start to a shader??

Cargo.lock

@@ -81,6 +81,71 @@ version = "2.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "320119579fcad9c21884f5c4861d16174d0e06250625266f50fe6898340abefa"
 
+[[package]]
+name = "aeronet"
+version = "0.19.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "745a8013cf5cf00933422a43ddd500bcdf50e48de2f5ddfa54b89e80ca98b176"
+dependencies = [
+ "aeronet_io",
+ "aeronet_transport",
+ "bevy_app",
+]
+
+[[package]]
+name = "aeronet_io"
+version = "0.19.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f05b43f128690e5eb9636b8a227078b2a4e577450da145d26ea1cd14688d80bc"
+dependencies = [
+ "anyhow",
+ "bevy_app",
+ "bevy_ecs",
+ "bevy_platform",
+ "bevy_reflect",
+ "bytes",
+ "derive_more",
+ "log",
+]
+
+[[package]]
+name = "aeronet_replicon"
+version = "0.19.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4970822b3030b79c6dcba0933929176c5310836e67d707cc80cac6d29fe90c5a"
+dependencies = [
+ "aeronet_io",
+ "aeronet_transport",
+ "bevy_app",
+ "bevy_ecs",
+ "bevy_platform",
+ "bevy_reflect",
+ "bevy_replicon",
+ "bevy_state",
+ "log",
+]
+
+[[package]]
+name = "aeronet_transport"
+version = "0.19.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fd63172db760f378f31e1d546fc581b79c2ba3f084a9dfe73ce65c07c4527b9b"
+dependencies = [
+ "aeronet_io",
+ "bevy_app",
+ "bevy_ecs",
+ "bevy_platform",
+ "bevy_reflect",
+ "bevy_time",
+ "bit-vec",
+ "derive_more",
+ "either",
+ "log",
+ "octs",
+ "ringbuf",
+ "typesize",
+]
+
 [[package]]
 name = "ahash"
 version = "0.8.12"
@@ -173,6 +238,12 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "anyhow"
+version = "1.0.101"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5f0e0fee31ef5ed1ba1316088939cea399010ed7731dba877ed44aeb407a75ea"
+
 [[package]]
 name = "approx"
 version = "0.5.1"
@@ -1291,6 +1362,26 @@ dependencies = [
  "syn",
 ]
 
+[[package]]
+name = "bevy_replicon"
+version = "0.38.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "aee12260a021e0d9e4437ba9a325deb4ca05c98ef29d670fc63b366799ecaad0"
+dependencies = [
+ "bevy",
+ "bitflags 2.10.0",
+ "bytes",
+ "deterministic-hash",
+ "log",
+ "petgraph",
+ "postcard",
+ "serde",
+ "smallbitvec",
+ "typeid",
+ "variadics_please",
+ "xxhash-rust",
+]
+
 [[package]]
 name = "bevy_scene"
 version = "0.18.0"
@@ -1773,6 +1864,9 @@ name = "bytes"
 version = "1.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b35204fbdc0b3f4446b89fc1ac2cf84a8a68971995d0bf2e925ec7cd960f9cb3"
+dependencies = [
+ "portable-atomic",
+]
 
 [[package]]
 name = "calloop"
@@ -1850,6 +1944,15 @@ dependencies = [
  "libloading",
 ]
 
+[[package]]
+name = "cobs"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0fa961b519f0b462e3a3b4a34b64d119eeaca1d59af726fe450bbba07a9fc0a1"
+dependencies = [
+ "thiserror 2.0.17",
+]
+
 [[package]]
 name = "codespan-reporting"
 version = "0.12.0"
@@ -2198,6 +2301,12 @@ dependencies = [
  "unicode-xid",
 ]
 
+[[package]]
+name = "deterministic-hash"
+version = "1.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "11277822c27bde750de02c5dc5159b91e88bf2661a2c1d98106f2fb1c5c6f590"
+
 [[package]]
 name = "dispatch"
 version = "0.2.0"
@@ -3818,6 +3927,15 @@ dependencies = [
  "cc",
 ]
 
+[[package]]
+name = "octs"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d3beef54705459f4a421ff43b6c9b8381f5b84769e4ae69942783dd8918837b7"
+dependencies = [
+ "bytes",
+]
+
 [[package]]
 name = "offset-allocator"
 version = "0.2.0"
@@ -4070,6 +4188,28 @@ dependencies = [
  "portable-atomic",
 ]
 
