This is a patch for gdk to include all of the logical functions for X graphic contexts.  Gdk supports only GXxor, GXcopy, and GXinvert.  This adds the following functions for GdkGC...

GdkFunction		X logical function
--------------------------------------------
GDK_CLEAR		GXclear
GDK_AND			GXand
GDK_AND_REVERSE		GXandReverse
GDK_AND_INVERT		GXandInverted
GDK_NOOP		GXnoop
GDK_OR			GXor
GDK_EQUIV		GXequiv
GDK_OR_REVERSE		GXorReverse
GDK_COPY_INVERT		GXcopyInverted
GDK_OR_INVERT		GXorInverted
GDK_NAND		GXnand
GDK_SET			GXset

The patch was created against the gdk directory (I'm a hardware guy, so this diff/patch/version control thing is something I don't do every day).  The patch only makes changes to gdkgc.c and gdktypes.h.  I'm not sure if chages are required elsewhere in the source tree... I tested a few of the functions and it seemed to work.