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>

2 files changed, 10 insertions, 15 deletions

diff --git a/examples/opengl/threadedqopenglwidget/glwidget.cpp b/examples/opengl/threadedqopenglwidget/glwidget.cpp
index cc528a734a..2101575fd4 100644
--- a/examples/opengl/threadedqopenglwidget/glwidget.cpp
+++ b/examples/opengl/threadedqopenglwidget/glwidget.cpp
@@ -115,12 +115,7 @@ void GLWidget::grabContext()
     m_renderer->unlockRenderer();
 }
 
-Renderer::Renderer(GLWidget *w)
-    : m_inited(false),
-      m_glwidget(w),
-      m_exiting(false)
-{
-}
+Renderer::Renderer(GLWidget *w) : m_glwidget(w) {}
 
 void Renderer::paintQtLogo()
 {
diff --git a/examples/opengl/threadedqopenglwidget/glwidget.h b/examples/opengl/threadedqopenglwidget/glwidget.h
index c33f7e51a7..8dc84dd0b1 100644
--- a/examples/opengl/threadedqopenglwidget/glwidget.h
+++ b/examples/opengl/threadedqopenglwidget/glwidget.h
@@ -88,29 +88,29 @@ private:
     void quad(qreal x1, qreal y1, qreal x2, qreal y2, qreal x3, qreal y3, qreal x4, qreal y4);
     void extrude(qreal x1, qreal y1, qreal x2, qreal y2);
 
-    bool m_inited;
-    qreal m_fAngle;
-    qreal m_fScale;
+    bool m_inited = false;
+    qreal m_fAngle = 0;
+    qreal m_fScale = 1;
     QVector<QVector3D> vertices;
     QVector<QVector3D> normals;
     QOpenGLShaderProgram program;
     QOpenGLBuffer vbo;
-    int vertexAttr;
-    int normalAttr;
-    int matrixUniform;
-    GLWidget *m_glwidget;
+    int vertexAttr = 0;
+    int normalAttr = 0;
+    int matrixUniform = 0;
+    GLWidget *m_glwidget = nullptr;
     QMutex m_renderMutex;
     QElapsedTimer m_elapsed;
     QMutex m_grabMutex;
     QWaitCondition m_grabCond;
-    bool m_exiting;
+    bool m_exiting = false;
 };
 
 class GLWidget : public QOpenGLWidget
 {
     Q_OBJECT
 public:
-    explicit GLWidget(QWidget *parent = 0);
+    explicit GLWidget(QWidget *parent = nullptr);
     ~GLWidget();
 
 protected: