GPX_VISHEIGHT
GPX_WIDTH, GPX_VISHEIGHT, scr->ss_depth);
ss->ss_adder->y_clip_max = GPX_VISHEIGHT;
ss->ss_adder->y_offset_pending = GPX_VISHEIGHT;
ss->ss_adder->y_offset_pending = 2 * GPX_VISHEIGHT;
ss->ss_adder->y_limit = GPX_VISHEIGHT;
ri->ri_height = GPX_VISHEIGHT;