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SAMP internals

Everything on this page is about SA-MP 0.3.7-R4

• Client console commands
• Vehicle categories (client)
• Vehicle damage status

Client console commands

See samp.dll+690D0.

• /audiomsg - toggles whether messages are printed when audio streams are played
• /cmpstat - does absolutely nothing
• /ctd - toggles camera target debug (what is the effect?)
• /dl - toggles debug labels on vehicles
• /fontsize <size> - changes chat window's font size
• /fpslimit <limit> - set fps limit of the game. only has effect if "Frame limiter" in game settings is enabled.
• /headmove - toggles whether other players' character head will move to the direction they're looking at
• /hudscalefix - toggles a fix that ensures the minimap radar is a circle on widescreen resolutions
• /interior - prints the current game interior
• /logurls - toggles whether messages are printend when files are downloaded. file downloading is leftover code that is not usable.
• /mem - prints the game's streaming memory limit
• /nametagstatus - toggles whether the "hourglass" icon is shown next to players' nametags when they are paused
• /pagesize <size> - sets amount of lines that the chat window shows on screen
• /q - alias of /quit
• /quit - quit the game
• /rcon <command> - sends rcon commands to the server
• /rs [comment] - saves current position, depending on your state:
  • when on foot, saves x,y,z,facingAngle ; comment in Documents\GTA San Andreas User Files\SAMP\rawpositions.txt
  • when in car, saves model,x,y,z,heading,col1,col2 ; comment in rawvehicles.txt in your game folder (this seems like an oversight and was probably supposed to be in User Files too)
• /save [comment] - saves current position in Documents\GTA San Andreas User Files\SAMP\savedpositions.txt formatted as a AddPlayerClass or AddStaticVehicle function call, depending on your state.
• /testdw - send test values to the death message list (death message list may be hidden with F9)
• /timestamp - toggles whether to show timestamp before chat messages
• /togobjlight - seems unused

• /player_skin <skinid>
• /set_weather <weatherid>
• /set_time <hour> <minute>
• /v <model> - alias of /vehicle
• /vehicle <modelid> - spawns a vehicle next to you. model value is unchecked, so this will crash the client if it's invalid
• /vsel - opens vehicle selection UI. Use the JUMP/SPRINT keys to select the model and ENTER VEHICLE key to spawn

Vehicle Categories (client)

Some vehicle things are handled differently by the client depending on the category of the vehicle. The category of a vehicle is determined at runtime by its vtable. SAMP defines following categories:

• 0: other, which effectively is: trailer/monstertruck(+dune/dumper)/quadbike⁽¹⁾
• 1: automobile (vtable 0x871120)
• 2: motorcycle (vtable 0x871360)
• 3: heli (vtable 0x871680)
• 4: boat (vtable 0x8721A0)
• 5: plane (vtable 0x871948)
• 6: bike (vtable 0x871528)
• 7: train (vtable 0x872370)

Notes

⁽¹⁾ vehicles with a vtable that isn't one of the explicitely checked values are put in category 0. Besides all trailers, this also (maybe unexpectedly) includes Dumper, Monster, Monster A, Monster B, Quadbike, Dune. This is because the Dumper, Dune and all Monster vehicles are instances of CMonsterTruck and the Quadbike has its own unique CQuadBike class.

Vehicle damage status

See https://basdon.github.io/documented-samp-pawn-api/main.xml#Appendix_Vehicle_Damage_Status for an overview of vehicle support, behavior, and some quirks.

Server receiving damage from client

Server ignores damage status updates if it's not coming from the driver of the vehicle, otherwise it's applied and synced unconditionally and OnVehicleDamageStatusUpdate is invoked.

Client receiving damage from server

Behavior depends on the vehicle model it's being applied to, see also Vehicle categories. Most import to take into account: Dumper, Monster, Monster A, Monster B, Quadbike, Dune are categorized as "unknown", meaning none of their damage gets synced. The bumper may get damaged in the driver's game (or tires of a quad bike), but none of the other players will see any damage to that vehicle.

