From fecc77e2255c130aac31682a5b360e998eb73fa3 Mon Sep 17 00:00:00 2001
From: ulteq <ulteq@web.de>
Date: Sat, 28 Oct 2017 18:19:42 +0200
Subject: [PATCH] Advanced Ballistics - Improved random seed generator

---
 .../functions/fnc_handleFired.sqf             |  4 +++-
 .../AdvancedBallistics.cpp                    | 22 +++++++------------
 2 files changed, 11 insertions(+), 15 deletions(-)

diff --git a/addons/advanced_ballistics/functions/fnc_handleFired.sqf b/addons/advanced_ballistics/functions/fnc_handleFired.sqf
index 806f40c624..81a167696f 100644
--- a/addons/advanced_ballistics/functions/fnc_handleFired.sqf
+++ b/addons/advanced_ballistics/functions/fnc_handleFired.sqf
@@ -112,7 +112,9 @@ if (_caliber > 0 && _bulletLength > 0 && _bulletMass > 0 && _barrelTwist > 0) th
 
 GVAR(currentbulletID) = (GVAR(currentbulletID) + 1) % 10000;
 
-"ace_advanced_ballistics" callExtension format["new:%1:%2:%3:%4:%5:%6:%7:%8:%9:%10:%11:%12:%13:%14:%15:%16:%17", GVAR(currentbulletID), _airFriction, _ballisticCoefficients, _velocityBoundaries, _atmosphereModel, _dragModel, _stabilityFactor, _twistDirection, _transonicStabilityCoef, getPosASL _projectile, _bulletVelocity, EGVAR(common,mapLatitude), EGVAR(weather,currentTemperature), EGVAR(common,mapAltitude), EGVAR(weather,currentHumidity), EGVAR(weather,currentOvercast), CBA_missionTime toFixed 6];
+private _ammoCount = _unit ammo _muzzle;
+
+"ace_advanced_ballistics" callExtension format["new:%1:%2:%3:%4:%5:%6:%7:%8:%9:%10:%11:%12:%13:%14:%15:%16:%17:%18", GVAR(currentbulletID), _ammoCount, _airFriction, _ballisticCoefficients, _velocityBoundaries, _atmosphereModel, _dragModel, _stabilityFactor, _twistDirection, _transonicStabilityCoef, getPosASL _projectile, _bulletVelocity, EGVAR(common,mapLatitude), EGVAR(weather,currentTemperature), EGVAR(common,mapAltitude), EGVAR(weather,currentHumidity), EGVAR(weather,currentOvercast), CBA_missionTime toFixed 6];
 
 GVAR(allBullets) pushBack [_projectile, _caliber, _bulletTraceVisible, GVAR(currentbulletID)];
 
diff --git a/extensions/advanced_ballistics/AdvancedBallistics.cpp b/extensions/advanced_ballistics/AdvancedBallistics.cpp
index 5760ae797d..2c00538569 100644
--- a/extensions/advanced_ballistics/AdvancedBallistics.cpp
+++ b/extensions/advanced_ballistics/AdvancedBallistics.cpp
@@ -322,6 +322,7 @@ void __stdcall RVExtension(char *output, int outputSize, const char *function)
         EXTENSION_RETURN();
     } else if (!strcmp(mode, "new")) {
         unsigned int index = 0;
+        unsigned int ammoCount = 0;
         double airFriction = 0.0;
         char* ballisticCoefficientArray;
         char* ballisticCoefficient;
@@ -348,6 +349,7 @@ void __stdcall RVExtension(char *output, int outputSize, const char *function)
         double tickTime = 0.0;
 
         index = strtol(strtok_s(NULL, ":", &next_token), NULL, 10);
+        ammoCount = strtol(strtok_s(NULL, ":", &next_token), NULL, 10);
         airFriction = strtod(strtok_s(NULL, ":", &next_token), NULL);
         ballisticCoefficientArray = strtok_s(NULL, ":", &next_token);
         ballisticCoefficientArray++;
@@ -415,20 +417,12 @@ void __stdcall RVExtension(char *output, int outputSize, const char *function)
         bulletDatabase[index].overcast = overcast;
         bulletDatabase[index].startTime = tickTime;
         bulletDatabase[index].lastFrame = tickTime;
-
-        int angle = (int)round(atan2(bulletDatabase[index].bulletVelocity[0], bulletDatabase[index].bulletVelocity[1]) * 360 / M_PI);
-        bulletDatabase[index].randSeed = (unsigned)(720 + angle) % 720;
-        bulletDatabase[index].randSeed *= 3;
-        bulletDatabase[index].randSeed += (unsigned)round(abs(bulletDatabase[index].bulletVelocity[2]) / 2);
-        bulletDatabase[index].randSeed *= 3;
-        bulletDatabase[index].randSeed += (unsigned)round(abs(bulletDatabase[index].origin[0] / 2));
-        bulletDatabase[index].randSeed *= 3;
-        bulletDatabase[index].randSeed += (unsigned)round(abs(bulletDatabase[index].origin[1] / 2));
-        bulletDatabase[index].randSeed *= 3;
-        bulletDatabase[index].randSeed += (unsigned)abs(bulletDatabase[index].temperature) * 10;
-        bulletDatabase[index].randSeed *= 3;
-        bulletDatabase[index].randSeed += (unsigned)abs(bulletDatabase[index].humidity) * 10;
-        bulletDatabase[index].randGenerator.seed(bulletDatabase[index].randSeed);
+        if (transonicStabilityCoef < 1) {
+            unsigned int k1 = (unsigned)round(tickTime / 2);
+            unsigned int k2 = ammoCount;
+            bulletDatabase[index].randSeed = 0.5 * (k1 + k2) * (k1 + k2 + 1) + k2;
+            bulletDatabase[index].randGenerator.seed(bulletDatabase[index].randSeed);
+        }
 
         strncpy_s(output, outputSize, "", _TRUNCATE);
         EXTENSION_RETURN();