Merge pull request #6965 from ctrlaltdavid/20793

Warn user if OpenGL version is too low (< 4.1)

interface/src/main.cpp

@@ -17,6 +17,7 @@
 #include <QSharedMemory>
 #include <QTranslator>
 
+#include <gl/OpenGLVersionChecker.h>
 #include <SharedUtil.h>
 
 #include "AddressManager.h"
@@ -83,6 +84,17 @@ int main(int argc, const char* argv[]) {
 #endif
     }
 
+    // Check OpenGL version.
+    // This is done separately from the main Application so that start-up and shut-down logic within the main Application is
+    // not made more complicated than it already is.
+    {
+        OpenGLVersionChecker openGLVersionChecker(argc, const_cast<char**>(argv));
+        if (!openGLVersionChecker.isValidVersion()) {
+            qCDebug(interfaceapp, "Early exit due to OpenGL version.");
+            return 0;
+        }
+    }
+
     QElapsedTimer startupTime;
     startupTime.start();
 
@@ -96,6 +108,7 @@ int main(int argc, const char* argv[]) {
         usecTimestampNowForceClockSkew(clockSkew);
         qCDebug(interfaceapp, "clockSkewOption=%s clockSkew=%d", clockSkewOption, clockSkew);
     }
+
     // Oculus initialization MUST PRECEDE OpenGL context creation.
     // The nature of the Application constructor means this has to be either here,
     // or in the main window ctor, before GL startup.

libraries/gl/src/gl/Config.h

@@ -19,6 +19,7 @@
 #define GPU_LEGACY 0
 #define GPU_CORE_41 410
 #define GPU_CORE_43 430
+#define GPU_CORE_MINIMUM GPU_CORE_41
 
 #if defined(__APPLE__)
 

libraries/gl/src/gl/OpenGLVersionChecker.cpp

@@ -0,0 +1,61 @@
+//
+//  OpenGLVersionChecker.cpp
+//  libraries/gl/src/gl
+//
+//  Created by David Rowe on 28 Jan 2016.
+//  Copyright 2016 High Fidelity, Inc.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+#include "OpenGLVersionChecker.h"
+
+#include <QMessageBox>
+#include <QRegularExpression>
+
+#include "Config.h"
+#include "GLWidget.h"
+
+OpenGLVersionChecker::OpenGLVersionChecker(int& argc, char** argv) :
+    QApplication(argc, argv)
+{
+}
+
+bool OpenGLVersionChecker::isValidVersion() {
+    bool valid = true;
+
+    // Retrieve OpenGL version
+    GLWidget* glWidget = new GLWidget();
+    glWidget->initializeGL();
+    QString glVersion = QString((const char*)glGetString(GL_VERSION));
+    delete glWidget;
+
+    // Compare against minimum
+    // The GL_VERSION string begins with a version number in one of these forms:
+    // - major_number.minor_number 
+    // - major_number.minor_number.release_number
+    // Reference: https://www.opengl.org/sdk/docs/man/docbook4/xhtml/glGetString.xml
+    QStringList versionParts = glVersion.split(QRegularExpression("[\\.\\s]"));
+    int majorNumber = versionParts[0].toInt();
+    int minorNumber = versionParts[1].toInt();
+    int minimumMajorNumber = GPU_CORE_MINIMUM / 100;
+    int minimumMinorNumber = (GPU_CORE_MINIMUM - minimumMajorNumber * 100) / 10;
+    valid = (majorNumber > minimumMajorNumber
+        || (majorNumber == minimumMajorNumber && minorNumber >= minimumMinorNumber));
+
+    // Prompt user if below minimum
+    if (!valid) {
+        QMessageBox messageBox;
+        messageBox.setWindowTitle("OpenGL Version Too Low");
+        messageBox.setIcon(QMessageBox::Warning);
+        messageBox.setText(QString().sprintf("Your OpenGL version of %i.%i is lower than the minimum of %i.%i.",
+            majorNumber, minorNumber, minimumMajorNumber, minimumMinorNumber));
+        messageBox.setInformativeText("Press OK to exit; Ignore to continue.");
+        messageBox.setStandardButtons(QMessageBox::Ok | QMessageBox::Ignore);
+        messageBox.setDefaultButton(QMessageBox::Ok);
+        valid = messageBox.exec() == QMessageBox::Ignore;
+    }
+
+    return valid;
+}

libraries/gl/src/gl/OpenGLVersionChecker.h

@@ -0,0 +1,25 @@
+//
+//  OpenGLVersionChecker.h
+//  libraries/gl/src/gl
+//
+//  Created by David Rowe on 28 Jan 2016.
+//  Copyright 2016 High Fidelity, Inc.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+#ifndef hifi_OpenGLVersionChecker_h
+#define hifi_OpenGLVersionChecker_h
+
+#include <QApplication>
+
+class OpenGLVersionChecker : public QApplication {
+
+public:
+    OpenGLVersionChecker(int& argc, char** argv);
+
+    static bool isValidVersion();
+};
+
+#endif // hifi_OpenGLVersionChecker_h