This patch enables support of the sixth valuator present in the xf86Wacom 
driver. The driver with support of six valuators are included in XFree86 
3.3.4 and newer.

The purpose of this patch is to enable the airbrush wheel on the Wacom Intous
airbrush device. The wheel is used in the upcoming new airbrush tool in Gimp
to regulate the virtual altitude of your airbrush. 

The patch is tested with Gtk+-1.2.4 (not the CVS version) and should apply
without problems. The patch is totally unsupported in both Gtk and GIMP.  

A good advice it to install a the patched version of Gtk+ and Gimp in a special
directory because of the binary incompatible (See notes below).

Here is how to make it work, 

cd gtk+-1.2.4
pacth -p0 ../patch_xinput_airbrush
./configure --prefix=/opt/gimp --with-xinput=xfree
make 
make install
cd ../gimp
export LD_LIBRARY_PATH=/opt/gimp/lib:$LD_LIBRARY_PATH
export PATH=/opt/gimp/bin:$PATH
./configure --prefix=/opt/gimp --enable-gimpdir=.gimpairbrush 
make
make install

Now make a special gimp startup script that you install in a directory
that is in your path.

Here is an example

#!/bin/sh
PREFIX=/opt/gimp
LD_LIBRARY_PATH=$PREFIX/lib:$LD_LIBRARY_PATH
exec $PREFIX/bin/gimp "$@"

OBSERVE that the patch makes Gtk+ binary and source incompatible, i.e you can't
run your old compiled Gtk+ apps (which includes GNOME apps) with Gtk+ patched
with this patch.

This is because the gdk_input_window_get_pointer is changed and now has nine
parameters instead of eight. The added parameter is gdouble *wheel see below,

void gdk_input_window_get_pointer     (GdkWindow       *window,
                                       guint32         deviceid,
                                       gdouble         *x,
                                       gdouble         *y,
                                       gdouble         *pressure,
                                       gdouble         *xtilt,
                                       gdouble         *ytilt,
                                       gdouble         *wheel,
                                       GdkModifierType *mask);   

gtkfeatures.h has a new define to enable you to check for the presence of this
patch in your program. You can e.g use it as below

#ifdef GTK_HAVE_SIX_VALUATORS

gdk_input_window_get_pointer (event->window, event->deviceid,
			      NULL, NULL, NULL, NULL, NULL, NULL, NULL);

#else /* !GTK_HAVE_SIX_VALUATORS */

gdk_input_window_get_pointer (event->window, event->deviceid,
			      NULL, NULL, NULL, NULL, NULL, NULL);

#endif /* GTK_HAVE_SIX_VALUATORS */

Happy Gimping 

Olof S Kylander