ml
11 KiB
Map Information
Map layout
Level information
L04, a compressed resource, contains the basic information about a level (a map).
In the original source, this structure is called
FullMap.
Level Information (58 bytes)
0000 sint32 X Size - always 64 in the archives.
0004 sint32 Y Size - always 64 in the archives.
0008 sint32 X Shift - always 6 in the archives.
000C sint32 Y Shift - always 6 in the archives.
0010 sint32 Z Shift
0014 byte[4] Placeholder - ignore
0018 byte Cyberspace flag. 0: real life, 1: cyberspace
0019 byte[12] Unused
0025 byte[21] Scheduler Info
The engine doesn't support maps with more than 4096 tiles. By default, this is a map of 64x64 tiles. While other combinations of X/Y sizes are feasible, as long as the respective shift parameter matches, there is hardly a point to try something different than 64x64.
The z shift determines the height of the level as well as the size of one height unit for tiles.
The level is one tile width high (perfect cube) if the shift value is 5.
A shift value of 0 gives 32 tiles of height, a value of 7 one fourth (1/4) of a tile. So it's 32, 16, 8, 4, 2, 1, 1/2, 1/4 for 0..7.
Most levels have a shift value of 3, giving 4 tile widths of height. Security (Level 8) has a shift value of 1 - 16 tiles.
One height unit is the 32th of the level height. The higher the level is, the larger are the visible jumps of any height value.
Although any level can be marked as cyberspace - even the starting level - only levels 10, 14 and 15 properly work. This is due to the engine considering 10 and everything above 13 to be cyberspace. Cyberspace items in other levels don't work as expected, especially the exit port either crashes the game or puts the player at the start of the cyberspace level again.
As a further hardcoded limitation, only cyberspace levels 14 and 15 have a time limit. Level 10 is without limit.
The placeholder has no use in the archives. In the engine, this field is used as a placeholder for a pointer within the game logic.
The schedule information is the primary entry for level-specific timers.
Level Scheduler Information (21 bytes)
0000 sint32 Size - always 64 in the archives
0004 sint32 Schedule count
0008 sint32 Element size - always 8 in the archives
000C byte Grow - always 0 in the archives
000D byte[4] Pointer1
0011 byte[4] Pointer2
Size and element size require to be set to the values 0x40 and 0x08 respectively. Otherwise the level timers (stored in L06) will not work properly.
The element size of 8 comes from the size of scheduler entries.
Grow, a boolean, would indicate to the scheduler system to allow reallocating the timer list to contain more than size amount of entries. Yet, the engine always initializes this with 0 (= don't grow).
The two pointer fields are used engine-internally.
Tile map
The tiles are described in the compressed resource L05, a table of tile map entries. The first entry describes the lower left tile and the next entries go east first, then north (first columns, then rows). All levels have a size of 64x64 tiles as the engine supports (and expects) only this layout.
The outermost tiles of the level (the 'border') should always be solid tiles. If these tiles are non-solid, the graphics engine may have rendering issues (walls not shown, just black) and entering these tiles freezes the game. This gives an effective available space of 62x62 tiles.
Tile Map Entry (16 bytes)
0000 byte Type
0001 byte Floor Info
0002 byte Ceiling Info
0003 byte Slope height. Valid for any non-flat tile.
0004 sint16 Index to first object in cross-reference table.
0006 uint16 Texture Info
0008 uint32 Flags
000C byte Sub Clip -- always 0xFF
000D byte Clear Solid -- unknown
000E byte Unused
000F byte Light delta
Type (1 byte)
The type is an enumeration with the following constants:
0x00 solid
0x01 open
0x02 diagonal open s/e (nw edge closed off)
0x03 diagonal open s/w (ne edge closed off)
0x04 diagonal open n/w (se edge closed off)
0x05 diagonal open n/e (sw edge closed off)
0x06 slope s->n
0x07 slope w->e
0x08 slope n->s
0x09 slope e->w
0x0A valley se->nw
0x0B valley sw->ne
0x0C valley nw->se
0x0D valley ne->sw
0x0E ridge nw->se
0x0F ridge ne->sw
0x10 ridge se->nw
0x11 ridge sw->ne
All non-open tiles are given as low -> high. Valleys have 3 vertexes higher and one lower (at floor level). Ridges have one vertex higher and the remaining three at floor level. The given direction is that between the one vertex and its opposite one.
Floor/Ceiling Info (1 byte)
bits 0-4 Height (ceiling is units down from 0x20)
bits 5-6 Texture rotation. When viewed from above: 1: 90°, 2: 180°, 3: 270° - always clockwise
bit 7 Hazard flag. Floor has biohazard, ceiling has radiation hazard.
The exact behaviour for the hazard flags is determined by the level variables.
Texture Info (2 bytes)
The texture info field contains information for the tile textures of the level. For real world, it contains index values into the texture map (see next resource below). Cyberspace levels specify the palette color index for floor and ceiling of the South-Western corner.
