Removing accidental use of double instead of qreal from QLine

QLine contained a number of places where conversions and calculations
were done as double where qreal should have been used instead. This
is caused by the use of raw floating point literals. The fix is to
construct the literals as qreal. The angle conversions are simplified
to reduce the risk of a growing loss of precision from this change.

On Symbian, where qreal is float, this gives a 5-10% performance
improvement to the affected functions, as tested by a new benchmark
test. The auto tests pass, these contain precision tests which indicates
that there is no significant loss of precision with this change.

On Windows, where qreal is double, this has no significant effect on
performance.

Task-number: QTBUG-4894
Reviewed-by: Shane Kearns

3 files changed, 170 insertions, 0 deletions

diff --git a/tests/benchmarks/corelib/tools/qline/main.cpp b/tests/benchmarks/corelib/tools/qline/main.cpp
new file mode 100644
index 0000000..d7f93ba
--- /dev/null
+++ b/tests/benchmarks/corelib/tools/qline/main.cpp
@@ -0,0 +1,157 @@
+/****************************************************************************
+**
+** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** 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.
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+// This file contains benchmarks for QLineF functions.
+
+#include <QDebug>
+#include <qtest.h>
+#include <QLine>
+
+class tst_qline : public QObject
+{
+    Q_OBJECT
+private slots:
+    void fromPolar();
+    void intersect_data();
+    void intersect();
+    void length();
+    void setLength();
+    void angle();
+    void setAngle();
+    void angleTo();
+    void unitVector();
+    void normalVector();
+    void angle2();
+};
+
+void tst_qline::fromPolar()
+{
+    QBENCHMARK {
+        QLineF::fromPolar(10, 2);
+    }
+}
+
+void tst_qline::intersect_data()
+{
+    QTest::addColumn<QLineF>("l1");
+    QTest::addColumn<QLineF>("l2");
+    QTest::newRow("cross") << QLineF(-1,-1,1,1) << QLineF(-1,1,1,-1);
+    QTest::newRow("miss") << QLineF(1,1,2,2) << QLineF(1,11,2,12);
+}
+
+void tst_qline::intersect()
+{
+    QFETCH(QLineF, l1);
+    QFETCH(QLineF, l2);
+    QPointF intersection;
+    QBENCHMARK {
+        l1.intersect(l2, &intersection);
+    }
+}
+
+void tst_qline::length()
+{
+    QLineF line(1,2,3,4);
+    QBENCHMARK {
+        line.length();
+    }
+}
+
+void tst_qline::setLength()
+{
+    QLineF line(1,2,3,4);
+    QBENCHMARK {
+        line.setLength(5);
+    }
+}
+
+void tst_qline::angle()
+{
+    QLineF line(1,2,3,4);
+    QBENCHMARK {
+        line.angle();
+    }
+}
+
+void tst_qline::setAngle()
+{
+    QLineF line(1,2,3,4);
+    QBENCHMARK {
+        line.setAngle(1);
+    }
+}
+
+void tst_qline::angleTo()
+{
+    QLineF line1(1,2,3,4);
+    QLineF line2(8,7,6,5);
+    QBENCHMARK {
+        line1.angleTo(line2);
+    }
+}
+
+void tst_qline::unitVector()
+{
+    QLineF line(1,2,3,4);
+    QBENCHMARK {
+        line.unitVector();
+    }
+}
+
+void tst_qline::normalVector()
+{
+    QLineF line(1,2,3,4);
+    QBENCHMARK {
+        line.normalVector();
+    }
+}
+
+void tst_qline::angle2()
+{
+    QLineF line1(1,2,3,4);
+    QLineF line2(8,7,6,5);
+    QBENCHMARK {
+        line1.angle(line2);
+    }
+}
+
+QTEST_MAIN(tst_qline)
+
+#include "main.moc"
diff --git a/tests/benchmarks/corelib/tools/qline/qline.pro b/tests/benchmarks/corelib/tools/qline/qline.pro
new file mode 100644
index 0000000..ae6bf5e
--- /dev/null
+++ b/tests/benchmarks/corelib/tools/qline/qline.pro
@@ -0,0 +1,12 @@
+load(qttest_p4)
+TEMPLATE = app
+TARGET = tst_bench_qline
+DEPENDPATH += .
+INCLUDEPATH += .
+
+QT -= gui
+
+CONFIG += release
+
+# Input
+SOURCES += main.cpp
diff --git a/tests/benchmarks/corelib/tools/tools.pro b/tests/benchmarks/corelib/tools/tools.pro
index 44e8973..83a9411 100644
--- a/tests/benchmarks/corelib/tools/tools.pro
+++ b/tests/benchmarks/corelib/tools/tools.pro
@@ -3,6 +3,7 @@ SUBDIRS = \
         containers-associative \
         containers-sequential \
         qbytearray \
+        qline \
         qlist \
         qrect \
         qregexp \