add uw8-window crate

uw8-window/.gitignore

@@ -0,0 +1 @@
+/target

uw8-window/Cargo.toml

@@ -0,0 +1,17 @@
+[package]
+name = "uw8-window"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+winit = "0.26.1"
+env_logger = "0.9"
+log = "0.4"
+wgpu = "0.13.1"
+pollster = "0.2"
+bytemuck = { version = "1.4", features = [ "derive" ] }
+anyhow = "1"
+minifb = { version = "0.23.0", default-features = false, features = ["x11"] }
+winapi = "0.3.9"

uw8-window/src/cpu.rs

@@ -0,0 +1,53 @@
+use std::time::Instant;
+
+use crate::Framebuffer;
+use minifb::{Key, Window, WindowOptions};
+
+pub fn run(mut update: Box<dyn FnMut(&mut dyn Framebuffer, u32, bool) -> Instant + 'static>) -> ! {
+    #[cfg(target_os = "windows")]
+    unsafe {
+        winapi::um::timeapi::timeBeginPeriod(1);
+    }
+
+    let mut buffer: Vec<u32> = vec![0; 320 * 240];
+
+    let options = WindowOptions {
+        scale: minifb::Scale::X2,
+        scale_mode: minifb::ScaleMode::AspectRatioStretch,
+        resize: true,
+        ..Default::default()
+    };
+    let mut window = Window::new("MicroW8", 320, 240, options).unwrap();
+
+    let mut next_frame = Instant::now();
+    while window.is_open() && !window.is_key_down(Key::Escape) {
+        if let Some(sleep) = next_frame.checked_duration_since(Instant::now()) {
+            std::thread::sleep(sleep);
+        }
+        next_frame = update(
+            &mut CpuFramebuffer {
+                buffer: &mut buffer,
+            },
+            0,
+            false,
+        );
+        window.update_with_buffer(&buffer, 320, 240).unwrap();
+    }
+    std::process::exit(0);
+}
+
+struct CpuFramebuffer<'a> {
+    buffer: &'a mut Vec<u32>,
+}
+
+impl<'a> Framebuffer for CpuFramebuffer<'a> {
+    fn update(&mut self, framebuffer: &[u8], palette: &[u8]) {
+        for (i, &color_index) in framebuffer.iter().enumerate() {
+            let offset = color_index as usize * 4;
+            self.buffer[i] = 0xff000000
+                | ((palette[offset] as u32) << 16)
+                | ((palette[offset + 1] as u32) << 8)
+                | palette[offset + 2] as u32;
+        }
+    }
+}