Real World:
bits 0-5 Wall texture
bits 6-10 Ceiling texture
bits 11-15 Floor texture
Cyberspace:
bits 0-7 Floor palette index
bits 8-15 Ceiling palette index
Flags (4 bytes)
Real World:
0x80000000 Tile visited (automapper)
0x70000000 Unused
0x0F000000 Ceiling shadow
0x00F00000 Unused
0x000F0000 Floor shadow
0x0000E000 Music index
0x00001000 Music "peril"
0x00000C00 Slope control. See below.
0x00000200 Deconstructed flag ("spooky" music)
0x00000100 Use wall texture from adjacent tile
0x00000080 Unused -- only set for computer room on level 7
0x00000040 Flip wall texture horizontally alternating
0x00000020 Flip wall texture horizontally
0x0000001F Offset for wall textures
Cyberspace:
0x01000000 Flight pull: Strong pull towards floor
0x000F0000 Flight pull
0x0000E000 Music index
0x00001000 Music "peril"
0x00000C00 Slope control. See below.
0x00000060 Game-Of-Life flags (either needs to be set)
Ceiling shadow and Floor shadow specify the darkness intensity for the south-western corner of the tile.
The ceiling value darkens all four surrounding ceilings.
The walls made by surrounding top-pillars are darkened starting from the ceiling.
The walls made by surrounding bottom-pillars are darkened starting from their floor.
The floor value darkens all four surrounding floors. The walls made by surrounding bottom-pillars are darkened starting from the floor. The walls made by surrounding top-pillars are darkened starting from their ceiling.
The actions to modify the light values can only give tiles more light, or remove previously added light. Thus, with shadow values of 0, these tiles are as bright as possible, without any chance of making them darker.
Slope control specifies for the floor and ceiling how slopes (and valleys and ridges) should look like.
0: Ceiling is inverted to floor; A slope height of 0x1F will have ceiling and floor seal of the tile.
1: Ceiling is mirroring the floor; A slope height of 0x10 will have their most extent vertexes touch each other.
2: Ceiling is flat.
3: Floor is flat.
Flip wall texture horizontally
Wall textures can be flipped horizontally.
In the alternating case, flipping is based on the parities of the tile's two coordinates (even/odd status of the X and Y values).
Furthermore, North/South wall textures are flipped separately to East/West wall textures; If the North/South walls are flipped for a certain tile, the corresponding East/West walls will not be flipped. If the North/South walls are not flipped, then the East/West walls will be flipped.
This ensures mirrored patterns are kept across corners without the need to change the flags for every other tile. This is heavily used on level 9 for the infested walls.
The North/South texture is to be flipped if the parities of the tile's two coordinates are different - East/West would be normal in this case.
The North/Shouth texture is normal if the parities of the tile's two coordinates match - East/West would be flipped in this case.
This alternation is inverted if additionally bit ```0x00000020```` is set.
Flight pull specifies what default translation/rotation forces are in play
0: None
1: Weak pull towards East
2: Weak pull towards West
3: Weak pull towards North
4: Weak pull towards South
5: Medium pull towards East
6: Medium pull towards West
7: Medium pull towards North
8: Medium pull towards South
9: Strong pull towards East
10: Strong pull towards West
11: Strong pull towards North
12: Strong pull towards South
13: Medium pull towards ceiling
14: Medium pull towards floor
15: Strong pull towards ceiling
16: Strong pull towards floor (requires separate extra bit)
The engine applies the force to the 'nose' of the hacker, i.e. it will pull the heading until the hacker looks straight at the origin of the force. This causes the implicit rotation. Only if the heading is exactly opposite to the origin, then no rotation happens (i.e., pulled backwards). All but the 'Strong' pulls can be countered.
Light delta (1 byte)
The high nibble specifies the light delta to the ceiling shadow. The low nibble specifies the light delta to the floor shadow. The Change lighting action modifies these values.
Texture map
This resource is a list of int16 texture identifier in resource L07 with a fixed length of 108 bytes.
The Texture Info fields in the tile map refer to these identifier.
Although the field for wall textures would allow for 64 textures, the resource can only hold up to 54 textures.
The first 32 textures can be used for floor/ceiling as well.
The engine caches these textures when reloading a savegame with the same level. In the original source this list is also referred to as
loaded texturesorloved_textures. The 'texture' index for space is 0x00CD, the observation grating has 0x00B1 (ceiling on groves and bridge)
See Level Textures for further information.
Map notes
Text Data
Text for the map notes is stored in the level-specific resource L46. The notes are stored sequentially, with the 0x00 character terminating a note.
The maximum length of one note is 40 bytes (including the termination character). The resource itself is pre-initialized with 0x00 bytes to a total length of 0x800 bytes.
Data in this resource is always defragmented. If a note is modified or removed, the notes are rearranged.
Next available space
Resource L47 is a single uint32 offset, pointing to the first available byte in the text data resource.