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Actions
Level traps and various fixtures (buttons and the like) make use of actions that perform some state change and/or give some indication to the player. They are essentially what make a level (and the game in total) come to life.
Actions can be triggered by various sources. They may have conditions that first have to be met before the action is actually performed. The type of the action determines how to interpret the details (parameters) of the action.
Quest Value Key
Some actions make use of quest value keys, which are used to either resolve a raw value, or a value from the game variables ("quest values").
- If bit
0x1000is set in the key, the current integer game variable value of indexkey & 0x0FFFis referenced. - If bit
0x2000is set in the key, the current boolean game variable value of indexkey & 0x0FFFis referenced. - For resolving values, if the key is less than 0x1000, then the resulting value is the value key itself.
Action Data
Action Data (22 bytes)
0000 byte Action type
0001 byte Use quota
0002 [4]byte Condition
0006 [16]byte Action details
The Use quota indicates how often more this action can be executed. 0 means endless.
The value is only decremented if it is not zero and the condition was met.
If the value is decremented to zero after the action was executed, the object where the action is in is deleted.
Internally the action details are processed as four sint32 values. This documentation dissects them further where appropriate.
Action Type 1: Transport hacker
Transport Hacker Action Details (16 byte)
0000 int32 Target X
0004 int32 Target Y
0008 int32 Target Z
000C int32 Target Level
For all three target axis values, if they are 0x4000 or greater, they are ignored and the respective axis is not changed in the transport.
The X and Y axes specify tile numbers, the Z axis is interpreted in level units.
In the main game, this axis-preservation is used only on level 2 for the Z axis on the experimental transporter, which incidentally has both platforms at the same height.
If to be considered, the target values are then used as quest value keys to resolve the actual location for the respective axis.
The main game does not make use of this quest value lookup feature. All encounterd values are direct values.
The target level specifies a cross-level transfer to the identified level if the value is smaller than 0x1000.
If it is 0x1000 or greater, transportation is only done within the same level, regardless of the value.
Cross-level transport is used only for a same-level transfer on level 4 (restoration chamber), and twice for two groves, to transport the hacker to the restoration chamber on level 6. Other instances are set to
0x2222, which are ignored.
Action Type 2: Change Health
This action is also called "damage", probably based on the first parameter.
Change Health Action Details (16 byte)
0000 int32 Damage delta
0004 int16 Health delta
0006 byte Health change flag; 0: remove delta, 1: add delta
0007 byte Damage type -- used if removing health
0008 int16 Power delta
000A int16 Power change flag; 0: remove delta, 1: add delta
000C int16 Fatigue delta
000E int16 Fatigue change flag; 0: add delta, 1: remove delta
All four delta values are used as quest value keys to resolve the actual delta value.
The
damage deltais not used in the main game. Although intended to cause explosion damage, due to mixed up parameters in the code, a fixed amount of damage is done, with the delta value being interpreted as damage type.
Reducing health to/below 0 causes death. Reducing power below 0 causes an underflow and hacker is fully powered again.
Action Type 3: Clone/Move Object
This action is internally called "Create Object". Name not kept to describe actual functionality better.
Clone/Move Action Details (16 byte)
0000 int16 Source object index -- quest value key
0002 int16 Move flag
0004 int32 Target X tile
0008 int32 Target Y tile
000C int32 Target Z
The move flag has a dual purpose. First, it is used to determine whether the object shall be moved or cloned.
If it is zero, then the object is cloned; If it has bit 0x1000 set, then the object is cloned as well; All other values cause the source object to be moved.
If the object is cloned, then the move flag parameter will be used as quest value key to store the object index of the newly created object.
The game archive has various values for the
move flag.
For all three target axis values, if they are 0x4000 or greater, they are ignored and the respective axis is not changed.
The X and Y axes specify tile numbers, the Z axis is interpreted in level units.
In the main game, this axis-preservation is used with various values, including
0x4400.
If to be considered, the target values are then used as quest value keys to resolve the actual location for the respective axis.
The orientation and in-tile position of the source object will be kept.
Action Type 4: Set Game Variable
This action is internally called "Quest Bit". Name not kept to describe actual functionality better.
