Qt 4.8
Public Functions | Properties | List of all members
QPolygonClipper< InType, OutType, CastType > Class Template Reference

#include <qpolygonclipper_p.h>

Public Functions

QRect boundingRect ()
 
void clipPolygon (const InType *inPoints, int inCount, OutType **outPoints, int *outCount, bool closePolygon=true)
 
OutType intersectBottom (const OutType &p1, const OutType &p2)
 
OutType intersectLeft (const OutType &p1, const OutType &p2)
 
OutType intersectRight (const OutType &p1, const OutType &p2)
 
OutType intersectTop (const OutType &p1, const OutType &p2)
 
 QPolygonClipper ()
 
void setBoundingRect (const QRect bounds)
 
 ~QPolygonClipper ()
 

Properties

QDataBuffer< OutType > buffer1
 
QDataBuffer< OutType > buffer2
 
int x1
 
int x2
 
int y1
 
int y2
 

Detailed Description

template<typename InType, typename OutType, typename CastType>
class QPolygonClipper< InType, OutType, CastType >

Definition at line 62 of file qpolygonclipper_p.h.

Constructors and Destructors

◆ QPolygonClipper()

template<typename InType, typename OutType, typename CastType>
QPolygonClipper< InType, OutType, CastType >::QPolygonClipper ( )
inline

Definition at line 65 of file qpolygonclipper_p.h.

65  :
66  buffer1(0), buffer2(0)
67  {
68  x1 = y1 = x2 = y2 = 0;
69  }
QPolygonClipper::buffer1
QDataBuffer< OutType > buffer1
Definition: qpolygonclipper_p.h:311
QPolygonClipper::buffer2
QDataBuffer< OutType > buffer2
Definition: qpolygonclipper_p.h:312

◆ ~QPolygonClipper()

template<typename InType, typename OutType, typename CastType>
QPolygonClipper< InType, OutType, CastType >::~QPolygonClipper ( )
inline

Definition at line 71 of file qpolygonclipper_p.h.

72  {
73  }

Functions

◆ boundingRect()

template<typename InType, typename OutType, typename CastType>
QRect QPolygonClipper< InType, OutType, CastType >::boundingRect ( )
inline

Definition at line 83 of file qpolygonclipper_p.h.

84  {
85  return QRect(QPoint(x1, y1), QPoint(x2, y2));
86  }
QPoint
The QPoint class defines a point in the plane using integer precision.
Definition: qpoint.h:53
QRect
The QRect class defines a rectangle in the plane using integer precision.
Definition: qrect.h:58

◆ clipPolygon()

template<typename InType, typename OutType, typename CastType>
void QPolygonClipper< InType, OutType, CastType >::clipPolygon ( const InType *  inPoints,
int  inCount,
OutType **  outPoints,
int *  outCount,
bool  closePolygon = true 
)
inline

Definition at line 128 of file qpolygonclipper_p.h.

