---
name: "SDL_LockSurface"
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_LockSurface"
---

# SDL\_LockSurface(3)

Set up a surface for directly accessing the pixels.

## NAME

SDL\_LockSurface - Set up a surface for directly accessing the pixels.

## HEADER FILE

Defined in SDL3/SDL\_surface.h

## SYNOPSIS

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

**bool SDL\_LockSurface(SDL\_Surface \*surface);**

## DESCRIPTION

Between calls to  **SDL\_LockSurface** () /

**SDL\_UnlockSurface** (), you can write to and read from **surface-\>pixels** , using the pixel format stored in **surface-\>format** . Once you are done accessing the surface, you should use

**SDL\_UnlockSurface** () to release it.

Not all surfaces require locking. If **SDL\_MUSTLOCK(surface)** evaluates to 0, then you can read and write to the surface at any time, and the pixel format of the surface will not change.

## FUNCTION PARAMETERS

- *surface*

  the  **SDL\_Surface**\
    structure to be locked.

## RETURN VALUE

Returns true on success or false on failure; call

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

## THREAD SAFETY

This function is not thread safe. The locking referred to by this function is making the pixels available for direct access, not thread-safe locking.

## AVAILABILITY

This function is available since SDL 3.2.0.

## SEE ALSO

**•**(3), [**SDL\_MUSTLOCK**(3)](/SDL_MUSTLOCK/3.md), **•**(3), [**SDL\_UnlockSurface**(3)](/SDL_UnlockSurface/3.md)