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/**
* libdmtx - Data Matrix Encoding/Decoding Library
* Copyright 2008, 2009 Mike Laughton. All rights reserved.
* Copyright 2012-2016 Vadim A. Misbakh-Soloviov. All rights reserved.
*
* See LICENSE file in the main project directory for full
* terms of use and distribution.
*
* Contact:
* Vadim A. Misbakh-Soloviov <dmtx@mva.name>
* Mike Laughton <mike@dragonflylogic.com>
*
* \file dmtxvector2.c
* \brief 2D Vector math
*/
/**
*
*
*/
extern DmtxVector2 *
dmtxVector2AddTo(DmtxVector2 *v1, const DmtxVector2 *v2)
{
v1->X += v2->X;
v1->Y += v2->Y;
return v1;
}
/**
*
*
*/
extern DmtxVector2 *
dmtxVector2Add(DmtxVector2 *vOut, const DmtxVector2 *v1, const DmtxVector2 *v2)
{
*vOut = *v1;
return dmtxVector2AddTo(vOut, v2);
}
/**
*
*
*/
extern DmtxVector2 *
dmtxVector2SubFrom(DmtxVector2 *v1, const DmtxVector2 *v2)
{
v1->X -= v2->X;
v1->Y -= v2->Y;
return v1;
}
/**
*
*
*/
extern DmtxVector2 *
dmtxVector2Sub(DmtxVector2 *vOut, const DmtxVector2 *v1, const DmtxVector2 *v2)
{
*vOut = *v1;
return dmtxVector2SubFrom(vOut, v2);
}
/**
*
*
*/
extern DmtxVector2 *
dmtxVector2ScaleBy(DmtxVector2 *v, double s)
{
v->X *= s;
v->Y *= s;
return v;
}
/**
*
*
*/
extern DmtxVector2 *
dmtxVector2Scale(DmtxVector2 *vOut, const DmtxVector2 *v, double s)
{
*vOut = *v;
return dmtxVector2ScaleBy(vOut, s);
}
/**
*
*
*/
extern double
dmtxVector2Cross(const DmtxVector2 *v1, const DmtxVector2 *v2)
{
return (v1->X * v2->Y) - (v1->Y * v2->X);
}
/**
*
*
*/
extern double
dmtxVector2Norm(DmtxVector2 *v)
{
double mag;
mag = dmtxVector2Mag(v);
if(mag <= DmtxAlmostZero)
return -1.0; /* XXX this doesn't look clean */
dmtxVector2ScaleBy(v, 1/mag);
return mag;
}
/**
*
*
*/
extern double
dmtxVector2Dot(const DmtxVector2 *v1, const DmtxVector2 *v2)
{
return (v1->X * v2->X) + (v1->Y * v2->Y);
}
/**
*
*
*/
extern double
dmtxVector2Mag(const DmtxVector2 *v)
{
return sqrt(v->X * v->X + v->Y * v->Y);
}
/**
*
*
*/
extern double
dmtxDistanceFromRay2(const DmtxRay2 *r, const DmtxVector2 *q)
{
DmtxVector2 vSubTmp;
/* Assumes that v is a unit vector */
assert(fabs(1.0 - dmtxVector2Mag(&(r->v))) <= DmtxAlmostZero);
return dmtxVector2Cross(&(r->v), dmtxVector2Sub(&vSubTmp, q, &(r->p)));
}
/**
*
*
*/
extern double
dmtxDistanceAlongRay2(const DmtxRay2 *r, const DmtxVector2 *q)
{
DmtxVector2 vSubTmp;
#ifdef DEBUG
/* Assumes that v is a unit vector */
if(fabs(1.0 - dmtxVector2Mag(&(r->v))) > DmtxAlmostZero) {
; /* XXX big error goes here */
}
#endif
return dmtxVector2Dot(dmtxVector2Sub(&vSubTmp, q, &(r->p)), &(r->v));
}
/**
*
*
*/
extern DmtxPassFail
dmtxRay2Intersect(DmtxVector2 *point, const DmtxRay2 *p0, const DmtxRay2 *p1)
{
double numer, denom;
DmtxVector2 w;
denom = dmtxVector2Cross(&(p1->v), &(p0->v));
if(fabs(denom) <= DmtxAlmostZero)
return DmtxFail;
dmtxVector2Sub(&w, &(p1->p), &(p0->p));
numer = dmtxVector2Cross(&(p1->v), &w);
return dmtxPointAlongRay2(point, p0, numer/denom);
}
/**
*
*
*/
extern DmtxPassFail
dmtxPointAlongRay2(DmtxVector2 *point, const DmtxRay2 *r, double t)
{
DmtxVector2 vTmp;
/* Ray should always have unit length of 1 */
assert(fabs(1.0 - dmtxVector2Mag(&(r->v))) <= DmtxAlmostZero);
dmtxVector2Scale(&vTmp, &(r->v), t);
dmtxVector2Add(point, &(r->p), &vTmp);
return DmtxPass;
}
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