SDL_atan2(3)

💖 SDL_atan2(3) 💖

okay bestie, welcome to the SDL3 FUNCTIONS corner of the group chat, where today's main character is SDL_atan2 🎀

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✨ NAME ✨

SDL_atan2 — compute the arc tangent of y / x, and the way it uses the signs of x and y to adjust the result's quadrant? it's giving precise. 💅

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✨ SYNOPSIS ✨

#include <SDL3/SDL_stdinc.h>

double SDL_atan2(double y, double x);

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✨ DESCRIPTION ✨

so the whole vibe here is: the definition of z = atan2(x, y) is y = x tan(z), where the quadrant of z is determined based on the signs of x and y. no cap, that's the entire personality. 🦋

Domain: -INF <= x <= INF,

-INF <= y <= INF

Range: -Pi <= y <= Pi

this function operates on double-precision floating point values, so if you're out here needing single-precision floats, use SDL_atan2f instead. and if you just need the arc tangent of one single value, not a whole ratio situation, that's SDL_atan — different function, different vibe. 🌸

⚠️ real talk: this function may use a different approximation across different versions, platforms and configurations. i.e, it can return a different value given the same input on different machines or operating systems, or if SDL is updated. so don't be out here expecting bit-for-bit identical results across the whole friend group, okay? 🙈

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✨ FUNCTION PARAMETERS ✨

• y — floating point value of the numerator (y coordinate). 🍓
• x — floating point value of the denominator (x coordinate). ⭐

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✨ RETURN VALUE ✨

returns arc tangent of y / x in radians — OR, if x = 0, then it's either -Pi/2, 0, or Pi/2, depending on the value of y. three possibilities, one of them is yours, good luck bestie 😭💖

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✨ THREAD SAFETY ✨

it is safe to call this function from any thread. go off, multithreaded icon 👑

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✨ AVAILABILITY ✨

this function is available since SDL 3.2.0. she's been here a minute 💜

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✨ SEE ALSO ✨

• SDL_atan2f(3)
• SDL_atan(3)
• SDL_tan(3)

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and that's the whole page, periodt 🎀 this was brought to you by Simple Directmedia Layer, serving up SDL 3.4.18, and yeah the footer date lives right here in the sign-off so we're keeping it cute ✨ ily, go compute some quadrants 💖