src/kits/interface/Polygon.cpp

   1 /*
   2  * Copyright 2001-2009, Haiku Inc. All rights reserved.
   3  * Distributed under the terms of the MIT license.
   4  *
   5  * Authors:
   6  *              Stephan Aßmus, superstippi@gmx.de
   7  *              Marc Flerackers, mflerackers@androme.be
   8  *              Marcus Overhagen
   9  */
  10
  11
  12 #include <Polygon.h>
  13
  14 #include <stdio.h>
  15 #include <stdlib.h>
  16 #include <string.h>
  17
  18 #include <AffineTransform.h>
  19
  20
  21 // Limit to avoid integer overflow when calculating the size to allocate
  22 #define MAX_POINT_COUNT 10000000
  23
  24
  25 BPolygon::BPolygon(const BPoint* points, int32 count)
  26         :
  27         fBounds(0.0f, 0.0f, -1.0f, -1.0f),
  28         fCount(0),
  29         fPoints(NULL)
  30 {
  31         _AddPoints(points, count, true);
  32 }
  33
  34
  35 BPolygon::BPolygon(const BPolygon& other)
  36         :
  37         fBounds(0.0f, 0.0f, -1.0f, -1.0f),
  38         fCount(0),
  39         fPoints(NULL)
  40 {
  41         *this = other;
  42 }
  43
  44
  45 BPolygon::BPolygon(const BPolygon* other)
  46         :
  47         fBounds(0.0f, 0.0f, -1.0f, -1.0f),
  48         fCount(0),
  49         fPoints(NULL)
  50 {
  51         *this = *other;
  52 }
  53
  54
  55 BPolygon::BPolygon()
  56         :
  57         fBounds(0.0f, 0.0f, -1.0f, -1.0f),
  58         fCount(0),
  59         fPoints(NULL)
  60 {
  61 }
  62
  63
  64 BPolygon::~BPolygon()
  65 {
  66         free(fPoints);
  67 }
  68
  69
  70 BPolygon&
  71 BPolygon::operator=(const BPolygon& other)
  72 {
  73         // Make sure we aren't trying to perform a "self assignment".
  74         if (this == &other)
  75                 return *this;
  76
  77         free(fPoints);
  78         fPoints = NULL;
  79         fCount = 0;
  80         fBounds.Set(0.0f, 0.0f, -1.0f, -1.0f);
  81
  82         if (_AddPoints(other.fPoints, other.fCount, false))
  83                 fBounds = other.fBounds;
  84
  85         return *this;
  86 }
  87
  88
  89 BRect
  90 BPolygon::Frame() const
  91 {
  92         return fBounds;
  93 }
  94
  95
  96 void
  97 BPolygon::AddPoints(const BPoint* points, int32 count)
  98 {
  99         _AddPoints(points, count, true);
 100 }
 101
 102
 103 int32
 104 BPolygon::CountPoints() const
 105 {
 106         return fCount;
 107 }
 108
 109
 110 void
 111 BPolygon::MapTo(BRect source, BRect destination)
 112 {
 113         for (uint32 i = 0; i < fCount; i++)
 114                 _MapPoint(fPoints + i, source, destination);
 115
 116         _MapRectangle(&fBounds, source, destination);
 117 }
 118
 119
 120 void
 121 BPolygon::PrintToStream() const
 122 {
 123         for (uint32 i = 0; i < fCount; i++)
 124                 fPoints[i].PrintToStream();
 125 }
 126
 127
 128 //void
 129 //BPolygon::TransformBy(const BAffineTransform& transform)
 130 //{
 131 //      transform.Apply(fPoints, (int32)fCount);
 132 //      _ComputeBounds();
 133 //}
 134 //
 135 //
 136 //BPolygon&
 137 //BPolygon::TransformBySelf(const BAffineTransform& transform)
 138 //{
 139 //      TransformBy(transform);
 140 //      return *this;
 141 //}
 142 //
 143 //
 144 //BPolygon
 145 //BPolygon::TransformByCopy(const BAffineTransform& transform) const
 146 //{
 147 //      BPolygon copy(this);
 148 //      copy.TransformBy(transform);
 149 //      return copy;
 150 //}
 151
 152
 153 // #pragma mark - BPolygon private methods
 154
 155
 156 bool
 157 BPolygon::_AddPoints(const BPoint* points, int32 count, bool computeBounds)
 158 {
 159         if (points == NULL || count <= 0)
 160                 return false;
 161         if (count > MAX_POINT_COUNT || (fCount + count) > MAX_POINT_COUNT) {
 162                 fprintf(stderr, "BPolygon::_AddPoints(%" B_PRId32 ") - too many points"
 163                         "\n", count);
 164                 return false;
 165         }
 166
 167         BPoint* newPoints = (BPoint*)realloc(fPoints, (fCount + count)
 168                 * sizeof(BPoint));
 169         if (newPoints == NULL) {
 170                 fprintf(stderr, "BPolygon::_AddPoints(%" B_PRId32 ") out of memory\n",
 171                         count);
 172                 return false;
 173         }
 174
 175         fPoints = newPoints;
 176         memcpy(fPoints + fCount, points, count * sizeof(BPoint));
 177         fCount += count;
 178
 179         if (computeBounds)
 180                 _ComputeBounds();
 181
 182         return true;
 183 }
 184
 185
 186 void
 187 BPolygon::_ComputeBounds()
 188 {
 189         if (fCount == 0) {
 190                 fBounds = BRect(0.0, 0.0, -1.0f, -1.0f);
 191                 return;
 192         }
 193
 194         fBounds = BRect(fPoints[0], fPoints[0]);
 195
 196         for (uint32 i = 1; i < fCount; i++) {
 197                 if (fPoints[i].x < fBounds.left)
 198                         fBounds.left = fPoints[i].x;
 199
 200                 if (fPoints[i].y < fBounds.top)
 201                         fBounds.top = fPoints[i].y;
 202
 203                 if (fPoints[i].x > fBounds.right)
 204                         fBounds.right = fPoints[i].x;
 205
 206                 if (fPoints[i].y > fBounds.bottom)
 207                         fBounds.bottom = fPoints[i].y;
 208         }
 209 }
 210
 211
 212 void
 213 BPolygon::_MapPoint(BPoint* point, const BRect& source,
 214         const BRect& destination)
 215 {
 216         point->x = (point->x - source.left) * destination.Width() / source.Width()
 217                 + destination.left;
 218         point->y = (point->y - source.top) * destination.Height() / source.Height()
 219                 + destination.top;
 220 }
 221
 222
 223 void
 224 BPolygon::_MapRectangle(BRect* rect, const BRect& source,
 225         const BRect& destination)
 226 {
 227         BPoint leftTop = rect->LeftTop();
 228         BPoint bottomRight = rect->RightBottom();
 229
 230         _MapPoint(&leftTop, source, destination);
 231         _MapPoint(&bottomRight, source, destination);
 232
 233         *rect = BRect(leftTop, bottomRight);
 234 }