uw8-window/src/crt.wgsl

@@ -0,0 +1,78 @@
+struct VertexOutput {
+    @builtin(position) clip_position: vec4<f32>,
+    @location(0) tex_coords: vec2<f32>,
+}
+
+struct Uniforms {
+    texture_scale: vec4<f32>,
+}
+
+@group(0) @binding(1) var<uniform> uniforms: Uniforms;
+
+@vertex
+fn vs_main(
+    @builtin(vertex_index) in_vertex_index: u32,
+) -> VertexOutput {
+    var out: VertexOutput;
+    let x = (1.0 - f32(in_vertex_index)) * 3.0;
+    let y = f32(in_vertex_index & 1u) * 3.0 - 1.0;
+    out.clip_position = vec4<f32>(x, y, 0.0, 1.0);
+    out.tex_coords = vec2<f32>(x, y) * uniforms.texture_scale.xy + vec2<f32>(160.0, 120.0);
+    return out;
+}
+
+@group(0) @binding(0) var screen_texture: texture_2d<f32>;
+
+fn sample_pixel(coords: vec2<i32>, offset: vec4<f32>) -> vec3<f32> {
+    let is_outside = any(vec2<u32>(coords) >= vec2<u32>(320u, 240u));
+    if(is_outside) {
+        return vec3<f32>(0.0);
+    } else {
+        let f = max(vec4<f32>(0.01) / offset - vec4<f32>(0.003), vec4<f32>(0.0));
+        return textureLoad(screen_texture, coords, 0).rgb * (f.x + f.y + f.z + f.w);
+    }
+}
+
+@fragment
+fn fs_main(in: VertexOutput) -> @location(0) vec4<f32> {
+    let pixel = floor(in.tex_coords);
+    let o = vec2<f32>(0.5) - (in.tex_coords - pixel);
+    let pixel = vec2<i32>(pixel);
+    
+    if(pixel.x < -1 || pixel.y < -1 || pixel.x > 320 || pixel.y > 240) {
+        return vec4<f32>(0.0, 0.0, 0.0, 1.0);
+    }
+    
+    let offset_x = o.xxxx + vec4<f32>(-0.125, 0.375, 0.125, -0.375) * uniforms.texture_scale.z;
+    let offset_y = o.yyyy + vec4<f32>(-0.375, -0.125, 0.375, 0.125) * uniforms.texture_scale.z;
+    
+    let offset_x0 = max(abs(offset_x + vec4<f32>(-1.0)) - vec4<f32>(0.5), vec4<f32>(0.0));
+    let offset_x1 = max(abs(offset_x) - vec4<f32>(0.5), vec4<f32>(0.0));
+    let offset_x2 = max(abs(offset_x + vec4<f32>(1.0)) - vec4<f32>(0.5), vec4<f32>(0.0));
+    
+    let offset_x0 = offset_x0 * offset_x0;
+    let offset_x1 = offset_x1 * offset_x1;
+    let offset_x2 = offset_x2 * offset_x2;
+    
+    let offset_yr = offset_y + vec4<f32>(-1.0);
+    let offset_yr = vec4<f32>(0.02) + offset_yr * offset_yr;
+    
+    var acc = sample_pixel(pixel + vec2<i32>(-1, -1), offset_x0 + offset_yr);
+    acc = acc + sample_pixel(pixel + vec2<i32>(0, -1), offset_x1 + offset_yr);
+    acc = acc + sample_pixel(pixel + vec2<i32>(1, -1), offset_x2 + offset_yr);
+
+    let offset_yr = vec4<f32>(0.02) + offset_y * offset_y;
+    
+    acc = acc + sample_pixel(pixel + vec2<i32>(-1, 0), offset_x0 + offset_yr);
+    acc = acc + sample_pixel(pixel, offset_x1 + offset_yr);
+    acc = acc + sample_pixel(pixel + vec2<i32>(1, 0), offset_x2 + offset_yr);
+
+    let offset_yr = offset_y + vec4<f32>(1.0);
+    let offset_yr = vec4<f32>(0.02) + offset_yr * offset_yr;
+    
+    acc = acc + sample_pixel(pixel + vec2<i32>(-1, 1), offset_x0 + offset_yr);
+    acc = acc + sample_pixel(pixel + vec2<i32>(0, 1), offset_x1 + offset_yr);
+    acc = acc + sample_pixel(pixel + vec2<i32>(1, 1), offset_x2 + offset_yr);
+
+    return vec4<f32>(acc, 1.0);
+}

