From 0374a15398ff05c31eda5a73eb60085d57cef1fb Mon Sep 17 00:00:00 2001
From: "Ryan C. Gordon" <icculus@icculus.org>
Date: Sun, 17 Apr 2005 10:32:41 +0000
Subject: [PATCH] Holding down shift while moving the mouse's scrollwheel on
 MacOS X makes the  OS report these are "horizontal scrollwheel" events, which
 confuses gaming  apps in several legitimate conditions. Now all scrollwheel
 events are made  to look vertical when passed to the app.

Patch by John Knottenbelt.

 http://www.libsdl.org/pipermail/sdl/2005-March/067978.html
---
 src/video/quartz/SDL_QuartzEvents.m | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/video/quartz/SDL_QuartzEvents.m b/src/video/quartz/SDL_QuartzEvents.m
index e75038e92..58cd89c60 100644
--- a/src/video/quartz/SDL_QuartzEvents.m
+++ b/src/video/quartz/SDL_QuartzEvents.m
@@ -900,10 +900,11 @@ void QZ_PumpEvents (_THIS)
                     break;
                 case NSScrollWheel:
                     if ( isInGameWin ) {
-                        float dy;
+                        float dy, dx;
                         Uint8 button;
                         dy = [ event deltaY ];
-                        if ( dy > 0.0 ) /* Scroll up */
+                        dx = [ event deltaX ];
+                        if ( dy > 0.0 || dx > 0.0 ) /* Scroll up */
                             button = SDL_BUTTON_WHEELUP;
                         else /* Scroll down */
                             button = SDL_BUTTON_WHEELDOWN;