firmware/src/Fusion/FusionMath.h
2024-06-11 17:47:45 -05:00

504 lines
15 KiB
C

/**
* @file FusionMath.h
* @author Seb Madgwick
* @brief Math library.
*/
#ifndef FUSION_MATH_H
#define FUSION_MATH_H
//------------------------------------------------------------------------------
// Includes
#include <math.h> // M_PI, sqrtf, atan2f, asinf
#include <stdbool.h>
#include <stdint.h>
//------------------------------------------------------------------------------
// Definitions
/**
* @brief 3D vector.
*/
typedef union {
float array[3];
struct {
float x;
float y;
float z;
} axis;
} FusionVector;
/**
* @brief Quaternion.
*/
typedef union {
float array[4];
struct {
float w;
float x;
float y;
float z;
} element;
} FusionQuaternion;
/**
* @brief 3x3 matrix in row-major order.
* See http://en.wikipedia.org/wiki/Row-major_order
*/
typedef union {
float array[3][3];
struct {
float xx;
float xy;
float xz;
float yx;
float yy;
float yz;
float zx;
float zy;
float zz;
} element;
} FusionMatrix;
/**
* @brief Euler angles. Roll, pitch, and yaw correspond to rotations around
* X, Y, and Z respectively.
*/
typedef union {
float array[3];
struct {
float roll;
float pitch;
float yaw;
} angle;
} FusionEuler;
/**
* @brief Vector of zeros.
*/
#define FUSION_VECTOR_ZERO ((FusionVector){.array = {0.0f, 0.0f, 0.0f}})
/**
* @brief Vector of ones.
*/
#define FUSION_VECTOR_ONES ((FusionVector){.array = {1.0f, 1.0f, 1.0f}})
/**
* @brief Identity quaternion.
*/
#define FUSION_IDENTITY_QUATERNION ((FusionQuaternion){.array = {1.0f, 0.0f, 0.0f, 0.0f}})
/**
* @brief Identity matrix.
*/
#define FUSION_IDENTITY_MATRIX ((FusionMatrix){.array = {{1.0f, 0.0f, 0.0f}, {0.0f, 1.0f, 0.0f}, {0.0f, 0.0f, 1.0f}}})
/**
* @brief Euler angles of zero.
*/
#define FUSION_EULER_ZERO ((FusionEuler){.array = {0.0f, 0.0f, 0.0f}})
/**
* @brief Pi. May not be defined in math.h.
*/
#ifndef M_PI
#define M_PI (3.14159265358979323846)
#endif
/**
* @brief Include this definition or add as a preprocessor definition to use
* normal square root operations.
*/
// #define FUSION_USE_NORMAL_SQRT
//------------------------------------------------------------------------------
// Inline functions - Degrees and radians conversion
/**
* @brief Converts degrees to radians.
* @param degrees Degrees.
* @return Radians.
*/
static inline float FusionDegreesToRadians(const float degrees)
{
return degrees * ((float)M_PI / 180.0f);
}
/**
* @brief Converts radians to degrees.
* @param radians Radians.
* @return Degrees.
*/
static inline float FusionRadiansToDegrees(const float radians)
{
return radians * (180.0f / (float)M_PI);
}
//------------------------------------------------------------------------------
// Inline functions - Arc sine
/**
* @brief Returns the arc sine of the value.
* @param value Value.
* @return Arc sine of the value.
*/
static inline float FusionAsin(const float value)
{
if (value <= -1.0f) {
return (float)M_PI / -2.0f;
}
if (value >= 1.0f) {
return (float)M_PI / 2.0f;
}
return asinf(value);
}
//------------------------------------------------------------------------------
// Inline functions - Fast inverse square root
#ifndef FUSION_USE_NORMAL_SQRT
/**
* @brief Calculates the reciprocal of the square root.
* See https://pizer.wordpress.com/2008/10/12/fast-inverse-square-root/
* @param x Operand.
