ACE3/addons/atragmx/functions/fnc_calculate_solution.sqf

/*
 * Author: Ruthberg
 * Calculates the fireing solution
 *
 * Arguments:
 * 0: Scope base angle <NUMBER>
 * 1: Bullet mass <NUMBER>
 * 2: Bore height <NUMBER>
 * 3: air friction <NUMBER>
 * 4: muzzle velocity <NUMBER>
 * 5: temperature <NUMBER>
 * 6: barometric pressure <NUMBER>
 * 7: relative humidity <NUMBER>
 * 8: simulation steps <NUMBER>
 * 9: wind speed <ARRAY>
 * 10: wind direction <NUMBER>
 * 11: inclination angle <NUMBER>
 * 12: target speed <NUMBER>
 * 13: target range <NUMBER>
 * 14: ballistic coefficient <NUMBER>
 * 15: drag model <NUMBER>
 * 16: atmosphere model <STRING>
 * 17: Store range card data? <BOOL>
 * 18: Stability factor <NUMBER>
 * 19: Twist Direction <NUMBER>
 * 20: Latitude <NUMBER>
 *
 * Return Value:
 * 0: Elevation (MOA) <NUMBER>
 * 1: Windage (MOA) <ARRAY>
 * 2: Lead (MOA) <NUMBER>
 * 3: Time of fligth (SECONDS) <NUMBER>
 * 4: Remaining velocity (m/s) <NUMBER>
 * 5: Remaining kinetic energy (ft·lb) <NUMBER>
 * 6: Vertical coriolis drift (MOA) <NUMBER>
 * 7: Horizontal coriolis drift (MOA) <NUMBER>
 * 8: Spin drift (MOA) <NUMBER>
 *
 * Example:
 * call ace_atragmx_calculate_target_range_assist
 *
 * Public: No
 */
#include "script_component.hpp"

private ["_scopeBaseAngle", "_bulletMass", "_boreHeight", "_airFriction", "_muzzleVelocity", "_temperature", "_barometricPressure", "_relativeHumidity", "_simSteps", "_windSpeed1", "_windSpeed2", "_windDirection", "_inclinationAngle", "_targetSpeed", "_targetRange", "_drag", "_bc", "_dragModel", "_atmosphereModel", "_storeRangeCardData", "_stabilityFactor", "_twistDirection", "_latitude", "_directionOfFire"];
_scopeBaseAngle     = _this select 0;
_bulletMass         = _this select 1;
_boreHeight         = _this select 2;
_airFriction        = _this select 3;
_muzzleVelocity     = _this select 4;
_temperature        = _this select 5;
_barometricPressure = _this select 6;
_relativeHumidity   = _this select 7;
_simSteps           = _this select 8;
_windSpeed1          = (_this select 9) select 0;
_windSpeed2          = (_this select 9) select 1;
_windDirection      = _this select 10;
_inclinationAngle   = _this select 11;
_targetSpeed        = _this select 12;
_targetRange        = _this select 13;
_bc                 = _this select 14;
_dragModel          = _this select 15;
_atmosphereModel    = _this select 16;
_storeRangeCardData = _this select 17;
_stabilityFactor    = _this select 18;
_twistDirection     = _this select 19;
_latitude           = _this select 20;
_directionOfFire    = _this select 21;

private ["_bulletPos", "_bulletVelocity", "_bulletAccel", "_bulletSpeed", "_gravity", "_deltaT"];
_bulletPos = [0, 0, 0];
_bulletVelocity = [0, 0, 0];
_bulletAccel = [0, 0, 0];
_bulletSpeed = 0;
_gravity = [0, sin(_scopeBaseAngle + _inclinationAngle) * -9.80665, cos(_scopeBaseAngle + _inclinationAngle) * -9.80665];
_deltaT = 1 / _simSteps;

