Move FCS calculation to extension

addons/fcs/functions/fnc_keyUp.sqf

@@ -105,59 +105,28 @@ if (_viewDiff != 0) then {
     _FCSAzimuth = (atan (_distance / _viewDiff) - (abs _viewDiff / _viewDiff) * 90) + _movingAzimuth;
 };
 
-// CALCULATE OFFSET FOR CURRENT WEAPON
+// CALCULATE OFFSET
 _FCSMagazines = [];
 _FCSElevation = [];
 
-_magazineType   = currentMagazine _vehicle;
-_ammoType       = getText   (configFile >> "CfgMagazines" >> _magazineType >> "ammo");
+{
+    _ammoType = getText   (configFile >> "CfgMagazines" >> _x >> "ammo");
     if !(getText (configFile >> "CfgAmmo" >> _ammoType >> "simulation") == "shotMissile") then {
         _maxElev        = getNumber (configFile >> "CfgVehicles" >> typeOf _vehicle >> "Turrets" >> "MainTurret" >> "maxElev");
-    _initSpeed      = getNumber (configFile >> "CfgMagazines" >> _magazineType >> "initSpeed");
+        _initSpeed      = getNumber (configFile >> "CfgMagazines" >> _x >> "initSpeed");
         _airFriction    = getNumber (configFile >> "CfgAmmo" >> _ammoType >> "airFriction");
-    _timeToLive     = getNumber (configFile >> "CfgAmmo" >> _ammoType >> "timeToLive");
-    _simulationStep = getNumber (configFile >> "CfgAmmo" >> _ammoType >> "simulationStep");
 
-    _offset = [_distance, _angleTarget, _maxElev, _initSpeed, _airFriction, _timeToLive, _simulationStep] call FUNC(getAngle);
+        _offset = "ace_fcs" callExtension format ["%1,%2,%3,%4", _initSpeed, _airFriction, _angleTarget, _distance];
+        _offset = parseNumber _offset;
 
-    _FCSMagazines = _FCSMagazines + [_magazineType];
+        _FCSMagazines = _FCSMagazines + [_x];
         _FCSElevation = _FCSElevation + [_offset];
     };
+} forEach _magazines;
 
 _vehicle setVariable [QGVAR(Distance),  _distance,     true];
 _vehicle setVariable [QGVAR(Magazines), _FCSMagazines, true];
 _vehicle setVariable [QGVAR(Elevation), _FCSElevation, true];
 _vehicle setVariable [QGVAR(Azimuth),   _FCSAzimuth,   true];
 
-// CALCULATE OFFSETS FOR OTHER WEAPONS IN THE BACKGROUND
-GVAR(backgroundCalculation) = [_vehicle, _magazines, _distance, _angleTarget, _FCSMagazines, _FCSElevation] spawn {
-    _vehicle      = _this select 0;
-    _magazines    = _this select 1;
-    _distance     = _this select 2;
-    _angleTarget  = _this select 3;
-    _FCSMagazines = _this select 4;
-    _FCSElevation = _this select 5;
-
-    {
-        if !(_x in _FCSMagazines) then {
-            _ammoType       = getText   (configFile >> "CfgMagazines" >> _x >> "ammo");
-            if !(getText (configFile >> "CfgAmmo" >> _ammoType >> "simulation") == "shotMissile") then {
-                _maxElev        = getNumber (configFile >> "CfgVehicles" >> typeOf _vehicle >> "Turrets" >> "MainTurret" >> "maxElev");
-                _initSpeed      = getNumber (configFile >> "CfgMagazines" >> _x >> "initSpeed");
-                _airFriction    = getNumber (configFile >> "CfgAmmo" >> _ammoType >> "airFriction");
-                _timeToLive     = getNumber (configFile >> "CfgAmmo" >> _ammoType >> "timeToLive");
-                _simulationStep = getNumber (configFile >> "CfgAmmo" >> _ammoType >> "simulationStep");
-
-                _offset = [_distance, _angleTarget, _maxElev, _initSpeed, _airFriction, _timeToLive, _simulationStep] call FUNC(getAngle);
-
-                _FCSMagazines = _FCSMagazines + [_x];
-                _FCSElevation = _FCSElevation + [_offset];
-            };
-        };
-    } forEach _magazines;
-
-    _vehicle setVariable [QGVAR(Magazines), _FCSMagazines, true];
-    _vehicle setVariable [QGVAR(Elevation), _FCSElevation, true];
-};
-
 [format ["%1: %2", localize "STR_ACE_FCS_ZeroedTo", _distance]] call EFUNC(common,displayTextStructured);

