3 files changed, 8 insertions, 10 deletions
diff --git a/src/gui/opengl/qopenglpaintengine.cpp b/src/gui/opengl/qopenglpaintengine.cpp
index c23e0c28ea..576558022e 100644
--- a/src/gui/opengl/qopenglpaintengine.cpp
+++ b/src/gui/opengl/qopenglpaintengine.cpp
@@ -462,8 +462,8 @@ void QOpenGL2PaintEngineExPrivate::updateMatrix()
     // anti-aliased text rendering. In such cases, we snap the translate to the pixel grid.
     if (snapToPixelGrid && transform.type() == QTransform::TxTranslate) {
         // 0.50 needs to rounded down to 0.0 for consistency with raster engine:
-        dx = ceilf(dx - 0.5f);
-        dy = ceilf(dy - 0.5f);
+        dx = std::ceil(dx - 0.5f);
+        dy = std::ceil(dy - 0.5f);
     }
     pmvMatrix[0][0] = (wfactor * transform.m11())  - transform.m13();
     pmvMatrix[1][0] = (wfactor * transform.m21())  - transform.m23();
diff --git a/src/gui/opengl/qtriangulatingstroker_p.h b/src/gui/opengl/qtriangulatingstroker_p.h
index 2561810d7a..dd46cbe1e5 100644
--- a/src/gui/opengl/qtriangulatingstroker_p.h
+++ b/src/gui/opengl/qtriangulatingstroker_p.h
@@ -134,11 +134,11 @@ inline void QTriangulatingStroker::normalVector(float x1, float y1, float x2, fl
     float pw;
 
     if (dx == 0)
-        pw = m_width / qAbs(dy);
+        pw = m_width / std::abs(dy);
     else if (dy == 0)
-        pw = m_width / qAbs(dx);
+        pw = m_width / std::abs(dx);
     else
-        pw = m_width / sqrt(dx*dx + dy*dy);
+        pw = m_width / std::sqrt(dx*dx + dy*dy);
 
     *nx = -dy * pw;
     *ny = dx * pw;
diff --git a/src/gui/opengl/qtriangulator.cpp b/src/gui/opengl/qtriangulator.cpp
index b0d754b87e..6574fe9975 100644
--- a/src/gui/opengl/qtriangulator.cpp
+++ b/src/gui/opengl/qtriangulator.cpp
@@ -49,8 +49,6 @@
 #include <private/qopenglextensions_p.h>
 #include <private/qrbtree_p.h>
 
-#include <math.h>
-
 QT_BEGIN_NAMESPACE
 
 //#define Q_TRIANGULATOR_DEBUG
@@ -1700,8 +1698,8 @@ void QTriangulator<T>::ComplexToSimple::DebugDialog::paintEvent(QPaintEvent *)
         QPodPoint q = vertices.at(splits.at(i).vertex);
         QPodPoint u = vertices.at(edges.at(splits.at(i).edge).from) - q;
         QPodPoint v = vertices.at(edges.at(splits.at(i).edge).to) - q;
-        qreal uLen = sqrt(qreal(qDot(u, u)));
-        qreal vLen = sqrt(qreal(qDot(v, v)));
+        qreal uLen = qSqrt(qDot(u, u));
+        qreal vLen = qSqrt(qDot(v, v));
         if (uLen) {
             u.x *= 2 * halfPointSize / uLen;
             u.y *= 2 * halfPointSize / uLen;
@@ -1719,7 +1717,7 @@ void QTriangulator<T>::ComplexToSimple::DebugDialog::paintEvent(QPaintEvent *)
 template <typename T>
 void QTriangulator<T>::ComplexToSimple::DebugDialog::wheelEvent(QWheelEvent *event)
 {
-    qreal scale = exp(-0.001 * event->delta());
+    qreal scale = qExp(-0.001 * event->delta());
     QPointF center = m_window.center();
     QPointF delta = scale * (m_window.bottomRight() - center);
     m_window = QRectF(center - delta, center + delta);