Crimson config blob (crimson.cfg)¶

crimson.cfg is the fixed-size configuration blob used by the classic Crimsonland executable. It is not the save/status file (that is game.cfg).

Location and size¶

• Path: game_base_path\\crimson.cfg (built via game_build_path).
• Size: 0x480 bytes (1152 bytes).
• Endianness: little-endian for integer/float fields.

Struct view (crimson_cfg_t)¶

config_blob at 0x00480348 is typed as crimson_cfg_t. The recovered crimsonShared.h::config_t supplies the source identities for the direction flags, render toggles, control arrays, config_for, logging flag, and two installation IDs:

typedef struct player_input_config_t {
    int move_key_forward;
    int move_key_backward;
    int turn_key_left;
    int turn_key_right;
    int fire_key;
    int key_reserved_0;
    int key_reserved_1;
    int aim_key_left;
    int aim_key_right;
    int axis_aim_y;
    int axis_aim_x;
    int axis_move_y;
    int axis_move_x;
    int reserved[3];
} player_input_config_t;

typedef struct crimson_cfg_t {
    unsigned char sound_disabled;
    unsigned char music_disabled;
    unsigned char highscore_date_mode;
    unsigned char highscore_duplicate_mode;
    unsigned char direction_arrow_flags[10];
    unsigned char shadows_enabled;
    unsigned char sharp_ground_enabled;
    unsigned char flame_glow_enabled;
    unsigned char smoke_enabled;
    unsigned char padding_12[2];
    int player_count;
    game_mode_id_t game_mode;
    int movement_schemes[10];
    int aim_schemes[10];
    int config_for;
    float texture_scale;
    char player_name_buf[12];
    int selected_saved_name_slot;
    int saved_name_count;
    int saved_name_order[8];
    char saved_names[8][27];
    char player_name[32];
    int player_name_length;
    unsigned char startup_defaults_only[0x0c];
    int aim_pov_right;
    int aim_pov_left;
    int display_bpp;
    int screen_width;
    int screen_height;
    unsigned char windowed;
    unsigned char windowed_padding[3];
    player_input_config_t input_config[10];
    unsigned char hardcore;
    unsigned char ui_info_texts;
    unsigned char hardcore_info_padding[2];
    int level_up_count;
    int ten_tons_logging_completed;
    int unique_id_1;
    int unique_id_2;
    int reserved_identity_word;
    unsigned char sound_frequency_adjustment;
    unsigned char sound_frequency_padding[3];
    float sfx_volume;
    float music_volume;
    unsigned char violence_disabled;
    unsigned char show_online_scores;
    unsigned char safe_mode_backend_enabled;
    unsigned char detail_padding;
    int detail_preset;
    float mouse_sensitivity;
    int key_pick_perk;
    int key_reload;
} crimson_cfg_t;

Control scheme notes¶

For player controls, movement and aiming are stored separately in the blob:

• config_movement_schemes[player] controls movement mode.
• config_aim_schemes[player] controls aiming mode.

On the original EXE, these can be mixed in practice (for example move_mode = 2 static movement with aim_scheme = 5 computer aiming).

Observed file:

• game_bins/crimsonland/1.9.93-gog/crimson.cfg
• size 0x480
• width 1024, height 768
• windowed flag = 1
• texture scale = 1.0

Hardcoded defaults (from config_sync_from_grim when grim_config_invoked is set):

• width 800, height 600
• windowed flag = 0 (fullscreen)
• bpp = 32
• sfx/music volume = 1.0
• player name defaults to 10tons
• saved names default to "default" x8

Load / write behavior¶

From config_init_defaults (0x004028f0) and config_sync_from_grim (0x0041ec60):

• config_load_presets reads the 0x480-byte blob into config_blob.
• config_sync_from_grim:
• seeds a default blob (in memory)
• reads Grim config values (vtable +0x24)
• loads crimson.cfg overrides when present
• writes the 0x480-byte blob back out
• config_ensure_file writes crimson.cfg when missing.

This means the file is treated as a fixed struct and rewritten wholesale.

Field layout¶

Base address in the decompile is config_blob. Offsets below are relative to the blob start.

Source-identified render toggles (0x0E..0x11)¶

These three bytes live inside the 0x000..0x0A7 “header/mixed” region of the blob:

How config_detail_preset maps to the flags¶

config_apply_detail_preset (0x00447580) applies the “Graphics detail” preset to these flags:

Notes:

• The options UI clamps config_detail_preset to 1..5, then calls config_apply_detail_preset (options_menu_update at 0x004475d0).
• Default init (config_init_defaults at 0x004028f0) sets flag0/1/2 to 1 and config_detail_preset to 5.

Keybind Block Structure¶

Each player block is 52 bytes (13 dwords), followed by 12 bytes padding. The values map to DirectInput key codes (scancodes).

Offset refers to index within the block (0-12).

The blob contains ten 64-byte binding slots beginning at 0x1c8, along with ten movement/aim scheme slots. Native gameplay loads two player bindings; the Python port uses four slots for its local co-op extension. The remaining space is structured slot storage, not an unexplained gap. See src/grim/config.py for the wire layout and local controls for native consumers.

Notes¶

• Native writes use the full blob. A forensic byte-preserving editor should retain unmodified bytes. The Python game codec instead builds a canonical wire image from its typed config: unsupported fields/padding and unused player slots are reset to defaults by encode_crimson_cfg. It is not a lossless editor for arbitrary native configuration bytes.

• game.cfg is a different file (save/status) and does not share this layout.