From 9e2fd0e51ccc7e27f4e35155c4b08d08d75ca90d Mon Sep 17 00:00:00 2001
From: Martin Budden <mjbudden@gmail.com>
Date: Sat, 17 Dec 2016 08:10:46 +0000
Subject: [PATCH] Replaced use of power function

---
 src/main/common/maths.h | 1 +
 src/main/fc/mw.c        | 3 +--
 src/main/flight/pid.c   | 4 ++--
 3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/main/common/maths.h b/src/main/common/maths.h
index 61675514ee..78fd819d77 100644
--- a/src/main/common/maths.h
+++ b/src/main/common/maths.h
@@ -20,6 +20,7 @@
 #ifndef sq
 #define sq(x) ((x)*(x))
 #endif
+#define power3(x) ((x)*(x)*(x))
 
 // Undefine this for use libc sinf/cosf. Keep this defined to use fast sin/cos approximations
 #define FAST_MATH             // order 9 approximation
diff --git a/src/main/fc/mw.c b/src/main/fc/mw.c
index 0364878aa3..ad8201d203 100644
--- a/src/main/fc/mw.c
+++ b/src/main/fc/mw.c
@@ -147,7 +147,6 @@ bool isCalibrating()
 }
 
 #define RC_RATE_INCREMENTAL 14.54f
-#define RC_EXPO_POWER 3
 
 void calculateSetpointRate(int axis, int16_t rc) {
     float angleRate, rcRate, rcSuperfactor, rcCommandf;
@@ -167,7 +166,7 @@ void calculateSetpointRate(int axis, int16_t rc) {
 
     if (rcExpo) {
         float expof = rcExpo / 100.0f;
-        rcCommandf = rcCommandf * powerf(rcInput[axis], RC_EXPO_POWER) * expof + rcCommandf * (1-expof);
+        rcCommandf = rcCommandf * power3(rcInput[axis]) * expof + rcCommandf * (1-expof);
     }
 
     angleRate = 200.0f * rcRate * rcCommandf;
diff --git a/src/main/flight/pid.c b/src/main/flight/pid.c
index 26dd218fed..a534223850 100644
--- a/src/main/flight/pid.c
+++ b/src/main/flight/pid.c
@@ -263,10 +263,10 @@ void pidController(const pidProfile_t *pidProfile, uint16_t max_angle_inclinatio
                 dynC = c[axis];
                 if (setpointRate[axis] > 0) {
                     if ((setpointRate[axis] - previousSetpoint[axis]) < previousSetpoint[axis])
-                        dynC = dynC * powerf(rcInput[axis], 2) * relaxFactor[axis] + dynC * (1-relaxFactor[axis]);
+                        dynC = dynC * sq(rcInput[axis]) * relaxFactor[axis] + dynC * (1-relaxFactor[axis]);
                 } else if (setpointRate[axis] < 0) {
                     if ((setpointRate[axis] - previousSetpoint[axis]) > previousSetpoint[axis])
-                        dynC = dynC * powerf(rcInput[axis], 2) * relaxFactor[axis] + dynC * (1-relaxFactor[axis]);
+                        dynC = dynC * sq(rcInput[axis]) * relaxFactor[axis] + dynC * (1-relaxFactor[axis]);
                 }
             }
             const float rD = dynC * setpointRate[axis] - PVRate;    // cr - y