---
name: "al_set_shader_sampler"
section: "3alleg5"
platform: "linux"
package: "allegro5-doc"
version: "2:5.2.10.1+dfsg-1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/al_set_shader_sampler/3alleg5"
---

# al\_set\_shader\_sampler(3alleg5)

Allegro 5 API

## NAME

al\_set\_shader\_sampler - Allegro 5 API

## SYNOPSIS

-

  ```
  #include <allegro5/allegro.h>
  bool al_set_shader_sampler(const char *name,
     ALLEGRO_BITMAP *bitmap, int unit)
  ```

## DESCRIPTION

Sets a texture sampler uniform and texture unit of the current target bitmap’s shader. The given bitmap must be a video bitmap.

Different samplers should use different units. The bitmap passed to Allegro’s drawing functions uses the 0th unit, so if you’re planning on using the `al_tex` variable in your pixel shader as well as another sampler, set the other sampler to use a unit different from 0. With the primitives addon, it is possible to free up the 0th unit by passing `NULL` as the texture argument to the relevant drawing functions. In this case, you may set a sampler to use the 0th unit and thus not use `al_tex` (the `al_use_tex` variable will be set to `false`).

Returns true on success. Otherwise returns false, e.g. if the uniform by that name does not exist in the shader.

## SINCE

5\.1.0

## SEE ALSO

al\_use\_shader(3alleg5)