---
title: "glAlphaFuncx(_:_:)"
framework: OpenGL ES
role: symbol
role_heading: Function
platforms: [iOS 2.0+, iPadOS 2.0+, Mac Catalyst 2.0+, tvOS 9.0+]
path: "opengles/glalphafuncx(_:_:)"
---

# glAlphaFuncx(_:_:)

## Declaration

```swift
func glAlphaFuncx(_ func: GLenum, _ ref: GLclampx)
```