Documentation work

docs/input.dox

@@ -736,9 +736,10 @@ the largest available index for each array.
 
 @subsection gamepad_mapping Gamepad mappings
 
-Newer ones can be added with @ref glfwUpdateGamepadMappings.  This function
+GLFW contains a copy of the mappings available in
-supports everything from single lines up to the entire unmodified contents of
+[SDL_GameControllerDB](https://github.com/gabomdq/SDL_GameControllerDB) at the
-the `gamecontrollerdb.txt` file.
+time of release.  Newer ones can be added at runtime with @ref
+glfwUpdateGamepadMappings.
 
 @code
 const char* mappings = load_file_contents("gamecontrollerdb.txt");
@@ -746,6 +747,9 @@ const char* mappings = load_file_contents("gamecontrollerdb.txt");
 glfwUpdateGamepadMappings(mappings);
 @endcode
 
+This function supports everything from single lines up to and including the
+unmodified contents of the whole `gamecontrollerdb.txt` file.
+
 Below is a description of the mapping format.  Please keep in mind that __this
 description is not authoritative__.  The format is defined by the SDL and
 SDL_GameControllerDB projects and their documentation and code takes precedence.
@@ -786,8 +790,20 @@ There is also the special `platform` field that specifies which platform the
 mapping is valid for.  Possible values are `Windows`, `Mac OS X` and `Linux`.
 Mappings without this field will always be considered valid.
 
+Below is an example of what a gamepad mapping might look like.  It is the
+one built into GLFW for Xbox controllers accessed via the XInput API on Windows.
+This example has been broken into several lines to fit on the page, but real
+gamepad mappings must be a single line.
+
+@code{.unparsed}
+78696e70757401000000000000000000,XInput Gamepad (GLFW),platform:Windows,a:b0,
+b:b1,x:b2,y:b3,leftshoulder:b4,rightshoulder:b5,back:b6,start:b7,leftstick:b8,
+rightstick:b9,leftx:a0,lefty:a1,rightx:a2,righty:a3,lefttrigger:a4,
+righttrigger:a5,dpup:h0.1,dpright:h0.2,dpdown:h0.4,dpleft:h0.8,
+@endcode
+
 @note GLFW does not yet support the range and inversion modifiers `+`, `-` and
-`~`.
+`~` that were recently added to SDL.
 
 
 @section time Time input