From 279dfb9607094d0b99b47da054e8909889060fe2 Mon Sep 17 00:00:00 2001
From: Mark Watkins <jedimark@users.sourceforge.net>
Date: Mon, 2 Jun 2014 20:28:05 +1000
Subject: [PATCH] Fix OpenGL glGetString crash

---
 sleepyhead/common_gui.cpp |  1 +
 sleepyhead/common_gui.h   |  6 ++++
 sleepyhead/main.cpp       |  7 +++--
 sleepyhead/mainwindow.cpp | 60 +++++++++++++++++++++++----------------
 4 files changed, 48 insertions(+), 26 deletions(-)

diff --git a/sleepyhead/common_gui.cpp b/sleepyhead/common_gui.cpp
index 551eba2f..7e413b73 100644
--- a/sleepyhead/common_gui.cpp
+++ b/sleepyhead/common_gui.cpp
@@ -15,6 +15,7 @@
 # include <unistd.h>
 #endif
 
+
 #if (QT_VERSION >= QT_VERSION_CHECK(4,8,0))
 // Qt 4.8 makes this a whole lot easier
 Qt::DayOfWeek firstDayOfWeekFromLocale()
diff --git a/sleepyhead/common_gui.h b/sleepyhead/common_gui.h
index e19d1515..b64dcec9 100644
--- a/sleepyhead/common_gui.h
+++ b/sleepyhead/common_gui.h
@@ -18,6 +18,12 @@
 //! \brief Gets the first day of week from the system locale, to show in the calendars.
 Qt::DayOfWeek firstDayOfWeekFromLocale();
 
+//! \brief Returns a text string naming the current graphics engine
+QString getGraphicsEngine();
+
+QString getOpenGLVersion();
+
+
 // Flag Colors
 extern QColor COLOR_Hypopnea;
 extern QColor COLOR_Obstructive;
diff --git a/sleepyhead/main.cpp b/sleepyhead/main.cpp
index 3880b223..050bcb76 100644
--- a/sleepyhead/main.cpp
+++ b/sleepyhead/main.cpp
@@ -32,6 +32,7 @@
 #include "profileselect.h"
 #include "newprofile.h"
 #include "translation.h"
+#include "common_gui.h"
 
 // Gah! I must add the real darn plugin system one day.
 #include "SleepLib/loader_plugins/prs1_loader.h"
@@ -182,11 +183,13 @@ int main(int argc, char *argv[])
 
 #if defined(Q_OS_WIN)
     // True openGL will meanly return nothing here, but ANGLE will give useful info
-    QString glversion = (char *)glGetString(GL_VERSION);
+
+
+    QString glversion = getGraphicsEngine();
 
  #ifndef BROKEN_OPENGL_BUILD
     if (QSysInfo::windowsVersion() < QSysInfo::WV_VISTA) {
-        if (glversion.contains("ANGLE")) {
+        if (glversion.compare("ANGLE")==0) {
             QMessageBox::warning(nullptr, QObject::tr("You have the wrong version of SleepyHead"),
                                  QObject::tr("This build of SleepyHead was designed to work with computers lacking full OpenGL 2.0 support, and only runs on (native) Windows Vista or higher.") + "<br/><br/>"+
                                  QObject::tr("There is another special build available for computers that do not support OpenGL 2.0 via ANGLE, tagged '-BrokenGL', that has been designed to work with Windows XP, Virtual Box, VMware, etc.")+"<br/><br/>"+
diff --git a/sleepyhead/mainwindow.cpp b/sleepyhead/mainwindow.cpp
index 351a4c46..0dfa6af9 100644
--- a/sleepyhead/mainwindow.cpp
+++ b/sleepyhead/mainwindow.cpp
@@ -65,6 +65,40 @@ QStatusBar *qstatusbar;
 
 extern Profile *profile;
 
+const char * CSTR_GFX_ANGLE = "ANGLE";
+const char * CSTR_GFX_OpenGL = "OpenGL";
+const char * CSTR_GFX_BrokenGL = "BrokenGL";
+
+QString getOpenGLVersion()
+{
+    static QString glversion;
+
+    if (glversion.isEmpty()) {
+        QGLWidget w;
+        w.makeCurrent();
+
+        glversion = QString(QLatin1String(reinterpret_cast<const char*>(glGetString(GL_VERSION))));
+        qDebug() << "OpenGL Version:" << glversion;
+    }
+    return glversion;
+}
+
+QString getGraphicsEngine()
+{
+    QString gfxEngine = QString();
+#ifdef BROKEN_OPENGL_BUILD
+    gfxEngine = CSTR_GFX_BrokenGL;
+#else
+    QString glversion = getOpenGLVersion();
+    if (glversion.contains(CSTR_GFX_ANGLE)) {
+        gfxEngine = CSTR_GFX_ANGLE;
+    } else {
+        gfxEngine = CSTR_GFX_OpenGL;
+    }
+#endif
+    return gfxEngine;
+}
+
 void MainWindow::Log(QString s)
 {
 
@@ -109,17 +143,8 @@ MainWindow::MainWindow(QWidget *parent) :
     ui->warningLabel->hide();
 #endif
 
-#ifdef BROKEN_OPENGL_BUILD
-    version += " BrokenGL2";
-#else
-    QString glversion = (char *)glGetString(GL_VERSION);
-    if (glversion.contains("ANGLE")) {
-        version += " ANGLE";
-    } else {
-        version += " OpenGL";
-    }
+    version += " "+getGraphicsEngine();
 
-#endif
     if (QString(GIT_BRANCH) != "master") { version += " [" + QString(GIT_BRANCH)+" branch]"; }
 
 
@@ -1061,19 +1086,6 @@ void MainWindow::aboutBoxLinkClicked(const QUrl &url)
 
 void MainWindow::on_action_About_triggered()
 {
-    QString gfxengine;
-#ifdef BROKEN_OPENGL_BUILD
-    gfxengine = "BrokenGL2";
-#else
-    QString glversion = (char *)glGetString(GL_VERSION);
-    if (glversion.contains("ANGLE")) {
-        gfxengine = "ANGLE";
-    } else {
-        gfxengine = "OpenGL";
-    }
-
-#endif
-
     QString gitrev = QString(GIT_REVISION);
 
     if (!gitrev.isEmpty()) { gitrev = tr("Revision:")+" " + gitrev + " (" + QString(GIT_BRANCH) + " " + tr("branch") + ")"; }
@@ -1092,7 +1104,7 @@ void MainWindow::on_action_About_triggered()
                 QString(" v%1 (%2)</h1></p><font color=black><p>").arg(VersionString).arg(ReleaseStatus) +
                 tr("Build Date: %1 %2").arg(__DATE__).arg(__TIME__) +
                 QString("<br/>%1<br/>").arg(gitrev) +
-                tr("Graphics Engine: %1").arg(gfxengine)+
+                tr("Graphics Engine: %1").arg(getGraphicsEngine())+
                 "<br/>" +
                 tr("Data Folder Location: %1").arg(QDir::toNativeSeparators(GetAppRoot()) +
                 "<hr/>"+tr("Copyright") + " &copy;2011-2014 Mark Watkins (jedimark) <br/> \n" +