* @return Reciprocal of the square root of x.
*/
static inline float FusionFastInverseSqrt(const float x)
{
typedef union {
float f;
int32_t i;
} Union32;
Union32 union32 = {.f = x};
union32.i = 0x5F1F1412 - (union32.i >> 1);
return union32.f * (1.69000231f - 0.714158168f * x * union32.f * union32.f);
}
#endif
//------------------------------------------------------------------------------
// Inline functions - Vector operations
/**
* @brief Returns true if the vector is zero.
* @param vector Vector.
* @return True if the vector is zero.
*/
static inline bool FusionVectorIsZero(const FusionVector vector)
{
return (vector.axis.x == 0.0f) && (vector.axis.y == 0.0f) && (vector.axis.z == 0.0f);
}
/**
* @brief Returns the sum of two vectors.
* @param vectorA Vector A.
* @param vectorB Vector B.
* @return Sum of two vectors.
*/
static inline FusionVector FusionVectorAdd(const FusionVector vectorA, const FusionVector vectorB)
{
const FusionVector result = {.axis = {
.x = vectorA.axis.x + vectorB.axis.x,
.y = vectorA.axis.y + vectorB.axis.y,
.z = vectorA.axis.z + vectorB.axis.z,
}};
return result;
}
/**
* @brief Returns vector B subtracted from vector A.
* @param vectorA Vector A.
* @param vectorB Vector B.
* @return Vector B subtracted from vector A.
*/
static inline FusionVector FusionVectorSubtract(const FusionVector vectorA, const FusionVector vectorB)
{
const FusionVector result = {.axis = {
.x = vectorA.axis.x - vectorB.axis.x,
.y = vectorA.axis.y - vectorB.axis.y,
.z = vectorA.axis.z - vectorB.axis.z,
}};
return result;
}
/**
* @brief Returns the sum of the elements.
* @param vector Vector.
* @return Sum of the elements.
*/
static inline float FusionVectorSum(const FusionVector vector)
{
return vector.axis.x + vector.axis.y + vector.axis.z;
}
/**
* @brief Returns the multiplication of a vector by a scalar.
* @param vector Vector.
* @param scalar Scalar.
* @return Multiplication of a vector by a scalar.
*/
static inline FusionVector FusionVectorMultiplyScalar(const FusionVector vector, const float scalar)
{
const FusionVector result = {.axis = {
.x = vector.axis.x * scalar,
.y = vector.axis.y * scalar,
.z = vector.axis.z * scalar,
}};
return result;
}
/**
* @brief Calculates the Hadamard product (element-wise multiplication).
* @param vectorA Vector A.
* @param vectorB Vector B.
* @return Hadamard product.
*/
static inline FusionVector FusionVectorHadamardProduct(const FusionVector vectorA, const FusionVector vectorB)
{
const FusionVector result = {.axis = {
.x = vectorA.axis.x * vectorB.axis.x,
.y = vectorA.axis.y * vectorB.axis.y,
.z = vectorA.axis.z * vectorB.axis.z,
}};
return result;
}
/**
* @brief Returns the cross product.
* @param vectorA Vector A.
* @param vectorB Vector B.
* @return Cross product.
*/
static inline FusionVector FusionVectorCrossProduct(const FusionVector vectorA, const FusionVector vectorB)
{
#define A vectorA.axis
#define B vectorB.axis
const FusionVector result = {.axis = {
.x = A.y * B.z - A.z * B.y,
.y = A.z * B.x - A.x * B.z,
.z = A.x * B.y - A.y * B.x,
}};
return result;
#undef A
#undef B
}
/**
* @brief Returns the dot product.
* @param vectorA Vector A.
* @param vectorB Vector B.
* @return Dot product.
*/
static inline float FusionVectorDotProduct(const FusionVector vectorA, const FusionVector vectorB)
{
return FusionVectorSum(FusionVectorHadamardProduct(vectorA, vectorB));
}
/**
* @brief Returns the vector magnitude squared.
