GLBuffer: fix isVBOSupported()

src/Gui/GLBuffer.cpp

@@ -71,8 +71,11 @@ OpenGLBuffer::~OpenGLBuffer()
  * When calling this function there must be a current OpenGL context.
  * \return
  */
-bool OpenGLBuffer::isVBOSupported()
+bool OpenGLBuffer::isVBOSupported(uint32_t ctx)
 {
+    auto glue = cc_glglue_instance(ctx);
+    if (!glue || !cc_glglue_has_vertex_buffer_object(glue))
+        return false;
     const GLubyte * str = glGetString(GL_EXTENSIONS);
     if (!str)
         return false;

src/Gui/GLBuffer.h

@@ -34,7 +34,7 @@ public:
     OpenGLBuffer(GLenum type);
     ~OpenGLBuffer();
 
-    static bool isVBOSupported();
+    static bool isVBOSupported(uint32_t ctx);
 
     void setCurrentContext(uint32_t ctx);
     bool create();

src/Mod/Mesh/Gui/SoFCIndexedFaceSet.cpp

@@ -106,7 +106,7 @@ bool MeshRenderer::Private::canRenderGLArray(SoGLRenderAction *action) const
     static bool init = false;
     static bool vboAvailable = false;
     if (!init) {
-        vboAvailable = Gui::OpenGLBuffer::isVBOSupported();
+        vboAvailable = Gui::OpenGLBuffer::isVBOSupported(action->getCacheContext());
         if (!vboAvailable) {
             SoDebugError::postInfo("MeshRenderer",
                                    "GL_ARB_vertex_buffer_object extension not supported");