---
title: prepareToDraw()
framework: GLKit
role: symbol
role_heading: Instance Method
platforms: [iOS 5.0+, iPadOS 5.0+, macOS 10.8+, tvOS 9.0+]
path: glkit/glknamedeffect/preparetodraw()
---

# prepareToDraw()

Prepares an effect for OpenGL ES rendering.

## Declaration

```swift
func prepareToDraw()
```

## Discussion

Discussion An effect binds a compiled shader program to the context and returns. Many effects also bind data to other OpenGL state variables—see the appropriate reference for each effect class.