de-duplicate degrees to radians code.

Note, this also makes the operator precedence clearer.

src/boardalignment.c

@@ -29,10 +29,9 @@ void initBoardAlignment(boardAlignment_t *boardAlignment)
 
     standardBoardAlignment = false;
 
-    // deg2rad
+    roll = degreesToRadians(boardAlignment->rollDegrees);
-    roll = boardAlignment->rollDegrees * M_PI / 180.0f;
+    pitch = degreesToRadians(boardAlignment->pitchDegrees);
-    pitch = boardAlignment->pitchDegrees * M_PI / 180.0f;
+    yaw = degreesToRadians(boardAlignment->yawDegrees);
-    yaw = boardAlignment->yawDegrees * M_PI / 180.0f;
 
     cosx = cosf(roll);
     sinx = sinf(roll);

src/maths.c

@@ -1,3 +1,4 @@
+#include <stdint.h>
 #include <math.h>
 
 #include "maths.h"
@@ -40,3 +41,9 @@ float devStandardDeviation(stdev_t *dev)
 {
     return sqrtf(devVariance(dev));
 }
+
+float degreesToRadians(int16_t degrees)
+{
+    return degrees * RAD;
+}
+

src/maths.h

@@ -12,6 +12,8 @@
 #define RADX10 (M_PI / 1800.0f)                  // 0.001745329252f
 #define RAD    (M_PI / 180.0f)
 
+#define DEG2RAD(degrees) (degrees * RAD)
+
 #define min(a, b) ((a) < (b) ? (a) : (b))
 #define max(a, b) ((a) > (b) ? (a) : (b))
 #define abs(x) ((x) > 0 ? (x) : -(x))
@@ -28,3 +30,4 @@ void devClear(stdev_t *dev);
 void devPush(stdev_t *dev, float x);
 float devVariance(stdev_t *dev);
 float devStandardDeviation(stdev_t *dev);
+float degreesToRadians(int16_t degrees);

src/mw.c

@@ -142,7 +142,7 @@ void annexCode(void)
     rcCommand[THROTTLE] = lookupThrottleRC[tmp2] + (tmp - tmp2 * 100) * (lookupThrottleRC[tmp2 + 1] - lookupThrottleRC[tmp2]) / 100;    // [0;1000] -> expo -> [MINTHROTTLE;MAXTHROTTLE]
 
     if (f.HEADFREE_MODE) {
-        float radDiff = (heading - headFreeModeHold) * M_PI / 180.0f;
+        float radDiff = degreesToRadians(heading - headFreeModeHold);
         float cosDiff = cosf(radDiff);
         float sinDiff = sinf(radDiff);
         int16_t rcCommand_PITCH = rcCommand[PITCH] * cosDiff + rcCommand[ROLL] * sinDiff;