Methods to call shader functions in SwiftUI

[Treata11]

Hi @fwrs

Just wanted to ask if you know any other ways to call [[ stitchable ]] MSL functions in SwiftUI other than these four methods:

Abide either the colorEffect, layerEffect or the distortionEffect function signatures & then create View extensions which utilizes the filterEffect ...

Create a struct which conforms to ShapeStyle, View, Sendable & call the shader function in the func resolve() which is required for the struct to conform to ShapeStyle (The approach you used in your package).
This approach has a small downside. The metal function is called in a method that returns some ShapeStyle & as the result, you don't get some advantages of a method which returns some View (Shader doesn't conform to View) ...
So, in order to gain those advantages, you'd have to create another View struct & call the former ShapeStyle inside var body.

[fwrs]

Hi. ShapeStyles based on Shader, such as the ones created in this package can be used as Views:

Because of this extension that's included in SwiftUI:

[Treata11]

The ShapeStyles surely can be treated as a View when called in a View-Hierarchy or even a preview, but the implementations of a ShapeStyle (like OKLCHLinearGradient) relies on a func resolve() & not a var body which is limiting. You don't have the power of which a view has (i.e. you can't call viewModifiers on them; can't embed them inside a ViewBuilder etc).
You'd have to create a View that uses the ShapeStyle in order to gain those abilities.

[fwrs]

Sorry, I don't follow how it's limiting. The built-in conformance makes it a View like any other. If you'd like to customize how it's rendered and apply some default modifiers you could override the body property and set the modifiers or use builders inside of it:

[Treata11]

Sorry, I don't follow how it's limiting. The built-in conformance makes it a View like any other.

I'm talking about the implementation of the ShapeStyle gradients. They don't have a var body; instead they got a func resolve():

    public func resolve(in environment: EnvironmentValues) -> some ShapeStyle {
        return ShaderLibrary.bundle(Bundle.module).oklchLinearGradient(
            .boundingRect,
            .colorArray(stops.map(\.color)),
            .floatArray(stops.map(\.location).map(Float.init)),
            .float2(startPoint.x, startPoint.y),
            .float2(endPoint.x, endPoint.y)
        )
    }

Excerpted from OKLCHLinearGradient

You don't have the capabilities of a View in func resolve() & you only gain those capabilities when you call the ShapeStyle in another View's body ... exactly like what you did in ContentView in the screenshot above.