point.h

/*== SAGITTARIUS =====================================================================
 * Copyright (c) 2012, Jesse K Medley
 * 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.
    * Neither the name of The University of Washington nor the
      names of its contributors may be used to endorse or promote products
      derived from this software without specific prior written permission.

 * 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 HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE
 * 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.
 */

//== FILEDOC =========================================================================

//== BEGINNING OF CODE ===============================================================

#ifndef __SBNW_LAYOUT_POINT_H_
#define __SBNW_LAYOUT_POINT_H_

//== INCLUDES ========================================================================

#include "graphfab/core/SagittariusCore.h"

#include <math.h>

//-- C++ code --
#ifdef __cplusplus

#include <iostream>

namespace Graphfab {
    
    struct Point; // a pain...
    
    Point operator- (const Point& p, const Point& q);
    Point operator+ (const Point& p, const Point& q);
    
    Point operator* (const Point& p, const Real s);
    Point operator* (const Real s, const Point& p);
    
    Point operator/ (const Point& p, const Real s);
    
    std::ostream& operator<< (std::ostream&, const Point& p);

    struct Point {
        Point() {x = y = 0;}
        
        Point(Real x_, Real y_)
            : x(x_), y(y_) {}
        
        static Point polar(Real mag, Real theta);

        Point operator-() const {
            return Point(-x, -y);
        }
        
        Real mag() const {
            return sqrt(x*x + y*y);
        }
        
        Real mag2() const {
            return x*x + y*y;
        }

        Real theta() const {
          const Real ep = 1e-4;
          if (std::abs(x) < ep) {
            if (std::abs(y) < ep)
              return 0;
            if (y > 0)
              return pi/2.;
            else
              return -pi/2.;
          }

          Real t = atan(y/x);

          if (x > 0)
            return t;
          else
            return t+pi;
        }
        
        Point squareTerms() const {
            return Point(x*x, y*y);
        }
        
        Point sqrtTerms() const {
            AT(x >= 0 && y >= 0, "Cannot take negative square root");
            return Point(sqrt(x), sqrt(y));
        }
        
        Point capMag(const Real cap) const {
            Real m = mag2();
            Real xx = x, yy = y;
            if(m > cap*cap) {
                m = sqrt(m);
                xx *= cap/m;
                yy *= cap/m;
            }
            return Point(xx,yy);
        }
        
        void capMag2_(const Real cap2) {
            Real m = mag2();
            if(m > cap2) {
                m = sqrt(cap2/m);
                x *= m;
                y *= m;
            }
        }
        
        Point normed() const {
            Real o = mag();
            if(o < 1e-6)
                return *this;
            return (*this)*(1./o);
        }
        
        void norm_() {
            Real o = mag();
            if(o < 1e-6)
                return;
            x /= o;
            y /= o;
        }

        Point operator = (const Point& p) { x =p.x; y = p.y; return *this; }
        
        Point operator+= (const Point& p) { x+=p.x; y+=p.y; return *this; }
        
        Point operator-= (const Point& p) { x-=p.x; y-=p.y; return *this; }
        
        static Real min(Real x, Real y) { return x < y ? x : y; }
        static Real max(Real x, Real y) { return x < y ? y : x; }
        
        // element-wise min
        static Point emin(const Point& u, const Point& v) {
            return Point(min(u.x, v.x), min(u.y,v.y));
        }
        
        // element-wise max
        static Point emax(const Point& u, const Point& v) {
            return Point(max(u.x, v.x), max(u.y,v.y));
        }

        Point dextro() const {
          return polar(mag(), theta() - 0.5*pi);
        }

        Point sinister() const {
          return polar(mag(), theta() + 0.5*pi);
        }

        std::string rep() const;
        
        Real x;
        Real y;
    };
    
}

#endif

#endif