/* File StraightLine2D.java 
    *
    * Project : Java Geometry Library
    *
    * ===========================================
    * 
    * This library is free software; you can redistribute it and/or modify it 
    * under the terms of the GNU Lesser General Public License as published by
    * the Free Software Foundation, either version 2.1 of the License, or (at
   * your option) any later version.
   *
   * This library 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 Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public License
   * along with this library. if not, write to :
   * The Free Software Foundation, Inc., 59 Temple Place, Suite 330,
   * Boston, MA 02111-1307, USA.
   */
  
  // package
  
  package math.geom2d.line;
  
  //Imports
  
  import java.awt.Graphics2D;
  import java.awt.geom.GeneralPath;
  import java.util.ArrayList;
  import java.util.Collection;
  
  import math.geom2d.AffineTransform2D;
  import math.geom2d.Angle2D;
  import math.geom2d.Box2D;
  import math.geom2d.Point2D;
  import math.geom2d.Shape2D;
  import math.geom2d.UnboundedShapeException;
  import math.geom2d.Vector2D;
  import math.geom2d.circulinear.CircleLine2D;
  import math.geom2d.conic.Circle2D;
  import math.geom2d.domain.ContinuousBoundary2D;
  import math.geom2d.domain.Domain2D;
  import math.geom2d.domain.GenericDomain2D;
  import math.geom2d.domain.SmoothBoundary2D;
  import math.geom2d.polygon.Polyline2D;
  import math.geom2d.transform.CircleInversion2D;
  
  /**
   * Implementation of a straight line. Such a line can be constructed using two
   * points, a point and a parallel line or straight object, or with coefficient
   * of the Cartesian equation.
   */
  public class StraightLine2D extends AbstractLine2D implements
          SmoothBoundary2D, Cloneable, CircleLine2D {
  
      // ===================================================================
      // constants
  
      // ===================================================================
      // class variables
  
      // ===================================================================
      // static methods
  
      /**
       * Creates a straight line going through a point and with a given angle.
       */
      public final static StraightLine2D create(java.awt.geom.Point2D point,
              double angle) {
          return new StraightLine2D(point.getX(), point.getY(), Math.cos(angle),
                  Math.sin(angle));
      }
  
      /**
       * Creates a straight line through 2 points.
       */
      public final static StraightLine2D create(java.awt.geom.Point2D p1,
              java.awt.geom.Point2D p2) {
          return new StraightLine2D(p1, p2);
      }
  
      /**
       * Creates a straight line through a point and with a given direction
       * vector.
       */
      public final static StraightLine2D create(java.awt.geom.Point2D origin,
              Vector2D direction) {
          return new StraightLine2D(origin, direction);
      }
  
      /**
       * @deprecated use create(Point2D, Point2D) instead
       */
      @Deprecated
      public final static StraightLine2D createStraightLine2D(
              java.awt.geom.Point2D p1, java.awt.geom.Point2D p2) {
         return new StraightLine2D(p1, p2);
     }
 
     /**
      * Creates a median between 2 points.
      * 
      * @param p1 one point
      * @param p2 another point
      * @return the median of points p1 and p2
      * @since 0.6.3
      */
     public final static StraightLine2D createMedian(java.awt.geom.Point2D p1,
             java.awt.geom.Point2D p2) {
         Point2D mid = Point2D.midPoint(p1, p2);
         StraightLine2D line = StraightLine2D.create(p1, p2);
         return StraightLine2D.createPerpendicular(line, mid);
     }
 
     /**
      * Creates a median between 2 points.
      * 
      * @param p1 one point
      * @param p2 another point
      * @return the median of points p1 and p2
      * @deprecated since 0.6.3, use createMedian instead
      */
     @Deprecated
     public final static StraightLine2D createMedian2D(java.awt.geom.Point2D p1,
             java.awt.geom.Point2D p2) {
         Point2D mid = Point2D.midPoint(p1, p2);
         StraightLine2D line = StraightLine2D.create(p1, p2);
         return StraightLine2D.createPerpendicular(line, mid);
     }
 
