From f56724f7dff1f6d1167f4fd61015ffe24a64c8c9 Mon Sep 17 00:00:00 2001
From: Andrew Tridgell <tridge@samba.org>
Date: Thu, 3 Jul 2014 14:02:05 +1000
Subject: [PATCH] lib/conversion: added rotate_3f()

will be used for user specified rotations in sensor drivers
---
 src/lib/conversion/rotation.cpp | 142 ++++++++++++++++++++++++++++++++
 src/lib/conversion/rotation.h   |   8 ++
 2 files changed, 150 insertions(+)

diff --git a/src/lib/conversion/rotation.cpp b/src/lib/conversion/rotation.cpp
index 614877b183..e177157333 100644
--- a/src/lib/conversion/rotation.cpp
+++ b/src/lib/conversion/rotation.cpp
@@ -49,3 +49,145 @@ get_rot_matrix(enum Rotation rot, math::Matrix<3,3> *rot_matrix)
 
 	rot_matrix->from_euler(roll, pitch, yaw);
 }
+
+#define HALF_SQRT_2 0.70710678118654757f
+
+__EXPORT void
+rotate_3f(enum Rotation rot, float &x, float &y, float &z)
+{
+    float tmp;
+    switch (rot) {
+    case ROTATION_NONE:
+    case ROTATION_MAX:
+        return;
+    case ROTATION_YAW_45: {
+        tmp = HALF_SQRT_2*(x - y);
+        y   = HALF_SQRT_2*(x + y);
+        x = tmp;
+        return;
+    }
+    case ROTATION_YAW_90: {
+        tmp = x; x = -y; y = tmp;
+        return;
+    }
+    case ROTATION_YAW_135: {
+        tmp = -HALF_SQRT_2*(x + y);
+        y   =  HALF_SQRT_2*(x - y);
+        x = tmp;
+        return;
+    }
+    case ROTATION_YAW_180:
+        x = -x; y = -y;
+        return;
+    case ROTATION_YAW_225: {
+        tmp = HALF_SQRT_2*(y - x);
+        y   = -HALF_SQRT_2*(x + y);
+        x = tmp;
+        return;
+    }
+    case ROTATION_YAW_270: {
+        tmp = x; x = y; y = -tmp;
+        return;
+    }
+    case ROTATION_YAW_315: {
+        tmp = HALF_SQRT_2*(x + y);
+        y   = HALF_SQRT_2*(y - x);
+        x = tmp;
+        return;
+    }
+    case ROTATION_ROLL_180: {
+        y = -y; z = -z;
+        return;
+    }
+    case ROTATION_ROLL_180_YAW_45: {
+        tmp = HALF_SQRT_2*(x + y);
+        y   = HALF_SQRT_2*(x - y);
+        x = tmp; z = -z;
+        return;
+    }
+    case ROTATION_ROLL_180_YAW_90: {
+        tmp = x; x = y; y = tmp; z = -z;
+        return;
+    }
+    case ROTATION_ROLL_180_YAW_135: {
+        tmp = HALF_SQRT_2*(y - x);
+        y   = HALF_SQRT_2*(y + x);
+        x = tmp; z = -z;
+        return;
+    }
+    case ROTATION_PITCH_180: {
+        x = -x; z = -z;
+        return;
+    }
+    case ROTATION_ROLL_180_YAW_225: {
+        tmp = -HALF_SQRT_2*(x + y);
+        y   =  HALF_SQRT_2*(y - x);
+        x = tmp; z = -z;
+        return;
+    }
+    case ROTATION_ROLL_180_YAW_270: {
+        tmp = x; x = -y; y = -tmp; z = -z;
+        return;
+    }
+    case ROTATION_ROLL_180_YAW_315: {
+        tmp =  HALF_SQRT_2*(x - y);
+        y   = -HALF_SQRT_2*(x + y);
+        x = tmp; z = -z;
+        return;
+    }
+    case ROTATION_ROLL_90: {
+        tmp = z; z = y; y = -tmp;
+        return;
+    }
+    case ROTATION_ROLL_90_YAW_45: {
+        tmp = z; z = y; y = -tmp;
+        tmp = HALF_SQRT_2*(x - y);
+        y   = HALF_SQRT_2*(x + y);
+        x = tmp;
+        return;
+    }
+    case ROTATION_ROLL_90_YAW_90: {
+        tmp = z; z = y; y = -tmp;
+        tmp = x; x = -y; y = tmp;
+        return;
+    }
+    case ROTATION_ROLL_90_YAW_135: {
+        tmp = z; z = y; y = -tmp;
+        tmp = -HALF_SQRT_2*(x + y);
+        y   =  HALF_SQRT_2*(x - y);
+        x = tmp;
+        return;
+    }
+    case ROTATION_ROLL_270: {
+        tmp = z; z = -y; y = tmp;
+        return;
+    }
+    case ROTATION_ROLL_270_YAW_45: {
+        tmp = z; z = -y; y = tmp;
+        tmp = HALF_SQRT_2*(x - y);
+        y   = HALF_SQRT_2*(x + y);
+        x = tmp;
+        return;
+    }
+    case ROTATION_ROLL_270_YAW_90: {
+        tmp = z; z = -y; y = tmp;
+        tmp = x; x = -y; y = tmp;
+        return;
+    }
+    case ROTATION_ROLL_270_YAW_135: {
+        tmp = z; z = -y; y = tmp;
+        tmp = -HALF_SQRT_2*(x + y);
+        y   =  HALF_SQRT_2*(x - y);
+        x = tmp;
+        return;
+    }
+    case ROTATION_PITCH_90: {
+        tmp = z; z = -x; x = tmp;
+        return;
+    }
+    case ROTATION_PITCH_270: {
+        tmp = z; z = x; x = -tmp;
+        return;
+    }
+    }
+}
diff --git a/src/lib/conversion/rotation.h b/src/lib/conversion/rotation.h
index 0c56494c5e..5187b448f2 100644
--- a/src/lib/conversion/rotation.h
+++ b/src/lib/conversion/rotation.h
@@ -118,4 +118,12 @@ const rot_lookup_t rot_lookup[] = {
 __EXPORT void
 get_rot_matrix(enum Rotation rot, math::Matrix<3,3> *rot_matrix);
 
+
+/**
+ * rotate a 3 element float vector in-place
+ */
+__EXPORT void
+rotate_3f(enum Rotation rot, float &x, float &y, float &z);
+
+
 #endif /* ROTATION_H_ */