scroll_screen(3)                Allegro manual                scroll_screen(3)



NAME
       scroll_screen - Requests a hardware scroll request. Allegro game
       programming library.

SYNOPSIS
       #include <allegro.h>


       int scroll_screen(int x, int y);

DESCRIPTION
       Attempts to scroll the hardware screen to display a different part of
       the virtual screen (initially it will be positioned at 0, 0, which is
       the top left corner). You can use this to move the screen display
       around in a large virtual screen space, or to page flip back and forth
       between two non-overlapping areas of the virtual screen. Note that to
       draw outside the original position in the screen bitmap you will have
       to alter the clipping rectangle with set_clip_rect().

       Mode-X scrolling is reliable and will work on any card, other drivers
       may not work or not work reliably. See the platform-specific section of
       the docs for more information.

       Allegro will handle any necessary vertical retrace synchronisation when
       scrolling the screen, so you don't need to call vsync() before it. This
       means that scroll_screen() has the same time delay effects as vsync().

RETURN VALUE
       Returns zero on success. Returns non-zero if the graphics driver can't
       handle hardware scrolling or the virtual screen is not large enough.


SEE ALSO
       set_gfx_mode(3), show_video_bitmap(3), request_scroll(3),
       request_video_bitmap(3), exscroll(3)



Allegro                          version 4.2.3                scroll_screen(3)
