bevy/crates/bevy_ui/src/layout/mod.rs
Aldrich Suratos 5c3c8e7189 Fix typo in resolve_outlines_system (#10730)
# Objective

Resolves  #10727.

`outline.width` was being assigned to `node.outline_offset` instead of
`outline.offset`.

## Solution

Changed `.width` to `.offset` in line 413.
2023-11-29 16:53:56 -08:00

826 lines
29 KiB
Rust

mod convert;
pub mod debug;
use crate::{ContentSize, Node, Outline, Style, UiScale};
use bevy_ecs::{
change_detection::{DetectChanges, DetectChangesMut},
entity::Entity,
event::EventReader,
query::{With, Without},
removal_detection::RemovedComponents,
system::{Query, Res, ResMut, Resource},
world::Ref,
};
use bevy_hierarchy::{Children, Parent};
use bevy_log::warn;
use bevy_math::Vec2;
use bevy_transform::components::Transform;
use bevy_utils::{default, HashMap};
use bevy_window::{PrimaryWindow, Window, WindowResolution, WindowScaleFactorChanged};
use std::fmt;
use taffy::Taffy;
use thiserror::Error;
pub struct LayoutContext {
pub scale_factor: f64,
pub physical_size: Vec2,
pub min_size: f32,
pub max_size: f32,
}
impl LayoutContext {
/// create new a [`LayoutContext`] from the window's physical size and scale factor
fn new(scale_factor: f64, physical_size: Vec2) -> Self {
Self {
scale_factor,
physical_size,
min_size: physical_size.x.min(physical_size.y),
max_size: physical_size.x.max(physical_size.y),
}
}
}
#[derive(Debug, Clone, PartialEq, Eq)]
struct RootNodePair {
// The implicit "viewport" node created by Bevy
implicit_viewport_node: taffy::node::Node,
// The root (parentless) node specified by the user
user_root_node: taffy::node::Node,
}
#[derive(Resource)]
pub struct UiSurface {
entity_to_taffy: HashMap<Entity, taffy::node::Node>,
window_roots: HashMap<Entity, Vec<RootNodePair>>,
taffy: Taffy,
}
fn _assert_send_sync_ui_surface_impl_safe() {
fn _assert_send_sync<T: Send + Sync>() {}
_assert_send_sync::<HashMap<Entity, taffy::node::Node>>();
_assert_send_sync::<Taffy>();
_assert_send_sync::<UiSurface>();
}
impl fmt::Debug for UiSurface {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
f.debug_struct("UiSurface")
.field("entity_to_taffy", &self.entity_to_taffy)
.field("window_nodes", &self.window_roots)
.finish()
}
}
impl Default for UiSurface {
fn default() -> Self {
let mut taffy = Taffy::new();
taffy.disable_rounding();
Self {
entity_to_taffy: Default::default(),
window_roots: Default::default(),
taffy,
}
}
}
impl UiSurface {
/// Retrieves the Taffy node associated with the given UI node entity and updates its style.
/// If no associated Taffy node exists a new Taffy node is inserted into the Taffy layout.
pub fn upsert_node(&mut self, entity: Entity, style: &Style, context: &LayoutContext) {
let mut added = false;
let taffy = &mut self.taffy;
let taffy_node = self.entity_to_taffy.entry(entity).or_insert_with(|| {
added = true;
taffy.new_leaf(convert::from_style(context, style)).unwrap()
});
if !added {
self.taffy
.set_style(*taffy_node, convert::from_style(context, style))
.unwrap();
}
}
/// Update the `MeasureFunc` of the taffy node corresponding to the given [`Entity`].
pub fn update_measure(&mut self, entity: Entity, measure_func: taffy::node::MeasureFunc) {
let taffy_node = self.entity_to_taffy.get(&entity).unwrap();
self.taffy.set_measure(*taffy_node, Some(measure_func)).ok();
}
/// Update the children of the taffy node corresponding to the given [`Entity`].
pub fn update_children(&mut self, entity: Entity, children: &Children) {
let mut taffy_children = Vec::with_capacity(children.len());
for child in children {
if let Some(taffy_node) = self.entity_to_taffy.get(child) {
taffy_children.push(*taffy_node);
} else {
warn!(
"Unstyled child in a UI entity hierarchy. You are using an entity \
without UI components as a child of an entity with UI components, results may be unexpected."