uw8-window/src/gpu.rs

@@ -0,0 +1,466 @@
+use crate::Framebuffer;
+use anyhow::{anyhow, Result};
+use std::{num::NonZeroU32, time::Instant};
+
+use wgpu::util::DeviceExt;
+use winit::{
+    dpi::PhysicalSize,
+    event::{Event, VirtualKeyCode, WindowEvent},
+    event_loop::{ControlFlow, EventLoop},
+    window::{Fullscreen, WindowBuilder},
+};
+
+pub struct Window {
+    event_loop: EventLoop<()>,
+    window: winit::window::Window,
+    instance: wgpu::Instance,
+    surface: wgpu::Surface,
+    adapter: wgpu::Adapter,
+    device: wgpu::Device,
+    queue: wgpu::Queue,
+}
+
+impl Window {
+    pub fn new() -> Result<Window> {
+        async fn create() -> Result<Window> {
+            let event_loop = EventLoop::new();
+            let window = WindowBuilder::new()
+                .with_inner_size(PhysicalSize::new(640u32, 480))
+                .with_min_inner_size(PhysicalSize::new(320u32, 240))
+                .with_title("MicroW8")
+                .build(&event_loop)?;
+
+            window.set_cursor_visible(false);
+
+            let instance = wgpu::Instance::new(wgpu::Backends::all());
+            let surface = unsafe { instance.create_surface(&window) };
+            let adapter = instance
+                .request_adapter(&wgpu::RequestAdapterOptions {
+                    power_preference: wgpu::PowerPreference::LowPower,
+                    compatible_surface: Some(&surface),
+                    force_fallback_adapter: false,
+                })
+                .await
+                .ok_or_else(|| anyhow!("Request adapter failed"))?;
+
+            let (device, queue) = adapter
+                .request_device(&wgpu::DeviceDescriptor::default(), None)
+                .await?;
+
+            Ok(Window {
+                event_loop,
+                window,
+                instance,
+                surface,
+                adapter,
+                device,
+                queue,
+            })
+        }
+
+        pollster::block_on(create())
+    }
+
+    pub fn run(
+        self,
+        mut update: Box<dyn FnMut(&mut dyn Framebuffer, u32, bool) -> Instant + 'static>,
+    ) -> ! {
+        let Window {
+            event_loop,
+            window,
+            instance,
+            surface,
+            adapter,
+            device,
+            queue,
+        } = self;
+        let framebuffer_texture = device.create_texture(&wgpu::TextureDescriptor {
+            size: wgpu::Extent3d {
+                width: 320,
+                height: 240,
+                depth_or_array_layers: 1,
+            },
+            mip_level_count: 1,
+            sample_count: 1,
+            dimension: wgpu::TextureDimension::D2,
+            format: wgpu::TextureFormat::R8Uint,
+            usage: wgpu::TextureUsages::TEXTURE_BINDING | wgpu::TextureUsages::COPY_DST,
+            label: None,
+        });
+
+        let palette_texture = device.create_texture(&wgpu::TextureDescriptor {
+            size: wgpu::Extent3d {
+                width: 256,
+                height: 1,
+                depth_or_array_layers: 1,
+            },
+            mip_level_count: 1,
+            sample_count: 1,
+            dimension: wgpu::TextureDimension::D1,
+            format: wgpu::TextureFormat::Rgba8UnormSrgb,
+            usage: wgpu::TextureUsages::TEXTURE_BINDING | wgpu::TextureUsages::COPY_DST,
+            label: None,
+        });
+
+        let screen_texture = device.create_texture(&wgpu::TextureDescriptor {
+            size: wgpu::Extent3d {
+                width: 320,
+                height: 240,
+                depth_or_array_layers: 1,
+            },
+            mip_level_count: 1,
+            sample_count: 1,
+            dimension: wgpu::TextureDimension::D2,
+            format: wgpu::TextureFormat::Rgba8UnormSrgb,
+            usage: wgpu::TextureUsages::TEXTURE_BINDING | wgpu::TextureUsages::RENDER_ATTACHMENT,
+            label: None,
+        });
+
+        let framebuffer_texture_view =
+            framebuffer_texture.create_view(&wgpu::TextureViewDescriptor::default());
+        let palette_texture_view =
+            palette_texture.create_view(&wgpu::TextureViewDescriptor::default());
+        let screen_texture_view =
+            screen_texture.create_view(&wgpu::TextureViewDescriptor::default());
+
+        let mut uniforms = Uniforms {
+            texture_scale: texture_scale_from_resolution(window.inner_size()),
+        };
+
+        let uniform_buffer = device.create_buffer_init(&wgpu::util::BufferInitDescriptor {
+            label: None,
