mgcdistvec2elp2.h

3D Game Engine Design Source Code非常棒

// Magic Software, Inc.
// http://www.magic-software.com
// Copyright (c) 2000, All Rights Reserved
//
// Source code from Magic Software is supplied under the terms of a license
// agreement and may not be copied or disclosed except in accordance with the
// terms of that agreement.  The various license agreements may be found at
// the Magic Software web site.  This file is subject to the license
//
// FREE SOURCE CODE
// http://www.magic-software.com/License/free.pdf

#ifndef MGCDISTVEC2ELP2_H
#define MGCDISTVEC2ELP2_H

// Input:   Ellipse (x/a)^2+(y/b)^2 = 1, point (u,v).
//          rkExtent = (a,b)
// Output:  Closest point (x,y) on ellipse to (u,v), function returns
//          the distance sqrt((x-u)^2+(y-v)^2).
//          rkPoint = (u,v), rkClosest = (x,y)
//
// Method sets up the distance as the maximum root to a fourth degree
// polynomial.  The root is found by Newton's method.  If the return value
// is -1, then the iterates failed to converge.

#include "MgcEllipse.h"

MgcReal MgcSqrDistance (const MgcEllipseStandard& rkEllipse,
    const MgcVector2& rkPoint, MgcVector2& rkClosest);

MgcReal MgcDistance (const MgcEllipseStandard& rkEllipse,
    const MgcVector2& rkPoint, MgcVector2& rkClosest);

#endif