Extend documentation of fl_begin_offscreen()

git-svn-id: file:///fltk/svn/fltk/branches/branch-1.4@12885 ea41ed52-d2ee-0310-a9c1-e6b18d33e121
2018-04-30 09:25:52 +00:00 · 2018-04-30 09:25:52 +00:00 · 599909135b
commit 599909135b
parent 4ad52ebaf7
1 changed files with 1 additions and 0 deletions
--- a/src/Fl_Image_Surface.cxx
+++ b/src/Fl_Image_Surface.cxx
@ -173,6 +173,7 @@ void fl_delete_offscreen(Fl_Offscreen ctx) {

 /**  Send all subsequent drawing commands to this offscreen buffer.
   \param ctx     the offscreen buffer.
+   \note The \p ctx argument must have been created by fl_create_offscreen().
   */
 void fl_begin_offscreen(Fl_Offscreen ctx) {
  for (int i = 0; i < count_offscreens; i++) {