Initial support for context flags.

src/Context.cpp

@@ -286,6 +286,16 @@ Context::Context() {
     #endif
     _version = static_cast<Version>(_majorVersion*100+_minorVersion*10);
 
+    /* Context flags are supported since GL 3.0 */
+    #ifndef MAGNUM_TARGET_GLES
+    /**
+     * @todo According to KHR_debug specs this should be also present in ES2
+     *      if KHR_debug is available, but in headers it is nowhere to be found
+     */
+    if(isVersionSupported(Version::GL300))
+        glGetIntegerv(GL_CONTEXT_FLAGS, reinterpret_cast<GLint*>(&_flags));
+    #endif
+
     /* Get first future (not supported) version */
     std::vector<Version> versions{
         #ifndef MAGNUM_TARGET_GLES

src/Context.h

@@ -30,6 +30,7 @@
 
 #include <bitset>
 #include <vector>
+#include <Containers/EnumSet.h>
 
 #include "Magnum.h"
 #include "OpenGL.h"
@@ -144,13 +145,36 @@ class MAGNUM_EXPORT Context {
     Context& operator=(Context&&) = delete;
 
     public:
+        /**
+         * @brief Context flag
+         *
+         * @see Flags, flags()
+         */
+        enum class Flag: GLint {
+            #ifndef MAGNUM_TARGET_GLES3
+            /**
+             * Debug context
+             * @requires_gl43 %Extension @es_extension{KHR,debug}
+             * @requires_es_extension %Extension @es_extension{KHR,debug}
+             */
+            Debug = GL_CONTEXT_FLAG_DEBUG_BIT
+            #endif
+        };
+
+        /**
+         * @brief Context flags
+         *
+         * @see flags()
+         */
+        typedef Corrade::Containers::EnumSet<Flag, GLint> Flags;
+
         /**
          * @brief Constructor
          *
          * Constructed automatically, see class documentation for more
          * information.
          * @see @fn_gl{Get} with @def_gl{MAJOR_VERSION}, @def_gl{MINOR_VERSION},
-         *      @fn_gl{GetString} with @def_gl{EXTENSIONS}
+         *      @def_gl{CONTEXT_FLAGS}, @fn_gl{GetString} with @def_gl{EXTENSIONS}
          */
         explicit Context();
 
@@ -221,6 +245,9 @@ class MAGNUM_EXPORT Context {
             return reinterpret_cast<const char*>(glGetString(GL_SHADING_LANGUAGE_VERSION));
         }
 
+        /** @brief Context flags */
+        inline Flags flags() const { return _flags; }
+
         /**
          * @brief Supported extensions
          *
@@ -302,6 +329,7 @@ class MAGNUM_EXPORT Context {
         Version _version;
         Int _majorVersion;
         Int _minorVersion;
+        Flags _flags;
 
         std::bitset<128> extensionStatus;
         std::vector<Extension> _supportedExtensions;