With gimp_guide_custom_new(), you can create a custom guide with a different
style on canvas (other pattern/color/width). A custom guide won't be saved
and could be used, for instance, for specific GEGL op guiding.
and get the shell from gimp_canvas_item_get_shell() if needed. Remove
some cairo_translate() that didn't have any effect and were leftovers
from a very early canvas item code.
This is a gross hack that typedefs around between GdkRegion and
cairo_region_t and has some evil #ifdefs. This is going to die
immeditately once we can depend on cairo 1.10.
of the guide and sample point canvas items. They are too obscure to
additionally hide them, and these items are used rarely enough to
justify the additional parameter to the new() functions.
Before, the pattern offset was always relative to the widget, which
completely destroyed the stipples when the got scrolled in. Now we
simply set the shell's scroll offsets as cairo translation and
everything looks perfect.
