Add mouse wheel event handler.

1 files changed, 14 insertions, 0 deletions

diff --git a/doc/api.texi b/doc/api.texi
index 8a06690..96ac394 100644
--- a/doc/api.texi
+++ b/doc/api.texi
@@ -172,6 +172,20 @@ mouse was moved.
 @end enumerate
 
 @item
+@var{mouse-wheel}: Called with two arguments when the mouse wheel is
+scrolled:
+
+@enumerate
+
+@item
+@var{x}: The scroll amount along the X axis.
+
+@item
+@var{y}: The scroll amount along the Y axis.
+
+@end enumerate
+
+@item
 @var{controller-add}: Called with a single argument, an SDL game
 controller object, when a game controller is connected.