private ["_elevation", "_windage1", "_windage2", "_lead", "_TOF", "_trueVelocity", "_trueSpeed", "_kineticEnergy", "_verticalCoriolis", "_verticalDeflection", "_horizontalCoriolis", "_horizontalDeflection", "_spinDrift", "_spinDeflection"];
_elevation = 0;
_windage1 = 0;
_windage2 = 0;
_lead = 0;
_TOF = 0;
_trueVelocity = [0, 0, 0];
_trueSpeed = 0;
_verticalCoriolis = 0;
_verticalDeflection = 0;
_horizontalCoriolis = 0;
_horizontalDeflection = 0;
_spinDrift = 0;
_spinDeflection = 0;

private ["_n", "_range", "_rangeFactor"];
_n = 0;
_range = 0;
_rangeFactor = 1;
if (_storeRangeCardData) then {
    if (GVAR(currentUnit) == 1) then {
        _rangeFactor = 1.0936133;
    };
    GVAR(rangeCardData) = [];
};

private ["_wind1", "_wind2", "_windDrift"];
_wind1 = [cos(270 - _windDirection * 30) * _windSpeed1, sin(270 - _windDirection * 30) * _windSpeed1, 0];
_wind2 = [cos(270 - _windDirection * 30) * _windSpeed2, sin(270 - _windDirection * 30) * _windSpeed2, 0];
_windDrift = 0;
if (missionNamespace getVariable [QEGVAR(advanced_ballistics,enabled), false]) then {
    _bc = [_bc, _temperature, _barometricPressure, _relativeHumidity, _atmosphereModel] call EFUNC(advanced_ballistics,calculateAtmosphericCorrection);
};

private ["_speedTotal", "_stepsTotal", "_speedAverage"];
_speedTotal = 0;
_stepsTotal = 0;
_speedAverage = 0;

private ["_eoetvoesMultiplier"];
_eoetvoesMultiplier = 0;
if (missionNamespace getVariable [QEGVAR(advanced_ballistics,enabled), false]) then {
    _eoetvoesMultiplier = 2 * (0.0000729 * _muzzleVelocity / -9.80665) * cos(_latitude) * sin(_directionOfFire);
};

_TOF = 0;

_bulletPos set [0, 0];
_bulletPos set [1, 0];
_bulletPos set [2, -(_boreHeight / 100)];

_bulletVelocity set [0, 0];
_bulletVelocity set [1, Cos(_scopeBaseAngle) * _muzzleVelocity];
_bulletVelocity set [2, Sin(_scopeBaseAngle) * _muzzleVelocity];

while {_TOF < 15 && (_bulletPos select 1) < _targetRange} do {
    _bulletSpeed = vectorMagnitude _bulletVelocity;
    
    _speedTotal = _speedTotal + _bulletSpeed;
    _stepsTotal = _stepsTotal + 1;
    _speedAverage = (_speedTotal / _stepsTotal);

    _trueVelocity = _bulletVelocity vectorDiff _wind1;
    _trueSpeed = vectorMagnitude _trueVelocity;

    if (missionNamespace getVariable [QEGVAR(advanced_ballistics,enabled), false]) then {
        _drag = if (missionNamespace getVariable [QEGVAR(advanced_ballistics,extensionAvailable), false]) then {
            parseNumber(("ace_advanced_ballistics" callExtension format["retard:%1:%2:%3", _dragModel, _bc, _trueSpeed]))
        } else {
            ([_dragModel, _bc, _trueSpeed] call EFUNC(advanced_ballistics,calculateRetardation))
        };
        _bulletAccel = (vectorNormalized _trueVelocity) vectorMultiply (-1 * _drag);
    } else {
        _bulletAccel = _trueVelocity vectorMultiply (_trueSpeed * _airFriction);
    };

    _bulletAccel = _bulletAccel vectorAdd _gravity;

    _bulletVelocity = _bulletVelocity vectorAdd (_bulletAccel vectorMultiply _deltaT);
    _bulletPos = _bulletPos vectorAdd (_bulletVelocity vectorMultiply _deltaT);

