Added glext header explanation.

src/internal.h

@@ -59,6 +59,10 @@
 #include "config.h"
 
 #include "../include/GL/glfw3.h"
+
+// This path may need to be changed if you build GLFW using your own setup
+// We ship and use our own copy of glext.h since GLFW uses fairly new
+// extensions and not all operating systems come with an up-to-date version
 #include "../support/GL/glext.h"
 
 #if defined(_GLFW_COCOA_NSGL)

src/win32_platform.h

@@ -43,6 +43,9 @@
 #include <windows.h>
 #include <mmsystem.h>
 
+// This path may need to be changed if you build GLFW using your own setup
+// We ship and use our own copy of wglext.h since GLFW uses fairly new
+// extensions and not all operating systems come with an up-to-date version
 #include "../support/GL/wglext.h"
 
 

src/x11_platform.h

@@ -41,6 +41,9 @@
 #define GLX_GLXEXT_LEGACY
 #include <GL/glx.h>
 
+// This path may need to be changed if you build GLFW using your own setup
+// We ship and use our own copy of glxext.h since GLFW uses fairly new
+// extensions and not all operating systems come with an up-to-date version
 #include "../support/GL/glxext.h"