+/**
+ * \brief Possible return values from the SDL_HitTest callback.
+ *
+ * \sa SDL_HitTest
+ */
+typedef enum
+{
+ SDL_HITTEST_NORMAL, /**< Region is normal. No special properties. */
+ SDL_HITTEST_DRAGGABLE, /**< Region can drag entire window. */
+ SDL_HITTEST_RESIZE_TOPLEFT,
+ SDL_HITTEST_RESIZE_TOP,
+ SDL_HITTEST_RESIZE_TOPRIGHT,
+ SDL_HITTEST_RESIZE_RIGHT,
+ SDL_HITTEST_RESIZE_BOTTOMRIGHT,
+ SDL_HITTEST_RESIZE_BOTTOM,
+ SDL_HITTEST_RESIZE_BOTTOMLEFT,
+ SDL_HITTEST_RESIZE_LEFT
+} SDL_HitTestResult;
+
+/**
+ * \brief Callback used for hit-testing.
+ *
+ * \sa SDL_SetWindowHitTest
+ */
+typedef SDL_HitTestResult (SDLCALL *SDL_HitTest)(SDL_Window *win,
+ const SDL_Point *area,
+ void *data);
+
+/**
+ * \brief Provide a callback that decides if a window region has special properties.
+ *
+ * Normally windows are dragged and resized by decorations provided by the
+ * system window manager (a title bar, borders, etc), but for some apps, it
+ * makes sense to drag them from somewhere else inside the window itself; for
+ * example, one might have a borderless window that wants to be draggable
+ * from any part, or simulate its own title bar, etc.
+ *
+ * This function lets the app provide a callback that designates pieces of
+ * a given window as special. This callback is run during event processing
+ * if we need to tell the OS to treat a region of the window specially; the
+ * use of this callback is known as "hit testing."
+ *
+ * Mouse input may not be delivered to your application if it is within
+ * a special area; the OS will often apply that input to moving the window or
+ * resizing the window and not deliver it to the application.
+ *
+ * Specifying NULL for a callback disables hit-testing. Hit-testing is
+ * disabled by default.
+ *
+ * Platforms that don't support this functionality will return -1
+ * unconditionally, even if you're attempting to disable hit-testing.
+ *
+ * Your callback may fire at any time, and its firing does not indicate any
+ * specific behavior (for example, on Windows, this certainly might fire
+ * when the OS is deciding whether to drag your window, but it fires for lots
+ * of other reasons, too, some unrelated to anything you probably care about
+ * _and when the mouse isn't actually at the location it is testing_).
+ * Since this can fire at any time, you should try to keep your callback
+ * efficient, devoid of allocations, etc.
+ *
+ * \param window The window to set hit-testing on.
+ * \param callback The callback to call when doing a hit-test.
+ * \param callback_data An app-defined void pointer passed to the callback.
+ * \return 0 on success, -1 on error (including unsupported).
+ */
+extern DECLSPEC int SDLCALL SDL_SetWindowHitTest(SDL_Window * window,
+ SDL_HitTest callback,
+ void *callback_data);
+