+            contents: bytemuck::cast_slice(&[uniforms]),
+            usage: wgpu::BufferUsages::UNIFORM | wgpu::BufferUsages::COPY_DST,
+        });
+
+        let palette_bind_group_layout =
+            device.create_bind_group_layout(&wgpu::BindGroupLayoutDescriptor {
+                entries: &[
+                    wgpu::BindGroupLayoutEntry {
+                        binding: 0,
+                        visibility: wgpu::ShaderStages::FRAGMENT,
+                        ty: wgpu::BindingType::Texture {
+                            multisampled: false,
+                            view_dimension: wgpu::TextureViewDimension::D2,
+                            sample_type: wgpu::TextureSampleType::Uint,
+                        },
+                        count: None,
+                    },
+                    wgpu::BindGroupLayoutEntry {
+                        binding: 1,
+                        visibility: wgpu::ShaderStages::FRAGMENT,
+                        ty: wgpu::BindingType::Texture {
+                            multisampled: false,
+                            view_dimension: wgpu::TextureViewDimension::D1,
+                            sample_type: wgpu::TextureSampleType::Float { filterable: false },
+                        },
+                        count: None,
+                    },
+                ],
+                label: None,
+            });
+
+        let palette_bind_group = device.create_bind_group(&wgpu::BindGroupDescriptor {
+            layout: &palette_bind_group_layout,
+            entries: &[
+                wgpu::BindGroupEntry {
+                    binding: 0,
+                    resource: wgpu::BindingResource::TextureView(&framebuffer_texture_view),
+                },
+                wgpu::BindGroupEntry {
+                    binding: 1,
+                    resource: wgpu::BindingResource::TextureView(&palette_texture_view),
+                },
+            ],
+            label: None,
+        });
+
+        let crt_bind_group_layout =
+            device.create_bind_group_layout(&wgpu::BindGroupLayoutDescriptor {
+                entries: &[
+                    wgpu::BindGroupLayoutEntry {
+                        binding: 0,
+                        visibility: wgpu::ShaderStages::FRAGMENT,
+                        ty: wgpu::BindingType::Texture {
+                            multisampled: false,
+                            view_dimension: wgpu::TextureViewDimension::D2,
+                            sample_type: wgpu::TextureSampleType::Float { filterable: false },
+                        },
+                        count: None,
+                    },
+                    wgpu::BindGroupLayoutEntry {
+                        binding: 1,
+                        visibility: wgpu::ShaderStages::VERTEX_FRAGMENT,
+                        ty: wgpu::BindingType::Buffer {
+                            ty: wgpu::BufferBindingType::Uniform,
+                            has_dynamic_offset: false,
+                            min_binding_size: None,
+                        },
+                        count: None,
+                    },
+                ],
+                label: None,
+            });
+
+        let crt_bind_group = device.create_bind_group(&wgpu::BindGroupDescriptor {
+            layout: &crt_bind_group_layout,
+            entries: &[
+                wgpu::BindGroupEntry {
+                    binding: 0,
+                    resource: wgpu::BindingResource::TextureView(&screen_texture_view),
+                },
+                wgpu::BindGroupEntry {
+                    binding: 1,
+                    resource: uniform_buffer.as_entire_binding(),
+                },
+            ],
+            label: None,
+        });
+
+        let palette_shader = device.create_shader_module(wgpu::ShaderModuleDescriptor {
+            label: None,
+            source: wgpu::ShaderSource::Wgsl(include_str!("palette.wgsl").into()),
+        });
+
+        let palette_pipeline_layout =
+            device.create_pipeline_layout(&wgpu::PipelineLayoutDescriptor {
+                label: None,
+                bind_group_layouts: &[&palette_bind_group_layout],
+                push_constant_ranges: &[],
+            });
+
+        let palette_pipeline = device.create_render_pipeline(&wgpu::RenderPipelineDescriptor {
+            label: None,
+            layout: Some(&palette_pipeline_layout),
+            vertex: wgpu::VertexState {
+                module: &palette_shader,
+                entry_point: "vs_main",
+                buffers: &[],
+            },
