---
name: "SDL_GetDirect3D9AdapterIndex"
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_GetDirect3D9AdapterIndex"
---

# SDL\_GetDirect3D9AdapterIndex(3)

Get the D3D9 adapter index that matches the specified display.

## NAME

SDL\_GetDirect3D9AdapterIndex - Get the D3D9 adapter index that matches the specified display.

## HEADER FILE

Defined in SDL3/SDL\_system.h

## SYNOPSIS

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

**int SDL\_GetDirect3D9AdapterIndex(SDL\_DisplayID displayID);**

## DESCRIPTION

The returned adapter index can be passed to **IDirect3D9::CreateDevice** and controls on which monitor a full screen application will appear.

## FUNCTION PARAMETERS

- *displayID*

  the instance of the display to query.

## RETURN VALUE

Returns the D3D9 adapter index on success or -1 on failure; call

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

## AVAILABILITY

This function is available since SDL 3.2.0.