2004-03-20  Pedro Gimeno  <pggimeno@wanadoo.es>

	Fixed several off-by-one problems in display:

	* app/display/gimpdisplayshell.h (PROJ_ROUND): New macro to apply
	to a float the same rounding method as the one used when rendering.
	(SCALEX, SCALEY): Use PROJ_ROUND instead of truncating.

	* app/display/gimpdisplayshell-transform.c
	(gimp_display_shell_transform_xy): Accept gdouble image coordinates
	even if the returned screen coordinates are integer. Use PROJ_ROUND
	instead of (gint) to apply proper rounding. Fixes bug #137566.

	* app/display/gimpdisplayshell-transform.h
	(gimp_display_shell_transform_xy): changed accordingly.

	* app/display/gimpdisplayshell-draw.c
	* app/tools/gimpdrawtool.c: make sure everywhere that PROJ_ROUND
	is used either directly or through gimp_display_shell_transform_xy,
	instead of using arbitrary rounding methods.