windjammer-ui 0.3.6

//! Desktop wgpu renderer for UI

#[cfg(feature = "desktop")]
use wgpu::{Device, Queue, Surface, SurfaceConfiguration};
#[cfg(feature = "desktop")]
use winit::window::Window;

#[allow(unused_imports)]
use crate::vdom::VNode;

/// Desktop renderer using wgpu
pub struct DesktopRenderer {
    #[cfg(feature = "desktop")]
    device: Device,
    #[cfg(feature = "desktop")]
    queue: Queue,
    #[cfg(feature = "desktop")]
    surface: Surface<'static>,
    #[cfg(feature = "desktop")]
    config: SurfaceConfiguration,
}

#[cfg(feature = "desktop")]
impl DesktopRenderer {
    /// Create a new desktop renderer
    pub async fn new(window: std::sync::Arc<Window>) -> Result<Self, String> {
        // Create wgpu instance
        let instance = wgpu::Instance::new(wgpu::InstanceDescriptor {
            backends: wgpu::Backends::all(),
            ..Default::default()
        });

        // Create surface
        let surface = instance
            .create_surface(window.clone())
            .map_err(|e| format!("Failed to create surface: {}", e))?;

        // Request adapter
        let adapter = instance
            .request_adapter(&wgpu::RequestAdapterOptions {
                power_preference: wgpu::PowerPreference::HighPerformance,
                compatible_surface: Some(&surface),
                force_fallback_adapter: false,
            })
            .await
            .ok_or("Failed to find suitable graphics adapter")?;

        // Request device and queue
        let (device, queue) = adapter
            .request_device(
                &wgpu::DeviceDescriptor {
                    label: Some("Windjammer UI Device"),
                    required_features: wgpu::Features::empty(),
                    required_limits: wgpu::Limits::default(),
                    memory_hints: Default::default(),
                },
                None,
            )
            .await
            .map_err(|e| format!("Failed to create device: {}", e))?;

        // Configure surface
        let size = window.inner_size();
        let config = SurfaceConfiguration {
            usage: wgpu::TextureUsages::RENDER_ATTACHMENT,
            format: surface.get_capabilities(&adapter).formats[0],
            width: size.width,
            height: size.height,
            present_mode: wgpu::PresentMode::Fifo,
            alpha_mode: wgpu::CompositeAlphaMode::Auto,
            view_formats: vec![],
            desired_maximum_frame_latency: 2,
        };
        surface.configure(&device, &config);

        Ok(Self {
            device,
            queue,
            surface,
            config,
        })
    }

    /// Render a frame
    pub fn render(&mut self, _vdom: &VNode) -> Result<(), String> {
        let output = self
            .surface
            .get_current_texture()
            .map_err(|e| format!("Failed to get surface texture: {}", e))?;

        let view = output
            .texture
            .create_view(&wgpu::TextureViewDescriptor::default());

        let mut encoder = self
            .device
            .create_command_encoder(&wgpu::CommandEncoderDescriptor {
                label: Some("Render Encoder"),
            });

        {
            let _render_pass = encoder.begin_render_pass(&wgpu::RenderPassDescriptor {
                label: Some("Render Pass"),
                color_attachments: &[Some(wgpu::RenderPassColorAttachment {
                    view: &view,
                    resolve_target: None,
                    ops: wgpu::Operations {
                        load: wgpu::LoadOp::Clear(wgpu::Color {
                            r: 0.1,
                            g: 0.1,
                            b: 0.1,
                            a: 1.0,
                        }),
                        store: wgpu::StoreOp::Store,
                    },
                })],
                depth_stencil_attachment: None,
                timestamp_writes: None,
                occlusion_query_set: None,
            });

            // TODO: Render VNode tree to GPU
            // This would involve:
            // 1. Converting VNode tree to render commands
            // 2. Creating vertex buffers for UI elements
            // 3. Rendering text with a font atlas
            // 4. Handling images and textures
        }

        self.queue.submit(std::iter::once(encoder.finish()));
        output.present();

        Ok(())
    }

    /// Resize the surface
    pub fn resize(&mut self, width: u32, height: u32) {
        if width > 0 && height > 0 {
            self.config.width = width;
            self.config.height = height;
            self.surface.configure(&self.device, &self.config);
        }
    }
}