130  {
131  Q_ASSERT(outPoints);
132  Q_ASSERT(outCount);
133 
134  if (inCount < 2) {
135  *outCount = 0;
136  return;
137  }
138 
139  buffer1.reset();
140  buffer2.reset();
141 
142  QDataBuffer<OutType> *source = &buffer1;
143  QDataBuffer<OutType> *clipped = &buffer2;
144 
145  // Gather some info since we are iterating through the points anyway..
146  bool doLeft = false, doRight = false, doTop = false, doBottom = false;
147  OutType ot;
148  for (int i=0; i<inCount; ++i) {
149  ot = inPoints[i];
150  clipped->add(ot);
151 
152  if (ot.x < x1)
153  doLeft = true;
154  else if (ot.x > x2)
155  doRight = true;
156  if (ot.y < y1)
157  doTop = true;
158  else if (ot.y > y2)
159  doBottom = true;
160  }
161 
162  if (doLeft && clipped->size() > 1) {
163  QDataBuffer<OutType> *tmp = source;
164  source = clipped;
165  clipped = tmp;
166  clipped->reset();
167  int lastPos, start;
168  if (closePolygon) {
169  lastPos = source->size() - 1;
170  start = 0;
171  } else {
172  lastPos = 0;
173  start = 1;
174  if (source->at(0).x >= x1)
175  clipped->add(source->at(0));
176  }
177  for (int i=start; i<inCount; ++i) {
178  const OutType &cpt = source->at(i);
179  const OutType &ppt = source->at(lastPos);
180 
181  if (cpt.x >= x1) {
182  if (ppt.x >= x1) {
183  clipped->add(cpt);
184  } else {
185  clipped->add(intersectLeft(cpt, ppt));
186  clipped->add(cpt);
187  }
188  } else if (ppt.x >= x1) {
189  clipped->add(intersectLeft(cpt, ppt));
190  }
191  lastPos = i;
192  }
193  }
194 
195  if (doRight && clipped->size() > 1) {
196  QDataBuffer<OutType> *tmp = source;
197  source = clipped;
198  clipped = tmp;
199  clipped->reset();
200  int lastPos, start;
201  if (closePolygon) {
202  lastPos = source->size() - 1;
203  start = 0;
204  } else {
205  lastPos = 0;
206  start = 1;
207  if (source->at(0).x <= x2)
208  clipped->add(source->at(0));
209  }
210  for (int i=start; i<source->size(); ++i) {
211  const OutType &cpt = source->at(i);
212  const OutType &ppt = source->at(lastPos);
213 
214  if (cpt.x <= x2) {
215  if (ppt.x <= x2) {
216  clipped->add(cpt);
217  } else {
218  clipped->add(intersectRight(cpt, ppt));
219  clipped->add(cpt);
220  }
221  } else if (ppt.x <= x2) {
222  clipped->add(intersectRight(cpt, ppt));
223  }
224 
225  lastPos = i;
226  }
227 
228  }
229 
230  if (doTop && clipped->size() > 1) {
231  QDataBuffer<OutType> *tmp = source;
232  source = clipped;
233  clipped = tmp;
234  clipped->reset();
235  int lastPos, start;
236  if (closePolygon) {
237  lastPos = source->size() - 1;
238  start = 0;
239  } else {
240  lastPos = 0;
241  start = 1;
242  if (source->at(0).y >= y1)
243  clipped->add(source->at(0));
244  }
245  for (int i=start; i<source->size(); ++i) {
246  const OutType &cpt = source->at(i);
247  const OutType &ppt = source->at(lastPos);
248 
249  if (cpt.y >= y1) {
250  if (ppt.y >= y1) {
251  clipped->add(cpt);
252  } else {
253  clipped->add(intersectTop(cpt, ppt));
254  clipped->add(cpt);
255  }
256  } else if (ppt.y >= y1) {
257  clipped->add(intersectTop(cpt, ppt));
258  }
259 
260  lastPos = i;
261  }
262  }
263 
264  if (doBottom && clipped->size() > 1) {
265  QDataBuffer<OutType> *tmp = source;
266  source = clipped;
267  clipped = tmp;
268  clipped->reset();
269  int lastPos, start;
270  if (closePolygon) {
271  lastPos = source->size() - 1;
272  start = 0;
273  } else {
274  lastPos = 0;
275  start = 1;
276  if (source->at(0).y <= y2)
277  clipped->add(source->at(0));
278  }
279  for (int i=start; i<source->size(); ++i) {
280  const OutType &cpt = source->at(i);
281  const OutType &ppt = source->at(lastPos);
282 
283  if (cpt.y <= y2) {
284  if (ppt.y <= y2) {
285  clipped->add(cpt);
286  } else {
287  clipped->add(intersectBottom(cpt, ppt));
288  clipped->add(cpt);
289  }
290  } else if (ppt.y <= y2) {
291  clipped->add(intersectBottom(cpt, ppt));
292  }
293  lastPos = i;
294  }
295  }
296 
297  if (closePolygon && clipped->size() > 0) {
298  // close clipped polygon
299  if (clipped->at(0).x != clipped->at(clipped->size()-1).x ||
300  clipped->at(0).y != clipped->at(clipped->size()-1).y) {
301  OutType ot = clipped->at(0);
302  clipped->add(ot);
303  }
304  }
305  *outCount = clipped->size();
306  *outPoints = clipped->data();
307  }
QPolygonClipper::buffer1
QDataBuffer< OutType > buffer1
Definition: qpolygonclipper_p.h:311
QPolygonClipper::buffer2
QDataBuffer< OutType > buffer2
Definition: qpolygonclipper_p.h:312
QDataBuffer::data
Type * data() const
Definition: qdatabuffer_p.h:84
Q_ASSERT
#define Q_ASSERT(cond)
Definition: qglobal.h:1823
QDataBuffer::at
Type & at(int i)
Definition: qdatabuffer_p.h:86
QDataBuffer::add
void add(const Type &t)
Definition: qdatabuffer_p.h:93
QPolygonClipper::intersectBottom
OutType intersectBottom(const OutType &p1, const OutType &p2)
Definition: qpolygonclipper_p.h:118
QPolygonClipper::intersectRight
OutType intersectRight(const OutType &p1, const OutType &p2)
Definition: qpolygonclipper_p.h:98
QPolygonClipper::intersectLeft
OutType intersectLeft(const OutType &p1, const OutType &p2)
Definition: qpolygonclipper_p.h:88
QPolygonClipper::intersectTop
OutType intersectTop(const OutType &p1, const OutType &p2)
Definition: qpolygonclipper_p.h:108
QDataBuffer::reset
void reset()
Definition: qdatabuffer_p.h:79
QDataBuffer::size
int size() const
Definition: qdatabuffer_p.h:83