Set Game Variable Action Details (16 byte)
0000 int32 Quest value key
0004 int16 Value
0006 int16 Operation
0008 int32 Message 1 (within resource 0x0867)
000C int32 Message 2 (within resource 0x0867)
Depending on the quest value key, different sets of variables are modified.
The variables are stored in the Game State Structure.
If no bit in the nibble of 0xF000 is set, the quest value key defaults to boolean variables.
For the most part in the main game, the boolean variable selector
0x2000is not set and thus relies on this default handling. There are a few cases where this boolean variable selector is set.
For the int16 variables, value must be in the range 0..0x0FFF. Operation can be one of the following:
0: Set value
1: Add value
2: Subtract value
3: Multiply with value
4: Divide by value (Resulting fractions are cut, divide by 0 is ignored)
5: Modulo by value
For the boolean variables, operation is ignored and always 0.
The values are either 0 or 1 to set that value, or 2 to toggle the current value.
If the resulting value is not zero, the (optional) message 1 is played/shown. If the resulting value is zero, the (optional) message 2 is played/shown. Both message parameters are quest value keys.
Operations other than Set or Add are not used in the game for the int16 values.
Action Type 5: Cutscene
Cutscene Action Details (16 byte)
0000 int32 Cutscene index; 0: Death, 1: Intro, 2: Ending
0004 int32 End game flag
0008 [8]byte Unused
End game flag must be 1. Setting it to 0 leaves the game in an unplayable state after the cutscene.
What happens after the cutscene is dependent on the cutscene itself: The death and intro cutscenes return to the main menu, the ending cutscene ends the game (showing score and credits).
In the regular game, this action is used only once when defeating SHODAN.
Action Type 6: Trigger other objects
Trigger Objects Action Details (16 byte)
0000 int16 Object 1 index
0002 int16 Object 1 delay
...
000C int16 Object 4 index
000E int16 Object 4 delay
The delays are all relative to the execution start of the action. Their unit is 0.1 of a second.
All four object indices are quest value keys. They are resolved when this action is executed, not after the delay.
Action Type 7: Change lighting
Change Lighting Action Details (16 byte)
0000 int16 Light type extent - quest value key
0002 int16 Reference object index - quest value key
0004 int16 Transition type. 0x0000: immediate, 0x0001: fade, 0x0100: flicker
0006 int16 Transition state
0008 byte Light type
0009 byte Unused
000A int16 Light surface. 0x0000: floor, 0x0001: ceiling, 0x0002: floor and ceiling
000C [4]byte Light type parameter
These actions modify the light deltas of the affected tiles. Such actions can not change the base darkness values of a tile. If a tile is fully bright by default, nothing can change that. The configured light parameters are absolute values.
The transition state is a bitmask storing the state for a change.
Transition state (2 bytes)
0x0FFF Step counter
0x1000 0: light on, 1: light off
Light type (1 byte)
0x00 Rectangular
0x01 Linear gradient (East-West smooth)
0x02 Linear gradient (North-South smooth)
0x03 Radial gradient
Gradient light type parameter (4 bytes)
0000 byte Off light begin intensity
0001 byte Off light end intensity
0002 byte On light begin intensity
0003 byte On light end intensity
Rectangular light (type 0x00)
For this light type, the light type extent specifies a second object index. All tiles within this rectangle are affected.
Light type parameter (4 bytes)
0000 byte Off light value 0x00..0x0F
0001 byte On light value 0x00..0x0F
0002 [2]byte Unused
Linear gradient light (types 0x01, 0x02)
For this light type, the light type extent specifies a second object index to define the affected area.
For these types, the gradient light type parameter intensity values have a range of 0x00..0x0F.
These light types are not used in the regular game.
Radial gradient light (type 0x03)
For this light type, the light type extent specifies a radius, in tiles, of affected tiles. The begin of the gradient is always the
tile of the triggering object (reference object index is ignored).
The intensity values of the gradient light type parameter have a range of 0x00..0x7F.
A value of around 0x14 lights a tile as if it were fully lit.
Values above will spill over to the surrounding tiles.
