//! Demonstrates UV mappings of the [`CircularSector`] and [`CircularSegment`] primitives. //! //! Also draws the bounding boxes and circles of the primitives. use std::f32::consts::FRAC_PI_2; use bevy::{ color::palettes::css::{BLUE, DARK_SLATE_GREY, RED}, math::{ bounding::{Bounded2d, BoundingVolume}, Isometry2d, }, prelude::*, render::mesh::{CircularMeshUvMode, CircularSectorMeshBuilder, CircularSegmentMeshBuilder}, }; fn main() { App::new() .add_plugins(DefaultPlugins) .add_systems(Startup, setup) .add_systems( Update, ( draw_bounds::<CircularSector>, draw_bounds::<CircularSegment>, ), ) .run(); } #[derive(Component, Debug)] struct DrawBounds<Shape: Bounded2d + Send + Sync + 'static>(Shape); fn setup( mut commands: Commands, asset_server: Res<AssetServer>, mut meshes: ResMut<Assets<Mesh>>, mut materials: ResMut<Assets<ColorMaterial>>, ) { let material = materials.add(asset_server.load("branding/icon.png")); commands.spawn(( Camera2d, Camera { clear_color: ClearColorConfig::Custom(DARK_SLATE_GREY.into()), ..default() }, )); const UPPER_Y: f32 = 50.0; const LOWER_Y: f32 = -50.0; const FIRST_X: f32 = -450.0; const OFFSET: f32 = 100.0; const NUM_SLICES: i32 = 8; // This draws NUM_SLICES copies of the Bevy logo as circular sectors and segments, // with successively larger angles up to a complete circle. for i in 0..NUM_SLICES { let fraction = (i + 1) as f32 / NUM_SLICES as f32; let sector = CircularSector::from_turns(40.0, fraction); // We want to rotate the circular sector so that the sectors appear clockwise from north. // We must rotate it both in the Transform and in the mesh's UV mappings. let sector_angle = -sector.half_angle(); let sector_mesh = CircularSectorMeshBuilder::new(sector).uv_mode(CircularMeshUvMode::Mask { angle: sector_angle, }); commands.spawn(( Mesh2d(meshes.add(sector_mesh)), MeshMaterial2d(material.clone()), Transform { translation: Vec3::new(FIRST_X + OFFSET * i as f32, 2.0 * UPPER_Y, 0.0), rotation: Quat::from_rotation_z(sector_angle), ..default() }, DrawBounds(sector), )); let segment = CircularSegment::from_turns(40.0, fraction); // For the circular segment, we will draw Bevy charging forward, which requires rotating the // shape and texture by 90 degrees. // // Note that this may be unintuitive; it may feel like we should rotate the texture by the // opposite angle to preserve the orientation of Bevy. But the angle is not the angle of the // texture itself, rather it is the angle at which the vertices are mapped onto the texture. // so it is the negative of what you might otherwise expect. let segment_angle = -FRAC_PI_2; let segment_mesh = CircularSegmentMeshBuilder::new(segment).uv_mode(CircularMeshUvMode::Mask { angle: -segment_angle, }); commands.spawn(( Mesh2d(meshes.add(segment_mesh)), MeshMaterial2d(material.clone()), Transform { translation: Vec3::new(FIRST_X + OFFSET * i as f32, LOWER_Y, 0.0), rotation: Quat::from_rotation_z(segment_angle), ..default() }, DrawBounds(segment), )); } } fn draw_bounds<Shape: Bounded2d + Send + Sync + 'static>( q: Query<(&DrawBounds<Shape>, &GlobalTransform)>, mut gizmos: Gizmos, ) { for (shape, transform) in &q { let (_, rotation, translation) = transform.to_scale_rotation_translation(); let translation = translation.truncate(); let rotation = rotation.to_euler(EulerRot::XYZ).2; let isometry = Isometry2d::new(translation, Rot2::radians(rotation)); let aabb = shape.0.aabb_2d(isometry); gizmos.rect_2d(aabb.center(), aabb.half_size() * 2.0, RED); let bounding_circle = shape.0.bounding_circle(isometry); gizmos.circle_2d(bounding_circle.center, bounding_circle.radius(), BLUE); } }