+            fragment: Some(wgpu::FragmentState {
+                module: &palette_shader,
+                entry_point: "fs_main",
+                targets: &[Some(wgpu::ColorTargetState {
+                    format: wgpu::TextureFormat::Rgba8UnormSrgb,
+                    blend: None,
+                    write_mask: wgpu::ColorWrites::ALL,
+                })],
+            }),
+            primitive: Default::default(),
+            depth_stencil: None,
+            multisample: Default::default(),
+            multiview: None,
+        });
+
+        let crt_shader = device.create_shader_module(wgpu::ShaderModuleDescriptor {
+            label: None,
+            source: wgpu::ShaderSource::Wgsl(include_str!("crt.wgsl").into()),
+        });
+
+        let render_pipeline_layout =
+            device.create_pipeline_layout(&wgpu::PipelineLayoutDescriptor {
+                label: None,
+                bind_group_layouts: &[&crt_bind_group_layout],
+                push_constant_ranges: &[],
+            });
+
+        let mut surface_config = wgpu::SurfaceConfiguration {
+            usage: wgpu::TextureUsages::RENDER_ATTACHMENT,
+            format: surface.get_supported_formats(&adapter)[0],
+            width: window.inner_size().width,
+            height: window.inner_size().height,
+            present_mode: wgpu::PresentMode::AutoNoVsync,
+        };
+
+        let render_pipeline = device.create_render_pipeline(&wgpu::RenderPipelineDescriptor {
+            label: None,
+            layout: Some(&render_pipeline_layout),
+            vertex: wgpu::VertexState {
+                module: &crt_shader,
+                entry_point: "vs_main",
+                buffers: &[],
+            },
+            fragment: Some(wgpu::FragmentState {
+                module: &crt_shader,
+                entry_point: "fs_main",
+                targets: &[Some(wgpu::ColorTargetState {
+                    format: surface_config.format,
+                    blend: None,
+                    write_mask: wgpu::ColorWrites::ALL,
+                })],
+            }),
+            primitive: Default::default(),
+            depth_stencil: None,
+            multisample: Default::default(),
+            multiview: None,
+        });
+
+        surface.configure(&device, &surface_config);
+
+        event_loop.run(move |event, _, control_flow| {
+            let _ = (&window, &instance, &surface, &adapter, &device);
+
+            match event {
+                Event::WindowEvent { event, .. } => match event {
+                    WindowEvent::Resized(new_size) => {
+                        surface_config.width = new_size.width;
+                        surface_config.height = new_size.height;
+                        surface.configure(&device, &surface_config);
+                        uniforms.texture_scale = texture_scale_from_resolution(new_size);
+                        queue.write_buffer(&uniform_buffer, 0, bytemuck::cast_slice(&[uniforms]));
+                    }
+                    WindowEvent::CloseRequested => *control_flow = ControlFlow::Exit,
+                    WindowEvent::KeyboardInput { input, .. } => {
+                        if input.state == winit::event::ElementState::Pressed {
+                            match input.virtual_keycode {
+                                Some(VirtualKeyCode::Escape) => *control_flow = ControlFlow::Exit,
+                                Some(VirtualKeyCode::F) => {
+                                    window.set_fullscreen(if window.fullscreen().is_some() {
+                                        None
+                                    } else {
+                                        Some(Fullscreen::Borderless(None))
+                                    });
+                                }
+                                _ => (),
+                            }
+                        }
+                    }
+                    _ => (),
+                },
+                Event::MainEventsCleared => {
+                    if let ControlFlow::WaitUntil(t) = *control_flow {
+                        if Instant::now() < t {
+                            return;
+                        }
+                    }
+                    let next_frame = update(
+                        &mut GpuFramebuffer {
+                            queue: &queue,
+                            framebuffer: &framebuffer_texture,
+                            palette: &palette_texture,
+                        },
+                        0,
+                        false,
+                    );
