[gnome-games/wip/aplazas/gamepad-events: 1/2] gamepad: Comment the hat mapping parsing

[Adrien Plazas <aplazas src gnome org>]

commit 616197d9cb5a26a187f749e4cf6e4a2068a75e95
Author: Adrien Plazas <kekun plazas laposte net>
Date:   Mon May 15 14:51:42 2017 +0200

    gamepad: Comment the hat mapping parsing
    
    Comment how the mappings are parsed, making them more undertandable.

 src/gamepad/gamepad-mapping.c |    8 ++++++++
 1 files changed, 8 insertions(+), 0 deletions(-)
---
diff --git a/src/gamepad/gamepad-mapping.c b/src/gamepad/gamepad-mapping.c
index 2327567..d17d306 100644
--- a/src/gamepad/gamepad-mapping.c
+++ b/src/gamepad/gamepad-mapping.c
@@ -54,6 +54,14 @@ parse_dpad_source (GamesGamepadMapping *self,
 
   g_strfreev (dpad_parse_array);
 
+  /* Convert the value of dpad_position_2pow into an index:
+   *  - 0001 = 1 => 1 = up
+   *  - 0010 = 2 => 2 = right
+   *  - 0100 = 4 => 3 = down
+   *  - 1000 = 8 => 4 = left
+   *
+   * Anything else is an error.
+   */
   while (dpad_position_2pow > 1) {
     dpad_position_2pow >>= 1;
     dpad_position++;