Action Type 8: Effect
Effect Action Details (16 byte)
0000 int16 Sound index, based on 0x00C9; 0: Play nothing
0002 int16 Sound play count; 0: endless
0004 int16 Visual effect
0006 [2]byte Unused
0008 int16 Additional visual effect
000A [2]byte Unused
000C int16 Additional visual effect time; 0: endless
000E [2]byte Unused
All parameters are used as quest value keys.
Visual Effects:
0: None
1: Power on: Dim level lights and fade back to normal; Plays generator sound as well
2: Quake: Shake cam and play rumble sound
3: Escape pod: Shows launch sequence, cam shake and abort; Plays SHODAN message afterwards
4: Red static (fullscreen)
5: Red static (interference)
Additional Visual Effects:
0: None
1: White flash
2: Pink flash
3: Gray static (fullscreen)
4: Vertical panning (including HUD)
Action Type 9: Change tile heights
0000 int32 Tile X
0004 int32 Tile Y
0008 int16 Target floor height; 0..31, measured from floor absolute zero
000A int16 Target ceiling height; 1..31, measured from floor absolute zero
000C [2]byte Unused
000E int16 Silent flag; 0: play sound, 1: no sound
Tile coordinates, as well as the heights, are used as quest value keys.
For the height fields a value equal to, or greater than 0x0100 indicates "don't move".
The ceiling height has also been encountered to be
0x0020, also not moving.
The silent flag only works for floor changes. If the ceiling changes height, it makes sound regardless of this parameter.
Action Type 10: Change Terrain
0000 int32 Tile X
0004 int32 Tile Y
0008 int32 Tile type
000C int32 Terrain parameter (slope height)
All four parameters are used as quest value keys.
If tile type or terrain parameter has the bit 0x4000 set, the respective property will not be changed.
This action is not used in the main game.
Action Type 11: Scheduled Trap
Scheduled Trap Action Details (16 byte)
0000 int32 Object index
0004 int32 Time interval
0008 int32 Activation value
000C int16 Variance
000E [2]byte Unused
Parameters object index, time interval, and variance (if set != 0) are used as quest value keys.
The time interval specifies in 0.1 seconds units within which time span the identified object shall be triggered regularly.
The variance adds some randomness to the interval. Usually low numbers are encountered in the main game.
The unit of the variance is that of the engine-internal ticks.
The activation value has three different uses:
- greater than or equal to
0xFFFF: endless scheduling. - bit
0x1000set AND boolean game variable identified by this value key is true: schedule trigger - value between
0x0000(exclusive) and0x1000(exclusive): remaining schedule amount, down to zero
The game has the
Activation valuetypically set to0xFFFF,0x10000or0x11111in the main game.
Action Type 12: Cycle Objects
Internally, this action is called "Alternating splitter"
Cycle Objects Action Details (16 byte)
0000 [3]int32 Object indices
000C int32 Next object
All three object indices are interpreted as quest value keys.
This action triggers objects from the list of object indices. The next object field indicates which entry to trigger next.
Afterwards, the next object field is incremented. It is reset to 0 if it is either greater than 2, or it is 2 and the third object index is 0.
Action Type 13: Destroy Object
Destroy Object Action Details (16 byte)
0000 int16 Object 1 index
0002 int16 Unused
0004 int16 Object 2 index
0006 int16 Unused
0008 int16 Object 3 index
000A int16 Unused
000C int32 Message index (within resource 0x0867); 0: no message
All three object indices are interpreted as quest value keys.
Action Type 14: Unused
This action is not used and does nothing.
Action Type 15: Receive EMail
Receive EMail Action Details (16 byte)
0000 int16 EMail index, based on 0x0989
0002 [2]byte Unused
0004 int16 Delay
0008 [10]byte Unused
The Delay is roughly counted in seconds. Tests showed their actual unit seems to be somewhere at 0.9 seconds.
Action Type 16: Expose
Change Effect Action Details (16 byte)
0000 int16 Delta value
0002 int16 Effect change flag; 0: add delta, 1: remove delta
0004 int32 Effect type
0008 [8]byte Unused
This action exposes the hacker to some typed hazard or treatment.
