Improved documentation related to access to OpenGL 3 under X11 platform.

git-svn-id: file:///fltk/svn/fltk/branches/branch-1.4@13022 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

1 files changed, 4 insertions, 3 deletions

diff --git a/documentation/src/opengl.dox b/documentation/src/opengl.dox
index 08ab000ee..7e75e82b7 100644
--- a/documentation/src/opengl.dox
+++ b/documentation/src/opengl.dox
@@ -456,6 +456,9 @@ showing how to use OpenGL 3.0 (or higher versions) with FLTK in a cross-platform
 It contains also OpenGL3-glut-test.cxx which shows how to use FLTK's GLUT compatibility
 and OpenGL 3.
 
+To access OpenGL 3.0 (or higher versions), use the <tt>FL_OPENGL3</tt> flag
+when calling Fl_Gl_Window::mode(int a) or glutInitDisplayMode().
+
 <b>On the Windows and Unix/Linux platforms</b>, FLTK creates contexts
 implementing the highest OpenGL version supported by the hardware,
 which are also compatible with lower OpenGL versions. Thus, FLTK allows
@@ -463,9 +466,7 @@ source code targeting any version of OpenGL. Access to functions from OpenGL
 versions above 1.1 requires to load function pointers at runtime on these platforms.
 FLTK recommends to use the GLEW library to perform this. It is therefore
 necessary to install the GLEW library (see below).  <b>On the macOS platform</b>,
-FLTK creates by default contexts implementing OpenGL versions 1 or 2.
-To access OpenGL 3.0 (or higher versions), use the <tt>FL_OPENGL3</tt> flag (see below).
-Mac OS 10.7 or above is required; GLEW is possible but not necessary.
+MacOS 10.7 or above is required; GLEW is possible but not necessary.
 
 \par GLEW installation (Unix/Linux and Windows platforms)
 GLEW is available as a package for most Linux distributions and in source