fli_pal_dirty_from(3alleg4)

💅 fli_pal_dirty_from — bestie edition

okay so this is from the Allegro manual (yes, the Allegro game programming library, we love her) and the page is called fli_pal_dirty_from(3alleg4). Two lil global ints, one big job: telling you which slice of your palette just changed. let's get into it 🎀

✨ NAME ✨

fli_pal_dirty_from, fli_pal_dirty_to — indicate which parts of the palette have changed. Allegro game programming library. periodt.

🌸 SYNOPSIS 🌸

#include <allegro.h>

extern int fli_pal_dirty_from;

extern int fli_pal_dirty_to;

🦋 DESCRIPTION 🦋

okay so picture this: these two variables get set by next_fli_frame(), and what they're telling you is which part of the fli_palette has changed since the last time somebody called reset_fli_variables(). it's giving receipts 📋

here's the tea tho, the logic is lowkey backwards-cute:

• if fli_pal_dirty_from is greater than fli_pal_dirty_to, that means the palette has not changed at all. nothing happened. go home. 💀
• otherwise, colors fli_pal_dirty_from to fli_pal_dirty_to (inclusive, bestie, don't forget the endpoints) have altered. 👑

and the whole point of knowing this?? it's so you can use it while you're updating the hardware palette and avoid unnecessary calls to set_palette(). no cap, stop wasting cycles on palette ranges that didn't even move. she's efficient. she's iconic. 🫶

example, fresh from the source:

if (fli_pal_dirty_from <= fli_pal_dirty_to)
   set_palette_range(fli_palette, fli_pal_dirty_from,
                     fli_pal_dirty_to, 1);

see how she checks the condition first? main character energy fr fr 🔥

💖 SEE ALSO 💖

• fli_palette(3alleg4)
• reset_fli_variables(3alleg4)

go read those next, iykyk 📚

ngl this is the kind of tiny optimization that makes you feel like a genius. use it. 💅

and that's the whole page babes ✨ this was Allegro, version 4.4.3 — fli_pal_dirty_from(3alleg4), brought to you with love, extern int energy, and exactly zero unnecessary set_palette() calls. mwah 💖🌈