diff --git a/examples/select.rs b/examples/select.rs new file mode 100644 index 0000000..6e3a93d --- /dev/null +++ b/examples/select.rs @@ -0,0 +1,167 @@ +#![feature(iter_next_chunk)] + +/// Example to illustrate selecting objects in 3d space +/// +use bevy::{ + prelude::*, + render::mesh::MeshVertexAttribute, + render::render_resource::{Extent3d, TextureDimension, TextureFormat}, + render::{mesh::VertexAttributeValues, render_resource::VertexFormat}, + window::PrimaryWindow, +}; + +fn main() { + App::new() + .add_plugins(DefaultPlugins) + .add_systems(Startup, startup) + .add_systems(Update, select) + .run(); +} + +fn startup( + mut commands: Commands, + mut meshes: ResMut>, + mut materials: ResMut>, + mut images: ResMut>, +) { + let debug_material = materials.add(StandardMaterial { + base_color_texture: Some(images.add(uv_debug_texture())), + ..default() + }); + + commands.spawn(Camera3dBundle { + transform: Transform::from_xyz(5.0, 5.0, 5.0).looking_at(Vec3::ZERO, Vec3::Y), + ..default() + }); + + commands.spawn(PointLightBundle { + transform: Transform::from_xyz(0.0, 0.0, 5.0), + ..default() + }); + + commands.spawn(PbrBundle { + mesh: meshes.add(shape::Plane::default().into()), + material: debug_material.clone(), + transform: Transform::from_xyz(1.0, 1.0, 1.0), + ..default() + }); + + // commands.spawn(PbrBundle { + // mesh: meshes.add(shape::Cube::default().into()), + // material: debug_material.clone(), + // transform: Transform::from_xyz(0.0, 0.0, 0.0), + // ..default() + // }); + + // commands.spawn(PbrBundle { + // mesh: meshes.add(shape::Torus::default().into()), + // material: debug_material.clone(), + // transform: Transform::from_xyz(3.0, 0.0, 0.0), + // ..default() + // }); + + // commands.spawn(PbrBundle { + // mesh: meshes.add(shape::Icosphere::default().try_into().unwrap()), + // material: debug_material.clone(), + // transform: Transform::from_xyz(0.0, 3.0, 0.0), + // ..default() + // }); +} + +/// Creates a colorful test pattern +fn uv_debug_texture() -> Image { + const TEXTURE_SIZE: usize = 8; + + let mut palette: [u8; 32] = [ + 255, 102, 159, 255, 255, 159, 102, 255, 236, 255, 102, 255, 121, 255, 102, 255, 102, 255, + 198, 255, 102, 198, 255, 255, 121, 102, 255, 255, 236, 102, 255, 255, + ]; + + let mut texture_data = [0; TEXTURE_SIZE * TEXTURE_SIZE * 4]; + for y in 0..TEXTURE_SIZE { + let offset = TEXTURE_SIZE * y * 4; + texture_data[offset..(offset + TEXTURE_SIZE * 4)].copy_from_slice(&palette); + palette.rotate_right(4); + } + + Image::new_fill( + Extent3d { + width: TEXTURE_SIZE as u32, + height: TEXTURE_SIZE as u32, + depth_or_array_layers: 1, + }, + TextureDimension::D2, + &texture_data, + TextureFormat::Rgba8UnormSrgb, + ) +} + +fn select( + query: Query<(Entity, &Handle, &GlobalTransform)>, + meshes: Res>, + cameras: Query<(&Camera, &GlobalTransform)>, + windows: Query<&Window, With>, +) { + // TODO: + // When mouse moves + // Ray trace to find object being selected + windows.iter().for_each(|window| { + if let Some(pos) = window.cursor_position() { + cameras.iter().for_each(|(camera, gt)| { + if let Some(ray) = camera.viewport_to_world(gt, pos) { + query + .iter() + .filter_map(|(entity, handle, gt)| { + meshes.get(handle).map(|mesh| (entity, mesh, gt)) + }) + .for_each(|(entity, mesh, gt)| { + let hit = intersects(&ray, >, mesh); + if hit.is_some() { + info!("We got a hit at {:?}", entity); + } + }); + } + }); + } + }); + panic!("Lol"); +} + +fn intersects(ray: &Ray, gt: &GlobalTransform, mesh: &Mesh) -> Option { + info!("Ray: {:#?}", ray); + let attr = MeshVertexAttribute::new("Vertex_Position", 0, VertexFormat::Float32x3); + if let Some(verts) = mesh.attribute(attr) { + if let Some(idxs) = mesh.indices() { + match verts { + VertexAttributeValues::Float32x3(vals) => { + let mut itr = idxs.iter(); + while let Ok(points) = itr + .next_chunk::<3>() + .map(|[x, y, z]| { + [ + Vec3::from_array(vals[x]), + Vec3::from_array(vals[y]), + Vec3::from_array(vals[z]), + ] + }) + .map(|[a, b, c]| { + [ + gt.transform_point(a), + gt.transform_point(b), + gt.transform_point(c), + ] + }) + { + info!("Does ray intersect with points: {:?}", points); + // OK so I have a ray with an origin and direction + // And I have a triangle made of 3 points + // How do I test if ray intersects with tri??? + } + } + _ => warn!("Unrecognized indexes"), + } + } + } + + None +}