--- a/gldragon.cpp	Thu Dec 05 18:32:13 2019 +0200
+++ b/gldragon.cpp	Thu Dec 05 21:05:43 2019 +0200
@@ -39,6 +39,70 @@
 
 /* Helpers
  */
+#ifdef GL_GLEXT_PROTOTYPES
+#define DM_GLEXT_INIT(extproctype, extprocname) /* stub */
+#else
+// GL_GLEXT_PROTOTYPES not defined
+
+#define DM_GLEXT_INIT(extproctype, extprocname) extproctype extprocname = NULL;
+#include "dmglexts.h"
+#undef DM_GLEXT_INIT
+
+
+void * dmGLExtTry(const std::string &name)
+{
+    bool res = SDL_GL_ExtensionSupported(name.c_str());
+    void *ptr = SDL_GL_GetProcAddress(name.c_str());
+    res = true;
+
+    printf(" - Checking '%s' : %s : %p\n",
+        name.c_str(),
+        res ? "YES" : "no",
+        ptr);
+
+    if (res && ptr != NULL)
+        return ptr;
+    else
+        return NULL;
+}
+
+void * dmGLExtInit(const std::string &name, bool &status)
+{
+    void *ptr;
+
+    if ((ptr = dmGLExtTry(name)) != NULL)
+        return ptr;
+    else
+    if ((ptr = dmGLExtTry(name + "EXT")) != NULL)
+        return ptr;
+    else
+    if ((ptr = dmGLExtTry(name + "ARB")) != NULL)
+        return ptr;
+
+    status = false;
+    return NULL;
+}
+
+
+#define DM_GLEXT_INIT(extproctype, extprocname) \
+    extprocname = (extproctype) dmGLExtInit(#extprocname, status);
+
+#endif
+
+
+
+bool dmInitGLExtensions(void)
+{
+#ifdef GL_GLEXT_PROTOTYPES
+    return true;
+#else
+    bool status = true;
+#include "dmglexts.h"
+    return status;
+#endif
+}
+
+
 bool dmInitSDLGL(const int width, const int height, const char *title)
 {
     int ret;
@@ -114,6 +178,10 @@
         return false;
     }
 
+    // Get/initialize OpenGL extension function pointers
+    if (optUseShaders && !dmInitGLExtensions())
+        return false;
+
     // Dump some information
     printf(
         "GL_VENDOR   : %s\n"