);
}
}
let taffy_node = self.entity_to_taffy.get(&entity).unwrap();
self.taffy
.set_children(*taffy_node, &taffy_children)
.unwrap();
}
/// Removes children from the entity's taffy node if it exists. Does nothing otherwise.
pub fn try_remove_children(&mut self, entity: Entity) {
if let Some(taffy_node) = self.entity_to_taffy.get(&entity) {
self.taffy.set_children(*taffy_node, &[]).unwrap();
}
}
/// Removes the measure from the entity's taffy node if it exists. Does nothing otherwise.
pub fn try_remove_measure(&mut self, entity: Entity) {
if let Some(taffy_node) = self.entity_to_taffy.get(&entity) {
self.taffy.set_measure(*taffy_node, None).unwrap();
}
}
/// Set the ui node entities without a [`Parent`] as children to the root node in the taffy layout.
pub fn set_window_children(
&mut self,
window_id: Entity,
children: impl Iterator<Item = Entity>,
) {
let viewport_style = taffy::style::Style {
display: taffy::style::Display::Grid,
// Note: Taffy percentages are floats ranging from 0.0 to 1.0.
// So this is setting width:100% and height:100%
size: taffy::geometry::Size {
width: taffy::style::Dimension::Percent(1.0),
height: taffy::style::Dimension::Percent(1.0),
},
align_items: Some(taffy::style::AlignItems::Start),
justify_items: Some(taffy::style::JustifyItems::Start),
..default()
};
let existing_roots = self.window_roots.entry(window_id).or_default();
let mut new_roots = Vec::new();
for entity in children {
let node = *self.entity_to_taffy.get(&entity).unwrap();
let root_node = existing_roots
.iter()
.find(|n| n.user_root_node == node)
.cloned()
.unwrap_or_else(|| RootNodePair {
implicit_viewport_node: self
.taffy
.new_with_children(viewport_style.clone(), &[node])
.unwrap(),
user_root_node: node,
});
new_roots.push(root_node);
}
// Cleanup the implicit root nodes of any user root nodes that have been removed
for old_root in existing_roots {
if !new_roots.contains(old_root) {
self.taffy.remove(old_root.implicit_viewport_node).unwrap();
}
}
self.window_roots.insert(window_id, new_roots);
}
/// Compute the layout for each window entity's corresponding root node in the layout.
pub fn compute_window_layout(&mut self, window: Entity, window_resolution: &WindowResolution) {
let available_space = taffy::geometry::Size {
width: taffy::style::AvailableSpace::Definite(window_resolution.physical_width() as f32),
height: taffy::style::AvailableSpace::Definite(
window_resolution.physical_height() as f32
),
};
for root_nodes in self.window_roots.entry(window).or_default() {
self.taffy
.compute_layout(root_nodes.implicit_viewport_node, available_space)
.unwrap();
}
}
/// Removes each entity from the internal map and then removes their associated node from taffy
pub fn remove_entities(&mut self, entities: impl IntoIterator<Item = Entity>) {
for entity in entities {
if let Some(node) = self.entity_to_taffy.remove(&entity) {
self.taffy.remove(node).unwrap();
}
}
}
/// Get the layout geometry for the taffy node corresponding to the ui node [`Entity`].
