---
name: "identity_matrix"
section: "3alleg4"
platform: "linux"
package: "allegro4-doc"
version: "2:4.4.3.1-5"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/identity_matrix/3alleg4"
---

# identity\_matrix(3alleg4)

Global containing the identity matrix. Allegro game programming library.

## NAME

identity\_matrix, identity\_matrix\_f - Global containing the identity matrix. Allegro game programming library.

## SYNOPSIS

**#include \<allegro.h\>**

**extern MATRIX identity\_matrix;**

**extern MATRIX\_f identity\_matrix\_f;**

## DESCRIPTION

Global variables containing the 'do nothing' identity matrix. Multiplying  by the identity matrix has no effect.