ACE3/addons/advanced_ballistics/functions/fnc_calculateBarrelLengthVelocityShift.sqf
PabstMirror 54397abaa2 AB - Handle subsonic ammo when not defined
Fix #3062
- Add basic AB configs for subsonic russian bullets.
- When building ab ammo cache, if round is subsonic and does not have AB
configured
attempt to use the parent's config, scaled down to the subsonic's round
speed.
2016-01-07 15:06:12 -06:00

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/*
* Author: Ruthberg, MikeMatrix, joko // Jonas
*
* Calculates the muzzle velocity shift caused by different barrel lengths
*
* Arguments:
* 0: barrel length - mm
* 1: muzzle velocity lookup table - m/s <ARRAY>
* 2: barrel length lookup table - mm <ARRAY>
* 3: muzzle velocity - m/s <NUMBER>
*
* Return Value:
* muzzle velocity shift - m/s <NUMBER>
*
* Public: No
*/
#include "script_component.hpp"
scopeName "main";
private ["_muzzleVelocityTableCount", "_barrelLengthTableCount", "_lowerDataIndex",
"_upperDataIndex", "_lowerBarrelLength", "_upperBarrelLength", "_lowerMuzzleVelocity",
"_upperMuzzleVelocity", "_interpolationRatio"];
params ["_barrelLength", "_muzzleVelocityTable", "_barrelLengthTable", "_muzzleVelocity"];
TRACE_4("params",_barrelLength,_muzzleVelocityTable,_barrelLengthTable,_muzzleVelocity);
// If barrel length is not defined, then there is no point in calculating muzzle velocity
if (_barrelLength == 0) exitWith { 0 };
_muzzleVelocityTableCount = count _muzzleVelocityTable;
_barrelLengthTableCount = count _barrelLengthTable;
// Exit if tables are different sizes, have no elements or have only one element
if (_muzzleVelocityTableCount != _barrelLengthTableCount || _muzzleVelocityTableCount == 0 || _barrelLengthTableCount == 0) exitWith { 0 };
if (_muzzleVelocityTableCount == 1) exitWith { (_muzzleVelocityTable select 0) - _muzzleVelocity };
// If we have the precise barrel length value, return result immediately
if (_barrelLength in _barrelLengthTable) exitWith {
(_muzzleVelocityTable select (_barrelLengthTable find _barrelLength)) - _muzzleVelocity
};
// Limit values to lower and upper bound of data we have available
if (_barrelLength <= (_barrelLengthTable select 0)) exitWith { (_muzzleVelocityTable select 0) - _muzzleVelocity };
if (_barrelLength >= (_barrelLengthTable select _barrelLengthTableCount - 1)) exitWith { (_muzzleVelocityTable select _barrelLengthTableCount - 1) - _muzzleVelocity };
// Find closest bordering values for barrel length
{
if (_barrelLength <= _x) then {
_upperDataIndex = _forEachIndex;
_lowerDataIndex = _upperDataIndex - 1;
breakTo "main";
};
} forEach _barrelLengthTable;
// Worst case scenario
if (isNil "_lowerDataIndex" || isNil "_upperDataIndex") exitWith {0};
_lowerBarrelLength = _barrelLengthTable select _lowerDataIndex;
_upperBarrelLength = _barrelLengthTable select _upperDataIndex;
_lowerMuzzleVelocity = _muzzleVelocityTable select _lowerDataIndex;
_upperMuzzleVelocity = _muzzleVelocityTable select _upperDataIndex;
// Calculate interpolation ratio
_interpolationRatio = if (abs (_lowerBarrelLength - _upperBarrelLength) > 0) then {
(_upperBarrelLength - _barrelLength) / (_upperBarrelLength - _lowerBarrelLength)
} else {
0
};
// Calculate interpolated muzzle velocity shift
(_lowerMuzzleVelocity + ((_upperMuzzleVelocity - _lowerMuzzleVelocity) * (1 - _interpolationRatio))) - _muzzleVelocity // Return