/*
 * Author: PabstMirror
 * DEV to find a firing solution for a given range
 *
 * Arguments:
 * 0: Range to Hit (Meters)<NUMBER>
 * 1: Height To Hit (Meters)<NUMBER>
 * 2: Muzzle Velocity (M/S)<NUMBER>
 * 3: Air Friction <NUMBER>
 * 4: Time Step (seconds) (eg 1/50 will simulate 50 cycles per second) <NUMBER>
 *
 * Return Value:
 * ARRAY - [NUMBER - Elevation In Degrees, NUMBER - Shot Durration]
 *
 * Example:
 * [_rangeToHit, _heightToHit, _muzzleVelocity, _airFriction, TIME_STEP] call FUNC(simulateFindSolution);
 *
 * Public: No
 */
#include "script_component.hpp"

private ["_rangeToHit", "_heightToHit", "_muzzleVelocity", "_airFriction", "_maxElev", "_minElev", "_error", "_solutionElevation", "_lastTestResult", "_numberOfAttempts"];

#define MAX_ATTEMPTS 22

_rangeToHit = _this select 0;
_heightToHit = _this select 1;
_muzzleVelocity = _this select 2;
_airFriction = _this select 3;
_timeStep = _this select 4;

_maxElev = 90;
_minElev = 45; //todo - Low Angle Howitzers???

_error = 10000;
_solutionElevation = -1;
_lastTestResult = [];
_numberOfAttempts = 0;

//(binary search)
while {(_numberOfAttempts < MAX_ATTEMPTS) && {(abs _error) > 0.2}} do {
    _numberOfAttempts = _numberOfAttempts + 1;
    _solutionElevation = (_maxElev + _minElev) / 2;
    _lastTestResult = [_solutionElevation, _muzzleVelocity, _airFriction, 15, 1, 0, 0, _heightToHit, _timeStep] call FUNC(dev_simulateShot);
    _error = _rangeToHit - (_lastTestResult select 0);
    if (_error > 0) then {
        _maxElev = _solutionElevation; //test range was short
    } else {
        _minElev = _solutionElevation; //test range was long
    };
};
if (_numberOfAttempts >= MAX_ATTEMPTS) exitWith {[]};

//return the elevation and ACE_time required
[_solutionElevation, (_lastTestResult select 1)]