     /**
      * Return a new Straight line going through the given point, and with the
      * specified direction vector.
      * 
      * @deprecated since 0.6.3, use create() instead
      */
     @Deprecated
     public final static StraightLine2D createStraightLine2D(
             java.awt.geom.Point2D point, double dx, double dy) {
         return new StraightLine2D(point, dx, dy);
     }
 
     /**
      * Return a new Straight line, parallel to another straight object (ray,
      * straight line or edge), and going through the given point.
      * 
      * @since 0.6.3
      */
     public final static StraightLine2D createParallel(LinearShape2D line,
             java.awt.geom.Point2D point) {
         return new StraightLine2D(line, point);
     }
 
     /**
      * Return a new Straight line, parallel to another straight object (ray,
      * straight line or edge), and going through the given point.
      * 
      * @deprecated since 0.6.3, use createParallel() instead
      */
     @Deprecated
     public final static StraightLine2D createParallelLine2D(LinearShape2D line,
             java.awt.geom.Point2D point) {
         return new StraightLine2D(line, point);
     }
 
     /**
      * Return a new Straight line, parallel to another straight object (ray,
      * straight line or edge), and going through the given point.
      * 
      * @since 0.6.3
      */
     public final static StraightLine2D createParallel(LinearShape2D linear,
             double d) {
         StraightLine2D line = linear.getSupportingLine();
         double dd = Math.hypot(line.dx, line.dy);
         return new StraightLine2D(line.x0+line.dy*d/dd, line.y0-line.dx*d/dd,
                 line.dx, line.dy);
     }
 
     /**
      * Return a new Straight line, parallel to another straight object (ray,
      * straight line or edge), and going through the given point.
      * 
      * @deprecated since 0.6.3, use createParallel() instead
      */
     @Deprecated
     public final static StraightLine2D createParallelLine2D(
             LinearShape2D linear, double d) {
         StraightLine2D line = linear.getSupportingLine();
         double dd = Math.hypot(line.dx, line.dy);
         return new StraightLine2D(line.x0+line.dy*d/dd, line.y0-line.dx*d/dd,
                 line.dx, line.dy);
     }
 
     /**
      * Return a new Straight line, perpendicular to a straight object (ray,
      * straight line or edge), and going through the given point.
      * 
      * @since 0.6.3
      */
     public final static StraightLine2D createPerpendicular(
             LinearShape2D linear, Point2D point) {
         StraightLine2D line = linear.getSupportingLine();
         return new StraightLine2D(point, -line.dy, line.dx);
     }
 
     /**
      * Return a new Straight line, parallel to another straight object (ray,
      * straight line or edge), and going through the given point.
      * 
      * @deprecated since 0.6.3, use createPerpendicular instead
      */
     @Deprecated
     public final static StraightLine2D createOrthogonalLine2D(
             LinearShape2D linear, Point2D point) {
         StraightLine2D line = linear.getSupportingLine();
         return new StraightLine2D(point, -line.dy, line.dx);
     }
 
     /**
      * Return a new Straight line, with the given coefficient of the cartesian
      * equation (a*x + b*y + c = 0).
      */
     public final static StraightLine2D createCartesian(double a, double b,
             double c) {
         return new StraightLine2D(a, b, c);
     }
 
     /**
      * Return a new Straight line, with the given coefficient of the cartesian
      * equation (a*x + b*y + c = 0).
      * 
      * @deprecated since 0.6.3, use createCartesian instead
      */
     @Deprecated
     public final static StraightLine2D createCartesianLine2D(double a,
             double b, double c) {
         return new StraightLine2D(a, b, c);
     }
 
     /**
      * Compute the intersection point of the two (infinite) lines going through
      * p1 and p2 for the first one, and p3 and p4 for the second one. Returns
      * null if two lines are parallel.
      */
     public final static Point2D getIntersection(java.awt.geom.Point2D p1,
             java.awt.geom.Point2D p2, java.awt.geom.Point2D p3,
             java.awt.geom.Point2D p4) {
         StraightLine2D line1 = new StraightLine2D(p1, p2);
         StraightLine2D line2 = new StraightLine2D(p3, p4);
         return line1.getIntersection(line2);
     }
 
     // ===================================================================
     // constructors
 