+                    *control_flow = ControlFlow::WaitUntil(next_frame);
+
+                    let output = surface.get_current_texture().unwrap();
+                    let view = output
+                        .texture
+                        .create_view(&wgpu::TextureViewDescriptor::default());
+                    let mut encoder = device
+                        .create_command_encoder(&wgpu::CommandEncoderDescriptor { label: None });
+
+                    {
+                        let mut render_pass =
+                            encoder.begin_render_pass(&wgpu::RenderPassDescriptor {
+                                label: None,
+                                color_attachments: &[Some(wgpu::RenderPassColorAttachment {
+                                    view: &screen_texture_view,
+                                    resolve_target: None,
+                                    ops: wgpu::Operations {
+                                        load: wgpu::LoadOp::Load,
+                                        store: true,
+                                    },
+                                })],
+                                depth_stencil_attachment: None,
+                            });
+
+                        render_pass.set_pipeline(&palette_pipeline);
+                        render_pass.set_bind_group(0, &palette_bind_group, &[]);
+                        render_pass.draw(0..3, 0..1);
+                    }
+
+                    {
+                        let mut render_pass =
+                            encoder.begin_render_pass(&wgpu::RenderPassDescriptor {
+                                label: None,
+                                color_attachments: &[Some(wgpu::RenderPassColorAttachment {
+                                    view: &view,
+                                    resolve_target: None,
+                                    ops: wgpu::Operations {
+                                        load: wgpu::LoadOp::Load,
+                                        store: true,
+                                    },
+                                })],
+                                depth_stencil_attachment: None,
+                            });
+
+                        render_pass.set_pipeline(&render_pipeline);
+                        render_pass.set_bind_group(0, &crt_bind_group, &[]);
+                        render_pass.draw(0..3, 0..1);
+                    }
+
+                    queue.submit(std::iter::once(encoder.finish()));
+                    output.present();
+                }
+                _ => (),
+            }
+        });
+    }
+}
+
+struct GpuFramebuffer<'a> {
+    framebuffer: &'a wgpu::Texture,
+    palette: &'a wgpu::Texture,
+    queue: &'a wgpu::Queue,
+}
+
+impl<'a> Framebuffer for GpuFramebuffer<'a> {
+    fn update(&mut self, pixels: &[u8], palette: &[u8]) {
+        self.queue.write_texture(
+            wgpu::ImageCopyTexture {
+                texture: self.framebuffer,
+                mip_level: 0,
+                origin: wgpu::Origin3d::ZERO,
+                aspect: wgpu::TextureAspect::All,
+            },
+            &bytemuck::cast_slice(pixels),
+            wgpu::ImageDataLayout {
+                offset: 0,
+                bytes_per_row: NonZeroU32::new(320),
+                rows_per_image: None,
+            },
+            wgpu::Extent3d {
+                width: 320,
+                height: 240,
+                depth_or_array_layers: 1,
+            },
+        );
+        self.queue.write_texture(
+            wgpu::ImageCopyTexture {
+                texture: self.palette,
+                mip_level: 0,
+                origin: wgpu::Origin3d::ZERO,
+                aspect: wgpu::TextureAspect::All,
+            },
+            &bytemuck::cast_slice(palette),
+            wgpu::ImageDataLayout {
+                offset: 0,
+                bytes_per_row: NonZeroU32::new(256 * 4),
+                rows_per_image: None,
+            },
+            wgpu::Extent3d {
+                width: 256,
+                height: 1,
+                depth_or_array_layers: 1,
+            },
+        );
+    }
+}
+
+fn texture_scale_from_resolution(res: PhysicalSize<u32>) -> [f32; 4] {
+    let scale = ((res.width as f32) / 160.0).min((res.height as f32) / 120.0);
+    [
+        res.width as f32 / scale,
+        res.height as f32 / scale,
+        2.0 / scale,
+        0.0,
+    ]
+}
+
+#[repr(C)]
+#[derive(Debug, Copy, Clone, bytemuck::Pod, bytemuck::Zeroable)]
+struct Uniforms {
+    texture_scale: [f32; 4],
+}