+[[package]]
+name = "postcard"
+version = "1.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6764c3b5dd454e283a30e6dfe78e9b31096d9e32036b5d1eaac7a6119ccb9a24"
+dependencies = [
+ "cobs",
+ "postcard-derive",
+ "serde",
+]
+
+[[package]]
+name = "postcard-derive"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e0232bd009a197ceec9cc881ba46f727fcd8060a2d8d6a9dde7a69030a6fe2bb"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "pp-rs"
 version = "0.2.1"
@@ -4351,6 +4491,17 @@ version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "19b30a45b0cd0bcca8037f3d0dc3421eaf95327a17cad11964fb8179b4fc4832"
 
+[[package]]
+name = "ringbuf"
+version = "0.4.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fe47b720588c8702e34b5979cb3271a8b1842c7cb6f57408efa70c779363488c"
+dependencies = [
+ "crossbeam-utils",
+ "portable-atomic",
+ "portable-atomic-util",
+]
+
 [[package]]
 name = "robust"
 version = "1.2.0"
@@ -4622,6 +4773,12 @@ dependencies = [
  "version_check",
 ]
 
+[[package]]
+name = "smallbitvec"
+version = "2.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d31d263dd118560e1a492922182ab6ca6dc1d03a3bf54e7699993f31a4150e3f"
+
 [[package]]
 name = "smallvec"
 version = "1.15.1"
@@ -4844,8 +5001,11 @@ dependencies = [
 name = "time_travel"
 version = "0.1.0"
 dependencies = [
+ "aeronet",
+ "aeronet_replicon",
  "avian2d",
  "bevy",
+ "bevy_replicon",
 ]
 
 [[package]]
@@ -5029,6 +5189,26 @@ version = "1.19.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "562d481066bde0658276a35467c4af00bdc6ee726305698a55b86e61d7ad82bb"
 
+[[package]]
+name = "typesize"
+version = "0.1.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7da66c62c5b7017a2787e77373c03e6a5aafde77a73bff1ff96e91cd2e128179"
+dependencies = [
+ "typesize-derive",
+]
+
+[[package]]
+name = "typesize-derive"
+version = "0.1.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "536b6812192bda8551cfa0e52524e328c6a951b48e66529ee4522d6c721243d6"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "typewit"
 version = "1.14.2"
@@ -6094,6 +6274,12 @@ version = "0.8.28"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3ae8337f8a065cfc972643663ea4279e04e7256de865aa66fe25cec5fb912d3f"
 
+[[package]]
+name = "xxhash-rust"
+version = "0.8.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fdd20c5420375476fbd4394763288da7eb0cc0b8c11deed431a91562af7335d3"
+
 [[package]]
 name = "yazi"
 version = "0.2.1"

Cargo.toml

@@ -4,5 +4,8 @@ version = "0.1.0"
 edition = "2024"
 
 [dependencies]
+aeronet = "0.19.0"
+aeronet_replicon = { version = "0.19.0", features = ["client", "server"] }
 avian2d = "0.5.0"
-bevy = "0.18.0"
+bevy = { version = "0.18.0", features = ["debug"] }
+bevy_replicon = "0.38.2"