    _TOF = _TOF + _deltaT;

    if (_storeRangeCardData) then {
        _range = GVAR(rangeCardStartRange) + _n * GVAR(rangeCardIncrement);
        if ((_bulletPos select 1) * _rangeFactor >= _range && _range <= GVAR(rangeCardEndRange)) then {
            if ((_bulletPos select 1) > 0) then {
                _elevation = - atan((_bulletPos select 2) / (_bulletPos select 1));
                _windage1 = - atan((_bulletPos select 0) / (_bulletPos select 1));
                _windDrift = (_wind2 select 0) * (_TOF - (_range / _rangeFactor) / _muzzleVelocity);
                _windage2 = - atan(_windDrift / (_bulletPos select 1));
            };
            if (_range != 0) then {
                _lead = (_targetSpeed * _TOF) / (Tan(3.38 / 60) * _range);
            };
            _kineticEnergy = 0.5 * (_bulletMass / 1000 * (_bulletSpeed ^ 2));
            _kineticEnergy = _kineticEnergy * 0.737562149;
            
            if ((missionNamespace getVariable [QEGVAR(advanced_ballistics,enabled), false]) && (_bulletPos select 1) > 0) then {
                // Coriolis
                _horizontalDeflection = 0.0000729 * ((_bulletPos select 1) ^ 2) * sin(_latitude) / _speedAverage;
                _horizontalCoriolis = - atan(_horizontalDeflection / (_bulletPos select 1));
                _windage1 = _windage1 + _horizontalCoriolis;
                _windage2 = _windage2 + _horizontalCoriolis;
                // Eoetvoes
                _verticalDeflection = (_bulletPos select 2) * _eoetvoesMultiplier;
                _verticalCoriolis = - atan(_verticalDeflection / (_bulletPos select 1));
                _elevation = _elevation + _verticalCoriolis;
                // Spin drift
                _spinDeflection = _twistDirection * 0.0254 * 1.25 * (_stabilityFactor + 1.2) * _TOF ^ 1.83;
                _spinDrift = - atan(_spinDeflection / (_bulletPos select 1));
                _windage1 = _windage1 + _spinDrift;
                _windage2 = _windage2 + _spinDrift;
            };
            
            GVAR(rangeCardData) set [_n, [_range, _elevation * 60, [_windage1 * 60, _windage2 * 60], _lead, _TOF, _bulletSpeed, _kineticEnergy]];
            _n = _n + 1;
        };
    };
};

if ((_bulletPos select 1) > 0) then {
    _elevation = - atan((_bulletPos select 2) / (_bulletPos select 1));
    _windage1 = - atan((_bulletPos select 0) / (_bulletPos select 1));
    _windDrift = (_wind2 select 0) * (_TOF - _targetRange / _muzzleVelocity);
    _windage2 = - atan(_windDrift / (_bulletPos select 1));
};

if (_targetRange != 0) then {
    _lead = (_targetSpeed * _TOF) / (Tan(3.38 / 60) * _targetRange);
};

_kineticEnergy = 0.5 * (_bulletMass / 1000 * (_bulletSpeed ^ 2));
_kineticEnergy = _kineticEnergy * 0.737562149;

if ((missionNamespace getVariable [QEGVAR(advanced_ballistics,enabled), false]) && (_bulletPos select 1) > 0) then {
    // Coriolis
    _horizontalDeflection = 0.0000729 * ((_bulletPos select 1) ^ 2) * sin(_latitude) / _speedAverage;
    _horizontalCoriolis = - atan(_horizontalDeflection / (_bulletPos select 1));
    _windage1 = _windage1 + _horizontalCoriolis;
    _windage2 = _windage2 + _horizontalCoriolis;
    // Eoetvoes
    _verticalDeflection = (_bulletPos select 2) * _eoetvoesMultiplier;
    _verticalCoriolis = - atan(_verticalDeflection / (_bulletPos select 1));
    _elevation = _elevation + _verticalCoriolis;
    // Spin drift
    _spinDeflection = _twistDirection * 0.0254 * 1.25 * (_stabilityFactor + 1.2) * _TOF ^ 1.83;
    _spinDrift = - atan(_spinDeflection / (_bulletPos select 1));
    _windage1 = _windage1 + _spinDrift;
    _windage2 = _windage2 + _spinDrift;
};

[_elevation * 60, [_windage1 * 60, _windage2 * 60], _lead, _TOF, _bulletSpeed, _kineticEnergy, _verticalCoriolis * 60, _horizontalCoriolis * 60, _spinDrift * 60]