Triangulate face

This commit is contained in:
hodasemi 2023-05-13 16:08:26 +02:00
parent 49c3a1517d
commit 63464c9be4
2 changed files with 174 additions and 60 deletions

View file

@ -1,14 +1,12 @@
mod global_state;
mod polygon;
///! This example illustrates how to resize windows, and how to respond to a window being resized.
use bevy::{
input::{
mouse::{MouseButtonInput, MouseWheel},
ButtonState,
},
prelude::*,
sprite::MaterialMesh2dBundle,
window::WindowResized,
};
@ -22,35 +20,17 @@ fn main() {
.add_plugin(EguiPlugin)
.insert_resource(GlobalState::default())
.insert_resource(ObjectInfos::default())
.add_startup_systems((setup_camera, setup))
.add_systems((
print_mouse_events_system,
update_ui_side_panel,
on_resize_system,
))
.add_startup_system(setup_camera)
.add_systems((mouse_event_system, update_ui_side_panel, on_resize_system))
.run();
}
fn setup(
mut commands: Commands,
mut meshes: ResMut<Assets<Mesh>>,
mut materials: ResMut<Assets<ColorMaterial>>,
) {
commands.spawn(MaterialMesh2dBundle {
mesh: meshes.add(Mesh::from(shape::Quad::default())).into(),
transform: Transform::default()
.with_scale(Vec3::splat(4.))
.with_translation(Vec3::new(100.0, 10.0, 0.0)),
material: materials.add(ColorMaterial::from(Color::YELLOW)),
..default()
});
}
// Spawns the camera that draws UI
// Spawns the camera
fn setup_camera(mut cmd: Commands) {
cmd.spawn(Camera2dBundle::default());
}
// Create UI
fn update_ui_side_panel(mut contexts: EguiContexts, mut global_state: ResMut<GlobalState>) {
egui::Window::new("Hello").show(contexts.ctx_mut(), |ui| {
if global_state.polygon_started {
@ -63,8 +43,8 @@ fn update_ui_side_panel(mut contexts: EguiContexts, mut global_state: ResMut<Glo
});
}
/// This system prints out all mouse events as they come in
fn print_mouse_events_system(
/// Handles all mouse events
fn mouse_event_system(
mut mouse_button_input_events: EventReader<MouseButtonInput>,
mut cursor_moved_events: EventReader<CursorMoved>,
mut mouse_wheel_events: EventReader<MouseWheel>,
@ -78,33 +58,21 @@ fn print_mouse_events_system(
match event.button {
MouseButton::Left => match event.state {
ButtonState::Pressed => {
println!(
"Left mouse button pressed at {:?}",
global_state.cursor_position
);
// only add new points if "New Polygon" button got pressed
if global_state.polygon_started {
let polygon = match object_infos.active_polygon() {
Some(polygon) => polygon,
None => object_infos.add_polygon(),
};
let polygon = match object_infos.active_polygon() {
Some(polygon) => polygon,
None => object_infos.add_polygon(),
};
if polygon.add_point(global_state.cursor_position) {
global_state.polygon_started = false;
// TODO remove single points -> draw full polygon
} else {
commands.spawn(MaterialMesh2dBundle {
mesh: meshes.add(Mesh::from(shape::Quad::default())).into(),
transform: Transform::default()
.with_scale(Vec3::splat(4.0))
.with_translation(
(global_state.cursor_position
- (global_state.window_extent * 0.5))
.extend(0.0),
),
material: materials.add(ColorMaterial::from(Color::BLACK)),
..default()
});
if polygon.add_point(
&global_state,
&mut commands,
&mut meshes,
&mut materials,
) {
global_state.polygon_started = false;
}
}
}
ButtonState::Released => (),
@ -124,6 +92,7 @@ fn print_mouse_events_system(
}
}
// Handles resize events
fn on_resize_system(
mut resize_reader: EventReader<WindowResized>,
mut global_state: ResMut<GlobalState>,

