vec2.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 VEC2_H_INCLUDED
#define VEC2_H_INCLUDED

#include "utility.h"

struct kmMat3;

#pragma pack(push)  /* push current alignment to stack */
#pragma pack(1)     /* set alignment to 1 byte boundary */
typedef struct kmVec2 {
    kmScalar x;
    kmScalar y;
} kmVec2;

#pragma pack(pop)

#ifdef __cplusplus
extern "C" {
#endif

kmVec2* kmVec2Fill(kmVec2* pOut, kmScalar x, kmScalar y);
kmScalar kmVec2Length(const kmVec2* pIn); ///< Returns the length of the vector
kmScalar kmVec2LengthSq(const kmVec2* pIn); ///< Returns the square of the length of the vector
kmVec2* kmVec2Normalize(kmVec2* pOut, const kmVec2* pIn); ///< Returns the vector passed in set to unit length
kmVec2* kmVec2Add(kmVec2* pOut, const kmVec2* pV1, const kmVec2* pV2); ///< Adds 2 vectors and returns the result
kmScalar kmVec2Dot(const kmVec2* pV1, const kmVec2* pV2); /** Returns the Dot product which is the cosine of the angle between the two vectors multiplied by their lengths */
kmScalar kmVec2Cross(const kmVec2* pV1, const kmVec2* pV2);
kmVec2* kmVec2Subtract(kmVec2* pOut, const kmVec2* pV1, const kmVec2* pV2); ///< Subtracts 2 vectors and returns the result
kmVec2* kmVec2Transform(kmVec2* pOut, const kmVec2* pV1, const struct kmMat3* pM); /** Transform the Vector */
kmVec2* kmVec2TransformCoord(kmVec2* pOut, const kmVec2* pV, const struct kmMat3* pM); ///<Transforms a 2D vector by a given matrix, projecting the result back into w = 1.
kmVec2* kmVec2Scale(kmVec2* pOut, const kmVec2* pIn, const kmScalar s); ///< Scales a vector to length s
int	kmVec2AreEqual(const kmVec2* p1, const kmVec2* p2); ///< Returns 1 if both vectors are equal
kmVec2* kmVec2Assign(kmVec2* pOut, const kmVec2* pIn);
kmVec2* kmVec2RotateBy(kmVec2* pOut, const kmVec2* pIn, const kmScalar degrees, const kmVec2* center); ///<Rotates the point anticlockwise around a center by an amount of degrees.
kmScalar kmVec2DegreesBetween(const kmVec2* v1, const kmVec2* v2);
kmScalar kmVec2DistanceBetween(const kmVec2* v1, const kmVec2* v2);
kmVec2* kmVec2MidPointBetween(kmVec2* pOut, const kmVec2* v1, const kmVec2* v2);

#ifdef __cplusplus
}
#endif


#endif // VEC2_H_INCLUDED