/// Does not compute the layout geometry, `compute_window_layouts` should be run before using this function.
pub fn get_layout(&self, entity: Entity) -> Result<&taffy::layout::Layout, LayoutError> {
if let Some(taffy_node) = self.entity_to_taffy.get(&entity) {
self.taffy
.layout(*taffy_node)
.map_err(LayoutError::TaffyError)
} else {
warn!(
"Styled child in a non-UI entity hierarchy. You are using an entity \
with UI components as a child of an entity without UI components, results may be unexpected."
);
Err(LayoutError::InvalidHierarchy)
}
}
}
#[derive(Debug, Error)]
pub enum LayoutError {
#[error("Invalid hierarchy")]
InvalidHierarchy,
#[error("Taffy error: {0}")]
TaffyError(#[from] taffy::error::TaffyError),
}
/// Updates the UI's layout tree, computes the new layout geometry and then updates the sizes and transforms of all the UI nodes.
#[allow(clippy::too_many_arguments)]
pub fn ui_layout_system(
primary_window: Query<(Entity, &Window), With<PrimaryWindow>>,
windows: Query<(Entity, &Window)>,
ui_scale: Res<UiScale>,
mut scale_factor_events: EventReader<WindowScaleFactorChanged>,
mut resize_events: EventReader<bevy_window::WindowResized>,
mut ui_surface: ResMut<UiSurface>,
root_node_query: Query<Entity, (With<Node>, Without<Parent>)>,
style_query: Query<(Entity, Ref<Style>), With<Node>>,
mut measure_query: Query<(Entity, &mut ContentSize)>,
children_query: Query<(Entity, Ref<Children>), With<Node>>,
just_children_query: Query<&Children>,
mut removed_children: RemovedComponents<Children>,
mut removed_content_sizes: RemovedComponents<ContentSize>,
mut node_transform_query: Query<(&mut Node, &mut Transform)>,
mut removed_nodes: RemovedComponents<Node>,
) {
// assume one window for time being...
// TODO: Support window-independent scaling: https://github.com/bevyengine/bevy/issues/5621
let (primary_window_entity, logical_to_physical_factor, physical_size) =
if let Ok((entity, primary_window)) = primary_window.get_single() {
(
entity,
primary_window.resolution.scale_factor(),
Vec2::new(
primary_window.resolution.physical_width() as f32,
primary_window.resolution.physical_height() as f32,
),
)
} else {
return;
};
let resized = resize_events
.read()
.any(|resized_window| resized_window.window == primary_window_entity);
let scale_factor = logical_to_physical_factor * ui_scale.0;
let layout_context = LayoutContext::new(scale_factor, physical_size);
if !scale_factor_events.is_empty() || ui_scale.is_changed() || resized {
scale_factor_events.clear();
// update all nodes
for (entity, style) in style_query.iter() {
ui_surface.upsert_node(entity, &style, &layout_context);
}
} else {
for (entity, style) in style_query.iter() {
if style.is_changed() {
ui_surface.upsert_node(entity, &style, &layout_context);
}
}
}
// When a `ContentSize` component is removed from an entity, we need to remove the measure from the corresponding taffy node.
