fixadd(3)

🎀 NAME 🎀

okay so bestie, welcome to the Allegro manual ✨ this page is all about fixadd — the safe function to add fixed point numbers that clamps the overflow instead of letting it do something unhinged 💅 and yeah it's part of the Allegro game programming library, no cap 🎮

🌸 SYNOPSIS 🌸

#include <allegro.h>

fixed fixadd(fixed x, fixed y);

like literally that's it, that's the whole vibe 🫶

💖 DESCRIPTION 💖

so here's the tea ☕ you can totally add fixed point numbers with the normal '+' integer operator, sure, but the way that it gives you zero protection against overflow?? it's giving risky 🙈

so if overflow is a problem for you (and bestie, it usually is 😭), you should use this function instead. she's slower than using integer operators, lowkey — but if an overflow happens, she will set errno and clamp the result, rather than just letting it wrap like some feral little gremlin 💀

example time, look at this:

fixed result;
/* This will put 5035 into `result'. */
result = fixadd(itofix(5000), itofix(35));
/* Sets `errno' and puts -32768 into `result'. */
result = fixadd(itofix(-31000), itofix(-3000));
ASSERT(!errno); /* This will fail. */

see how the second one just calmly clamps and flags errno instead of wrapping around into chaos?? that's the whole point, she's the responsible one 👑

⭐ RETURN VALUE ⭐

returns the clamped result of adding x to y 💜 and if there was an overflow, she sets errno to ERANGE. that's it, that's the whole dealio ✨

🦋 SEE ALSO 🦋

• fixsub(3)
• fixmul(3)
• fixdiv(3)

go read those too, they're the rest of the squad fr fr 🫶

and that's a wrap, bestie!! this page is from the Allegro manual, specifically version 4.4.3, and it was last touched fixadd(3)-style 🎀 mwah, go clamp something responsibly 💅✨