Date: Thu, 18 Jul 2002 23:51:40 +0200 (MEST)

From: Krister Walfridsson
Subject: [SDL] src/joystick/bsd/SDL_sysjoystick.c patch

The *BSD USB HID joystick code has two serious bugs:

1. If a joystick reports unhandled hid_input usage (for example HUG_RZ or
   HUG_DIAL), then the last handled value will be overwritten with an
   arbitrary value. (Fixed in the patch below by adding a default case.)

2. The current code does only handle logical coordinates in the range 0-255,
   while a big part of available joysticks report -128 - 127. (This is solved
   in the patch below by first center the range around 0, and then stretch
   it to the correct range.)

--HG--
extra : convert_revision : svn%3Ac70aab31-4412-0410-b14c-859654838e24/trunk%40462

src/joystick/bsd/SDL_sysjoystick.c

@@ -332,23 +332,14 @@ SDL_SYS_JoystickUpdate(SDL_Joystick *joy)
 				case HUG_WHEEL:
 					naxe = JOYAXE_WHEEL;
 					goto scaleaxe;
+				default:
+					continue;
 				}
 scaleaxe:
 				v = (Sint32)hid_get_data(REP_BUF_DATA(rep),
 				    &hitem);
-				if (v != 127) {
-					if (v < 127) {
-						v = -(256 - v);
-						v <<= 7;
-						v++;
-					} else {
-						v++;
-						v <<= 7;
-						v--;
-					}
-				} else {
-					v = 0;
-				}
+				v -= (hitem.logical_maximum + hitem.logical_minimum + 1)/2;
+				v *= 32768/((hitem.logical_maximum - hitem.logical_minimum + 1)/2);
 				if (v != joy->axes[naxe]) {
 					SDL_PrivateJoystickAxis(joy, naxe, v);
 				}