Effect types are:
4: Radiation poisoning
8: Bio contamination
The main game uses this only once to remove the radiation in level R - treatment area.
Action Type 17: Set Object Parameter
Set Object Parameter Action Details (16 byte)
0000 int16 Object index 0
0002 int16 Object index 2
0004 int32 Value 1
0008 int32 Value 2
000C int32 Value 3
Both object indices are treated as quest value keys.
This action sets parameters of target objects. Which value is applied to which parameter is dependent on the target.
The following table lists the mappings.
| Target Class | Value 1 | Value 2 | Value 3 |
|---|---|---|---|
| Big Stuff | Cosmetic value | Data1 | Data2 |
| Door | Locked | 0xFF00: Message index, 0x00FF: Cosmetic value |
0xFF00: Access level, 0x00FF: Auto-close time |
| Fixture, Trap | Parameter Number (1..4) | Parameter Value | Unused |
For big stuff and door classes, if a value is -1 it doesn't modify the respective target parameter.
Which parameters are specifially affected for fixtures and traps depends on their respective interpretation of the 16 bytes.
Action Type 18: Set Screen Picture
Internally, this action is called "animate".
Set Screen Picture Action Details (16 byte)
0000 int16 Screen 1 object index
0002 int16 Screen 2 object index
0004 int32 Single sequence source
0008 int32 Loop sequence source
000C int32 Unused
This action sets the picture source for the given screen object(s).
If provided, the Single sequence source is played first. If provided, the Loop sequence is played
next and looped. If no loop is provided, the last frame of the single sequence will be kept.
Action Type 19: Hack
This action is a more generic one with several different interpretations, depending on the first field.
Hack Action Details (16 byte)
0000 int32 Hack type
0004 [12]byte Hack parameter
Hack Action Type 1: Toggle repulsor
Toggle Repulsor Details (12 byte)
0000 int32 Repulsor object index
0004 byte "Off" texture index (into level texture list)
0005 byte "On" texture index (into level texture list)
0006 [2]byte Unused
0008 byte Toggle type
0009 [3]byte Unused
Toggle type (1 byte)
0x00 Toggle On/Off
0x01 Toggle On, stay on
0x02 Toggle Off, stay off
Hack Action Type 2: Show Game Code Digit
Show Game Code Digit Details (12 byte)
0000 int32 Screen object index
0004 int32 Digit number 1..6 (= level number)
0008 [4]byte Unused
Hack Action Type 3: Set Fixture Parameter from Variable
Set Fixture Parameter From Variable Details (12 byte)
0000 int32 Fixture object index
0004 int32 Parameter number (1..4)
0008 int32 Game integer variable index
This hack is used only twice, exclusively to set the codes for the reactor in the base game. Similar to the "Set Object Parameter" action, the interpretation of the modified parameter is depending on the action in the target fixture.
Hack Action Type 4: Set Frame State
Although this hack is called "fixture frame", it doesn't check for the type of the target object and allows to modify any object's frame state.
Set Frame State Details (12 byte)
0000 int32 Button object index
0004 int32 New frame state; 0: off, 1: on
0008 int32 MFD update flag; 0: ignored, != 0: update MFD
Hack Action Type 5: Door Control
Door Control State Details (12 byte)
0000 int32 Door object index
0004 int32 Control value
0008 int32 Unused
Control values:
1: open door
2: close door
3: toggle door
4: disable auto-close
Hack Action Type 6: Return to main menu
This hack has no parameters (all 12 bytes 0x00) and directly returns to the main menu.
Hack Action Type 7: Rotate Object
Rotate Object State Details (12 byte)
0000 int32 Object index
0004 byte Amount
0005 byte Type -- 0x00: endless, != 0x00: back/forth
0006 byte Direction -- 0x00: forward, 0x01 when running backwards
0007 byte Axis -- 0x00: Z (yaw), 0x01: X (pitch), 0x02: Y (roll)
0008 byte Forward limit
0009 byte Backward limit
000A [2]byte Unused
This hack rotates an object along one axis. This rotation can be endless in one direction, or a back and forth rotation,
depending on the Type field.
If the rotation type is back and forth, then the object is rotated between the two limits. Should the object start outside of these limits, then rotation continues normally until it is within the limits.