* @param vector Vector.
* @return Vector magnitude squared.
*/
static inline float FusionVectorMagnitudeSquared(const FusionVector vector)
{
return FusionVectorSum(FusionVectorHadamardProduct(vector, vector));
}
/**
* @brief Returns the vector magnitude.
* @param vector Vector.
* @return Vector magnitude.
*/
static inline float FusionVectorMagnitude(const FusionVector vector)
{
return sqrtf(FusionVectorMagnitudeSquared(vector));
}
/**
* @brief Returns the normalised vector.
* @param vector Vector.
* @return Normalised vector.
*/
static inline FusionVector FusionVectorNormalise(const FusionVector vector)
{
#ifdef FUSION_USE_NORMAL_SQRT
const float magnitudeReciprocal = 1.0f / sqrtf(FusionVectorMagnitudeSquared(vector));
#else
const float magnitudeReciprocal = FusionFastInverseSqrt(FusionVectorMagnitudeSquared(vector));
#endif
return FusionVectorMultiplyScalar(vector, magnitudeReciprocal);
}
//------------------------------------------------------------------------------
// Inline functions - Quaternion operations
/**
* @brief Returns the sum of two quaternions.
* @param quaternionA Quaternion A.
* @param quaternionB Quaternion B.
* @return Sum of two quaternions.
*/
static inline FusionQuaternion FusionQuaternionAdd(const FusionQuaternion quaternionA, const FusionQuaternion quaternionB)
{
const FusionQuaternion result = {.element = {
.w = quaternionA.element.w + quaternionB.element.w,
.x = quaternionA.element.x + quaternionB.element.x,
.y = quaternionA.element.y + quaternionB.element.y,
.z = quaternionA.element.z + quaternionB.element.z,
}};
return result;
}
/**
* @brief Returns the multiplication of two quaternions.
* @param quaternionA Quaternion A (to be post-multiplied).
* @param quaternionB Quaternion B (to be pre-multiplied).
* @return Multiplication of two quaternions.
*/
static inline FusionQuaternion FusionQuaternionMultiply(const FusionQuaternion quaternionA, const FusionQuaternion quaternionB)
{
#define A quaternionA.element
#define B quaternionB.element
const FusionQuaternion result = {.element = {
.w = A.w * B.w - A.x * B.x - A.y * B.y - A.z * B.z,
.x = A.w * B.x + A.x * B.w + A.y * B.z - A.z * B.y,
.y = A.w * B.y - A.x * B.z + A.y * B.w + A.z * B.x,
.z = A.w * B.z + A.x * B.y - A.y * B.x + A.z * B.w,
}};
return result;
#undef A
#undef B
}
/**
* @brief Returns the multiplication of a quaternion with a vector. This is a
* normal quaternion multiplication where the vector is treated a
* quaternion with a W element value of zero. The quaternion is post-
* multiplied by the vector.
* @param quaternion Quaternion.
* @param vector Vector.
* @return Multiplication of a quaternion with a vector.
*/
static inline FusionQuaternion FusionQuaternionMultiplyVector(const FusionQuaternion quaternion, const FusionVector vector)
{
#define Q quaternion.element
#define V vector.axis
const FusionQuaternion result = {.element = {
.w = -Q.x * V.x - Q.y * V.y - Q.z * V.z,
.x = Q.w * V.x + Q.y * V.z - Q.z * V.y,
.y = Q.w * V.y - Q.x * V.z + Q.z * V.x,
.z = Q.w * V.z + Q.x * V.y - Q.y * V.x,
}};
return result;
#undef Q
#undef V
}
/**
* @brief Returns the normalised quaternion.
* @param quaternion Quaternion.
* @return Normalised quaternion.
