quaternion.h

/*
Copyright (c) 2008, Luke Benstead.
All rights reserved.

Redistribution and use in source and binary forms, with or without modification,
are permitted provided that the following conditions are met:

    * Redistributions of source code must retain the above copyright notice,
      this list of conditions and the following disclaimer.
    * Redistributions in binary form must reproduce the above copyright notice,
      this list of conditions and the following disclaimer in the documentation
      and/or other materials provided with the distribution.

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DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
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*/

#ifndef QUATERNION_H_INCLUDED
#define QUATERNION_H_INCLUDED

#ifdef __cplusplus
extern "C" {
#endif

#include "utility.h"

struct kmMat4;
struct kmMat3;
struct kmVec3;

typedef struct kmQuaternion {
	kmScalar x;
	kmScalar y;
	kmScalar z;
	kmScalar w;
} kmQuaternion;

kmQuaternion* const kmQuaternionConjugate(kmQuaternion* pOut, const kmQuaternion* pIn); ///< Returns pOut, sets pOut to the conjugate of pIn

const kmScalar 	kmQuaternionDot(const kmQuaternion* q1, const kmQuaternion* q2); ///< Returns the dot product of the 2 quaternions

kmQuaternion* kmQuaternionExp(kmQuaternion* pOut, const kmQuaternion* pIn); ///< Returns the exponential of the quaternion

///< Makes the passed quaternion an identity quaternion

kmQuaternion* kmQuaternionIdentity(kmQuaternion* pOut);

///< Returns the inverse of the passed Quaternion

kmQuaternion* kmQuaternionInverse(kmQuaternion* pOut,
											const kmQuaternion* pIn);

///< Returns true if the quaternion is an identity quaternion

int kmQuaternionIsIdentity(const kmQuaternion* pIn);

///< Returns the length of the quaternion

kmScalar kmQuaternionLength(const kmQuaternion* pIn);

///< Returns the length of the quaternion squared (prevents a sqrt)

kmScalar kmQuaternionLengthSq(const kmQuaternion* pIn);

///< Returns the natural logarithm

kmQuaternion* kmQuaternionLn(kmQuaternion* pOut, const kmQuaternion* pIn);

///< Multiplies 2 quaternions together

kmQuaternion* kmQuaternionMultiply(kmQuaternion* pOut, const kmQuaternion* q1, const kmQuaternion* q2);

///< Normalizes a quaternion

kmQuaternion* kmQuaternionNormalize(kmQuaternion* pOut, const kmQuaternion* pIn);

///< Rotates a quaternion around an axis

kmQuaternion* kmQuaternionRotationAxis(kmQuaternion* pOut, const struct kmVec3* pV, kmScalar angle);

///< Creates a quaternion from a rotation matrix

kmQuaternion* kmQuaternionRotationMatrix(kmQuaternion* pOut, const struct kmMat3* pIn);

///< Create a quaternion from yaw, pitch and roll

kmQuaternion* kmQuaternionRotationYawPitchRoll(kmQuaternion* pOut, kmScalar yaw, kmScalar pitch, kmScalar roll);
///< Interpolate between 2 quaternions
kmQuaternion* kmQuaternionSlerp(kmQuaternion* pOut, const kmQuaternion* q1, const kmQuaternion* q2, kmScalar t);

///< Get the axis and angle of rotation from a quaternion
void kmQuaternionToAxisAngle(const kmQuaternion* pIn, struct kmVec3* pVector, kmScalar* pAngle);

///< Scale a quaternion
kmQuaternion* kmQuaternionScale(kmQuaternion* pOut, const kmQuaternion* pIn, kmScalar s);
kmQuaternion* kmQuaternionAssign(kmQuaternion* pOut, const kmQuaternion* pIn);
kmQuaternion* kmQuaternionAdd(kmQuaternion* pOut, const kmQuaternion* pQ1, const kmQuaternion* pQ2);
kmQuaternion* kmQuaternionRotationBetweenVec3(kmQuaternion* pOut, const struct kmVec3* vec1, const struct kmVec3* vec2, const struct kmVec3* fallback);
struct kmVec3* kmQuaternionMultiplyVec3(struct kmVec3* pOut, const kmQuaternion* q, const struct kmVec3* v);

#ifdef __cplusplus
}
#endif

#endif