Shaders

Custom shaders are still experimental in WaterUI, but the architecture already exposes two hooks you can use today:

1. Native views – Wrap a platform-specific shader view just like the canvas chapter described.
2. Metadata – Pass shader parameters through the environment so renderers can pipe them into the GPU pipeline.

Embedding a Metal/WebGL View

On Apple platforms, create a SwiftUI Representable that hosts a Metal view. Expose it to Rust as a Native<MyShader> view (see component::native). Provide a lightweight Rust struct with the shader configuration (uniforms, textures) and let the backend translate it to GPU calls.

Declarative Uniforms

Even without an official shader DSL, you can keep uniforms reactive by storing them in bindings:

#![allow(unused)]
fn main() {
use waterui::prelude::*;
use waterui::reactive::binding;
use waterui::Binding;
use waterui::core::{Native, View};

pub struct PlasmaUniforms {
    pub time: f32,
    pub intensity: f32,
}

pub fn plasma() -> impl View {
    let time: Binding<f32> = binding(0.0).animated();
    Native(PlasmaUniforms {
        time: time.get(),
        intensity: 0.8,
    })
}
}

The backend reads PlasmaUniforms each frame and updates the shader. Once the official shader API lands, those bindings will plug directly into the declarative shader graph.

Roadmap

• Shared WGSL shading language compiled to Metal, WebGPU, and Vulkan targets.
• Editor tooling for hot-reloading shader parameters.
• Integration with the layout system so shaders participate in hit-testing and accessibility.

For now, treat shaders like any other native integration: define a Rust struct for configuration, render it with a backend-specific view, and keep the data reactive.