###### (This is the documentation for SDL3, which is the current stable version. [SDL2](https://wiki.libsdl.org/SDL2/) was the previous version!)
# SDL_UpdateWindowSurfaceRects

Copy areas of the window surface to the screen.

## Header File

Defined in [<SDL3/SDL_video.h>](https://github.com/libsdl-org/SDL/blob/main/include/SDL3/SDL_video.h)

## Syntax

```c
bool SDL_UpdateWindowSurfaceRects(SDL_Window *window, const SDL_Rect *rects, int numrects);
```

## Function Parameters

|                              |              |                                                                                                   |
| ---------------------------- | ------------ | ------------------------------------------------------------------------------------------------- |
| [SDL_Window](SDL_Window) *   | **window**   | the window to update.                                                                             |
| const [SDL_Rect](SDL_Rect) * | **rects**    | an array of [SDL_Rect](SDL_Rect) structures representing areas of the surface to copy, in pixels. |
| int                          | **numrects** | the number of rectangles.                                                                         |

## Return Value

(bool) Returns true on success or false on failure; call
[SDL_GetError](SDL_GetError)() for more information.

## Remarks

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](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.

## Thread Safety

This function should only be called on the main thread.

## Version

This function is available since SDL 3.1.3.

## See Also

- [SDL_GetWindowSurface](SDL_GetWindowSurface)
- [SDL_UpdateWindowSurface](SDL_UpdateWindowSurface)

----
[CategoryAPI](CategoryAPI), [CategoryAPIFunction](CategoryAPIFunction), [CategoryVideo](CategoryVideo)