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, 7 insertions, 5 deletions

diff --git a/examples/widgets/effects/blurpicker/blurpicker.cpp b/examples/widgets/effects/blurpicker/blurpicker.cpp
index f354a15c53..b5ac7950bd 100644
--- a/examples/widgets/effects/blurpicker/blurpicker.cpp
+++ b/examples/widgets/effects/blurpicker/blurpicker.cpp
@@ -41,6 +41,7 @@
 #include "blurpicker.h"
 
 #include <QtWidgets>
+#include <QtCore/qmath.h>
 
 #include "blureffect.h"
 
@@ -76,8 +77,8 @@ void BlurPicker::setIndex(qreal index)
     for (int i = 0; i < m_icons.count(); ++i) {
         QGraphicsItem *icon = m_icons[i];
         qreal a = ((i + m_index) * 2 * M_PI) / m_icons.count();
-        qreal xs = 170 * sin(a);
-        qreal ys = 100 * cos(a);
+        qreal xs = 170 * qSin(a);
+        qreal ys = 100 * qCos(a);
         QPointF pos(xs, ys);
         pos = QTransform().rotate(-20).map(pos);
         pos -= QPointF(40, 40);
diff --git a/examples/widgets/effects/lighting/lighting.cpp b/examples/widgets/effects/lighting/lighting.cpp
index 1bf18160b4..67bcb8147b 100644
--- a/examples/widgets/effects/lighting/lighting.cpp
+++ b/examples/widgets/effects/lighting/lighting.cpp
@@ -41,6 +41,7 @@
 #include "lighting.h"
 
 #include <QtWidgets>
+#include <QtCore/qmath.h>
 
 #ifndef M_PI
 #define M_PI 3.14159265358979323846
@@ -110,8 +111,8 @@ void Lighting::setupScene()
 void Lighting::animate()
 {
     angle += (M_PI / 30);
-    qreal xs = 200 * sin(angle) - 40 + 25;
-    qreal ys = 200 * cos(angle) - 40 + 25;
+    qreal xs = 200 * qSin(angle) - 40 + 25;
+    qreal ys = 200 * qCos(angle) - 40 + 25;
     m_lightSource->setPos(xs, ys);
 
     for (int i = 0; i < m_items.size(); ++i) {
@@ -125,7 +126,7 @@ void Lighting::animate()
 
         qreal dx = delta.x();
         qreal dy = delta.y();
-        qreal dd = sqrt(dx * dx + dy * dy);
+        qreal dd = qSqrt(dx * dx + dy * dy);
         QColor color = effect->color();
         color.setAlphaF(qBound(0.4, 1 - dd / 200.0, 0.7));
         effect->setColor(color);