for entity in removed_content_sizes.read() {
ui_surface.try_remove_measure(entity);
}
for (entity, mut content_size) in &mut measure_query {
if let Some(measure_func) = content_size.measure_func.take() {
ui_surface.update_measure(entity, measure_func);
}
}
// clean up removed nodes
ui_surface.remove_entities(removed_nodes.read());
// update window children (for now assuming all Nodes live in the primary window)
ui_surface.set_window_children(primary_window_entity, root_node_query.iter());
// update and remove children
for entity in removed_children.read() {
ui_surface.try_remove_children(entity);
}
for (entity, children) in &children_query {
if children.is_changed() {
ui_surface.update_children(entity, &children);
}
}
// compute layouts
for (entity, window) in windows.iter() {
ui_surface.compute_window_layout(entity, &window.resolution);
}
let inverse_target_scale_factor = 1. / scale_factor;
fn update_uinode_geometry_recursive(
entity: Entity,
ui_surface: &UiSurface,
node_transform_query: &mut Query<(&mut Node, &mut Transform)>,
children_query: &Query<&Children>,
inverse_target_scale_factor: f32,
parent_size: Vec2,
mut absolute_location: Vec2,
) {
if let Ok((mut node, mut transform)) = node_transform_query.get_mut(entity) {
let layout = ui_surface.get_layout(entity).unwrap();
let layout_size =
inverse_target_scale_factor * Vec2::new(layout.size.width, layout.size.height);
let layout_location =
inverse_target_scale_factor * Vec2::new(layout.location.x, layout.location.y);
absolute_location += layout_location;
let rounded_size = round_layout_coords(absolute_location + layout_size)
- round_layout_coords(absolute_location);
let rounded_location =
round_layout_coords(layout_location) + 0.5 * (rounded_size - parent_size);
// only trigger change detection when the new values are different
if node.calculated_size != rounded_size || node.unrounded_size != layout_size {
node.calculated_size = rounded_size;
node.unrounded_size = layout_size;
}
if transform.translation.truncate() != rounded_location {
transform.translation = rounded_location.extend(0.);
}
if let Ok(children) = children_query.get(entity) {
for &child_uinode in children {
update_uinode_geometry_recursive(
child_uinode,
ui_surface,
node_transform_query,
children_query,
inverse_target_scale_factor,
rounded_size,
absolute_location,
);
}
}
}
}
for entity in root_node_query.iter() {
update_uinode_geometry_recursive(
entity,
&ui_surface,
&mut node_transform_query,
&just_children_query,
inverse_target_scale_factor as f32,
Vec2::ZERO,
Vec2::ZERO,
);
}
}
/// Resolve and update the widths of Node outlines
pub fn resolve_outlines_system(
primary_window: Query<&Window, With<PrimaryWindow>>,
ui_scale: Res<UiScale>,
mut outlines_query: Query<(&Outline, &mut Node)>,
) {
let viewport_size = primary_window
.get_single()
.map(|window| Vec2::new(window.resolution.width(), window.resolution.height()))
.unwrap_or(Vec2::ZERO)
/ ui_scale.0 as f32;
for (outline, mut node) in outlines_query.iter_mut() {
let node = node.bypass_change_detection();
node.outline_width = outline
.width
.resolve(node.size().x, viewport_size)
.unwrap_or(0.)
.max(0.);
node.outline_offset = outline
.offset
.resolve(node.size().x, viewport_size)
.unwrap_or(0.)
.max(0.);
}
}
#[inline]
/// Round `value` to the nearest whole integer, with ties (values with a fractional part equal to 0.5) rounded towards positive infinity.
fn round_ties_up(value: f32) -> f32 {
if value.fract() != -0.5 {
// The `round` function rounds ties away from zero. For positive numbers "away from zero" is towards positive infinity.
// So for all positive values, and negative values with a fractional part not equal to 0.5, `round` returns the correct result.
value.round()
} else {
// In the remaining cases, where `value` is negative and its fractional part is equal to 0.5, we use `ceil` to round it up towards positive infinity.
value.ceil()
}
}
#[inline]
/// Rounds layout coordinates by rounding ties upwards.
///
/// Rounding ties up avoids gaining a pixel when rounding bounds that span from negative to positive.
///
/// Example: The width between bounds of -50.5 and 49.5 before rounding is 100, using:
/// - `f32::round`: width becomes 101 (rounds to -51 and 50).
