Major Stryker Level Format

From ModdingWiki
Jump to: navigation, search
Major Stryker Level Format
320px
There is no image of a map in this format — upload one!
Format typeMap/level
Map type2D tile-based
Layer count1
Tile size (pixels)16×16
Viewport (pixels)256×160
Games

File Format

The basic layout of a level file is as follows:

Data type Description
Char[12] cMaskTiles filename of the masked tile graphics
Char[12] cSolidTiles filename of the solid tile graphics
Char[12] cBackdrop filename of the backdrop tile graphics
Char[12] cUnused1 unused filename (always "dropa.dr1")
Char[12] cUnused2 unused filename (always "attr00.dr1")
Char[12] cMusic filename of the music file
Char[12] cUnused3 unused filename (always "mboss.dr1")
UINT16LE iFlags Flags for lights etc (see below)
UINT16LE iWidth Width of map, in tiles (always 32)
UINT16LE iActorSize Number of UINT16LE values in the actor data
UINT16LE[iActorSize] iActorData Actor entries (3 values per actor, see below)
BYTE[240] bMaskAttributes Tile attributes (one byte per tile, see below)
BYTE[240] bTileAttributes Tile attributes (one byte per tile, see below)
UINT16LE[16767] iTileData Tile codes for the entire level

The bits in the iFlags value have the following meaning:

Bit mask Effect
0x0001 none (this is ALWAYS set but has no effects at all)
0x0002 lightning (only used in E2M1)
0x0004 scroll bottom plane faster (for bosses in E1M12, E2M12, E3M12)

The tile attribute bits have the following effects:

Bit mask Effect
0x10 road
0x20 animated)
0x40 shootable
0x80 blocking (any direction)

Actor entries use the following data structure:

Data type Description
UINT16LE iType ID number of this actor
UINT16LE iPosX X coordinate of this actor, in tile units
UINT16LE iPosY Y coordinate of this actor, in tile units

The game ignores the iWidth value read from the file and sets it back to 32, thus the level's height will always be 523, leaving 31 UINT16LE values unused at the end of the tile data.

Tile Data

The range of valid tile data goes from 0 to 0x1ED0. Some levels also contain the invalid values 0x22C0 and 0x22E0 in the 31 unused tiles at the end, which must be handled separately.

  • Values smaller than $F0 are tile indices for the masked tileset.
  • Subtract $F0 from any other valid value to get an offset into the solid tileset in memory (divide the offset by 32 to get a tile index).

The map layout is special because the game uses parallax scrolling. The first 16 tiles of each row make up the actual map, the last 16 tiles of each row make up the layer that scrolls below the actual map (at half the speed). Actors can be placed in both of these "layers".

Credits

This file format was reverse engineered by K1n9_Duk3. If you find this information helpful in a project you're working on, please give credit where credit is due. (A link back to this wiki would be nice too!)