/*
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.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

#ifndef VEC3_H_INCLUDED
#define VEC3_H_INCLUDED

#include <assert.h>
#include "utility.h"

struct kmMat4;
struct kmMat3;
struct kmPlane;

typedef struct kmVec3 {
	kmScalar x;
	kmScalar y;
	kmScalar z;
} kmVec3;

#ifdef __cplusplus
extern "C" {
#endif

kmVec3* kmVec3Fill(kmVec3* pOut, kmScalar x, kmScalar y, kmScalar z);
kmScalar kmVec3Length(const kmVec3* pIn); /** Returns the length of the vector */
kmScalar kmVec3LengthSq(const kmVec3* pIn); /** Returns the square of the length of the vector */
kmVec3* kmVec3Lerp(kmVec3* pOut, const kmVec3* pV1, const kmVec3* pV2, kmScalar t);
kmVec3* kmVec3Normalize(kmVec3* pOut, const kmVec3* pIn); /** Returns the vector passed in set to unit length */
kmVec3* kmVec3Cross(kmVec3* pOut, const kmVec3* pV1, const kmVec3* pV2); /** Returns a vector perpendicular to 2 other vectors */
kmScalar kmVec3Dot(const kmVec3* pV1, const kmVec3* pV2); /** Returns the cosine of the angle between 2 vectors */
kmVec3* kmVec3Add(kmVec3* pOut, const kmVec3* pV1, const kmVec3* pV2); /** Adds 2 vectors and returns the result */
kmVec3* kmVec3Subtract(kmVec3* pOut, const kmVec3* pV1, const kmVec3* pV2); /** Subtracts 2 vectors and returns the result */
kmVec3* kmVec3Mul( kmVec3* pOut,const kmVec3* pV1, const kmVec3* pV2 ); 
kmVec3* kmVec3Div( kmVec3* pOut,const kmVec3* pV1, const kmVec3* pV2 );

kmVec3* kmVec3MultiplyMat3(kmVec3 *pOut, const kmVec3 *pV, const struct kmMat3* pM);
kmVec3* kmVec3MultiplyMat4(kmVec3* pOut, const kmVec3* pV, const struct kmMat4* pM);

kmVec3* kmVec3Transform(kmVec3* pOut, const kmVec3* pV1, const struct kmMat4* pM); /** Transforms a vector (assuming w=1) by a given matrix */
kmVec3* kmVec3TransformNormal(kmVec3* pOut, const kmVec3* pV, const struct kmMat4* pM);/**Transforms a 3D normal by a given matrix */
kmVec3* kmVec3TransformCoord(kmVec3* pOut, const kmVec3* pV, const struct kmMat4* pM); /**Transforms a 3D vector by a given matrix, projecting the result back into w = 1. */

kmVec3* kmVec3Scale(kmVec3* pOut, const kmVec3* pIn, const kmScalar s); /** Scales a vector to length s */
int 	kmVec3AreEqual(const kmVec3* p1, const kmVec3* p2);
kmVec3* kmVec3InverseTransform(kmVec3* pOut, const kmVec3* pV, const struct kmMat4* pM);
kmVec3* kmVec3InverseTransformNormal(kmVec3* pOut, const kmVec3* pVect, const struct kmMat4* pM);
kmVec3* kmVec3Assign(kmVec3* pOut, const kmVec3* pIn);
kmVec3* kmVec3Zero(kmVec3* pOut);
kmVec3* kmVec3GetHorizontalAngle(kmVec3* pOut, const kmVec3 *pIn); /** Get the rotations that would make a (0,0,1) direction vector point in the same direction as this direction vector. */
kmVec3* kmVec3RotationToDirection(kmVec3* pOut, const kmVec3* pIn, const kmVec3* forwards); /** Builds a direction vector from input vector. */

kmVec3* kmVec3ProjectOnToPlane(kmVec3* pOut, const kmVec3* point, const struct kmPlane* plane);

extern const kmVec3 KM_VEC3_NEG_Z;
extern const kmVec3 KM_VEC3_POS_Z;
extern const kmVec3 KM_VEC3_POS_Y;
extern const kmVec3 KM_VEC3_NEG_Y;
extern const kmVec3 KM_VEC3_NEG_X;
extern const kmVec3 KM_VEC3_POS_X;
extern const kmVec3 KM_VEC3_ZERO;

#ifdef __cplusplus
}
#endif
#endif /* VEC3_H_INCLUDED */