uw8-window/src/lib.rs

@@ -0,0 +1,19 @@
+use std::time::Instant;
+
+mod cpu;
+mod gpu;
+
+pub fn run<F: 'static + FnMut(&mut dyn Framebuffer, u32, bool) -> Instant>(update: F) -> ! {
+    match gpu::Window::new() {
+        Ok(window) => window.run(Box::new(update)),
+        Err(err) => eprintln!(
+            "Failed to create gpu window: {}\nFalling back to cpu window",
+            err
+        ),
+    }
+    cpu::run(Box::new(update));
+}
+
+pub trait Framebuffer {
+    fn update(&mut self, pixels: &[u8], palette: &[u8]);
+}

uw8-window/src/main.rs

@@ -0,0 +1,40 @@
+use std::time::{Duration, Instant};
+
+fn main() {
+    env_logger::Builder::from_env(env_logger::Env::default().default_filter_or("info")).init();
+
+    let mut framebuffer = vec![0u8; 320 * 240];
+    let start_time = Instant::now();
+
+    let mut palette = vec![0u32; 256];
+    for i in 0..256 {
+        let v = i & 15;
+        let r = ((i >> 2) & 12) * v;
+        let g = ((i >> 3) & 12) * v;
+        let b = ((i >> 4) & 12) * v;
+        palette[i as usize] = r + (g << 8) + (b << 16);
+    }
+
+    let mut prev_frame = Instant::now();
+
+    uw8_window::run(move |gpu_framebuffer, _gamepads, _reset| {
+        draw_frame(&mut framebuffer, start_time.elapsed().as_secs_f32());
+        gpu_framebuffer.update(&framebuffer, bytemuck::cast_slice(&palette));
+        prev_frame += Duration::from_secs_f32(1.0 / 60.0);
+        prev_frame
+    });
+}
+
+fn draw_frame(framebuffer: &mut [u8], time: f32) {
+    for x in 0..320 {
+        let xr = x as f32 - 160.0;
+        for y in 0..240 {
+            let yr = y as f32 - 120.0;
+            let f = 8192.0 / (xr * xr + yr * yr);
+            let u = xr * f + 512.0 + time * 32.0;
+            let v = yr * f + time * 29.0;
+            let c = (u.floor() as i32 ^ v.floor() as i32) as u32;
+            framebuffer[x + y * 320] = c as u8;
+        }
+    }
+}

uw8-window/src/palette.wgsl

@@ -0,0 +1,24 @@
+struct VertexOutput {
+    @builtin(position) clip_position: vec4<f32>,
+    @location(0) tex_coords: vec2<f32>,
+}
+
+@vertex
+fn vs_main(@builtin(vertex_index) vertex_index: u32) -> VertexOutput {
+    var out: VertexOutput;
+    let x = (1.0 - f32(vertex_index)) * 3.0;
+    let y = f32(vertex_index & 1u) * 3.0 - 1.0;
+    out.clip_position = vec4<f32>(x, y, 0.0, 1.0);
+    out.tex_coords = vec2<f32>((x + 1.0) * 160.0, (y + 1.0) * 120.0);
+    return out;
+}
+
+@group(0) @binding(0) var framebuffer_texture: texture_2d<u32>;
+@group(0) @binding(1) var palette_texture: texture_1d<f32>;
+
+@fragment
+fn fs_main(in: VertexOutput) -> @location(0) vec4<f32> {
+    let texel = vec2<i32>(floor(in.tex_coords));
+    let index = textureLoad(framebuffer_texture, texel, 0).r;
+    return textureLoad(palette_texture, i32(index), 0);
+}