From 9a65b766a22e80fdb62507c682b4a13a4b941ebf Mon Sep 17 00:00:00 2001
From: ctzsnooze <chris.thompson@sydney.edu.au>
Date: Tue, 7 Jul 2020 15:11:17 +1000
Subject: [PATCH] refactor Thrust Linear to initialise throttleCompensateAmount
 in pid_init.c

Maybe this could avoid recaculating throttleCompensateAmount every PID loop?
---
 src/main/flight/pid.c      | 3 +--
 src/main/flight/pid.h      | 1 +
 src/main/flight/pid_init.c | 1 +
 3 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/main/flight/pid.c b/src/main/flight/pid.c
index 8fbffdd53..ece7425f4 100644
--- a/src/main/flight/pid.c
+++ b/src/main/flight/pid.c
@@ -294,9 +294,8 @@ float pidCompensateThrustLinearization(float throttle)
 {
     if (pidRuntime.thrustLinearization != 0.0f) {
         // for whoops where a lot of TL is needed, allow more throttle boost
-        const float throttleCompensateAmount = (1.0f - 0.5f * pidRuntime.thrustLinearization);
         const float throttleReversed = (1.0f - throttle);
-        throttle /= 1.0f + throttleCompensateAmount * powerf(throttleReversed, 2) * pidRuntime.thrustLinearization;
+        throttle /= 1.0f + pidRuntime.throttleCompensateAmount * powerf(throttleReversed, 2) * pidRuntime.thrustLinearization;
     }
     return throttle;
 }
diff --git a/src/main/flight/pid.h b/src/main/flight/pid.h
index a13dd6e1f..dfc59fa28 100644
--- a/src/main/flight/pid.h
+++ b/src/main/flight/pid.h
@@ -351,6 +351,7 @@ typedef struct pidRuntime_s {
 
 #ifdef USE_THRUST_LINEARIZATION
     float thrustLinearization;
+    float throttleCompensateAmount;
 #endif
 
 #ifdef USE_AIRMODE_LPF
diff --git a/src/main/flight/pid_init.c b/src/main/flight/pid_init.c
index 4b7a7c94f..632a4e86d 100644
--- a/src/main/flight/pid_init.c
+++ b/src/main/flight/pid_init.c
@@ -375,6 +375,7 @@ void pidInitConfig(const pidProfile_t *pidProfile)
 
 #ifdef USE_THRUST_LINEARIZATION
     pidRuntime.thrustLinearization = pidProfile->thrustLinearization / 100.0f;
+    pidRuntime.throttleCompensateAmount = (1.0f - 0.5f * pidRuntime.thrustLinearization);
 #endif
 #if defined(USE_D_MIN)
     for (int axis = FD_ROLL; axis <= FD_YAW; ++axis) {