Cleanup QtOpenGL examples

Cleanup the OpenGL examples
 - use nullptr (clang-tidy)
 - use member-initialization
 - avoid redundant checks for != nullptr when deleting a pointer

Change-Id: I3e4702690ed79e71c3e952d51ceef83b907b45b7
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
Reviewed-by: Laszlo Agocs <laszlo.agocs@qt.io>

3 files changed, 21 insertions, 32 deletions

diff --git a/examples/gui/openglwindow/main.cpp b/examples/gui/openglwindow/main.cpp
index 90c93f0d37..d1e5d3871e 100644
--- a/examples/gui/openglwindow/main.cpp
+++ b/examples/gui/openglwindow/main.cpp
@@ -50,36 +50,30 @@
 
 #include "openglwindow.h"
 
-#include <QtGui/QGuiApplication>
-#include <QtGui/QMatrix4x4>
-#include <QtGui/QOpenGLShaderProgram>
-#include <QtGui/QScreen>
+#include <QGuiApplication>
+#include <QMatrix4x4>
+#include <QOpenGLShaderProgram>
+#include <QScreen>
+#include <QtMath>
 
-#include <QtCore/qmath.h>
 
 //! [1]
 class TriangleWindow : public OpenGLWindow
 {
 public:
-    TriangleWindow();
+    using OpenGLWindow::OpenGLWindow;
 
     void initialize() override;
     void render() override;
 
 private:
-    GLuint m_posAttr;
-    GLuint m_colAttr;
-    GLuint m_matrixUniform;
+    GLuint m_posAttr = 0;
+    GLuint m_colAttr = 0;
+    GLuint m_matrixUniform = 0;
 
-    QOpenGLShaderProgram *m_program;
-    int m_frame;
+    QOpenGLShaderProgram *m_program = nullptr;
+    int m_frame = 0;
 };
-
-TriangleWindow::TriangleWindow()
-    : m_program(0)
-    , m_frame(0)
-{
-}
 //! [1]
 
 //! [2]
@@ -144,7 +138,7 @@ void TriangleWindow::render()
     m_program->bind();
 
     QMatrix4x4 matrix;
-    matrix.perspective(60.0f, 4.0f/3.0f, 0.1f, 100.0f);
+    matrix.perspective(60.0f, 4.0f / 3.0f, 0.1f, 100.0f);
     matrix.translate(0, 0, -2);
     matrix.rotate(100.0f * m_frame / screen()->refreshRate(), 0, 1, 0);
 
diff --git a/examples/gui/openglwindow/openglwindow.cpp b/examples/gui/openglwindow/openglwindow.cpp
index a0c85006bd..bac887dca0 100644
--- a/examples/gui/openglwindow/openglwindow.cpp
+++ b/examples/gui/openglwindow/openglwindow.cpp
@@ -50,18 +50,13 @@
 
 #include "openglwindow.h"
 
-#include <QtCore/QCoreApplication>
-
-#include <QtGui/QOpenGLContext>
-#include <QtGui/QOpenGLPaintDevice>
-#include <QtGui/QPainter>
+#include <QOpenGLContext>
+#include <QOpenGLPaintDevice>
+#include <QPainter>
 
 //! [1]
 OpenGLWindow::OpenGLWindow(QWindow *parent)
     : QWindow(parent)
-    , m_animating(false)
-    , m_context(0)
-    , m_device(0)
 {
     setSurfaceType(QWindow::OpenGLSurface);
 }
diff --git a/examples/gui/openglwindow/openglwindow.h b/examples/gui/openglwindow/openglwindow.h
index 6e6c1d7449..8db943ddde 100644
--- a/examples/gui/openglwindow/openglwindow.h
+++ b/examples/gui/openglwindow/openglwindow.h
@@ -48,8 +48,8 @@
 **
 ****************************************************************************/
 
-#include <QtGui/QWindow>
-#include <QtGui/QOpenGLFunctions>
+#include <QWindow>
+#include <QOpenGLFunctions>
 
 QT_BEGIN_NAMESPACE
 class QPainter;
@@ -62,7 +62,7 @@ class OpenGLWindow : public QWindow, protected QOpenGLFunctions
 {
     Q_OBJECT
 public:
-    explicit OpenGLWindow(QWindow *parent = 0);
+    explicit OpenGLWindow(QWindow *parent = nullptr);
     ~OpenGLWindow();
 
     virtual void render(QPainter *painter);
@@ -82,10 +82,10 @@ protected:
     void exposeEvent(QExposeEvent *event) override;
 
 private:
-    bool m_animating;
+    bool m_animating = false;
 
-    QOpenGLContext *m_context;
-    QOpenGLPaintDevice *m_device;
+    QOpenGLContext *m_context = nullptr;
+    QOpenGLPaintDevice *m_device = nullptr;
 };
 //! [1]