+bool is_supported(const Version &core_version, const Version &deprecated_version)
+{
+ const Version &version = get_gl_version();
+ if(deprecated_version && version>=deprecated_version && get_gl_profile()==CORE_PROFILE)
+ return false;
+ return (version>=core_version);
+}
+
+bool is_disabled(const string &ext)
+{
+ static set<string> disabled_exts;
+ static bool init_done = false;
+
+ if(!init_done)
+ {
+ if(const char *disable_ptr = getenv("MSPGL_DISABLE_EXTENSIONS"))
+ {
+ vector<string> disable = split(disable_ptr);
+ disabled_exts.insert(disable.begin(), disable.end());
+ }
+
+ if(const char *renderer_ptr = reinterpret_cast<const char *>(glGetString(GL_RENDERER)))
+ {
+ string renderer = renderer_ptr;
+ if(renderer.find("Radeon")!=string::npos || renderer.find("AMD")!=string::npos)
+ {
+ // The core primitive restart feature does not work either.
+ disabled_exts.insert("GL_MSP_primitive_restart");
+
+ /* AMD's uniform buffer objects only work with the core version of
+ shaders. */
+ if(get_gl_version()<Version(2, 0))
+ disabled_exts.insert("GL_ARB_uniform_buffer_object");
+ }
+ }
+
+ init_done = true;
+ }
+
+ return disabled_exts.count(ext);
+}
+
+GLApi get_gl_api()
+{
+#ifdef GL_ES_VERSION_2_0
+ return OPENGL_ES2;
+#else
+ return OPENGL;
+#endif
+}
+
+inline GLProfile _get_gl_profile()
+{
+ if(get_gl_api()==OPENGL && get_gl_version()>=Version(3, 0))
+ {
+ int mask;
+ glGetIntegerv(GL_CONTEXT_PROFILE_MASK, &mask);
+ if(mask==GL_CONTEXT_CORE_PROFILE_BIT)
+ return CORE_PROFILE;
+ }
+
+ return COMPATIBILITY_PROFILE;
+}
+
+GLProfile get_gl_profile()
+{
+ static GLProfile profile = _get_gl_profile();
+ return profile;
+}
+
+inline Version _get_gl_version()
+{
+ const char *gl_ver_ptr = reinterpret_cast<const char *>(glGetString(GL_VERSION));
+ if(!gl_ver_ptr)
+ throw runtime_error("OpenGL version not available");
+
+ string gl_ver = gl_ver_ptr;
+ if(!gl_ver.compare(0, 10, "OpenGL ES "))
+ gl_ver.erase(0, 10);
+
+ Version ver(gl_ver.substr(0, gl_ver.find(' ')));
+
+ if(const char *force_ver_ptr = getenv("MSPGL_FORCE_VERSION"))
+ {
+ Version force_ver(force_ver_ptr);
+ if(force_ver<ver)
+ ver = force_ver;
+ }
+
+ return ver;
+}
+
+const Version &get_gl_version()
+{
+ static Version version = _get_gl_version();
+ return version;
+}
+
+inline Version _get_glsl_version()
+{
+ const char *glsl_ver_ptr = reinterpret_cast<const char *>(glGetString(GL_SHADING_LANGUAGE_VERSION));
+ if(!glsl_ver_ptr)
+ throw runtime_error("GLSL version not available");
+
+ string glsl_ver = glsl_ver_ptr;
+ if(!glsl_ver.compare(0, 18, "OpenGL ES GLSL ES "))
+ glsl_ver.erase(0, 18);
+
+ Version ver(glsl_ver.substr(0, glsl_ver.find(' ')));
+
+ if(const char *force_ver_ptr = getenv("MSPGL_FORCE_GLSL_VERSION"))
+ {
+ Version force_ver(force_ver_ptr);
+ if(force_ver<ver)
+ ver = force_ver;
+ }
+
+ return ver;
+}
+
+const Version &get_glsl_version()