---
name: "SDL_UpdateWindowSurfaceRects"
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_UpdateWindowSurfaceRects"
---

# SDL\_UpdateWindowSurfaceRects(3)

Copy areas of the window surface to the screen.

## NAME

SDL\_UpdateWindowSurfaceRects - Copy areas of the window surface to the screen.

## HEADER FILE

Defined in SDL3/SDL\_video.h

## SYNOPSIS

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

**bool SDL\_UpdateWindowSurfaceRects(SDL\_Window \*window, const SDL\_Rect \*rects, int numrects);**

## DESCRIPTION

This is the function you use to reflect changes to portions of the surface on the screen.

This function is equivalent to the SDL 1.2 API

**SDL\_UpdateRects** ().

Note that this function will update \_at least\_ the rectangles specified, but this is only intended as an optimization; in practice, this might update more of the screen (or all of the screen!), depending on what method SDL uses to send pixels to the system.

## FUNCTION PARAMETERS

- *window*

  the window to update.

- *rects*

  an array of  **SDL\_Rect**\
    structures representing areas of the surface to copy, in pixels.

- *numrects*

  the number of rectangles.

## RETURN VALUE

Returns true on success or false on failure; call

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

## THREAD SAFETY

This function should only be called on the main thread.

## AVAILABILITY

This function is available since SDL 3.2.0.

## SEE ALSO

**•**(3), [**SDL\_GetWindowSurface**(3)](/SDL_GetWindowSurface/3.md), **•**(3), [**SDL\_UpdateWindowSurface**(3)](/SDL_UpdateWindowSurface/3.md)