diff --git a/src/modelmeshbinder.cpp b/src/modelmeshbinder.cpp
index de042297..81092da2 100644
--- a/src/modelmeshbinder.cpp
+++ b/src/modelmeshbinder.cpp
@@ -36,12 +36,12 @@ void ModelMeshBinder::exportMeshAsObj(const QString &filename)
         if (file.open(QIODevice::WriteOnly)) {
             QTextStream stream(&file);
             stream << "# " << Ds3FileReader::m_applicationName << endl;
-            for (std::vector<const QVector3D>::iterator it = m_mesh->vertices().begin() ; it != m_mesh->vertices().end(); ++it) {
+            for (std::vector<QVector3D>::const_iterator it = m_mesh->vertices().begin() ; it != m_mesh->vertices().end(); ++it) {
                 stream << "v " << (*it).x() << " " << (*it).y() << " " << (*it).z() << endl;
             }
-            for (std::vector<const std::vector<int>>::iterator it = m_mesh->faces().begin() ; it != m_mesh->faces().end(); ++it) {
+            for (std::vector<std::vector<int>>::const_iterator it = m_mesh->faces().begin() ; it != m_mesh->faces().end(); ++it) {
                 stream << "f";
-                for (std::vector<const int>::iterator subIt = (*it).begin() ; subIt != (*it).end(); ++subIt) {
+                for (std::vector<int>::const_iterator subIt = (*it).begin() ; subIt != (*it).end(); ++subIt) {
                     stream << " " << (1 + *subIt);
                 }
                 stream << endl;
@@ -107,12 +107,14 @@ void ModelMeshBinder::paint()
     if (m_showWireframes) {
         if (m_renderEdgeVertexCount > 0) {
             QOpenGLVertexArrayObject::Binder vaoBinder(&m_vaoEdge);
-            glDrawArrays(GL_LINES, 0, m_renderEdgeVertexCount);
+			QOpenGLFunctions *f = QOpenGLContext::currentContext()->functions();
+            f->glDrawArrays(GL_LINES, 0, m_renderEdgeVertexCount);
         }
     }
     if (m_renderTriangleVertexCount > 0) {
         QOpenGLVertexArrayObject::Binder vaoBinder(&m_vaoTriangle);
-        glDrawArrays(GL_TRIANGLES, 0, m_renderTriangleVertexCount);
+		QOpenGLFunctions *f = QOpenGLContext::currentContext()->functions();
+        f->glDrawArrays(GL_TRIANGLES, 0, m_renderTriangleVertexCount);
     }
 }
 
diff --git a/src/modelofflinerender.cpp b/src/modelofflinerender.cpp
index 3101b245..385186df 100644
--- a/src/modelofflinerender.cpp
+++ b/src/modelofflinerender.cpp
@@ -67,11 +67,11 @@ QImage ModelOfflineRender::toImage(const QSize &size)
         meshBinder.hideWireframes();
 
         program->setUniformValue(program->lightPosLoc(), QVector3D(0, 0, 70));
-
-        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
-        glEnable(GL_DEPTH_TEST);
-        glEnable(GL_CULL_FACE);
-        glEnable(GL_LINE_SMOOTH);
+		
+        m_context->functions()->glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+        m_context->functions()->glEnable(GL_DEPTH_TEST);
+        m_context->functions()->glEnable(GL_CULL_FACE);
+        m_context->functions()->glEnable(GL_LINE_SMOOTH);
 
         camera.setToIdentity();
         camera.translate(0, 0, -2.1);
diff --git a/src/modelwidget.cpp b/src/modelwidget.cpp
index 474154c6..92017c1c 100644
--- a/src/modelwidget.cpp
+++ b/src/modelwidget.cpp
@@ -9,7 +9,7 @@
 
 // Modifed from http://doc.qt.io/qt-5/qtopengl-hellogl2-glwidget-cpp.html
 
-bool ModelWidget::m_transparent = true;
+bool ModelWidget::m_transparent = false;
 
 ModelWidget::ModelWidget(QWidget *parent)
     : QOpenGLWidget(parent),
diff --git a/src/skeletongraphicswidget.h b/src/skeletongraphicswidget.h
index 3d641bc2..a5f07ddb 100644
--- a/src/skeletongraphicswidget.h
+++ b/src/skeletongraphicswidget.h
@@ -13,6 +13,7 @@
 #include "skeletondocument.h"
 #include "turnaroundloader.h"
 #include "theme.h"
+#include "util.h"
 
 class SkeletonGraphicsSelectionItem : public QGraphicsRectItem
 {
diff --git a/src/util.h b/src/util.h
index 4f614e9b..841c717a 100644
--- a/src/util.h
+++ b/src/util.h
@@ -2,6 +2,11 @@
 #define UTIL_H
 #include <QString>
 #include <map>
+#include <cmath>
+
+#ifndef M_PI
+#define M_PI 3.14159265358979323846
+#endif
 
 QString valueOfKeyInMapOrEmpty(const std::map<QString, QString> &map, const QString &key);
 bool isTrueValueString(const QString &str);