From 71e01a2ee497684864673204d4a729aec288622a Mon Sep 17 00:00:00 2001
From: Bailey Danyluk <baileydanyluk@gmail.com>
Date: Mon, 4 Apr 2022 18:46:40 -0600
Subject: [PATCH] Update all Line guidance missiles

---
 addons/hot/CfgAmmo.hpp                        |  5 ++-
 addons/metis/CfgAmmo.hpp                      |  5 ++-
 .../functions/fnc_navigationType_line.sqf     | 34 +++++++++----------
 addons/sdb/CfgAmmo.hpp                        |  2 +-
 addons/vikhr/CfgAmmo.hpp                      |  5 ++-
 5 files changed, 23 insertions(+), 28 deletions(-)

diff --git a/addons/hot/CfgAmmo.hpp b/addons/hot/CfgAmmo.hpp
index 7905d23881..0b76370754 100644
--- a/addons/hot/CfgAmmo.hpp
+++ b/addons/hot/CfgAmmo.hpp
@@ -75,8 +75,8 @@ class CfgAmmo {
             defaultNavigationType = "Line";
             navigationTypes[] = { "Line" };
 
-            lineGainP = 35;
-            lineGainD = 30;
+            lineGainP = 7;
+            lineGainD = 6;
 
             initialPitch = 2;
 
@@ -87,7 +87,6 @@ class CfgAmmo {
             seekerMinRange = 75;
             seekerMaxRange = 4000;      // Range from the missile which the seeker can visually search
 
-            correctionDistance = 30; // distance from center of crosshair where missile slows down
             offsetFromCrosshair[] = { 0, 0, 0.5 }; // where the missile wants to stay in relation to the center of the crosshair.
 
             // Attack profile type selection
diff --git a/addons/metis/CfgAmmo.hpp b/addons/metis/CfgAmmo.hpp
index 98814f1034..c070343253 100644
--- a/addons/metis/CfgAmmo.hpp
+++ b/addons/metis/CfgAmmo.hpp
@@ -28,8 +28,8 @@ class CfgAmmo {
             defaultNavigationType = "Line";
             navigationTypes[] = { "Line" };
 
-            lineGainP = 30;
-            lineGainD = 30;
+            lineGainP = 10;
+            lineGainD = 9;
 
             seekLastTargetPos = 0;      // seek last target position [if seeker loses LOS of target, continue to last known pos]
             seekerAngle = 15;           // Angle from the shooter's view that can track the missile
@@ -38,7 +38,6 @@ class CfgAmmo {
             seekerMinRange = 80;
             seekerMaxRange = 2000;      // Range from the missile which the seeker can visually search
 
-            correctionDistance = 3; // distance from center of crosshair where missile slows down
             offsetFromCrosshair[] = { 0, 0, 0 }; // where the missile wants to stay in relation to the center of the crosshair.
 
             // Attack profile type selection
diff --git a/addons/missileguidance/functions/fnc_navigationType_line.sqf b/addons/missileguidance/functions/fnc_navigationType_line.sqf
index 9173d6eff1..8a9cef6744 100644
--- a/addons/missileguidance/functions/fnc_navigationType_line.sqf
+++ b/addons/missileguidance/functions/fnc_navigationType_line.sqf
@@ -20,26 +20,24 @@ _targetData params ["", "_targetDir", "_distance"];
 _flightParams params ["_pitchRate", "_yawRate"];
 
 _navigationParams params ["_proportionalGain", "", "_derivativeGain", "_lastErrorX", "_lastErrorY", "_correctionDistance"];
-private _targetDistance = _projectile vectorWorldToModelVisual (_targetDir vectorMultiply _distance);
+private _relativeTargetDirection = [0, (velocityModelSpace _projectile) select 1, 0] vectorAdd (_projectile vectorWorldToModelVisual (_targetDir vectorMultiply _distance));
 
-//_proportionalGain = 30;
-//_derivativeGain = 30;
-//_correctionDistance = 3;
-private _errorX = _targetDistance#0 / _correctionDistance;
-private _errorY = _targetDistance#2 / _correctionDistance;
+_proportionalGain = 50;
+_derivativeGain = 0;
 
-private _pX = _proportionalGain * _errorX;
-private _dX = if (_timestep != 0) then {
-    _derivativeGain * (_errorX - _lastErrorX) / _timestep
-} else {
-    0
+private _angleX = ((_relativeTargetDirection select 0) atan2 (_relativeTargetDirection select 1));
+private _angleY = ((_relativeTargetDirection select 2) atan2 (_relativeTargetDirection select 1));
+
+private _pX = _proportionalGain * _angleX;
+private _dX = 0;
+if (_timestep > 0) then {
+    _dX = _derivativeGain * (_angleX - _lastErrorX) / _timestep;
 };
 
-private _pY = _proportionalGain * _errorY;
-private _dY = if (_timestep != 0) then {
-    _derivativeGain * (_errorY - _lastErrorY) / _timestep
-} else {
-    0
+private _pY = _proportionalGain * _angleY;
+private _dY = 0;
+if (_timestep > 0) then {
+    _dY = _derivativeGain * (_angleY - _lastErrorY) / _timestep;
 };
 
 private _accelerationX = _pX + _dX;
@@ -51,7 +49,7 @@ private _commandedAcceleration = [
     _accelerationY
 ];
 
-_navigationParams set [3, _errorX];
-_navigationParams set [4, _errorY];
+_navigationParams set [3, _angleX];
+_navigationParams set [4, _angleY];
 
 _projectile vectorModelToWorldVisual _commandedAcceleration;
diff --git a/addons/sdb/CfgAmmo.hpp b/addons/sdb/CfgAmmo.hpp
index 2550f29fd2..824da78c27 100644
--- a/addons/sdb/CfgAmmo.hpp
+++ b/addons/sdb/CfgAmmo.hpp
@@ -22,7 +22,7 @@ class CfgAmmo {
             navigationTypes[] = { "LINE" };
 
             lineGainP = 50;
-            lineGainD = 1;
+            lineGainD = 0;
 
             seekLastTargetPos = 0;      // seek last target position [if seeker loses LOS of target, continue to last known pos]
             seekerAngle = 60;           // Angle from the shooter's view that can track the missile
diff --git a/addons/vikhr/CfgAmmo.hpp b/addons/vikhr/CfgAmmo.hpp
index f24a85fbb8..39cb2ee266 100644
--- a/addons/vikhr/CfgAmmo.hpp
+++ b/addons/vikhr/CfgAmmo.hpp
@@ -27,9 +27,8 @@ class CfgAmmo {
             defaultNavigationType = "Line";
             navigationTypes[] = { "Line" };
 
-            lineGainP = 40;
-            lineGainD = 30;
-            correctionDistance = 5;
+            lineGainP = 8;
+            lineGainD = 6;
 
             seekLastTargetPos = 0;      // seek last target position [if seeker loses LOS of target, continue to last known pos]
             seekerAngle = 15;           // Angle from the shooter's view that can track the missile