assets/logo.png

@@ -0,0 +1 @@
+/home/mitchell/Pictures/time_travel_logo.png

assets/shaders/bezier.wgsl

@@ -0,0 +1,61 @@
+struct Material {
+    p0: vec2<f32>,
+    c0: vec2<f32>,
+    c1: vec2<f32>,
+    p1: vec2<f32>,
+    width: f32,
+    color: vec4<f32>,
+};
+
+@group(2) @binding(0)
+var<uniform> mat: Material;
+
+fn bezier(p0: vec2<f32>, c0: vec2<f32>, c1: vec2<f32>, p1: vec2<f32>, t: f32) -> vec2<f32> {
+    let u = 1.0 - t;
+    return
+        u*u*u*p0 +
+        3.0*u*u*t*c0 +
+        3.0*u*t*t*c1 +
+        t*t*t*p1;
+}
+
+fn distance_to_bezier(p: vec2<f32>) -> f32 {
+    var min_d = 1e9;
+    let steps = 32;
+
+    var prev = mat.p0;
+    for (var i = 1; i <= steps; i++) {
+        let t = f32(i) / f32(steps);
+        let cur = bezier(mat.p0, mat.c0, mat.c1, mat.p1, t);
+
+        // distance to segment
+        let v = cur - prev;
+        let w = p - prev;
+        let t_seg = clamp(dot(w, v) / dot(v, v), 0.0, 1.0);
+        let proj = prev + t_seg * v;
+
+        min_d = min(min_d, distance(p, proj));
+        prev = cur;
+    }
+
+    return min_d;
+}
+
+@fragment
+fn fragment(
+    @location(0) world_pos: vec3<f32>,
+) -> @location(0) vec4<f32> {
+    let d = distance_to_bezier(world_pos.xy);
+
+    let half_w = mat.width * 0.5;
+    let aa = fwidth(d);
+
+    let alpha = smoothstep(half_w + aa, half_w - aa, d);
+
+    if (alpha <= 0.001) {
+        discard;
+    }
+
+    return vec4(mat.color.rgb, mat.color.a * alpha);
+}
+

src/main.rs

@@ -1,12 +1,26 @@
-use crate::avian::{CharacterControllerBundle, CharacterControllerPlugin};
+use crate::{
+    avian::{CharacterControllerBundle, CharacterControllerPlugin},
+    shaders::BezierMaterial,
+};
 use avian2d::{
     PhysicsPlugins,
     math::Vector,
     prelude::{Collider, Gravity, RigidBody},
 };
-use bevy::{camera::ScalingMode, color::palettes::css::GREEN, prelude::*};
+use bevy::{
+    camera::ScalingMode,
+    color::palettes::css::{GREEN, RED, WHITE},
+    input_focus::InputFocus,
+    prelude::*,
+    sprite_render::Material2dPlugin,
+};
 
 pub mod avian;
+pub mod shaders;
+
+const NORMAL_BUTTON: Color = Color::srgb(0.15, 0.15, 0.15);
+const HOVERED_BUTTON: Color = Color::srgb(0.25, 0.25, 0.25);
+const PRESSED_BUTTON: Color = Color::srgb(0.35, 0.75, 0.35);
 
 fn main() {
     App::new()
@@ -15,14 +29,63 @@ fn main() {
             // Add physics plugins and specify a units-per-meter scaling factor, 1 meter = 20 pixels.
             // The unit allows the engine to tune its parameters for the scale of the world, improving stability.
             PhysicsPlugins::default().with_length_unit(20.0),
+            Material2dPlugin::<BezierMaterial>::default(),
             CharacterControllerPlugin,
         ))
-        .add_systems(Startup, setup)
-        .add_systems(Update, debug_border)
+        .init_resource::<InputFocus>()
+        .add_systems(Startup, (setup, setup_ui))
+        .add_systems(Update, (debug_border, do_menu, move_bezier))
         .insert_resource(Gravity(Vector::ZERO))
         .run();
 }
 
+fn do_menu(
+    mut input_focus: ResMut<InputFocus>,
+    mut interaction_query: Query<
+        (
+            Entity,
+            &Interaction,
+            &mut BackgroundColor,
+            &mut BorderColor,
+            &mut Button,
+            &Children,
+        ),
+        Changed<Interaction>,
+    >,
+    mut text_query: Query<&mut Text>,
+) {
+    for (entity, interaction, mut color, mut border_color, mut button, children) in
+        &mut interaction_query
+    {
+        let mut text = text_query.get_mut(children[0]).unwrap();
+
+        match *interaction {
+            Interaction::Pressed => {
+                input_focus.set(entity);
+                **text = "Press".to_string();
+                *color = PRESSED_BUTTON.into();
+                *border_color = BorderColor::all(RED);
+
+                // The accessibility system's only update the button's state when the `Button` component is marked as changed.
+                button.set_changed();
+            }
+            Interaction::Hovered => {
+                input_focus.set(entity);
+                **text = "Hover".to_string();
+                *color = HOVERED_BUTTON.into();
+                *border_color = BorderColor::all(Color::WHITE);
+                button.set_changed();
+            }
+            Interaction::None => {
+                input_focus.clear();
+                **text = "Button".to_string();
+                *color = NORMAL_BUTTON.into();
+                *border_color = BorderColor::all(Color::BLACK);
+            }
+        }
+    }
+}
+
 fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
     let mut projection = OrthographicProjection::default_2d();
     projection.scaling_mode = ScalingMode::AutoMin {
@@ -51,6 +114,89 @@ fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
     ));
 }
 
