line.h

// This software is distributed as part of the Improla library. 
// Improla is a GUI framework for image processing.
// 
// Copyright (c) 2004, B. R. Siva Chandra, India
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
//
// In case you would like to contact the author, use the following e-mail
// address: sivachandra_br@yahoo.com

#ifndef __UTILITY_LINE_H__
#define __UTILITY_LINE_H__

#include <tnt/tnt_array1d.h>
#include <point.h>
#include <cmath>

namespace gutk
{ // Start of namespace brace.

enum State { INTERSECT, COINCIDE, PARALLEL, INF, FINITE };

class Line
{
friend State getIntersection(const Line& l1, const Line& l2, Point& p);

public:
    Line(void);
    
    Line(double x1, double y1, double x2, double y2); // Line from (x1, y1) to (x2, y2).
    
    virtual ~Line();
    
    bool isLine(void);
    
    virtual double side(double x, double y);
    
    double getSlope(void);
    
    virtual TNT::Array1D< double > equation(void);
    
    virtual double distance(double x, double y); 
    
    Line getParallelLine(double d, bool s);
    
    Line getParallelLine(double x, double y);
    
private:
    double a, b, c; // Store coefficients of the line ax + by + c = 0.
    double slope;
    bool SET;
    State slopeState;
};  

} // End of namespace brace.  

#endif // __UTILITY_LINE_H__

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