◆ intersectBottom()

template<typename InType, typename OutType, typename CastType>
OutType QPolygonClipper< InType, OutType, CastType >::intersectBottom ( const OutType &  p1,
const OutType &  p2 
)
inline

Definition at line 118 of file qpolygonclipper_p.h.

Referenced by QPolygonClipper< qt_float_point, qt_float_point, float >::clipPolygon().

119  {
120  OutType t;
121  qreal dx = (p1.x - p2.x) / qreal(p1.y - p2.y);
122  t.x = static_cast<CastType>(p2.x + (y2 - p2.y) * dx);
123  t.y = y2;
124  return t;
125  }
qreal
double qreal
Definition: qglobal.h:1193

◆ intersectLeft()

template<typename InType, typename OutType, typename CastType>
OutType QPolygonClipper< InType, OutType, CastType >::intersectLeft ( const OutType &  p1,
const OutType &  p2 
)
inline

Definition at line 88 of file qpolygonclipper_p.h.

Referenced by QPolygonClipper< qt_float_point, qt_float_point, float >::clipPolygon().

89  {
90  OutType t;
91  qreal dy = (p1.y - p2.y) / qreal(p1.x - p2.x);
92  t.x = x1;
93  t.y = static_cast<CastType>(p2.y + (x1 - p2.x) * dy);
94  return t;
95  }
qreal
double qreal
Definition: qglobal.h:1193

◆ intersectRight()

template<typename InType, typename OutType, typename CastType>
OutType QPolygonClipper< InType, OutType, CastType >::intersectRight ( const OutType &  p1,
const OutType &  p2 
)
inline

Definition at line 98 of file qpolygonclipper_p.h.

Referenced by QPolygonClipper< qt_float_point, qt_float_point, float >::clipPolygon().

99  {
100  OutType t;
101  qreal dy = (p1.y - p2.y) / qreal(p1.x - p2.x);
102  t.x = x2;
103  t.y = static_cast<CastType>(p2.y + (x2 - p2.x) * dy);
104  return t;
105  }
qreal
double qreal
Definition: qglobal.h:1193

◆ intersectTop()

template<typename InType, typename OutType, typename CastType>
OutType QPolygonClipper< InType, OutType, CastType >::intersectTop ( const OutType &  p1,
const OutType &  p2 
)
inline

Definition at line 108 of file qpolygonclipper_p.h.

Referenced by QPolygonClipper< qt_float_point, qt_float_point, float >::clipPolygon().

109  {
110  OutType t;
111  qreal dx = (p1.x - p2.x) / qreal(p1.y - p2.y);
112  t.x = static_cast<CastType>(p2.x + (y1 - p2.y) * dx);
113  t.y = y1;
114  return t;
115  }
qreal
double qreal
Definition: qglobal.h:1193

◆ setBoundingRect()

template<typename InType, typename OutType, typename CastType>
void QPolygonClipper< InType, OutType, CastType >::setBoundingRect ( const QRect  bounds)
inline

Definition at line 75 of file qpolygonclipper_p.h.

