ardupilot/libraries/AP_Math/vector3.cpp

/// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-
/*
 * vector3.cpp
 * Copyright (C) Andrew Tridgell 2012
 *
 * This file is free software: you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This file is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "AP_Math.h"

#define HALF_SQRT_2 0.70710678118654757

// rotate a vector by a standard rotation, attempting
// to use the minimum number of floating point operations
template <typename T>
void Vector3<T>::rotate(enum Rotation rotation)
{
    T tmp;
    switch (rotation) {
    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;
    }
    }
}

// vector cross product
template <typename T>
Vector3<T> Vector3<T>::operator %(const Vector3<T> &v) const
{
    Vector3<T> temp(y*v.z - z*v.y, z*v.x - x*v.z, x*v.y - y*v.x);
    return temp;
}

// dot product
template <typename T>
T Vector3<T>::operator *(const Vector3<T> &v) const
{
    return x*v.x + y*v.y + z*v.z;
}

template <typename T>
float Vector3<T>::length(void) const
{
    return (T)sqrt(*this * *this);
}

// only define for signed numbers
template void Vector3<float>::rotate(enum Rotation);
template float Vector3<float>::length(void) const;
template Vector3<float> Vector3<float>::operator %(const Vector3<float> &v) const;
template float Vector3<float>::operator *(const Vector3<float> &v) const;