If the rotation type is endless, whenever one limit is reached, the object immediately jumps to an orientation as per the other limit.
Hack Action Type 8: Remove Critters
This hack is called "armageddon" internally, most likely in a reference to a similar action in the game Lemmings.
Remove Critters State Details (12 byte)
0000 int32 Object type - 0x00CCSSTT
0004 int32 Radius
0008 int32 Unused
This hack removes critters of the specified object type from the level.
The radius specifies how many shall be removed around the tile of the action's object, in tiles.
Avoid using high amounts. The engine can remove only a certain amount of objects in one tick (100) and has no guard if more are removed. A memory overrun occurs in this case.
Hack Action Type 9: SHODAN pixelation
This hack has no parameters (all 12 bytes 0x00) and fills the screen with an image. The used image is hardcoded. The game returns to the main menu after the screen is filled. It should be used only in cyberspace; Using it in real world messes up tile textures.
Hack Action Type 10: Set Condition
Set Condition Details (12 byte)
0000 int32 Object index
0004 [4]byte Condition
0008 [4]byte Unused
Sets the condition values of specified object (fixture or trap).
Hack Action Type 11: Show System Analyzer
0000 int32 Page index (0..2)
0004 [8]byte Unused
Hack Action Type 12: Make Area Radioactive
Internally this hack is called "spew". Yet it only supports spillage of radiation.
Make Area Radioactive Details (12 byte)
0000 int32 Reference object index
0004 int16 Watched object index
0006 int16 Watched object trigger state
0008 int32 Spew type. Only value of 0 supported (= radiation).
The rectangular area defined by reference object and the object of the action emits radiation while watched object is in given state (1 = active/open).
This is used only once, on level 2 for the small room in Beta quadrant. The door is both the reference as well as the watched object.
Hack Action Type 13: Oriented Trigger Object
This hack is exclusively used on level 8 to trigger three different taunts from Diego. Hence it is also called "Diego Taunt" in the source.
Oriented Trigger Object Details (12 byte)
0000 uint16 Horizontal direction
0002 [2]byte Unused
0004 int32 Object index
0008 [4]byte Unused
This hack triggers the given object only if the player looks to the given Horizontal direction (+/- 45°).
Value 0x0000 specifies north, going clockwise with increasing numbers, meaning:
0x0000 North (matches between NW and NE)
0x4000 East (matches between NE and SE)
0x8000 South (matches between SE and SW)
0xC000 West (matches between SW and NW)
Hack Action Type 14: Close Data MFD
Close Data MFD Details (12 byte)
0000 int32 Displayed object index
0004 [8]byte Unused
If the specified object is currently displayed in the "Data" MFD, close it and return to previous display.
This hack is used only once to close the keypad panel from the reactor if an invalid combination is entered.
Hack Action Type 15: Earth destruction by laser
This hack has no parameters (all 12 bytes 0x00) and lets the player receive the message about the fired laser. The game continues after the message has played. Images and text are hardcoded.
Hack Action Type 16: Change Critter Type Global
Change Critter Type Global Action Details (16 byte)
0000 int32 Critter type - 0x00CCSSTT
0004 byte New type
0005 [7]byte Unused
This hack morphs all critters of given object type in the level and changes their type to the given one. Class and subclass stay the same. Stats, such as healthpoints, are maintained as well.
If new type specifies a value greater than 0x0F, the object will be destroyed.
Action Type 20: Set Tile Textures
This action is not used in the main game.
Set Tile Textures Action Details (16 byte)
0000 int32 Area
0004 int32 Floor Operation
0008 int32 Wall Operation
000C int32 Ceiling Operation
The area defines a rectangular area of affected tiles.
If area is less than 0x10000, then only one tile is affected, identified by 0xXXYY.
Otherwise, area is interpreted as two object indices (interpreted as quest value keys), that define the area by their respective location.
The three operation fields identify, per texture, what to do.
Texture Operation (4 byte)
0000 int16 Source filter
0002 int16 Destination texture
If source filter is either equal to or greater than 0x1000, or the tile uses the texture identified by this filter, then set the texture according to destination texture if this value is less than 0x1000.