76  {
77  x1 = bounds.x();
78  x2 = bounds.x() + bounds.width();
79  y1 = bounds.y();
80  y2 = bounds.y() + bounds.height();
81  }
QRect::width
int width() const
Returns the width of the rectangle.
Definition: qrect.h:303
QRect::height
int height() const
Returns the height of the rectangle.
Definition: qrect.h:306
QRect::y
int y() const
Returns the y-coordinate of the rectangle&#39;s top edge.
Definition: qrect.h:255
QRect::x
int x() const
Returns the x-coordinate of the rectangle&#39;s left edge.
Definition: qrect.h:252

Properties

◆ buffer1

template<typename InType, typename OutType, typename CastType>
QDataBuffer<OutType> QPolygonClipper< InType, OutType, CastType >::buffer1
private

Definition at line 311 of file qpolygonclipper_p.h.

Referenced by QPolygonClipper< qt_float_point, qt_float_point, float >::clipPolygon().

◆ buffer2

template<typename InType, typename OutType, typename CastType>
QDataBuffer<OutType> QPolygonClipper< InType, OutType, CastType >::buffer2
private

Definition at line 312 of file qpolygonclipper_p.h.

Referenced by QPolygonClipper< qt_float_point, qt_float_point, float >::clipPolygon().

◆ x1

template<typename InType, typename OutType, typename CastType>
int QPolygonClipper< InType, OutType, CastType >::x1
private

Definition at line 310 of file qpolygonclipper_p.h.

Referenced by QPolygonClipper< qt_float_point, qt_float_point, float >::boundingRect(), QPolygonClipper< qt_float_point, qt_float_point, float >::clipPolygon(), QPolygonClipper< qt_float_point, qt_float_point, float >::intersectLeft(), QPolygonClipper< qt_float_point, qt_float_point, float >::QPolygonClipper(), and QPolygonClipper< qt_float_point, qt_float_point, float >::setBoundingRect().

◆ x2

template<typename InType, typename OutType, typename CastType>
int QPolygonClipper< InType, OutType, CastType >::x2
private

Definition at line 310 of file qpolygonclipper_p.h.

Referenced by QPolygonClipper< qt_float_point, qt_float_point, float >::boundingRect(), QPolygonClipper< qt_float_point, qt_float_point, float >::clipPolygon(), QPolygonClipper< qt_float_point, qt_float_point, float >::intersectRight(), QPolygonClipper< qt_float_point, qt_float_point, float >::QPolygonClipper(), and QPolygonClipper< qt_float_point, qt_float_point, float >::setBoundingRect().

◆ y1

template<typename InType, typename OutType, typename CastType>
int QPolygonClipper< InType, OutType, CastType >::y1
private

Definition at line 310 of file qpolygonclipper_p.h.

Referenced by QPolygonClipper< qt_float_point, qt_float_point, float >::boundingRect(), QPolygonClipper< qt_float_point, qt_float_point, float >::clipPolygon(), QPolygonClipper< qt_float_point, qt_float_point, float >::intersectTop(), QPolygonClipper< qt_float_point, qt_float_point, float >::QPolygonClipper(), and QPolygonClipper< qt_float_point, qt_float_point, float >::setBoundingRect().

◆ y2

template<typename InType, typename OutType, typename CastType>
int QPolygonClipper< InType, OutType, CastType >::y2
private

Definition at line 310 of file qpolygonclipper_p.h.

Referenced by QPolygonClipper< qt_float_point, qt_float_point, float >::boundingRect(), QPolygonClipper< qt_float_point, qt_float_point, float >::clipPolygon(), QPolygonClipper< qt_float_point, qt_float_point, float >::intersectBottom(), QPolygonClipper< qt_float_point, qt_float_point, float >::QPolygonClipper(), and QPolygonClipper< qt_float_point, qt_float_point, float >::setBoundingRect().

The documentation for this class was generated from the following file:
Qt 4.8 Source Code Browser