/// - `round_ties_up`: width is 100 (rounds to -50 and 50).
fn round_layout_coords(value: Vec2) -> Vec2 {
Vec2 {
x: round_ties_up(value.x),
y: round_ties_up(value.y),
}
}
#[cfg(test)]
mod tests {
use crate::layout::round_layout_coords;
use crate::prelude::*;
use crate::ui_layout_system;
use crate::ContentSize;
use crate::UiSurface;
use bevy_ecs::entity::Entity;
use bevy_ecs::event::Events;
use bevy_ecs::schedule::Schedule;
use bevy_ecs::world::World;
use bevy_hierarchy::despawn_with_children_recursive;
use bevy_hierarchy::BuildWorldChildren;
use bevy_hierarchy::Children;
use bevy_math::vec2;
use bevy_math::Vec2;
use bevy_utils::prelude::default;
use bevy_utils::HashMap;
use bevy_window::PrimaryWindow;
use bevy_window::Window;
use bevy_window::WindowResized;
use bevy_window::WindowResolution;
use bevy_window::WindowScaleFactorChanged;
use taffy::tree::LayoutTree;
#[test]
fn round_layout_coords_must_round_ties_up() {
assert_eq!(round_layout_coords(vec2(-50.5, 49.5)), vec2(-50., 50.));
}
// these window dimensions are easy to convert to and from percentage values
const WINDOW_WIDTH: f32 = 1000.;
const WINDOW_HEIGHT: f32 = 100.;
fn setup_ui_test_world() -> (World, Schedule) {
let mut world = World::new();
world.init_resource::<UiScale>();
world.init_resource::<UiSurface>();
world.init_resource::<Events<WindowScaleFactorChanged>>();
world.init_resource::<Events<WindowResized>>();
// spawn a dummy primary window
world.spawn((
Window {
resolution: WindowResolution::new(WINDOW_WIDTH, WINDOW_HEIGHT),
..Default::default()
},
PrimaryWindow,
));
let mut ui_schedule = Schedule::default();
ui_schedule.add_systems(ui_layout_system);
(world, ui_schedule)
}
#[test]
fn ui_nodes_with_percent_100_dimensions_should_fill_their_parent() {
let (mut world, mut ui_schedule) = setup_ui_test_world();
// spawn a root entity with width and height set to fill 100% of its parent
let ui_root = world
.spawn(NodeBundle {
style: Style {
width: Val::Percent(100.),
height: Val::Percent(100.),
..default()
},
..default()
})
.id();
let ui_child = world
.spawn(NodeBundle {
style: Style {
width: Val::Percent(100.),
height: Val::Percent(100.),
..default()
},
..default()
})
.id();
world.entity_mut(ui_root).add_child(ui_child);
ui_schedule.run(&mut world);
let ui_surface = world.resource::<UiSurface>();
for ui_entity in [ui_root, ui_child] {
let layout = ui_surface.get_layout(ui_entity).unwrap();
assert_eq!(layout.size.width, WINDOW_WIDTH);
assert_eq!(layout.size.height, WINDOW_HEIGHT);
}
}
#[test]
fn ui_surface_tracks_ui_entities() {
let (mut world, mut ui_schedule) = setup_ui_test_world();
ui_schedule.run(&mut world);
// no UI entities in world, none in UiSurface
let ui_surface = world.resource::<UiSurface>();
assert!(ui_surface.entity_to_taffy.is_empty());
let ui_entity = world.spawn(NodeBundle::default()).id();
// `ui_layout_system` should map `ui_entity` to a ui node in `UiSurface::entity_to_taffy`
ui_schedule.run(&mut world);
let ui_surface = world.resource::<UiSurface>();
assert!(ui_surface.entity_to_taffy.contains_key(&ui_entity));
assert_eq!(ui_surface.entity_to_taffy.len(), 1);
world.despawn(ui_entity);
// `ui_layout_system` should remove `ui_entity` from `UiSurface::entity_to_taffy`
ui_schedule.run(&mut world);
let ui_surface = world.resource::<UiSurface>();
assert!(!ui_surface.entity_to_taffy.contains_key(&ui_entity));
assert!(ui_surface.entity_to_taffy.is_empty());