+fn setup_ui(
+    mut commands: Commands,
+    asset_server: Res<AssetServer>,
+    mut meshes: ResMut<Assets<Mesh>>,
+    mut materials: ResMut<Assets<BezierMaterial>>,
+) {
+    commands.spawn((
+        Node {
+            width: percent(100),
+            height: percent(100),
+            align_items: AlignItems::Center,
+            justify_content: JustifyContent::Center,
+            ..default()
+        },
+        children![(
+            Button,
+            Node {
+                width: px(150),
+                height: px(65),
+                border: UiRect::all(px(5)),
+                // horizontally center child text
+                justify_content: JustifyContent::Center,
+                // vertically center child text
+                align_items: AlignItems::Center,
+                border_radius: BorderRadius::MAX,
+                ..default()
+            },
+            BorderColor::all(Color::WHITE),
+            BackgroundColor(Color::BLACK),
+            children![(
+                Text::new("Button"),
+                TextFont {
+                    font: asset_server.load("FiraSans-Bold.ttf"),
+                    font_size: 33.0,
+                    ..default()
+                },
+                TextColor(Color::srgb(0.9, 0.9, 0.9)),
+                TextShadow::default(),
+            )]
+        )],
+    ));
+
+    // Curve points (world-space)
+    let p0 = Vec2::new(-200.0, -100.0);
+    let p1 = Vec2::new(200.0, 100.0);
+    let c0 = p0 + Vec2::new(150.0, 0.0);
+    let c1 = p1 + Vec2::new(-150.0, 0.0);
+
+    // Bounding quad (must contain entire curve + width)
+    let center = (p0 + p1) * 0.5;
+    let size = Vec2::new(500.0, 300.0);
+
+    commands.spawn((
+        Mesh2d(meshes.add(Rectangle::new(size.x, size.y))),
+        MeshMaterial2d(materials.add(BezierMaterial {
+            p0,
+            c0,
+            c1,
+            p1,
+            width: 12.0,
+            color: WHITE.into(),
+        })),
+        Transform::from_translation(center.extend(0.0)),
+    ));
+}
+
+fn move_bezier(mut materials: ResMut<Assets<BezierMaterial>>, windows: Query<&Window>) {
+    let Ok(window) = windows.single() else {
+        return;
+    };
+    let Some(mouse_pos) = window.cursor_position() else {
+        return;
+    };
+
+    for (_, mat) in materials.iter_mut() {
+        mat.p0 = mouse_pos;
+    }
+
+    // pos: Vec2, in logical pixels
+    // (0, 0) is bottom-left of the window
+    println!("Mouse window position: {:?}", mouse_pos);
+}
+
 fn debug_border(mut gizmos: Gizmos) {
     gizmos.rect_2d(Isometry2d::IDENTITY, Vec2::new(1920., 1080.), GREEN);
 }

src/shaders/mod.rs

@@ -0,0 +1,33 @@
+use bevy::prelude::*;
+use bevy::render::render_resource::*;
+use bevy::shader::ShaderRef;
+use bevy::sprite_render::{AlphaMode2d, Material2d};
+
+// This is the struct that will be passed to your shader
+#[derive(Asset, TypePath, AsBindGroup, Debug, Clone)]
+pub struct BezierMaterial {
+    #[uniform(0)]
+    pub p0: Vec2,
+    #[uniform(0)]
+    pub c0: Vec2,
+    #[uniform(0)]
+    pub c1: Vec2,
+    #[uniform(0)]
+    pub p1: Vec2,
+    #[uniform(0)]
+    pub width: f32,
+    #[uniform(0)]
+    pub color: LinearRgba,
+}
+
+/// The Material2d trait is very configurable, but comes with sensible defaults for all methods.
+/// You only need to implement functions for features that need non-default behavior. See the Material2d api docs for details!
+impl Material2d for BezierMaterial {
+    fn fragment_shader() -> ShaderRef {
+        "shaders/bezier.wgsl".into()
+    }
+
+    fn alpha_mode(&self) -> AlphaMode2d {
+        AlphaMode2d::Blend
+    }
+}