---
name: "SDL_copysign"
section: "3"
platform: "linux"
package: "libsdl3-doc"
version: "3.2.10+ds-1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/SDL_copysign"
---

# SDL\_copysign(3)

Copy the sign of one floating-point value to another.

## NAME

SDL\_copysign - Copy the sign of one floating-point value to another.

## HEADER FILE

Defined in SDL3/SDL\_stdinc.h

## SYNOPSIS

```
#include "SDL3/SDL.h"
```

**double SDL\_copysign(double x, double y);**

## DESCRIPTION

The definition of copysign is that copysign(x, y) = abs(x) \* sign(y) .

Domain: **-INF**\<=**x**\<=**INF** , -INF \<= y \<= f Range: **-INF**\<=**z**\<=**INF** This function operates on double-precision floating point values, use

**SDL\_copysignf**\
  for single-precision floats.

## FUNCTION PARAMETERS

- *x*

  floating point value to use as the magnitude.

- *y*

  floating point value to use as the sign.

## RETURN VALUE

Returns the floating point value with the sign of y and the magnitude of x.

## THREAD SAFETY

It is safe to call this function from any thread.

## AVAILABILITY

This function is available since SDL 3.2.0.

## SEE ALSO

**•**(3), [**SDL\_copysignf**(3)](/SDL_copysignf/3.md), **•**(3), [**SDL\_fabs**(3)](/SDL_fabs/3.md)