*/
static inline FusionQuaternion FusionQuaternionNormalise(const FusionQuaternion quaternion)
{
#define Q quaternion.element
#ifdef FUSION_USE_NORMAL_SQRT
const float magnitudeReciprocal = 1.0f / sqrtf(Q.w * Q.w + Q.x * Q.x + Q.y * Q.y + Q.z * Q.z);
#else
const float magnitudeReciprocal = FusionFastInverseSqrt(Q.w * Q.w + Q.x * Q.x + Q.y * Q.y + Q.z * Q.z);
#endif
const FusionQuaternion result = {.element = {
.w = Q.w * magnitudeReciprocal,
.x = Q.x * magnitudeReciprocal,
.y = Q.y * magnitudeReciprocal,
.z = Q.z * magnitudeReciprocal,
}};
return result;
#undef Q
}
//------------------------------------------------------------------------------
// Inline functions - Matrix operations
/**
* @brief Returns the multiplication of a matrix with a vector.
* @param matrix Matrix.
* @param vector Vector.
* @return Multiplication of a matrix with a vector.
*/
static inline FusionVector FusionMatrixMultiplyVector(const FusionMatrix matrix, const FusionVector vector)
{
#define R matrix.element
const FusionVector result = {.axis = {
.x = R.xx * vector.axis.x + R.xy * vector.axis.y + R.xz * vector.axis.z,
.y = R.yx * vector.axis.x + R.yy * vector.axis.y + R.yz * vector.axis.z,
.z = R.zx * vector.axis.x + R.zy * vector.axis.y + R.zz * vector.axis.z,
}};
return result;
#undef R
}
//------------------------------------------------------------------------------
// Inline functions - Conversion operations
/**
* @brief Converts a quaternion to a rotation matrix.
* @param quaternion Quaternion.
* @return Rotation matrix.
*/
static inline FusionMatrix FusionQuaternionToMatrix(const FusionQuaternion quaternion)
{
#define Q quaternion.element
const float qwqw = Q.w * Q.w; // calculate common terms to avoid repeated operations
const float qwqx = Q.w * Q.x;
const float qwqy = Q.w * Q.y;
const float qwqz = Q.w * Q.z;
const float qxqy = Q.x * Q.y;
const float qxqz = Q.x * Q.z;
const float qyqz = Q.y * Q.z;
const FusionMatrix matrix = {.element = {
.xx = 2.0f * (qwqw - 0.5f + Q.x * Q.x),
.xy = 2.0f * (qxqy - qwqz),
.xz = 2.0f * (qxqz + qwqy),
.yx = 2.0f * (qxqy + qwqz),
.yy = 2.0f * (qwqw - 0.5f + Q.y * Q.y),
.yz = 2.0f * (qyqz - qwqx),
.zx = 2.0f * (qxqz - qwqy),
.zy = 2.0f * (qyqz + qwqx),
.zz = 2.0f * (qwqw - 0.5f + Q.z * Q.z),
}};
return matrix;
#undef Q
}
/**
* @brief Converts a quaternion to ZYX Euler angles in degrees.
* @param quaternion Quaternion.
* @return Euler angles in degrees.
*/
static inline FusionEuler FusionQuaternionToEuler(const FusionQuaternion quaternion)
{
#define Q quaternion.element
const float halfMinusQySquared = 0.5f - Q.y * Q.y; // calculate common terms to avoid repeated operations
const FusionEuler euler = {.angle = {
.roll = FusionRadiansToDegrees(atan2f(Q.w * Q.x + Q.y * Q.z, halfMinusQySquared - Q.x * Q.x)),
.pitch = FusionRadiansToDegrees(FusionAsin(2.0f * (Q.w * Q.y - Q.z * Q.x))),
.yaw = FusionRadiansToDegrees(atan2f(Q.w * Q.z + Q.x * Q.y, halfMinusQySquared - Q.z * Q.z)),
}};
return euler;
#undef Q
}
#endif
//------------------------------------------------------------------------------
// End of file