}
#[test]
#[should_panic]
fn despawning_a_ui_entity_should_remove_its_corresponding_ui_node() {
let (mut world, mut ui_schedule) = setup_ui_test_world();
let ui_entity = world.spawn(NodeBundle::default()).id();
// `ui_layout_system` will insert a ui node into the internal layout tree corresponding to `ui_entity`
ui_schedule.run(&mut world);
// retrieve the ui node corresponding to `ui_entity` from ui surface
let ui_surface = world.resource::<UiSurface>();
let ui_node = ui_surface.entity_to_taffy[&ui_entity];
world.despawn(ui_entity);
// `ui_layout_system` will receive a `RemovedComponents<Node>` event for `ui_entity`
// and remove `ui_entity` from `ui_node` from the internal layout tree
ui_schedule.run(&mut world);
let ui_surface = world.resource::<UiSurface>();
// `ui_node` is removed, attempting to retrieve a style for `ui_node` panics
let _ = ui_surface.taffy.style(ui_node);
}
#[test]
fn changes_to_children_of_a_ui_entity_change_its_corresponding_ui_nodes_children() {
let (mut world, mut ui_schedule) = setup_ui_test_world();
let ui_parent_entity = world.spawn(NodeBundle::default()).id();
// `ui_layout_system` will insert a ui node into the internal layout tree corresponding to `ui_entity`
ui_schedule.run(&mut world);
let ui_surface = world.resource::<UiSurface>();
let ui_parent_node = ui_surface.entity_to_taffy[&ui_parent_entity];
// `ui_parent_node` shouldn't have any children yet
assert_eq!(ui_surface.taffy.child_count(ui_parent_node).unwrap(), 0);
let mut ui_child_entities = (0..10)
.map(|_| {
let child = world.spawn(NodeBundle::default()).id();
world.entity_mut(ui_parent_entity).add_child(child);
child
})
.collect::<Vec<_>>();
ui_schedule.run(&mut world);
// `ui_parent_node` should have children now
let ui_surface = world.resource::<UiSurface>();
assert_eq!(
ui_surface.entity_to_taffy.len(),
1 + ui_child_entities.len()
);
assert_eq!(
ui_surface.taffy.child_count(ui_parent_node).unwrap(),
ui_child_entities.len()
);
let child_node_map = HashMap::from_iter(
ui_child_entities
.iter()
.map(|child_entity| (*child_entity, ui_surface.entity_to_taffy[child_entity])),
);
// the children should have a corresponding ui node and that ui node's parent should be `ui_parent_node`
for node in child_node_map.values() {
assert_eq!(ui_surface.taffy.parent(*node), Some(ui_parent_node));
}
// delete every second child
let mut deleted_children = vec![];
for i in (0..ui_child_entities.len()).rev().step_by(2) {
let child = ui_child_entities.remove(i);
world.despawn(child);
deleted_children.push(child);
}
ui_schedule.run(&mut world);
let ui_surface = world.resource::<UiSurface>();
assert_eq!(
ui_surface.entity_to_taffy.len(),
1 + ui_child_entities.len()
);
assert_eq!(
ui_surface.taffy.child_count(ui_parent_node).unwrap(),
ui_child_entities.len()
);
// the remaining children should still have nodes in the layout tree
for child_entity in &ui_child_entities {
let child_node = child_node_map[child_entity];
assert_eq!(ui_surface.entity_to_taffy[child_entity], child_node);
assert_eq!(ui_surface.taffy.parent(child_node), Some(ui_parent_node));
assert!(ui_surface
.taffy
.children(ui_parent_node)
.unwrap()
.contains(&child_node));
}
// the nodes of the deleted children should have been removed from the layout tree
for deleted_child_entity in &deleted_children {
assert!(!ui_surface
.entity_to_taffy
.contains_key(deleted_child_entity));
