---
name: "SDL_SetTextureAlphaModFloat"
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_SetTextureAlphaModFloat"
---

# SDL\_SetTextureAlphaModFloat(3)

Set an additional alpha value multiplied into render copy operations.

## NAME

SDL\_SetTextureAlphaModFloat - Set an additional alpha value multiplied into render copy operations.

## HEADER FILE

Defined in SDL3/SDL\_render.h

## SYNOPSIS

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

**bool SDL\_SetTextureAlphaModFloat(SDL\_Texture \*texture, float alpha);**

## DESCRIPTION

When this texture is rendered, during the copy operation the source alpha value is modulated by this alpha value according to the following formula: **srcA**=**srcA**\***alpha** Alpha modulation is not always supported by the renderer; it will return false if alpha modulation is not supported.

## FUNCTION PARAMETERS

- *texture*

  the texture to update.

- *alpha*

  the source alpha value multiplied into copy operations.

## 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\_GetTextureAlphaModFloat**(3)](/SDL_GetTextureAlphaModFloat/3.md), **•**(3), [**SDL\_SetTextureAlphaMod**(3)](/SDL_SetTextureAlphaMod/3.md), **•**(3), [**SDL\_SetTextureColorModFloat**(3)](/SDL_SetTextureColorModFloat/3.md)