scroll_screen(3alleg4)

💖 scroll_screen(3alleg4) 💖

okay bestie, welcome to the Allegro manual ✨ this one's called scroll_screen, and it's giving "let me just nudge the whole hardware screen over there real quick" energy 🦋

✨ NAME ✨

scroll_screen — Requests a hardware scroll request. Allegro game programming library. no cap, that's literally the whole job 🎀

🌸 SYNOPSIS 🌸

#include <allegro.h>

int scroll_screen(int x, int y);

💅 DESCRIPTION 💅

So the way that this works: scroll_screen attempts to scroll the hardware screen so it shows a different part of the virtual screen. Where does the virtual screen start out? At 0, 0 — the top left corner, queen of origin points 👑.

You can use this to:

• move the screen display around inside a big ol' virtual screen space, or
• page flip back and forth between two non-overlapping areas of the virtual screen.

⚠️ But listen — if you wanna draw outside the original position in the screen bitmap, you're gonna have to alter the clipping rectangle with set_clip_rect(). Don't skip that step bestie, it's not optional 🙈

🧚 driver tea ☕

Mode-X scrolling is reliable and will work on any card.</purl> Other drivers? Lowkey may not work, or may not work reliably 😭. Check the platform-specific section of the docs for the deets.

⏱️ the vsync thing ⏱️

Allegro will handle any necessary vertical retrace synchronisation when scrolling the screen, so you do NOT need to call vsync() before it. Which means scroll_screen() has the exact same time delay effects as vsync() — iconic behaviour, honestly 💅✨

🌈 RETURN VALUE 🌈

• 0 — zero on success, slay 💚
• non-zero — returned if the graphics driver can't handle hardware scrolling, or if the virtual screen isn't large enough 💀

🎀 SEE ALSO 🎀

• set_gfx_mode(3alleg4)
• show_video_bitmap(3alleg4)
• request_scroll(3alleg4)
• request_video_bitmap(3alleg4)
• exscroll(3alleg4)

okay that's the whole page, mwah 🫶 this was brought to you by Allegro version 4.4.3 — and yes, scroll_screen(3alleg4) really is the name of the girl writing this, periodt 💜🌸