---
name: "SDL_PremultiplySurfaceAlpha"
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_PremultiplySurfaceAlpha"
---

# SDL\_PremultiplySurfaceAlpha(3)

Premultiply the alpha in a surface.

## NAME

SDL\_PremultiplySurfaceAlpha - Premultiply the alpha in a surface.

## HEADER FILE

Defined in SDL3/SDL\_surface.h

## SYNOPSIS

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

**bool SDL\_PremultiplySurfaceAlpha(SDL\_Surface \*surface, bool linear);**

## DESCRIPTION

This is safe to use with src == dst, but not for other overlapping areas.

## FUNCTION PARAMETERS

- *surface*

  the surface to modify.

- *linear*

  true to convert from sRGB to linear space for the alpha multiplication, false to do multiplication in sRGB space.

## RETURN VALUE

Returns true on success or false on failure; call

**SDL\_GetError** () for more information.

## THREAD SAFETY

This function is not thread safe.

## AVAILABILITY

This function is available since SDL 3.2.0.