001package com.hfg.svg.path;
002
003import java.awt.geom.Path2D;
004import java.awt.geom.Point2D;
005import java.util.List;
006                        
007//------------------------------------------------------------------------------
008/**
009 * Object representation of an SVG (Scalable Vector Graphics) path smooth quadratic curveTo ('T' or 't') command.
010 *
011 * @author J. Alex Taylor, hairyfatguy.com
012 */
013//------------------------------------------------------------------------------
014// com.hfg XML/HTML Coding Library
015//
016// This library is free software; you can redistribute it and/or
017// modify it under the terms of the GNU Lesser General Public
018// License as published by the Free Software Foundation; either
019// version 2.1 of the License, or (at your option) any later version.
020//
021// This library is distributed in the hope that it will be useful,
022// but WITHOUT ANY WARRANTY; without even the implied warranty of
023// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
024// Lesser General Public License for more details.
025//
026// You should have received a copy of the GNU Lesser General Public
027// License along with this library; if not, write to the Free Software
028// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
029//
030// J. Alex Taylor, President, Founder, CEO, COO, CFO, OOPS hairyfatguy.com
031// jataylor@hairyfatguy.com
032//------------------------------------------------------------------------------
033               
034public class SvgPathSmoothQuadCurveToCmd extends SvgPathQuadCurveToCmd
035{
036   private Point2D.Float mPrevCmdControlPoint;
037
038   //---------------------------------------------------------------------------
039   public SvgPathSmoothQuadCurveToCmd()
040   {
041      super('T');
042   }
043
044
045   //---------------------------------------------------------------------------
046   @Override
047   protected int getExpectedNumPoints()
048   {
049      return 2;
050   }
051
052   //---------------------------------------------------------------------------
053   public void setPrevCmdControlPoint(Point2D.Float inValue)
054   {
055      mPrevCmdControlPoint = inValue;
056   }
057
058
059   //--------------------------------------------------------------------------
060   // From http://www.w3.org/TR/SVG/paths.html
061   //
062   // Draws a quadratic Bézier curve from the current point to (x,y).
063   // The control point is assumed to be the reflection of the control point on the previous command relative to the current point.
064   // (If there is no previous command or if the previous command was not a Q, q, T or t, assume the control point is coincident
065   // with the current point.) T (uppercase) indicates that absolute coordinates will follow; t (lowercase) indicates that
066   // relative coordinates will follow. At the end of the command, the new current point becomes the final (x,y) coordinate pair
067   // used in the polybézier.
068   public Point2D.Float draw(Path2D.Float inPolyline)
069   {
070      List<Float> rawNumbers = getRawNumbers();
071      int numIndex = 0;
072
073      Point2D.Float currentPoint = getStartingPoint();
074
075      while (numIndex < rawNumbers.size() - 1)
076      {
077         Point2D.Float point = new Point2D.Float(rawNumbers.get(numIndex++), rawNumbers.get(numIndex++));
078
079         if (isRelative())
080         {
081            point.setLocation(point.getX() + currentPoint.getX(), point.getY() + currentPoint.getY());
082         }
083
084         Point2D.Float ctrlPoint = currentPoint;
085         if (mPrevCmdControlPoint != null)
086         {
087            // Calculate reflection of the prev second control point
088            ctrlPoint = new Point2D.Float((float) (currentPoint.getX() + (2 * (currentPoint.getX() - mPrevCmdControlPoint.getX()))),
089                                               (float) (currentPoint.getY() + (2 * (currentPoint.getY() - mPrevCmdControlPoint.getY()))));
090         }
091
092         inPolyline.quadTo(ctrlPoint.getX(), ctrlPoint.getY(), point.getX(), point.getY());
093
094         setControlPoint(ctrlPoint);
095
096         currentPoint = point;
097      }
098
099      // Return the last point.
100      return currentPoint;
101   }
102}