Use C++ <cmath> instead of <math.h>

Including math.h can pollute the default namespace, and break
some compilers if cmath versions of the method are declared as using.

Switching to C++ math functions also greatly simplifies handling of
float qreal as C++ automatically chooses the right method.

[ChangeLog][QtCore][QtMath] qmath.h no longer includes math.h, so any
sources depending on that indirect inclusion may fail to build.

Change-Id: I4d0e331dafba354ec05dc5052e61ef4ff8d387fe
Reviewed-by: Rafael Roquetto <rafael.roquetto@kdab.com>

2 files changed, 5 insertions, 5 deletions

diff --git a/src/plugins/platforms/cocoa/qpaintengine_mac.mm b/src/plugins/platforms/cocoa/qpaintengine_mac.mm
index 2df4c588cc..16eb281a2f 100644
--- a/src/plugins/platforms/cocoa/qpaintengine_mac.mm
+++ b/src/plugins/platforms/cocoa/qpaintengine_mac.mm
@@ -654,11 +654,11 @@ QCoreGraphicsPaintEngine::updateState(const QPaintEngineState &state)
                 d->cosmeticPenSize = 1.0;
         } else {
             d->cosmeticPen = QCoreGraphicsPaintEnginePrivate::CosmeticSetPenWidth;
-            static const float sqrt2 = sqrt(2);
+            static const float sqrt2 = std::sqrt(2.0f);
             qreal width = d->current.pen.widthF();
             if (!width)
                 width = 1;
-            d->cosmeticPenSize = sqrt(pow(d->pixelSize.y(), 2) + pow(d->pixelSize.x(), 2)) / sqrt2 * width;
+            d->cosmeticPenSize = std::sqrt(std::pow(d->pixelSize.y(), 2) + std::pow(d->pixelSize.x(), 2)) / sqrt2 * width;
         }
     }
 }
diff --git a/src/plugins/platforms/windows/qwindowstabletsupport.cpp b/src/plugins/platforms/windows/qwindowstabletsupport.cpp
index 1818d614fd..7b871be015 100644
--- a/src/plugins/platforms/windows/qwindowstabletsupport.cpp
+++ b/src/plugins/platforms/windows/qwindowstabletsupport.cpp
@@ -455,10 +455,10 @@ bool QWindowsTabletSupport::translateTabletPacketEvent()
             // X Tilt = arctan(X / Z)
             // Y Tilt = arctan(Y / Z)
             const double radAzim = (packet.pkOrientation.orAzimuth / 10.0) * (M_PI / 180);
-            const double tanAlt = tan((abs(packet.pkOrientation.orAltitude / 10.0)) * (M_PI / 180));
+            const double tanAlt = std::tan((std::abs(packet.pkOrientation.orAltitude / 10.0)) * (M_PI / 180));
 
-            const double degX = atan(sin(radAzim) / tanAlt);
-            const double degY = atan(cos(radAzim) / tanAlt);
+            const double degX = std::atan(std::sin(radAzim) / tanAlt);
+            const double degY = std::atan(std::cos(radAzim) / tanAlt);
             tiltX = int(degX * (180 / M_PI));
             tiltY = int(-degY * (180 / M_PI));
             rotation = 360.0 - (packet.pkOrientation.orTwist / 10.0);