vec4.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.

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 VEC4_H_INCLUDED
#define VEC4_H_INCLUDED

#include "utility.h"

struct kmMat4;

#pragma pack(push)  /* push current alignment to stack */
#pragma pack(1)     /* set alignment to 1 byte boundary */

typedef struct kmVec4
{
	kmScalar x;
	kmScalar y;
	kmScalar z;
	kmScalar w;
} kmVec4;

#pragma pack(pop)

#ifdef __cplusplus
extern "C" {
#endif

kmVec4* kmVec4Fill(kmVec4* pOut, kmScalar x, kmScalar y, kmScalar z,
                   kmScalar w);

/** Adds 2 4D vectors together. The result is store in pOut, the
 * function returns pOut so that it can be nested in another
 * function.*/
kmVec4* kmVec4Add(kmVec4* pOut, const kmVec4* pV1, const kmVec4* pV2);

/** Returns the dot product of 2 4D vectors*/
kmScalar kmVec4Dot(const kmVec4* pV1, const kmVec4* pV2);

/** Returns the length of a 4D vector, this uses a sqrt so if the
 * squared length will do use*/
kmScalar kmVec4Length(const kmVec4* pIn);

/** Returns the length of the 4D vector squared.*/
kmScalar kmVec4LengthSq(const kmVec4* pIn);

/** Returns the interpolation of 2 4D vectors based on t.*/
kmVec4* kmVec4Lerp(kmVec4* pOut, const kmVec4* pV1, const kmVec4* pV2,
                   kmScalar t);

/** Normalizes a 4D vector. The result is stored in pOut. pOut is returned*/
kmVec4* kmVec4Normalize(kmVec4* pOut, const kmVec4* pIn);

/** Scales a vector to the required length. This performs a Normalize
 * before multiplying by S.*/
kmVec4* kmVec4Scale(kmVec4* pOut, const kmVec4* pIn, const kmScalar s);

/** Subtracts one 4D pV2 from pV1. The result is stored in pOut. pOut
 * is returned*/
kmVec4* kmVec4Subtract(kmVec4* pOut, const kmVec4* pV1, const kmVec4* pV2);
kmVec4* kmVec4Mul( kmVec4* pOut,const kmVec4* pV1, const kmVec4* pV2 ); 
kmVec4* kmVec4Div( kmVec4* pOut,const kmVec4* pV1, const kmVec4* pV2 ); 

/** Multiplies a 4D vector by a matrix, the result is stored in pOut,
 * and pOut is returned.*/
kmVec4* kmVec4MultiplyMat4(kmVec4* pOut, const kmVec4* pV,
                           const struct kmMat4* pM);
kmVec4* kmVec4Transform(kmVec4* pOut, const kmVec4* pV,
                        const struct kmMat4* pM);

/** Loops through an input array transforming each vec4 by the
 * matrix.*/
kmVec4* kmVec4TransformArray(kmVec4* pOut, unsigned int outStride,
			const kmVec4* pV, unsigned int vStride, const struct kmMat4* pM,
                             unsigned int count);
int 	kmVec4AreEqual(const kmVec4* p1, const kmVec4* p2);

kmVec4* kmVec4Assign(kmVec4* pOut, const kmVec4* pIn);
void kmVec4Swap(kmVec4* pA, kmVec4* pB);

#ifdef __cplusplus
}
#endif

#endif /* VEC4_H_INCLUDED */