ACE3/addons/frag/functions/fnc_doSpall.sqf
2024-04-13 21:20:35 -05:00

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#include "..\script_component.hpp"
/*
* Author: Jaynus, NouberNou, Lambda.Tiger,
* This function creates spalling if the hit slowed the projectile speed down enough.
*
* Arguments:
* Arguments are the same as BI's "HitPart" EH:
* https://community.bistudio.com/wiki/Arma_3:_Event_Handlers#HitPart
*
* Return Value:
* None
*
* Example:
* [BIS_HITPART_EH_ARGS] call ace_frag_fnc_doSpall
*
* Public: No
*/
#define GLUE(g1,g2) g1##g2
if (CBA_missionTime < GVAR(nextSpallAllowTime)) exitWith {
TRACE_2("time exit",CBA_missionTime,GVAR(nextSpallAllowTime));
};
params ["_projectile", "_objectHit", "_lastPosASL", "_lastVelocity", "_surfaceNorm", "_surfaceType", "_ammo", "_shotParents", "_vectorUp"];
TRACE_9("doSpall",_projectile,_objectHit,_lastPosASL,_lastVelocity,_surfaceNorm,_surfaceType,_ammo,_shotParents,_vectorUp);
if (_ammo == "" || {_objectHit isKindOf "CAManBase"}) exitWith {
TRACE_4("invalid round or hit",CBA_missionTime,GVAR(nextSpallAllowTime),_objectHit,_lastPosASL);
};
private _material = _surfaceType call FUNC(getMaterialInfo);
if (_material == "ground") exitWith {
TRACE_1("ground",_surfaceType);
};
// Find spall speed / fragment info
_ammo call FUNC(getSpallInfo) params ["_caliber", "_explosive", "_indirectHit"];
private _vel = if (alive _projectile) then {
_explosive = 0; // didn't explode since it's alive a frame later
velocity _projectile
} else {
[0, 0, 0]
};
private _speedChange = 0 max (vectorMagnitude _lastVelocity - vectorMagnitude _vel);
/*
* This is all fudge factor since real spalling is too complex for calculation.
* There are two terms. The first is from round impact, taking a quasi scale
* of sqrt(2)/50 * round caliber * srqt(change in speed). The second term is
* explosive * indirect hit, for any explosive contribution
*/
private _spallPower = (ACE_FRAG_SPALL_CALIBER_COEF * _caliber * sqrt _speedChange + _explosive * _indirectHit) * GVAR(spallIntensity);
TRACE_3("found speed",_speedChange,_caliber,_spallPower);
if (_spallPower < ACE_FRAG_SPALL_POWER_MIN) exitWith {
TRACE_1("lowImpulse",_ammo);
};
private _lastVelocityNorm = vectorNormalized _lastVelocity;
private _deltaStep = _lastVelocityNorm vectorMultiply 0.05;
if (terrainIntersectASL [_lastPosASL vectorAdd _deltaStep, _lastPosASL]) exitWith {
TRACE_2("terrainIntersect",_lastPosASL,_deltaStep);
};
#ifdef DEBUG_MODE_DRAW
if GVAR(dbgSphere) then {
[_lastPosASL vectorAdd _lastVelocityNorm, "orange"] call FUNC(dev_sphereDraw);
[_lastPosASL, "yellow"] call FUNC(dev_sphereDraw);
};
#endif
/*
* Improve performance of finding otherside of object on shallow angle
* impacts. 120 degrees due to 90 degree offset with _lastVelocityNorm into object.
*/
private _spallPosASL = _lastPosASL vectorAdd _deltaStep;
if (120 > acos (_lastVelocityNorm vectorDotProduct _surfaceNorm)) then {
_spallPosASL = _spallPosASL vectorAdd (_deltaStep vectorMultiply 5);
};
private _insideObject = true;
for "_i" from 2 to 21 do
{
private _nextPos = _spallPosASL vectorAdd _deltaStep;
if (!lineIntersects [_spallPosASL, _nextPos]) then {
_spallPosASL = _nextPos vectorAdd (_deltaStep vectorMultiply 2);
_insideObject = false;
break
};
_spallPosASL = _nextPos;
};
if (_insideObject) exitWith {
TRACE_3("insideObj",_lastPosASL,_spallPosASL,alive _projectile);
};
// Passed all exitWiths
GVAR(nextSpallAllowTime) = CBA_missionTime + ACE_FRAG_SPALL_HOLDOFF;
#ifdef DEBUG_MODE_DRAW
if GVAR(dbgSphere) then {
[_spallPosASL, "green"] call FUNC(dev_sphereDraw);
};
#endif
private _spawnSize = switch (true) do
{
case (_spallPower < ACE_FRAG_SPALL_POWER_TINY_MAX): {"_spall_tiny"};
case (_spallPower < ACE_FRAG_SPALL_POWER_SMALL_MAX): {"_spall_small"};
case (_spallPower < ACE_FRAG_SPALL_POWER_MEDIUM_MAX): {"_spall_medium"};
case (_spallPower < ACE_FRAG_SPALL_POWER_LARGE_MAX): {"_spall_large"};
default {"_spall_huge"};
};
private _spallSpawner = createVehicle [
QUOTE(GLUE(ADDON,_)) + _material + _spawnSize,
ASLToATL _spallPosASL,
[],
0,
"CAN_COLLIDE"
];
_spallSpawner setVectorDirandUp [_lastVelocityNorm, _vectorUp];
_spallSpawner setVelocityModelSpace [0, _speedChange * ACE_FRAG_SPALL_VELOCITY_INHERIT_COEFF, 0];
_spallSpawner setShotParents _shotParents;
#ifdef DEBUG_MODE_FULL
systemChat ("spd: " + str speed _spallSpawner + ", spawner: " + _fragSpawnType + ", spallPow: " + str _spallPower);
#endif
#ifdef DEBUG_MODE_DRAW
_spallSpawner addEventHandler [
"SubmunitionCreated",
{
params ["", "_submunitionProjectile"];
_submunitionProjectile call FUNC(dev_addRound);
}
];
#endif