5 files changed, 35 insertions, 4 deletions
diff --git a/src/render/mglcheck.h b/src/render/mglcheck.h
new file mode 100644
index 000000000..8355d8ab9
--- /dev/null
+++ b/src/render/mglcheck.h
@@ -0,0 +1,31 @@
+/*
+ *  The ManaPlus Client
+ *  Copyright (C) 2012-2014  The ManaPlus Developers
+ *
+ *  This file is part of The ManaPlus Client.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef RENDER_MGLCHECK_H
+#define RENDER_MGLCHECK_H
+
+#include "main.h"
+#ifdef USE_OPENGL
+
+#define isGLNull(func) (!(func))
+#define isGLNotNull(func) ((func) != nullptr)
+
+#endif  // USE_OPENGL
+#endif  // RENDER_MGLCHECK_H
diff --git a/src/render/mobileopenglgraphics.cpp b/src/render/mobileopenglgraphics.cpp
index b0e78c534..339632f34 100644
--- a/src/render/mobileopenglgraphics.cpp
+++ b/src/render/mobileopenglgraphics.cpp
@@ -857,7 +857,7 @@ void MobileOpenGLGraphics::updateScreen()
     SDL_GL_SwapBuffers();
 #endif
 #ifdef DEBUG_OPENGL
-    if (mglFrameTerminator)
+    if (isGLNotNull(mglFrameTerminator))
         mglFrameTerminator();
 #endif
 // may be need clear?
diff --git a/src/render/modernopenglgraphics.cpp b/src/render/modernopenglgraphics.cpp
index fc5e40062..5d87d415f 100644
--- a/src/render/modernopenglgraphics.cpp
+++ b/src/render/modernopenglgraphics.cpp
@@ -830,7 +830,7 @@ void ModernOpenGLGraphics::updateScreen()
     SDL_GL_SwapBuffers();
 #endif
 #ifdef DEBUG_OPENGL
-    if (mglFrameTerminator)
+    if (isGLNotNull(mglFrameTerminator))
         mglFrameTerminator();
 #endif
 // may be need clear?
diff --git a/src/render/normalopenglgraphics.cpp b/src/render/normalopenglgraphics.cpp
index f32003d49..81ed5ea71 100644
--- a/src/render/normalopenglgraphics.cpp
+++ b/src/render/normalopenglgraphics.cpp
@@ -1190,7 +1190,7 @@ void NormalOpenGLGraphics::updateScreen()
     SDL_GL_SwapBuffers();
 #endif
 #ifdef DEBUG_OPENGL
-    if (mglFrameTerminator)
+    if (isGLNotNull(mglFrameTerminator))
         mglFrameTerminator();
 #endif
 // may be need clear?
diff --git a/src/render/safeopenglgraphics.cpp b/src/render/safeopenglgraphics.cpp
index 1f381b2b9..c40637f68 100644
--- a/src/render/safeopenglgraphics.cpp
+++ b/src/render/safeopenglgraphics.cpp
@@ -464,7 +464,7 @@ void SafeOpenGLGraphics::updateScreen()
     SDL_GL_SwapBuffers();
 #endif
 #ifdef DEBUG_OPENGL
-    if (mglFrameTerminator)
+    if (isGLNotNull(mglFrameTerminator))
         mglFrameTerminator();
 #endif
     BLOCK_END("Graphics::updateScreen")