Shamusworld >> Repos - architektonas/blob - src/base/rs_infoarea.cpp

   1 // rs_infoarea.cpp
   2 //
   3 // Part of the Architektonas Project
   4 // Originally part of QCad Community Edition by Andrew Mustun
   5 // Extensively rewritten and refactored by James L. Hammons
   6 // (C) 2010 Underground Software
   7 //
   8 // JLH = James L. Hammons <jlhamm@acm.org>
   9 //
  10 // Who  When        What
  11 // ---  ----------  -----------------------------------------------------------
  12 // JLH  06/01/2010  Added this text. :-)
  13 //
  14
  15 #include "rs_infoarea.h"
  16
  17 #include "rs_math.h"
  18 #include "rs_debug.h"
  19
  20 /**
  21  * Constructor.
  22  */
  23 RS_InfoArea::RS_InfoArea()
  24 {
  25 }
  26
  27 /**
  28  * Destructor.
  29  */
  30 RS_InfoArea::~RS_InfoArea()
  31 {
  32 }
  33
  34 /**
  35  * Adds a point to the internal list
  36  *
  37  * @param p co-ordinate of the point
  38  */
  39 void RS_InfoArea::addPoint(const Vector & p)
  40 {
  41         if (thePoints.empty())
  42                 baseY = p.y;
  43
  44         thePoints.append(p);
  45 }
  46
  47 /**
  48  * Resets the points.
  49  */
  50 void RS_InfoArea::reset()
  51 {
  52         thePoints.clear();
  53         area = 0.0;
  54         circumference = 0.0;
  55 }
  56
  57 /**
  58  * Closes the polygon if it is not closed already.
  59  */
  60 void RS_InfoArea::close()
  61 {
  62         if (isValid() && isClosed() == false)
  63         {
  64                 thePoints.append(thePoints.first());
  65
  66                 RS_DEBUG->print("RS_InfoArea::close: closed");
  67         }
  68 }
  69
  70 /**
  71  * @retval true If the area is closed (i.e. start point and end point are
  72  *   identical)
  73  * @retval false Otherwise.
  74  */
  75 bool RS_InfoArea::isClosed()
  76 {
  77         return (thePoints.first().distanceTo(thePoints.last()) < 1.0e-4);
  78 }
  79
  80 /**
  81  * @retval true If the area is defined (i.e. there are at least 3 points)
  82  * @retval false If there are only two or less points.
  83  */
  84 bool RS_InfoArea::isValid()
  85 {
  86         RS_DEBUG->print("RS_InfoArea::isValid: count: %d", thePoints.count());
  87         return (thePoints.count() > 2);
  88 }
  89
  90 /**
  91  * Calculates the area and the circumference of the area.
  92  */
  93 void RS_InfoArea::calculate()
  94 {
  95         area = 0.0;
  96         circumference = 0.0;
  97         Vector ptFirst;
  98         Vector p1;
  99         Vector p2;
 100
 101         // at least 3 points needed for an area
 102         if (isValid())
 103         {
 104                 ptFirst = thePoints.last();
 105                 thePoints.pop_back();
 106
 107                 p1 = ptFirst;
 108
 109                 while (!thePoints.empty())
 110                 {
 111                         p2 = thePoints.last();
 112                         thePoints.pop_back();
 113
 114                         area += calcSubArea(p1, p2);
 115                         circumference += p1.distanceTo(p2);
 116                         //if (p1 != ptFirst) {
 117                         //      delete p1;
 118                         //}
 119                         p1 = p2;
 120                 }
 121
 122                 area += calcSubArea(p1, ptFirst);
 123                 circumference += p1.distanceTo(ptFirst);
 124                 //delete p1;
 125                 //delete ptFirst;
 126         }
 127
 128         //thePoints.clear();
 129         area = fabs(area);
 130 }
 131
 132 double RS_InfoArea::getArea()
 133 {
 134         return area;
 135 }
 136
 137 double RS_InfoArea::getCircumference()
 138 {
 139         return circumference;
 140 }
 141
 142 int RS_InfoArea::count()
 143 {
 144         return thePoints.count();
 145 }
 146
 147 /**
 148  * Calculates a sub area.
 149  *
 150  * @param p1 first point
 151  * @param p2 second point
 152  */
 153 double RS_InfoArea::calcSubArea(const Vector & p1, const Vector & p2)
 154 {
 155         double width = p2.x - p1.x;
 156         double height = (p1.y - baseY) + (p2.y - baseY);
 157
 158         return (width * height) / 2.0;
 159 }
 160
 161 /*! Calculates a distance
 162     \param _p1 first point
 163     \param _p2 second point
 164 */
 165 /*double
 166 RS_InfoArea::calcDistance(Vector *_p1, Vector *_p2)
 167 {
 168         return mtGetDistance(_p1->getX(), _p1->getY(), _p2->getX(), _p2->getY());
 169 }*/