> The key to this turns out to be *when* I modify fltk's clip region. > If I modify the clip region *before* I obtain a Cairo context for the > window, all is well. > But if I obtain the Cairo context, *then* modify the clip region, all > the Cairo drawing is inverted and offset.
This probably has to do with the Fl_mac.cxx q_fill_context() API. One of the big differences between Quartz and QD is that Quartz coordinates space has the Y orientation inverted compared to QD. This is why in fltk, the q_fill_context() transforms the Quartz origin to be at the upper-left like QD so it turns upside down the Y coordinates... More info at : http://developer.apple.com/documentation/Carbon/Conceptual/QuickDrawToQuartz2D/tq_other/chapter_3_section_2.html Fabien _______________________________________________ fltk mailing list [email protected] http://lists.easysw.com/mailman/listinfo/fltk
