From 642e5b17c53f8178678da0ce8f91d1ce6c505ce5 Mon Sep 17 00:00:00 2001
From: annabunches <annabunches@gmail.com>
Date: Mon, 19 Jul 2021 21:29:27 -0400
Subject: [PATCH] Simplify lots of code in the launch sequence.

---
 launch.ks         | 41 +++++++++++++++++++----------------------
 lib/navigation.ks | 12 ++++++++++++
 lib/throttle.ks   | 25 +------------------------
 ui/rocket.ks      |  2 +-
 4 files changed, 33 insertions(+), 47 deletions(-)

diff --git a/launch.ks b/launch.ks
index 694b43e..35cbd7c 100644
--- a/launch.ks
+++ b/launch.ks
@@ -1,3 +1,4 @@
+// runoncepath("lib/sensors").
 runoncepath("lib/throttle").
 runoncepath("lib/navigation").
 
@@ -5,8 +6,9 @@ parameter APOAPSIS_TARGET is 80000.
 parameter GRAVITY_TURN_START is 8000.
 parameter GRAVITY_PITCH is 75.
 parameter INITIAL_PITCH is 85.
-parameter MINIMUM_PITCH is 40.
-SensorCheck().
+parameter MINIMUM_PITCH is 5.
+
+local ATMO_TWR is 1.6.
 
 // Configure subsystems.
 CORE:PART:GETMODULE("kOSProcessor"):DOEVENT("Open Terminal").
@@ -23,57 +25,52 @@ from { local x is 5. } until x = 0 step { set x to x - 1. } do {
 // Hold throttle to maintain 1.5 TWR.
 // We do *not* use a PID Loop here because we can
 // calculate the correct value discretely.
-lock THROTTLE to ThrottleToTWR(1.5).
+lock THROTTLE to ThrottleToTWR(ATMO_TWR).
+print "Throttling to maintain a TWR  of " + ATMO_TWR.
 
 // Main ascent control.
-lock THROTTLE to 1.0.
 lock STEERING to heading(90,90,270).
 stage.
-
 wait until SHIP:ALTITUDE > 200.
-lock STEERING to heading(90, INITIAL_PITCH, 270).
 
+print "Vectoring away from launchpad".
+lock STEERING to heading(90, INITIAL_PITCH, 270).
 wait until SHIP:ALTITUDE > GRAVITY_TURN_START.
 
 print "Pitching for gravity turn".
-
 // Pitch over...
 lock STEERING to heading(90, GRAVITY_PITCH, 270).
-print ("Locked to heading " + STEERINGMANAGER:TARGET). // debug?
 // Wait until we have rotated to (approximately) that pitch...
 wait until vectorangle(
   SHIP:FACING:FOREVECTOR,
   STEERINGMANAGER:TARGET:FOREVECTOR)
   < 0.5.
+
 // then wait until Prograde catches up.
 wait until vectorangle(
   SHIP:SRFPROGRADE:FOREVECTOR,
   STEERINGMANAGER:TARGET:FOREVECTOR)
   < 0.5.
 
-print "Locking to prograde".
+print "Locking to prograde, letting gravity do the hard work.".
+lock STEERING to GetAscentVector(MINIMUM_PITCH).
+wait until SHIP:ALTITUDE > 32000. // todo: if we have a pressure sensor we can use it to decide when to kick the throttle up instead, neat solution for e.g. Duna and Eve.
 
-until SHIP:ORBIT:APOAPSIS > 80000 {
-  // todo: we may need different values for bodies other than Kerbin.
-  local newHeading is lookdirup(SHIP:SRFPROGRADE:FOREVECTOR,
-    heading(90, 0, 270):TOPVECTOR).
-  if GetPitch(newHeading:FOREVECTOR) < MINIMUM_PITCH {
-    set newHeading to heading(90, MINIMUM_PITCH, 270).
-  }
-  lock STEERING to newHeading.
-  wait 0.001.
-}
+lock THROTTLE to 1.0.
+wait until SHIP:ORBIT:APOAPSIS > APOAPSIS_TARGET.
 
 lock THROTTLE to 0.0.
 set SHIP:CONTROL:PILOTMAINTHROTTLE to 0.
-wait 0.001.
+wait 0.001. // make sure these control updates get applied
+
 print "Target apoapsis acquired. Creating maneuver node".
-
 AddCircularizationNode().
-
 print "Releasing controls. Circularization maneuver added. Good luck, Kerman!".
 unlock THROTTLE.
 unlock STEERING.
 SAS on.
 wait 5.
+
+// todo - automatically execute the node
+
 CORE:PART:GETMODULE("kOSProcessor"):DOEVENT("Close Terminal").
diff --git a/lib/navigation.ks b/lib/navigation.ks
index ae70d11..c893aa3 100644
--- a/lib/navigation.ks
+++ b/lib/navigation.ks
@@ -6,6 +6,18 @@ function GetPitch {
   return 90 - vectorangle(SHIP:UP:FOREVECTOR, v).
 }
 
+function GetAscentVector {
+  parameter minPitch.
+  // face prograde, but hold a solid eastern heading and don't
+  // rotate the ship
+  local newHeading is lookdirup(SHIP:SRFPROGRADE:FOREVECTOR,
+    heading(90, 0, 270):TOPVECTOR).
+  if GetPitch(newHeading:FOREVECTOR) < minPitch {
+    set newHeading to heading(90, minPitch, 270).
+  }
+  return newHeading.
+}
+
 function AddCircularizationNode {
   parameter usePeriapsis is false.
   local target is SHIP:ORBIT:APOAPSIS.
diff --git a/lib/throttle.ks b/lib/throttle.ks
index ce34adb..99aaef9 100644
--- a/lib/throttle.ks
+++ b/lib/throttle.ks
@@ -2,14 +2,7 @@
 @lazyglobal off.
 
 local G is 9.81.
-lock G to GetGravAcc().
-
-function GetGravAcc {
-  if HAS_GRAV_SENSOR = true {
-    return SHIP:SENSORS:GRAV:MAG.
-  }
-  return SHIP:BODY:MU / ((SHIP:BODY:RADIUS+SHIP:ALTITUDE)^2).
-}
+lock G to SHIP:BODY:MU / ((SHIP:BODY:RADIUS+SHIP:ALTITUDE)^2).
 
 // Returns the throttle value you should use to achieve the
 // target TWR. If TWR can't be achieved, returns 1.0. (full throttle)
@@ -27,22 +20,6 @@ function TWR {
   return t/(m*G).
 }
 
-// Check for various sensors and set appropriate global constants.
-// Currently only checks for grav sensor, as that's the only one used by this library.
-global HAS_GRAV_SENSOR is false.
-function SensorCheck {
-  local SensorList is 0.
-  list SENSORS in SensorList.
-  for s in SensorList {
-    if s:type = "grav" {
-      print "Gravometric sensor detected".
-      set HAS_GRAV_SENSOR to true.
-      return.
-    }
-  }
-  set HAS_GRAV_SENSOR to false.
-}
-
 function BurnTime {
   parameter dV.
 
diff --git a/ui/rocket.ks b/ui/rocket.ks
index 9016142..72c1862 100644
--- a/ui/rocket.ks
+++ b/ui/rocket.ks
@@ -24,7 +24,7 @@ local initialPitch is hBox:AddTextField("85").
 
 local hBox is interface:AddHBox().
 hBox:AddLabel("Minimum Pitch").
-local minimumPitch is hBox:AddTextField("40").
+local minimumPitch is hBox:AddTextField("5").
 
 local hBox is interface:AddHBox().
 hBox:AddLabel("Gravity Turn @").