---
title: MTLVertexStepFunction.constant
framework: metal
role: symbol
role_heading: Case
path: metal/mtlvertexstepfunction/constant
---

# MTLVertexStepFunction.constant

The vertex function fetches attribute data once and uses that data for every vertex.

## Declaration

```swift
case constant
```

## See Also

### Step functions

- [MTLVertexStepFunction.perVertex](metal/mtlvertexstepfunction/pervertex.md)
- [MTLVertexStepFunction.perInstance](metal/mtlvertexstepfunction/perinstance.md)
- [MTLVertexStepFunction.perPatch](metal/mtlvertexstepfunction/perpatch.md)
- [MTLVertexStepFunction.perPatchControlPoint](metal/mtlvertexstepfunction/perpatchcontrolpoint.md)