Client applies tire damage at CSampVehicle::ApplyVehicleDamageTires(char) with following behavior:

• for CHeli/CPlane/CBmx/CBoat/CTrain/Unknown: nop
• for CAutomobile: apply to CAutomobile.m_damageManager.wheel[]
• for CBike: apply to CBike.m_acWheelDamageState[]

Client applies other damage at CSampVehicle::ApplyVehicleDamagePanelsDoorsLights(int,int,char) with following behavior:

• for CBike/CHeli/CPlane/CBmx/CBoat/CTrain/Unknown: nop
• for CAutomobile/CPlane:
  • if not all values are 0:
    • apply panels doors lights to CAutomobile::m_damageManager
    • call CAutomobile::mCC() (seems to apply damage status things, spawn flying components if things are detached, ...)
  • if all values are 0: call CAutomobile::Fix⁽¹⁾⁽³⁾

Notes

⁽¹⁾ while CPlane inherits from CAutomobile, it overrides the Fix method yet SAMP still calls the base CAutomobile::Fix for CPlane instances. This is what causes the 'ghost door' effect⁽⁶⁾ on some planes after doing RepairVehicle()⁽²⁾ or updating damage status to 0 on planes.

For comparison, MTA dispatches to specific overridden methods based on the vehicle's model info:

if (pModelInfo->IsCar() || pModelInfo->IsMonsterTruck() || pModelInfo->IsTrailer())
    dwFunc = FUNC_CAutomobile__Fix(3);
else if (pModelInfo->IsPlane())
    dwFunc = FUNC_CPlane__Fix(3);
else if (pModelInfo->IsHeli())
    dwFunc = FUNC_CHeli__Fix(3);
else if (pModelInfo->IsBike())
    dwFunc = FUNC_CBike_Fix(3);

Source: https://github.com/multitheftauto/mtasa-blue/blob/bb0b32cb90f3379853fb9eab0a651caabd837d6f/Client/game_sa/CVehicleSA.cpp#L1120.

It also defines FUNC_CQuadBike__Fix⁽³⁾, yet that is not used in the above.

⁽²⁾ RepairVehicle(vehicleid) is implemented in SAMP by doing SetVehicleHealth(vehicleid, 1000.0); UpdateVehicleDamageStatus(vehicleid, 0, 0, 0, 0);.

⁽³⁾ Implementations of the Fix proc:

• CAutomobile::Fix does the following:
  • CAutomobile::m_damageManager.reset()
  • if (!(CVehicle::pHandlingData->uiModelFlags & 0x100(4))) m_damageManager.door[2] = door[3] = door[4] = door[5] = 4(5);
  • clump stuff
  • CVehicle::m_nVehicleFlags[1] &= 0xFE; (clears bIsDamaged)
  • matrix stuff
  • m_damageManager.wheel[0] = wheel[1] = wheel[2] = wheel[3] = 0; (seems unnecessary as m_damageManager.reset() already did this)
  • reset bouncing panels^{[citation needed]}
• CPlane::Fix does the following:
  • CAutomobile::m_damageManager.reset()
  • if (!(CVehicle::pHandlingData->uiModelFlags & 0x100(4))) m_damageManager.door[2] = door[3] = door[4] = door[5] = 4(5);
  • CVehicle::m_nVehicleFlags[1] &= 0xFE; (clears bIsDamaged)
• CHeli::Fix does the following:
  • CAutomobile::m_damageManager.reset()
  • CVehicle::m_nVehicleFlags[1] &= 0xFE; (clears bIsDamaged)
• CBike::Fix does the following:
  • CVehicle::m_nVehicleFlags[1] &= 0xFE; (clears bIsDamaged)
  • CBike::m_cDamageFlags &= 0xBF; (unknown)
  • CBike::m_acWheelDamageState[0] = CBike::m_acWheelDamageState[1] = 0;
• CQuadBike::Fix does the following:
  • CAutomobile::m_damageManager.reset()
  • m_damageManager.door[2] = door[3] = door[4] = door[5] = 4(5);
  • clump stuff
  • m_damageManager.wheel[0] = wheel[1] = wheel[2] = wheel[3] = 0; (seems unnecessary as m_damageManager.reset() already did this)
  • CVehicle::m_nVehicleFlags[1] &= 0xFE; (clears bIsDamaged)

⁽⁴⁾ uiModelFlags mask 0x100 means NO_DOORS, as per data/handling.cfg comments (field modelFlags (af)).

⁽⁵⁾ a damagemanager door value of 4 means that the door is removed/detached.

⁽⁶⁾ https://basdon.github.io/documented-samp-pawn-api/main.xml#Appendix_Vehicle_Damage_Status_planeghostdoors

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