summaryrefslogtreecommitdiffstats
path: root/src/gui/math3d/qvector2d.cpp
blob: 27237c7c811c64c50ef04172d8f54f3cfb5c2eed (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
/****************************************************************************
**
** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
**
** This file is part of the QtGui module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Digia.  For licensing terms and
** conditions see http://qt.digia.com/licensing.  For further information
** use the contact form at http://qt.digia.com/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Digia gives you certain additional
** rights.  These rights are described in the Digia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
**
** $QT_END_LICENSE$
**
****************************************************************************/

#include "qvector2d.h"
#include "qvector3d.h"
#include "qvector4d.h"
#include <QtCore/qdebug.h>
#include <QtCore/qvariant.h>
#include <QtCore/qmath.h>

QT_BEGIN_NAMESPACE

#ifndef QT_NO_VECTOR2D

/*!
    \class QVector2D
    \brief The QVector2D class represents a vector or vertex in 2D space.
    \since 4.6
    \ingroup painting
    \ingroup painting-3D

    The QVector2D class can also be used to represent vertices in 2D space.
    We therefore do not need to provide a separate vertex class.

    \bold{Note:} By design values in the QVector2D instance are stored as \c float.
    This means that on platforms where the \c qreal arguments to QVector2D
    functions are represented by \c double values, it is possible to
    lose precision.

    \sa QVector3D, QVector4D, QQuaternion
*/

/*!
    \fn QVector2D::QVector2D()

    Constructs a null vector, i.e. with coordinates (0, 0, 0).
*/

/*!
    \fn QVector2D::QVector2D(qreal xpos, qreal ypos)

    Constructs a vector with coordinates (\a xpos, \a ypos).
*/

/*!
    \fn QVector2D::QVector2D(const QPoint& point)

    Constructs a vector with x and y coordinates from a 2D \a point.
*/

/*!
    \fn QVector2D::QVector2D(const QPointF& point)

    Constructs a vector with x and y coordinates from a 2D \a point.
*/

#ifndef QT_NO_VECTOR3D

/*!
    Constructs a vector with x and y coordinates from a 3D \a vector.
    The z coordinate of \a vector is dropped.

    \sa toVector3D()
*/
QVector2D::QVector2D(const QVector3D& vector)
{
    xp = vector.xp;
    yp = vector.yp;
}

#endif

#ifndef QT_NO_VECTOR4D

/*!
    Constructs a vector with x and y coordinates from a 3D \a vector.
    The z and w coordinates of \a vector are dropped.

    \sa toVector4D()
*/
QVector2D::QVector2D(const QVector4D& vector)
{
    xp = vector.xp;
    yp = vector.yp;
}

#endif

/*!
    \fn bool QVector2D::isNull() const

    Returns true if the x and y coordinates are set to 0.0,
    otherwise returns false.
*/

/*!
    \fn qreal QVector2D::x() const

    Returns the x coordinate of this point.

    \sa setX(), y()
*/

/*!
    \fn qreal QVector2D::y() const

    Returns the y coordinate of this point.

    \sa setY(), x()
*/

/*!
    \fn void QVector2D::setX(qreal x)

    Sets the x coordinate of this point to the given \a x coordinate.

    \sa x(), setY()
*/

/*!
    \fn void QVector2D::setY(qreal y)

    Sets the y coordinate of this point to the given \a y coordinate.

    \sa y(), setX()
*/

/*!
    Returns the length of the vector from the origin.

    \sa lengthSquared(), normalized()
*/
qreal QVector2D::length() const
{
    return qSqrt(xp * xp + yp * yp);
}

/*!
    Returns the squared length of the vector from the origin.
    This is equivalent to the dot product of the vector with itself.

    \sa length(), dotProduct()
*/
qreal QVector2D::lengthSquared() const
{
    return xp * xp + yp * yp;
}

/*!
    Returns the normalized unit vector form of this vector.

    If this vector is null, then a null vector is returned.  If the length
    of the vector is very close to 1, then the vector will be returned as-is.
    Otherwise the normalized form of the vector of length 1 will be returned.

    \sa length(), normalize()
*/
QVector2D QVector2D::normalized() const
{
    // Need some extra precision if the length is very small.
    double len = double(xp) * double(xp) +
                 double(yp) * double(yp);
    if (qFuzzyIsNull(len - 1.0f))
        return *this;
    else if (!qFuzzyIsNull(len))
        return *this / qSqrt(len);
    else
        return QVector2D();
}

/*!
    Normalizes the currect vector in place.  Nothing happens if this
    vector is a null vector or the length of the vector is very close to 1.

    \sa length(), normalized()
*/
void QVector2D::normalize()
{
    // Need some extra precision if the length is very small.
    double len = double(xp) * double(xp) +
                 double(yp) * double(yp);
    if (qFuzzyIsNull(len - 1.0f) || qFuzzyIsNull(len))
        return;

    len = qSqrt(len);

    xp /= len;
    yp /= len;
}

/*!
    \fn QVector2D &QVector2D::operator+=(const QVector2D &vector)

    Adds the given \a vector to this vector and returns a reference to
    this vector.

    \sa operator-=()
*/

/*!
    \fn QVector2D &QVector2D::operator-=(const QVector2D &vector)

    Subtracts the given \a vector from this vector and returns a reference to
    this vector.

    \sa operator+=()
*/

/*!
    \fn QVector2D &QVector2D::operator*=(qreal factor)

    Multiplies this vector's coordinates by the given \a factor, and
    returns a reference to this vector.