Said differently, try to set destination texture only if the value is less than 0x1000, and consider only tiles if set as a flood-fill, or if the source matches.
Action Type 21: Set Critter State
Set Critter State Action Details (16 byte)
0000 int16 Filter parameter
0002 int16 Filter type
0004 int32 Area
0008 int32 New critter mood -- ignored if value >= 0x1000
000C int32 New critter orders -- ignored if value >= 0x1000
Sets the state of critters. See Critters for the enumeration values of critter states.
The filter type parameter defines via bits which critters should be considered and how the filter parameter is interpreted.
Filter Type Bitfield (2 byte)
0x0001 Consider loner critters only. If not set, only consider pack critters.
0x0002 Ignore loner/pack property of critter.
0x0004 If set, ```filter parameter``` identifies one specific critter to affect (regardless of remaining bits). Use area otherwise.
0x0008 Affect every critter in the area, regardless of subtype/type. (Note: only works for small areas)
If neither bits 0x0004, nor 0x0008 are set, then filter parameter specifies the subclass and type of affected critters (0xSSTT).
The area parameter defines the affected tiles in the following ways:
- All zero: affect entire level
- Lower 16 bits zero: upper 16 bits define half of the side-length of a square, with the tile of the action object at its center.
- Two 16 bit values identifying reference objects that define a rectangular area.
Unless the new critter mood is friendly, mood is ignored on combat level 0.
Action Type 22: Trap Message
Internally, such messages are called "barks".
Trap Message Action Details (16 byte)
0000 sint32 Background image
0004 int32 Message index (within resource 0x0867)
0008 int32 Text colour
000C int32 MFD suppression flag; 0: Show in MFD, 1: Show only in HUD
The Background image and Text colour are only considered for display in MFD. The user needs to have messages set to "text" or "both" to see them.
For the Background image, the following values are possible:
-1 SHODAN (black and white)
-2 Diego
The game uses other image references as well, yet they don't work. This is due to the code being modified to ignore positive background image values.
Action Type 23: Spawn Objects
Spawn Objects Action Details (16 byte)
0000 int32 Object type; Format 0x00CCSSTT
0004 int32 Area
0008 int32 Quantity - quest value key
000C int32 Flags
This action spawns a random number of objects, randomly distributed within an area. The spawned objects are placed at the floor in the center of the tile.
The area field specifies a rectangular area, either based on two objects, or a square.
If area is less than 0x10000, then it specifies half of the final side-length of the resulting square, and the trap object's location is at the lower-right corner of this square. Otherwise, area specifies two object indices that define the rectangle with their locations.
Objects are only spawned if the Combat value is 1 or higher. If it is 3, then one more object than requested is spawned.
Not all classes can be spawned.
Although the game uses enemies exclusively, ammo, explosives, and patches can be spawned as well.
Spawn Objects Flags (4 byte)
0x00000001 Avoid spawn if tile is within a distance of 7 based on the sum of X and Y deltas.
0x00000002 Avoid spawn if hacker looks at the tile within a distance of 14 based on the sum of X and Y deltas.
0x00000004 Allow spawn if tile is an elevator tile (identified by elevator music).
0x00000008 Force spawn, even if the ceiling is too low, or the tile contains already a critter.
Action Type 24: Change Object Type
Internally, this action is called "transmogrify".
Change Object Type Action Details (16 byte)
0000 int32 Object index
0004 int16 New type
0006 int16 Reset mask
0008 [8]byte Unused
This action sets, or toggles, the type of an object. It is primarily used to extend and retract force bridges.
For bridges in their retracted state, the game uses "Elephant, Jorp" (
7/7/8), an invisible placeholder type.
The Reset mask is used when the specified object is already at given type. If the specified object is already at given type,
then the new type is calculated as New type XOR Reset mask.
So, to toggle between
0x08and0x09,New typeshould be0x08andReset maskmust be set to0x01. To toggle between0x08and0x07,New typeshould be0x07andReset maskmust be set to0x0F.
The first byte of unused field at
0008is set to1for only one force bridge in the game (on level 2) and is ignored. It appears that an earlier version of the code supported suppressing of animations.