al_fixdiv(3)

💅 al_fixdiv(3) — manual crew: Library Functions Manual 💅

okay so bestie, this is al_fixdiv(3) from the Library Functions Manual — it’s giving Allegro 5 API, fixed-point division, and one very important errno warning. Let’s get into it. ✨

🌸 NAME 🌸

al_fixdiv — Allegro 5 API

✨ SYNOPSIS ✨

#include <allegro5/allegro.h>

al_fixed al_fixdiv(al_fixed x, al_fixed y);

🫶 DESCRIPTION 🫶

okay so here’s the tea: a fixed point value can be divided by an integer with the normal / operator. But to divide two fixed point values? You must use this function, no cap.

⚠️ If a division by zero occurs, Allegro’s errno will be set and the maximum possible value will be returned. But — and this is the important bit — errno is not cleared if the operation is successful. So if you’re gonna test for division by zero, call al_set_errno(0) before calling al_fixdiv(3). 💀

Example, bestie:

al_fixed result;

/* This will put 0.06060 `result'. */
result = al_fixdiv(al_itofix(2), al_itofix(33));

/* This will put 0 into `result'. */
result = al_fixdiv(0, al_itofix(-30));

/* Sets errno and puts -32768 into `result'. */
result = al_fixdiv(al_itofix(-100), al_itofix(0));
assert(!al_get_errno()); /* This will fail. */

🚨 RETURN VALUE 🚨

It returns the result of dividing x by y. If y is zero, it returns the maximum possible fixed point value and sets Allegro’s errno to ERANGE. periodt. 💖

🔥 SEE ALSO 🔥

al_fixadd(3), al_fixsub(3), al_fixmul(3), al_get_errno(3).

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💖 that’s the whole page, bestie — source: Allegro reference manual; page: al_fixdiv(3). The footer didn’t list a date, so no fake date energy here. mwah 💋