In article <[email protected]>,
Michael Drake <[email protected]> wrote:
> So in riscos/window.c, ro_gui_window_redraw:
> ro_plot_origin_x = redraw->box.x0 - redraw->xscroll;
> ro_plot_origin_y = redraw->box.y1 - redraw->yscroll;
> Gets the coordinates of the top left of the area of the page/canvas
> which is at the top left of the visible area.
Sorry, that's a mistake. The os_box 'box' and 'clip' are in have the
origin at the screen bottom right. So that should be:
ro_plot_origin_x = redraw->box.x0 - redraw->xscroll;
ro_plot_origin_y = redraw->box.y1 - redraw->yscroll;
Gets the coordinates of the top left of the area of the page/canvas
in screen coordinates.
clip_x0 = (redraw->clip.x0 - ro_plot_origin_x) / 2;
clip_y0 = (ro_plot_origin_y - redraw->clip.y1) / 2;
clip_x1 = (redraw->clip.x1 - ro_plot_origin_x) / 2;
clip_y1 = (ro_plot_origin_y - redraw->clip.y0) / 2;
Gets the area of the page/canvas requested for redraw in NetSurf units,
from the origin at the top left of the page/canvas:
left: clip_x0
top: clip_y0
right: clip_x1
bottom: clip_y1
(i.e. the origin for the clip values is the top left of the document.)
Michael
--
Michael Drake (tlsa) http://www.netsurf-browser.org/
