gdk:cursor-new-from-surface (display surface x y)

display -- a gdk:display object for which the cursor will be created
surface -- a cairo:surface-t instance containing the cursor pixel data
x -- a number coerced to a double float with the horizontal offset of the 'hotspot' of the cursor
y -- a number coerced to a double float with the vertical offset of the 'hotspot' of the cursor

The new gdk:cursor object.

Creates a new cursor from a cairo image surface. Not all GDK backends support RGBA cursors. If they are not supported, a monochrome approximation will be displayed. The gdk:display-supports-cursor-alpha and gdk:display-supports-cursor-color functions can be used to determine whether RGBA cursors are supported. The gdk:display-default-cursor-size and gdk:display-maximal-cursor-size functions give information about cursor sizes.

On the X backend, support for RGBA cursors requires a sufficently new version of the X Render extension.