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request_video_bitmap(3) Allegro manual request_video_bitmap(3) NAME request_video_bitmap - Triple buffering page flip request. Allegro game programming library. SYNOPSIS #include <allegro.h> int request_video_bitmap(BITMAP *bitmap); DESCRIPTION This function is used for triple buffering. It requests a page flip to dis- play the specified video bitmap object, but returns immediately rather than waiting for a retrace. The flip will then take place during the next verti- cal retrace, but you can carry on running other code in the meantime and use the poll_scroll() routine to detect when the flip has actually taken place. Triple buffering is only possible on certain hardware: see the com- ments about request_scroll(). Example: int current_page; BITMAP *video_page[3]; ... /* Create pages for page flipping */ video_page[0] = create_video_bitmap(SCREEN_W, SCREEN_H); video_page[1] = create_video_bitmap(SCREEN_W, SCREEN_H); video_page[2] = create_video_bitmap(SCREEN_W, SCREEN_H); current_page = 0; ... /* draw the screen and flip pages */ draw_screen(video_page[current_page]); do { } while (poll_scroll()); request_video_bitmap(video_page[current_page]); current_page = (current_page+1)%3; ... RETURN VALUE Returns zero on success and non-zero on failure. SEE ALSO poll_scroll(3), request_scroll(3), gfx_capabilities(3), cre- ate_video_bitmap(3), scroll_screen(3), ex3buf(3), exupdate(3) Allegro version 4.4.3 request_video_bitmap(3)
NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | SEE ALSO
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