1// Copyright (C) 2016 The Qt Company Ltd.
2// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
3
4#ifndef QMATH_P_H
5#define QMATH_P_H
6
7//
8// W A R N I N G
9// -------------
10//
11// This file is not part of the Qt API. It exists purely as an
12// implementation detail. This header file may change from version to
13// version without notice, or even be removed.
14//
15// We mean it.
16//
17
18#include <qmath.h>
19#include <private/qglobal_p.h>
20#include <qtransform.h>
21
22QT_BEGIN_NAMESPACE
23
24static const qreal Q_PI = qreal(M_PI); // pi
25static const qreal Q_MM_PER_INCH = 25.4;
26
27inline QRect qt_mapFillRect(const QRectF &rect, const QTransform &xf)
28{
29 // Only for xf <= scaling or 90 degree rotations
30 Q_ASSERT(xf.type() <= QTransform::TxScale
31 || (xf.type() == QTransform::TxRotate && qFuzzyIsNull(xf.m11()) && qFuzzyIsNull(xf.m22())));
32 // Transform the corners instead of the rect to avoid hitting numerical accuracy limit
33 // when transforming topleft and size separately and adding afterwards,
34 // as that can sometimes be slightly off around the .5 point, leading to wrong rounding
35 QPoint pt1 = xf.map(p: rect.topLeft()).toPoint();
36 QPoint pt2 = xf.map(p: rect.bottomRight()).toPoint();
37 // Normalize and adjust for the QRect vs. QRectF bottomright
38 return QRect::span(p1: pt1, p2: pt2).adjusted(xp1: 0, yp1: 0, xp2: -1, yp2: -1);
39}
40
41QT_END_NAMESPACE
42
43#endif // QMATH_P_H
44

source code of qtbase/src/gui/painting/qmath_p.h