What is a good start for shaders on an iPhone?

A good start for shaders on an iPhone would be to explore the session titled "Create custom visual effects with SwiftUI" from WWDC 2024. This session provides a comprehensive introduction to using shaders in SwiftUI, including how to instantiate and apply them to views.

Here are some key points from the session:

1. Introduction to Shaders in SwiftUI:

   • Shaders are small programs that calculate rendering effects directly on the GPU.
   • SwiftUI uses shaders internally for many visual effects and allows you to write your own custom shaders.

2. Instantiating Shaders:

   • You can instantiate a shader in SwiftUI by calling a function with its name on the shader library.
   • Additional parameters like colors, numbers, or images can be passed to the shader function.
   • Shaders are written in the Metal shading language and executed on the GPU for each pixel of your view.

3. Practical Examples:

   • The session demonstrates how to use shaders for custom fills, text rendering, and creating unique visual effects.
   • Debugging and iterating on shaders using a debug UI to fine-tune parameters interactively.

For a detailed walkthrough, you can start watching the session from the chapter on Metal shaders:

• Create custom visual effects with SwiftUI (19:40)

Additionally, if you are familiar with C programming and want to leverage Metal for game development, the session "Port advanced games to Apple platforms" covers how to use Metal CPP and the Metal shader converter to bring shaders to Metal:

• Port advanced games to Apple platforms (09:29)

These resources should provide a solid foundation for getting started with shaders on an iPhone.