extensions/ace_fcs.cpp

@@ -0,0 +1,117 @@
+/*
+ * ace_fcs.cpp
+ *
+ * Calculates firing solution.
+ *
+ * Takes:
+ * initSpeed,airFriction,angle,distance as string
+ * Example: "900,-0.0004,2,1050"
+ *
+ * Returns:
+ * Correction to angle
+ */
+
+#include "stdafx.h"
+
+#define _USE_MATH_DEFINES
+
+#include <math.h>
+#include <sstream>
+#include <vector>
+#include <string>
+
+#define MAXELEVATION 20
+#define SIMULATIONSTEP 0.05
+#define MAXITERATIONS 120
+#define PRECISION 0.1
+#define RADIANS(X) (X / (180 / M_PI))
+
+static char version[] = "1.0";
+
+extern "C" {
+    __declspec (dllexport) void __stdcall RVExtension(char *output, int outputSize, const char *function);
+};
+
+std::vector<std::string> splitString(std::string input) {
+    std::istringstream ss(input);
+    std::string token;
+
+    std::vector<std::string> output;
+    while (std::getline(ss, token, ',')) {
+        output.push_back(token);
+    }
+
+    return output;
+}
+
+double traceBullet(double initSpeed, double airFriction, double angle, double angleTarget, double distance) {
+    double velX, velY, posX, posY, posTargetX, posTargetY, velMag;
+    velX = cos(RADIANS(angle)) * initSpeed;
+    velY = sin(RADIANS(angle)) * initSpeed;
+    posX = 0;
+    posY = 0;
+    posTargetX = cos(RADIANS(angleTarget)) * distance;
+    posTargetY = sin(RADIANS(angleTarget)) * distance;
+
+    int i = 0;
+    while (i < MAXITERATIONS) {
+        velMag = sqrt(pow(velX, 2) + pow(velY, 2));
+        velX += SIMULATIONSTEP * (velX * velMag * airFriction);
+        velY += SIMULATIONSTEP * (velY * velMag * airFriction - 9.81);
+        posX += velX * SIMULATIONSTEP;
+        posY += velY * SIMULATIONSTEP;
+        if (posX >= posTargetX) { break; }
+        i++;
+    }
+
+    return posY - posTargetY;
+}
+
+double getSolution(double initSpeed, double airFriction, double angleTarget, double distance) {
+    double posTargetX, posTargetY;
+    posTargetX = cos(RADIANS(angleTarget)) * distance;
+    posTargetY = sin(RADIANS(angleTarget)) * distance;
+
+    if (traceBullet(initSpeed, airFriction, MAXELEVATION, angleTarget, distance) < 0) {
+        return MAXELEVATION - angleTarget;
+    }
+
+    double a1 = angleTarget;
+    double a2 = MAXELEVATION;
+    double f1, f2, tmp;
+    f1 = traceBullet(initSpeed, airFriction, a1, angleTarget, distance);
+    if (fabs(f1) <= PRECISION) { return 0; }
+    while (fabs(f1) > PRECISION) {
+        f2 = traceBullet(initSpeed, airFriction, a2, angleTarget, distance);
+        tmp = a2 - f2 * (a2 - a1) / (f2 - f1);
+        a1 = a2;
+        a2 = tmp;
+        f1 = f2;
+    }
+
+    return a2 - angleTarget;
+}
+
+// i like to live dangerously. jk, fix strncpy sometime pls.
+#pragma warning( push )
+#pragma warning( disable : 4996 )
+
+void __stdcall RVExtension(char *output, int outputSize, const char *function) {
+    if (!strcmp(function, "version")) {
+        strncpy(output, version, outputSize);
+    } else {
+        std::vector<std::string> argStrings = splitString(function);
+        double initSpeed = std::stod(argStrings[0]);
+        double airFriction = std::stod(argStrings[1]);
+        double angleTarget = std::stod(argStrings[2]);
+        double distance = std::stod(argStrings[3]);
+
+        double result = getSolution(initSpeed, airFriction, angleTarget, distance);
+        std::string resultString = std::to_string(result);
+
+        strcpy(output, resultString.c_str());
+        output[outputSize - 1] = '\0';
+    }
+}
+
+#pragma warning( pop )

extensions/stdafx.cpp

@@ -0,0 +1,8 @@
+// stdafx.cpp : source file that includes just the standard includes
+// ace_fcs.pch will be the pre-compiled header
+// stdafx.obj will contain the pre-compiled type information
+
+#include "stdafx.h"
+
+// TODO: reference any additional headers you need in STDAFX.H
+// and not in this file

extensions/stdafx.h

@@ -0,0 +1,16 @@
+// stdafx.h : include file for standard system include files,
+// or project specific include files that are used frequently, but
+// are changed infrequently
+//
+
+#pragma once
+
+#include "targetver.h"
+
+#define WIN32_LEAN_AND_MEAN             // Exclude rarely-used stuff from Windows headers
+// Windows Header Files:
+#include <windows.h>
+
+
+
+// TODO: reference additional headers your program requires here