     /** Empty constructor: a straight line corresponding to horizontal axis. */
     public StraightLine2D() {
         this(0, 0, 1, 0);
     }
 
     /** Define a new Straight line going through the two given points. */
     public StraightLine2D(java.awt.geom.Point2D point1,
             java.awt.geom.Point2D point2) {
         this(point1, new Vector2D(point1, point2));
     }
 
     /**
      * Define a new Straight line going through the given point, and with the
      * specified direction vector.
      */
     public StraightLine2D(java.awt.geom.Point2D point, Vector2D direction) {
         this(point.getX(), point.getY(), direction.getX(), direction.getY());
     }
 
     /**
      * Define a new Straight line going through the given point, and with the
      * specified direction vector.
      */
     public StraightLine2D(java.awt.geom.Point2D point, double dx, double dy) {
         this(point.getX(), point.getY(), dx, dy);
     }
 
     /**
      * Define a new Straight line going through the given point, and with the
      * specified direction given by angle.
      */
     public StraightLine2D(java.awt.geom.Point2D point, double angle) {
         this(point.getX(), point.getY(), Math.cos(angle), Math.sin(angle));
     }
 
     /**
      * Define a new Straight line at the same position and with the same
      * direction than an other straight object (line, edge or ray).
      */
     public StraightLine2D(LinearShape2D line) {
         super(line);
     }
 
     /**
      * Define a new Straight line going through the point (xp, yp) and with the
      * direction dx, dy.
      */
     public StraightLine2D(double xp, double yp, double dx, double dy) {
         super(xp, yp, dx, dy);
     }
 
     /**
      * Define a new Straight line, parallel to another straigth object (ray,
      * straight line or edge), and going through the given point.
      */
     public StraightLine2D(LinearShape2D line, java.awt.geom.Point2D point) {
         this(point, line.getVector());
     }
 
     /**
      * Define a new straight line, from the coefficients of the cartesian
      * equation. The starting point of the line is then the point of the line
      * closest to the origin, and the direction vector has unit norm.
      */
     public StraightLine2D(double a, double b, double c) {
         this(0, 0, 1, 0);
         double d = a*a+b*b;
         x0 = -a*c/d;
         y0 = -b*c/d;
         double theta = Math.atan2(-a, b);
         dx = Math.cos(theta);
         dy = Math.sin(theta);
     }
 
     // ===================================================================
     // methods specific to StraightLine2D
 
     /**
      * @deprecated lines will become imutable in a future release
      */
     @Deprecated
     public void setLine(double x0, double y0, double dx, double dy) {
         this.x0 = x0;
         this.y0 = y0;
         this.dx = dx;
         this.dy = dy;
     }
 
     /**
      * @deprecated lines will become imutable in a future release
      */
     @Deprecated
     public void setPoints(double x1, double y1, double x2, double y2) {
         this.x0 = x1;
         this.y0 = y1;
         this.dx = x2-x1;
         this.dy = y2-y1;
     }
 
     /**
      * @deprecated lines will become imutable in a future release
      */
     @Deprecated
     public void setLine(java.awt.geom.Point2D p1, java.awt.geom.Point2D p2) {
         this.x0 = p1.getX();
         this.y0 = p1.getY();
         this.dx = p2.getX()-x0;
         this.dy = p2.getY()-y0;
     }
 
     /**
      * @deprecated lines will become imutable in a future release
      */
     @Deprecated
     public void setLine(LinearShape2D linear) {
         StraightLine2D line = linear.getSupportingLine();
         this.x0 = line.x0;
         this.y0 = line.y0;
         this.dx = line.dx;
         this.dy = line.dy;
     }
 
     /**
      * @deprecated lines will become imutable in a future release
      */
     @Deprecated
     public void setCartesianEquation(double a, double b, double c) {
         dx = -b;
         dy = a;
         x0 = -a*c/(a*a+b*b);
         y0 = -b*c/(a*a+b*b);
     }
 
     /**
      * Returns a new Straight line, parallel to another straight object (ray,
      * straight line or edge), and going through the given point.
      */
     public StraightLine2D getParallel(java.awt.geom.Point2D point) {
         return new StraightLine2D(point, dx, dy);
     }
 
