5 files changed, 12 insertions, 25 deletions
diff --git a/examples/widgets/animation/stickman/stickman.cpp b/examples/widgets/animation/stickman/stickman.cpp
index 7a4629c4d2..b7a2d87ada 100644
--- a/examples/widgets/animation/stickman/stickman.cpp
+++ b/examples/widgets/animation/stickman/stickman.cpp
@@ -53,13 +53,7 @@
 
 #include <QPainter>
 #include <QTimer>
-
-#define _USE_MATH_DEFINES
-#include <math.h>
-
-#ifndef M_PI
-#define M_PI 3.14159265358979323846
-#endif
+#include <qmath.h>
 
 static const qreal Coords[NodeCount * 2] = {
     0.0, -150.0, // head, #0
@@ -300,7 +294,7 @@ void StickMan::paint(QPainter *painter, const QStyleOptionGraphicsItem *, QWidge
             QPointF dist = node2->pos() - node1->pos();
 
             qreal sinAngle = dist.x() / sqrt(pow(dist.x(), 2) + pow(dist.y(), 2));
-            qreal angle = asin(sinAngle) * 180.0 / M_PI;
+            qreal angle = qRadiansToDegrees(asin(sinAngle));
 
             QPointF headPos = node1->pos();
             painter->translate(headPos);
diff --git a/examples/widgets/effects/lighting/lighting.cpp b/examples/widgets/effects/lighting/lighting.cpp
index 68350f32b7..1ba7dd9ce7 100644
--- a/examples/widgets/effects/lighting/lighting.cpp
+++ b/examples/widgets/effects/lighting/lighting.cpp
@@ -49,14 +49,9 @@
 ****************************************************************************/
 
 #include "lighting.h"
-
 #include <QtWidgets>
 #include <QtCore/qmath.h>
 
-#ifndef M_PI
-#define M_PI 3.14159265358979323846
-#endif
-
 Lighting::Lighting(QWidget *parent): QGraphicsView(parent), angle(0.0)
 {
     setScene(&m_scene);
@@ -120,7 +115,7 @@ void Lighting::setupScene()
 
 void Lighting::animate()
 {
-    angle += (M_PI / 30);
+    angle += qDegreesToRadians(qreal(6));
     qreal xs = 200 * qSin(angle) - 40 + 25;
     qreal ys = 200 * qCos(angle) - 40 + 25;
     m_lightSource->setPos(xs, ys);
diff --git a/examples/widgets/graphicsview/boxes/glbuffers.cpp b/examples/widgets/graphicsview/boxes/glbuffers.cpp
index 1481292e76..851cd17796 100644
--- a/examples/widgets/graphicsview/boxes/glbuffers.cpp
+++ b/examples/widgets/graphicsview/boxes/glbuffers.cpp
@@ -50,11 +50,11 @@
 
 #include "glbuffers.h"
 #include <QtGui/qmatrix4x4.h>
-
+#include <QtCore/qmath.h>
 
 void qgluPerspective(GLdouble fovy, GLdouble aspect, GLdouble zNear, GLdouble zFar)
 {
-    const GLdouble ymax = zNear * tan(fovy * M_PI / 360.0);
+    const GLdouble ymax = zNear * tan(qDegreesToRadians(fovy) / 2.0);
     const GLdouble ymin = -ymax;
     const GLdouble xmin = ymin * aspect;
     const GLdouble xmax = ymax * aspect;
diff --git a/examples/widgets/graphicsview/boxes/trackball.cpp b/examples/widgets/graphicsview/boxes/trackball.cpp
index 15f3af77d1..c350f6adee 100644
--- a/examples/widgets/graphicsview/boxes/trackball.cpp
+++ b/examples/widgets/graphicsview/boxes/trackball.cpp
@@ -50,6 +50,7 @@
 
 #include "trackball.h"
 #include "scene.h"
+#include <qmath.h>
 #include <cmath>
 
 //============================================================================//
@@ -101,10 +102,11 @@ void TrackBall::move(const QPointF& p, const QQuaternion &transformation)
     case Plane:
         {
             QLineF delta(m_lastPos, p);
-            m_angularVelocity = 180*delta.length() / (PI*msecs);
+            const float angleDelta = qRadiansToDegrees(float(delta.length()));
+            m_angularVelocity = angleDelta / msecs;
             m_axis = QVector3D(-delta.dy(), delta.dx(), 0.0f).normalized();
             m_axis = transformation.rotatedVector(m_axis);
-            m_rotation = QQuaternion::fromAxisAndAngle(m_axis, 180 / PI * delta.length()) * m_rotation;
+            m_rotation = QQuaternion::fromAxisAndAngle(m_axis, angleDelta) * m_rotation;
         }
         break;
     case Sphere:
@@ -124,7 +126,7 @@ void TrackBall::move(const QPointF& p, const QQuaternion &transformation)
                 currentPos3D.normalize();
 
             m_axis = QVector3D::crossProduct(lastPos3D, currentPos3D);
-            float angle = 180 / PI * std::asin(std::sqrt(QVector3D::dotProduct(m_axis, m_axis)));
+            float angle = qRadiansToDegrees(std::asin(std::sqrt(QVector3D::dotProduct(m_axis, m_axis))));
 
             m_angularVelocity = angle / msecs;
             m_axis.normalize();
diff --git a/examples/widgets/itemviews/chart/pieview.cpp b/examples/widgets/itemviews/chart/pieview.cpp
index 942bbe5ca5..3f85e397ee 100644
--- a/examples/widgets/itemviews/chart/pieview.cpp
+++ b/examples/widgets/itemviews/chart/pieview.cpp
@@ -49,12 +49,8 @@
 ****************************************************************************/
 
 #include <QtWidgets>
+#include <qmath.h>
 #include <cmath>
-
-#ifndef M_PI
-#define M_PI 3.1415927
-#endif
-
 #include "pieview.h"
 
 PieView::PieView(QWidget *parent)
@@ -125,7 +121,7 @@ QModelIndex PieView::indexAt(const QPoint &point) const
             return QModelIndex();
 
         // Determine the angle of the point.
-        double angle = (180 / M_PI) * std::atan2(cy, cx);
+        double angle = qRadiansToDegrees(std::atan2(cy, cx));
         if (angle < 0)
             angle = 360 + angle;