone_key > 0 ? object_count / standalone_key : object_count)];
+    else GameObject objects[object_count];
+    s32 version_verify_rooms;
+    s32 room_count;
+    if (ide_version < 600) Room rooms[(standalone_key > 0 ? room_count / standalone_key : room_count)];
+    else Room rooms[room_count];
+    s32 last_instance_id;
+    if (ide_version >= 420)
+        s32 last_tile_id;
+    GameInformation information;
+    if (ide_version >= 500) {
+        s32 version_verify_dummy;
+        s32 dummy_count;
+        padding[4*dummy_count];
+    }
+    s32 version_verify_resource_tree;
+    u32 active_room_count;
+    u32 active_room_ids[active_room_count];
+    TreeNode resource_tree[while(!std::mem::eof())];
+};
+
+GMD gmd @ 0x0;
diff --git a/tests/patterns/test_data/gmd.hexpat.gm6 b/tests/patterns/test_data/gmd.hexpat.gm6
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diff --git a/tests/patterns/test_data/gmd.hexpat.gmd b/tests/patterns/test_data/gmd.hexpat.gmd
new file mode 100644
index 00000000..e80086d4
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