     // ===================================================================
     // methods implementing the CirculinearCurve2D interface
 
    /**
      * Return the parallel line located at a distance d. Distance is positive in
      * the 'right' side of the line (outside of the limiting half-plane), and
      * negative in the 'left' of the line.
      */
     public StraightLine2D getParallel(double d) {
         double dd = Math.sqrt(dx*dx+dy*dy);
         return new StraightLine2D(x0+dy*d/dd, y0-dx*d/dd, dx, dy);
     }
 
     /**
      * Return a new Straight line, parallel to another straigth object (ray,
      * straight line or edge), and going through the given point.
      */
     @Override
     public StraightLine2D getPerpendicular(Point2D point) {
         return new StraightLine2D(point, -dy, dx);
     }
     
 	/* (non-Javadoc)
 	 * @see math.geom2d.circulinear.CirculinearCurve2D#transform(math.geom2d.transform.CircleInversion2D)
 	 */
 	@Override
 	public CircleLine2D transform(CircleInversion2D inv) {
 		// Extract inversion parameters
         Point2D center 	= inv.getCenter();
         double r 		= inv.getRadius();
         
         Point2D po 	= this.getProjectedPoint(center);
         double d 	= this.getDistance(po);
 
         // Degenerate case of a point belonging to the line:
         // the transform is the line itself.
         if (Math.abs(d)<Shape2D.ACCURACY){
         	return new StraightLine2D(this);
         }
         
         // angle from center to line
         double angle = Angle2D.getHorizontalAngle(center, po);
 
         // center of transformed circle
         double r2 	= r*r/d/2;
         Point2D c2 	= Point2D.createPolar(center, r2, angle);
 
         // choose direction of circle arc
         boolean direct = !this.isInside(center);
         
         // return the created circle
         return new Circle2D(c2, r2, direct);
     }
 	
 
     // ===================================================================
     // methods specific to Boundary2D interface
 
     public Collection<ContinuousBoundary2D> getBoundaryCurves() {
         ArrayList<ContinuousBoundary2D> list = new ArrayList<ContinuousBoundary2D>(
                 1);
         list.add(this);
         return list;
     }
 
     public Domain2D getDomain() {
         return new GenericDomain2D(this);
     }
 
     public void fill(Graphics2D g2) {
         g2.fill(this.getGeneralPath());
     }
 
     // ===================================================================
     // methods specific to OrientedCurve2D interface
 
     @Override
     public double getWindingAngle(java.awt.geom.Point2D point) {
 
         double angle1 = Angle2D.getHorizontalAngle(-dx, -dy);
         double angle2 = Angle2D.getHorizontalAngle(dx, dy);
 
         if (this.isInside(point)) {
             if (angle2>angle1)
                 return angle2-angle1;
             else
                 return 2*Math.PI-angle1+angle2;
         } else {
             if (angle2>angle1)
                 return angle2-angle1-2*Math.PI;
             else
                 return angle2-angle1;
         }
     }
 
     
     // ===================================================================
     // methods implementing the ContinuousCurve2D interface
 
     /**
      * Throws an exception when called.
      */
 	@Override
     public Polyline2D getAsPolyline(int n) {
         throw new UnboundedShapeException(this);
     }
 
     
     // ===================================================================
     // methods implementing the Curve2D interface
 
     /** Throws an infiniteShapeException */
 	@Override
     public Point2D getFirstPoint() {
         throw new UnboundedShapeException(this);
     }
 
 	/** Throws an infiniteShapeException */
 	@Override
 	public Point2D getLastPoint() {
 		throw new UnboundedShapeException(this);
 	}
 
     /** Returns an empty list of points. */
 	@Override
     public Collection<Point2D> getSingularPoints() {
         return new ArrayList<Point2D>(0);
     }
 
     /** Returns false, whatever the position. */
 	@Override
     public boolean isSingular(double pos) {
         return false;
     }
 
     /**
      * Returns the parameter of the first point of the line, which is always
      * Double.NEGATIVE_INFINITY.
      */
     public double getT0() {
         return Double.NEGATIVE_INFINITY;
     }
 