View file

@ -1,28 +1,134 @@
use bevy::prelude::*;
use bevy::{
prelude::*,
render::{mesh::Indices, render_resource::PrimitiveTopology},
sprite::MaterialMesh2dBundle,
};
use crate::global_state::GlobalState;
#[derive(Default, Debug, PartialEq)]
struct CollectionIDs {
points: Vec<Entity>,
lines: Vec<Entity>,
}
#[derive(Debug, PartialEq)]
enum PolygonState {
Collection(CollectionIDs),
Finished(Entity),
}
impl PolygonState {
fn collection_mut(&mut self) -> &mut CollectionIDs {
match self {
PolygonState::Collection(c) => c,
PolygonState::Finished(_) => panic!("called collection on finished state!"),
}
}
}
impl Default for PolygonState {
fn default() -> Self {
Self::Collection(CollectionIDs::default())
}
}
#[derive(Default, Debug, PartialEq)]
pub struct Polygon {
points: Vec<Vec2>,
finished: bool,
state: PolygonState,
}
impl Polygon {
const PROXIMITY_THRESHOLD: f32 = 5.0;
const PROXIMITY_THRESHOLD: f32 = 10.0;
pub fn add_point(&mut self, point: Vec2) -> bool {
debug_assert_eq!(self.finished, false);
pub fn add_point(
&mut self,
global_state: &GlobalState,
commands: &mut Commands,
meshes: &mut ResMut<Assets<Mesh>>,
materials: &mut ResMut<Assets<ColorMaterial>>,
) -> bool {
debug_assert_eq!(self.finished(), false);
let point = global_state.cursor_position;
// polygon must be at least an triangle
// and check if we can close up the polygon
if self.points.len() >= 3 && self.check_first_for_proximity(point) {
self.points.push(point);
self.finished = true;
// remove points and lines from collection state
{
let collection_ids = self.state.collection_mut();
for point_id in collection_ids.points.iter() {
commands.entity(*point_id).despawn();
}
for line_id in collection_ids.lines.iter() {
commands.entity(*line_id).despawn();
}
}
// create triangle mesh
let triangle_mesh = self.create_triangulated_mesh();
let triangle_id = commands
.spawn(MaterialMesh2dBundle {
mesh: meshes.add(triangle_mesh).into(),
transform: Transform::default()
.with_translation((-global_state.window_extent * 0.5).extend(0.0)),
material: materials.add(ColorMaterial::from(Color::BLACK)),
..default()
})
.id();
// store triangle entity id in state
self.state = PolygonState::Finished(triangle_id);
return true;
}
// deny too close points
if !self.check_all_for_proximity(point) {
let collection_ids = self.state.collection_mut();
// create point mesh at click position
let point_id = commands
.spawn(MaterialMesh2dBundle {
mesh: meshes.add(Mesh::from(shape::Quad::default())).into(),
transform: Transform::default()
.with_scale(Vec3::splat(4.0))
.with_translation(
(global_state.cursor_position - (global_state.window_extent * 0.5))
.extend(0.0),
),
material: materials.add(ColorMaterial::from(Color::BLACK)),
..default()
})
.id();
collection_ids.points.push(point_id);
// draw a line between new point and last point
if let Some(&last_point) = self.points.last() {
let a = Vec2::X.angle_between((point - last_point).normalize());
let line_id = commands
.spawn(MaterialMesh2dBundle {
mesh: meshes.add(Self::create_line_mesh(last_point, point)).into(),
transform: Transform::default()
.with_translation(
(last_point - (global_state.window_extent * 0.5)).extend(0.0),
)
.with_rotation(Quat::from_rotation_z(a)),
material: materials.add(ColorMaterial::from(Color::BLACK)),
..default()
})
.id();
collection_ids.lines.push(line_id);
}
self.points.push(point);
}
@ -30,7 +136,10 @@ impl Polygon {
}
pub fn finished(&self) -> bool {
self.finished
match &self.state {
PolygonState::Collection(_) => false,
PolygonState::Finished(_) => true,
}
}
fn check_all_for_proximity(&self, point: Vec2) -> bool {
@ -44,6 +153,42 @@ impl Polygon {
self.points.first().unwrap().distance(point) < Self::PROXIMITY_THRESHOLD
}
fn create_triangulated_mesh(&self) -> Mesh {
let vertices: Vec<_> = self.points.iter().map(|p| p.extend(0.0)).collect();
let indices = Indices::U32({
let mut v = Vec::new();
for i in 2..self.points.len() as u32 {
v.push(0);
v.push(i - 1);
v.push(i);
}
v
});
let mut mesh = Mesh::new(PrimitiveTopology::TriangleList);
mesh.set_indices(Some(indices));
mesh.insert_attribute(Mesh::ATTRIBUTE_POSITION, vertices);
mesh
}
fn create_line_mesh(start: Vec2, end: Vec2) -> Mesh {
let d = start.distance(end);
let vertices = [[0.0, 0.0, 0.0], [d, 0.0, 0.0]];
let mut mesh = Mesh::new(PrimitiveTopology::LineList);
mesh.insert_attribute(
Mesh::ATTRIBUTE_POSITION,
vertices.into_iter().map(|v| v).collect::<Vec<_>>(),
);
mesh
}
}
#[derive(Resource, Default, Debug, PartialEq)]