    \sa operator/=()
*/

/*!
    \fn QVector2D &QVector2D::operator*=(const QVector2D &vector)

    Multiplies the components of this vector by the corresponding
    components in \a vector.
*/

/*!
    \fn QVector2D &QVector2D::operator/=(qreal divisor)

    Divides this vector's coordinates by the given \a divisor, and
    returns a reference to this vector.

    \sa operator*=()
*/

/*!
    Returns the dot product of \a v1 and \a v2.
*/
qreal QVector2D::dotProduct(const QVector2D& v1, const QVector2D& v2)
{
    return v1.xp * v2.xp + v1.yp * v2.yp;
}

/*!
    \fn bool operator==(const QVector2D &v1, const QVector2D &v2)
    \relates QVector2D

    Returns true if \a v1 is equal to \a v2; otherwise returns false.
    This operator uses an exact floating-point comparison.
*/

/*!
    \fn bool operator!=(const QVector2D &v1, const QVector2D &v2)
    \relates QVector2D

    Returns true if \a v1 is not equal to \a v2; otherwise returns false.
    This operator uses an exact floating-point comparison.
*/

/*!
    \fn const QVector2D operator+(const QVector2D &v1, const QVector2D &v2)
    \relates QVector2D

    Returns a QVector2D object that is the sum of the given vectors, \a v1
    and \a v2; each component is added separately.

    \sa QVector2D::operator+=()
*/

/*!
    \fn const QVector2D operator-(const QVector2D &v1, const QVector2D &v2)
    \relates QVector2D

    Returns a QVector2D object that is formed by subtracting \a v2 from \a v1;
    each component is subtracted separately.

    \sa QVector2D::operator-=()
*/

/*!
    \fn const QVector2D operator*(qreal factor, const QVector2D &vector)
    \relates QVector2D

    Returns a copy of the given \a vector,  multiplied by the given \a factor.

    \sa QVector2D::operator*=()
*/

/*!
    \fn const QVector2D operator*(const QVector2D &vector, qreal factor)
    \relates QVector2D

    Returns a copy of the given \a vector,  multiplied by the given \a factor.

    \sa QVector2D::operator*=()
*/

/*!
    \fn const QVector2D operator*(const QVector2D &v1, const QVector2D &v2)
    \relates QVector2D

    Multiplies the components of \a v1 by the corresponding
    components in \a v2.
*/

/*!
    \fn const QVector2D operator-(const QVector2D &vector)
    \relates QVector2D
    \overload

    Returns a QVector2D object that is formed by changing the sign of
    the components of the given \a vector.

    Equivalent to \c {QVector2D(0,0) - vector}.
*/

/*!
    \fn const QVector2D operator/(const QVector2D &vector, qreal divisor)
    \relates QVector2D

    Returns the QVector2D object formed by dividing all three components of
    the given \a vector by the given \a divisor.

    \sa QVector2D::operator/=()
*/

/*!
    \fn bool qFuzzyCompare(const QVector2D& v1, const QVector2D& v2)
    \relates QVector2D

    Returns true if \a v1 and \a v2 are equal, allowing for a small
    fuzziness factor for floating-point comparisons; false otherwise.
*/

#ifndef QT_NO_VECTOR3D

/*!
    Returns the 3D form of this 2D vector, with the z coordinate set to zero.

    \sa toVector4D(), toPoint()
*/
QVector3D QVector2D::toVector3D() const
{
    return QVector3D(xp, yp, 0.0f, 1);
}

#endif

#ifndef QT_NO_VECTOR4D

/*!
    Returns the 4D form of this 2D vector, with the z and w coordinates set to zero.

    \sa toVector3D(), toPoint()
*/
QVector4D QVector2D::toVector4D() const
{
    return QVector4D(xp, yp, 0.0f, 0.0f, 1);
}

#endif

/*!
    \fn QPoint QVector2D::toPoint() const

    Returns the QPoint form of this 2D vector.

    \sa toPointF(), toVector3D()
*/

/*!
    \fn QPointF QVector2D::toPointF() const

    Returns the QPointF form of this 2D vector.

    \sa toPoint(), toVector3D()
*/

/*!
    Returns the 2D vector as a QVariant.
*/
QVector2D::operator QVariant() const
{
    return QVariant(QVariant::Vector2D, this);
}

#ifndef QT_NO_DEBUG_STREAM

QDebug operator<<(QDebug dbg, const QVector2D &vector)
{
    dbg.nospace() << "QVector2D(" << vector.x() << ", " << vector.y() << ')';
    return dbg.space();
}

#endif

#ifndef QT_NO_DATASTREAM

/*!
    \fn QDataStream &operator<<(QDataStream &stream, const QVector2D &vector)
    \relates QVector2D

    Writes the given \a vector to the given \a stream and returns a
    reference to the stream.

    \sa {Serializing Qt Data Types}
*/

QDataStream &operator<<(QDataStream &stream, const QVector2D &vector)
{
    stream << double(vector.x()) << double(vector.y());
    return stream;
}

/*!
    \fn QDataStream &operator>>(QDataStream &stream, QVector2D &vector)
    \relates QVector2D

    Reads a 2D vector from the given \a stream into the given \a vector
    and returns a reference to the stream.

    \sa {Serializing Qt Data Types}
*/

QDataStream &operator>>(QDataStream &stream, QVector2D &vector)
{
    double x, y;
    stream >> x;
    stream >> y;
    vector.setX(qreal(x));
    vector.setY(qreal(y));
    return stream;
}

#endif // QT_NO_DATASTREAM

#endif // QT_NO_VECTOR2D

QT_END_NAMESPACE