     /**
      * Returns the parameter of the last point of the line, which is always
      * Double.POSITIVE_INFINITY.
      */
     public double getT1() {
         return Double.POSITIVE_INFINITY;
     }
 
     /**
      * Gets the point specified with the parametric representation of the line.
      */
     public Point2D getPoint(double t) {
         return new Point2D(x0+dx*t, y0+dy*t);
     }
 
     /**
      * Need to override to cast the type.
      */
     @Override
     public Collection<? extends StraightLine2D> getContinuousCurves() {
         ArrayList<StraightLine2D> list = 
         	new ArrayList<StraightLine2D>(1);
         list.add(this);
         return list;
     }
 
     /**
      * Returns the straight line with same origin but with opposite direction
      * vector.
      */
     public StraightLine2D getReverseCurve() {
         return new StraightLine2D(this.x0, this.y0, -this.dx, -this.dy);
     }
 
     public GeneralPath appendPath(GeneralPath path) {
         throw new UnboundedShapeException(this);
     }
 
     // ===================================================================
     // methods implementing the Shape2D interface
 
     /** Always returns false, because a line is not bounded. */
     public boolean isBounded() {
         return false;
     }
 
     /**
      * Returns the distance of the point (x, y) to this straight line.
      */
     @Override
     public double getDistance(double x, double y) {
         Point2D proj = super.getProjectedPoint(x, y);
         return proj.distance(x, y);
     }
 
     public Box2D getBoundingBox() {
         if (Math.abs(dx)<0)
             return new Box2D(
                     x0, x0, 
                     Double.NEGATIVE_INFINITY, Double.POSITIVE_INFINITY);
         if (Math.abs(dy)<0)
             return new Box2D(
                     Double.NEGATIVE_INFINITY, Double.POSITIVE_INFINITY, 
                     x0, y0);
 
         return new Box2D(
                 Double.NEGATIVE_INFINITY, Double.POSITIVE_INFINITY,
                 Double.NEGATIVE_INFINITY, Double.POSITIVE_INFINITY);
     }
 
     /**
      * Returns the transformed line. The result is still a StraightLine2D.
      */
     @Override
     public StraightLine2D transform(AffineTransform2D trans) {
         double[] tab = trans.getCoefficients();
         return new StraightLine2D(
                 x0*tab[0]+y0*tab[1]+tab[2], 
                 x0*tab[3]+y0*tab[4]+tab[5], 
                 dx*tab[0]+dy*tab[1], 
                 dx*tab[3]+dy*tab[4]);
     }
 
     
     // ===================================================================
     // methods implementing the Shape interface
 
     /**
      * Returns true if the point (x, y) lies on the line, with precision given
      * by Shape2D.ACCURACY.
      */
     public boolean contains(double x, double y) {
         return super.supportContains(x, y);
     }
 
     /**
      * Returns true if the point p lies on the line, with precision given by
      * Shape2D.ACCURACY.
      */
     @Override
     public boolean contains(java.awt.geom.Point2D p) {
         return super.supportContains(p.getX(), p.getY());
     }
 
     /** Throws an infiniteShapeException */
     public java.awt.geom.GeneralPath getGeneralPath() {
         throw new UnboundedShapeException(this);
     }
 
    
     // ===================================================================
     // methods implementing the Object interface
 
     @Override
     public String toString() {
         return new String("StraightLine2D(" + x0 + "," + y0 + "," + 
         		dx + "," + dy + ")");
     }
     
     @Override
     public boolean equals(Object obj) {
         if (!(obj instanceof StraightLine2D))
             return false;
         StraightLine2D line = (StraightLine2D) obj;
         if (Math.abs(x0-line.x0)>Shape2D.ACCURACY)
             return false;
         if (Math.abs(y0-line.y0)>Shape2D.ACCURACY)
             return false;
         if (Math.abs(dx-line.dx)>Shape2D.ACCURACY)
             return false;
         if (Math.abs(dy-line.dy)>Shape2D.ACCURACY)
             return false;
         return true;
     }
     
     @Override
     public StraightLine2D clone() {
         return new StraightLine2D(x0, y0, dx, dy);
     }
 }