qt5base-lts/tests/auto/gui/painting/qpathclipper/pathcompare.h

127 lines
3.7 KiB
C
Raw Normal View History

/****************************************************************************
**
** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/
**
** This file is part of the test suite of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** GNU Lesser General Public License Usage
** 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, Nokia gives you certain additional
** rights. These rights are described in the Nokia 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.
**
** Other Usage
** Alternatively, this file may be used in accordance with the terms and
** conditions contained in a signed written agreement between you and Nokia.
**
**
**
**
**
**
** $QT_END_LICENSE$
**
****************************************************************************/
#ifndef PATHCOMPARE_H
#define PATHCOMPARE_H
#include <qmath.h>
namespace QPathCompare {
static const int precision = 8;
static const qreal epsilon = qPow(0.1, precision);
static inline bool fuzzyIsZero(qreal x, qreal relative)
{
if (qAbs(relative) < epsilon)
return qAbs(x) < epsilon;
else
return qAbs(x / relative) < epsilon;
}
static bool fuzzyCompare(const QPointF &a, const QPointF &b)
{
const QPointF delta = a - b;
const qreal x = qMax(qAbs(a.x()), qAbs(b.x()));
const qreal y = qMax(qAbs(a.y()), qAbs(b.y()));
return fuzzyIsZero(delta.x(), x) && fuzzyIsZero(delta.y(), y);
}
static bool isClosed(const QPainterPath &path)
{
if (path.elementCount() == 0)
return false;
QPointF first = path.elementAt(0);
QPointF last = path.elementAt(path.elementCount() - 1);
return fuzzyCompare(first, last);
}
// rotation and direction independent path comparison
// allows paths to be shifted or reversed relative to each other
static bool comparePaths(const QPainterPath &actual, const QPainterPath &expected)
{
const int endActual = isClosed(actual) ? actual.elementCount() - 1 : actual.elementCount();
const int endExpected = isClosed(expected) ? expected.elementCount() - 1 : expected.elementCount();
if (endActual != endExpected)
return false;
for (int i = 0; i < endActual; ++i) {
int k = 0;
for (k = 0; k < endActual; ++k) {
int i1 = k;
int i2 = (i + k) % endActual;
QPointF a = actual.elementAt(i1);
QPointF b = expected.elementAt(i2);
if (!fuzzyCompare(a, b))
break;
}
if (k == endActual)
return true;
for (k = 0; k < endActual; ++k) {
int i1 = k;
int i2 = (i + endActual - k) % endActual;
QPointF a = actual.elementAt(i1);
QPointF b = expected.elementAt(i2);
if (!fuzzyCompare(a, b))
break;
}
if (k == endActual)
return true;
}
return false;
}
}
#endif