let deleted_child_node = child_node_map[deleted_child_entity];
assert!(!ui_surface
.taffy
.children(ui_parent_node)
.unwrap()
.contains(&deleted_child_node));
}
// despawn the parent entity and its descendants
despawn_with_children_recursive(&mut world, ui_parent_entity);
ui_schedule.run(&mut world);
// all nodes should have been deleted
let ui_surface = world.resource::<UiSurface>();
assert!(ui_surface.entity_to_taffy.is_empty());
}
#[test]
fn ui_node_should_be_set_to_its_content_size() {
let (mut world, mut ui_schedule) = setup_ui_test_world();
let content_size = Vec2::new(50., 25.);
let ui_entity = world
.spawn((
NodeBundle {
style: Style {
align_self: AlignSelf::Start,
..Default::default()
},
..Default::default()
},
ContentSize::fixed_size(content_size),
))
.id();
ui_schedule.run(&mut world);
let ui_surface = world.resource::<UiSurface>();
let layout = ui_surface.get_layout(ui_entity).unwrap();
// the node should takes its size from the fixed size measure func
assert_eq!(layout.size.width, content_size.x);
assert_eq!(layout.size.height, content_size.y);
}
#[test]
fn measure_funcs_should_be_removed_on_content_size_removal() {
let (mut world, mut ui_schedule) = setup_ui_test_world();
let content_size = Vec2::new(50., 25.);
let ui_entity = world
.spawn((
NodeBundle {
style: Style {
align_self: AlignSelf::Start,
..Default::default()
},
..Default::default()
},
ContentSize::fixed_size(content_size),
))
.id();
ui_schedule.run(&mut world);
let ui_surface = world.resource::<UiSurface>();
let ui_node = ui_surface.entity_to_taffy[&ui_entity];
// a node with a content size needs to be measured
assert!(ui_surface.taffy.needs_measure(ui_node));
let layout = ui_surface.get_layout(ui_entity).unwrap();
assert_eq!(layout.size.width, content_size.x);
assert_eq!(layout.size.height, content_size.y);
world.entity_mut(ui_entity).remove::<ContentSize>();
ui_schedule.run(&mut world);
let ui_surface = world.resource::<UiSurface>();
// a node without a content size does not need to be measured
assert!(!ui_surface.taffy.needs_measure(ui_node));
// Without a content size, the node has no width or height constraints so the length of both dimensions is 0.
let layout = ui_surface.get_layout(ui_entity).unwrap();
assert_eq!(layout.size.width, 0.);
assert_eq!(layout.size.height, 0.);
}
#[test]
fn ui_rounding_test() {
let (mut world, mut ui_schedule) = setup_ui_test_world();
let parent = world
.spawn(NodeBundle {
style: Style {
display: Display::Grid,
grid_template_columns: RepeatedGridTrack::min_content(2),
margin: UiRect::all(Val::Px(4.0)),
..Default::default()
},
..Default::default()
})
.with_children(|commands| {
for _ in 0..2 {
commands.spawn(NodeBundle {
style: Style {
display: Display::Grid,
width: Val::Px(160.),
height: Val::Px(160.),
..Default::default()
},
..Default::default()
});
}
})
.id();
let children = world
.entity(parent)
.get::<Children>()
.unwrap()
.iter()
.copied()
.collect::<Vec<Entity>>();
for r in [2, 3, 5, 7, 11, 13, 17, 19, 21, 23, 29, 31].map(|n| (n as f64).recip()) {
let mut s = r;
while s <= 5. {
world.resource_mut::<UiScale>().0 = s;
ui_schedule.run(&mut world);
let width_sum: f32 = children
.iter()
.map(|child| world.get::<Node>(*child).unwrap().calculated_size.x)
.sum();
let parent_width = world.get::<Node>(parent).unwrap().calculated_size.x;
assert!((width_sum - parent_width).abs() < 0.001);
assert!((width_sum - 320.).abs() <= 1.);
s += r;
}
}
}
}