Minimal responsive FontSize support

crates/bevy_dev_tools/src/diagnostics_overlay.rs

@@ -307,7 +307,7 @@ fn rebuild_diagnostics_list(
                 children![(
                     Text::new(diagnostic_overlay_item.path.to_string()),
                     TextFont {
-                        font_size: 10.,
+                        font_size: FontSize::Px(10.),
                         ..Default::default()
                     },
                     Pickable::IGNORE,
@@ -324,7 +324,7 @@ fn rebuild_diagnostics_list(
                 children![(
                     Text::new(diagnostic),
                     TextFont {
-                        font_size: 10.,
+                        font_size: FontSize::Px(10.),
                         ..Default::default()
                     },
                     Pickable::IGNORE,
@@ -370,7 +370,7 @@ fn build_overlay(
                 children![(
                     Text::new(diagnostics_overlay.title.as_ref()),
                     TextFont {
-                        font_size: 12.,
+                        font_size: FontSize::Px(12.),
                         ..Default::default()
                     },
                     Pickable::IGNORE

crates/bevy_dev_tools/src/fps_overlay.rs

@@ -16,11 +16,11 @@ use bevy_ecs::{
 use bevy_picking::Pickable;
 use bevy_reflect::Reflect;
 use bevy_render::storage::ShaderBuffer;
-use bevy_text::{TextColor, TextFont, TextSpan};
+use bevy_text::{RemSize, TextColor, TextFont, TextSpan};
 use bevy_time::common_conditions::on_timer;
 use bevy_ui::{
     widget::{Text, TextUiWriter},
-    FlexDirection, GlobalZIndex, Node, PositionType, Val,
+    ComputedUiRenderTargetInfo, FlexDirection, GlobalZIndex, Node, PositionType, Val,
 };
 #[cfg(not(all(target_arch = "wasm32", not(feature = "webgpu"))))]
 use bevy_ui_render::prelude::MaterialNode;
@@ -220,7 +220,8 @@ fn setup(
             }
             #[cfg(not(all(target_arch = "wasm32", not(feature = "webgpu"))))]
             {
-                let font_size = overlay_config.text_config.font_size;
+                // Todo: Needs a better design that works with responsive sizing.
+                let font_size = 20.;
                 p.spawn((
                     Node {
                         width: Val::Px(font_size * FRAME_TIME_GRAPH_WIDTH_SCALE),
@@ -281,18 +282,25 @@ fn customize_overlay(
 
 fn toggle_display(
     overlay_config: Res<FpsOverlayConfig>,
-    mut text_node: Single<&mut Node, (With<FpsText>, Without<FrameTimeGraph>)>,
+    mut text_node: Single<
+        (&mut Node, &ComputedUiRenderTargetInfo),
+        (With<FpsText>, Without<FrameTimeGraph>),
+    >,
     mut graph_node: Single<&mut Node, (With<FrameTimeGraph>, Without<FpsText>)>,
+    rem_size: Res<RemSize>,
 ) {
     if overlay_config.enabled {
-        text_node.display = bevy_ui::Display::DEFAULT;
+        text_node.0.display = bevy_ui::Display::DEFAULT;
     } else {
-        text_node.display = bevy_ui::Display::None;
+        text_node.0.display = bevy_ui::Display::None;
     }
 
     if overlay_config.frame_time_graph_config.enabled {
         // Scale the frame time graph based on the font size of the overlay
-        let font_size = overlay_config.text_config.font_size;
+        let font_size = overlay_config
+            .text_config
+            .font_size
+            .eval(text_node.1.logical_size(), rem_size.0);
         graph_node.width = Val::Px(font_size * FRAME_TIME_GRAPH_WIDTH_SCALE);
         graph_node.height = Val::Px(font_size * FRAME_TIME_GRAPH_HEIGHT_SCALE);
 

crates/bevy_feathers/src/controls/button.rs

@@ -14,6 +14,7 @@ use bevy_ecs::{
 use bevy_input_focus::tab_navigation::TabIndex;
 use bevy_picking::{hover::Hovered, PickingSystems};
 use bevy_reflect::{prelude::ReflectDefault, Reflect};
+use bevy_text::FontSize;
 use bevy_ui::{AlignItems, InteractionDisabled, JustifyContent, Node, Pressed, UiRect, Val};
 use bevy_ui_widgets::Button;
 
@@ -86,7 +87,7 @@ pub fn button<C: SpawnableList<ChildOf> + Send + Sync + 'static, B: Bundle>(
         ThemeFontColor(tokens::BUTTON_TEXT),
         InheritableFont {
             font: HandleOrPath::Path(fonts::REGULAR.to_owned()),
-            font_size: 14.0,
+            font_size: FontSize::Px(14.0),
         },
         overrides,
         Children::spawn(children),

crates/bevy_feathers/src/controls/checkbox.rs

@@ -17,6 +17,7 @@ use bevy_input_focus::tab_navigation::TabIndex;
 use bevy_math::Rot2;
 use bevy_picking::{hover::Hovered, PickingSystems};
 use bevy_reflect::{prelude::ReflectDefault, Reflect};
+use bevy_text::FontSize;
 use bevy_ui::{
     AlignItems, BorderRadius, Checked, Display, FlexDirection, InteractionDisabled, JustifyContent,
     Node, PositionType, UiRect, UiTransform, Val,
@@ -79,7 +80,7 @@ pub fn checkbox<C: SpawnableList<ChildOf> + Send + Sync + 'static, B: Bundle>(
         ThemeFontColor(tokens::CHECKBOX_TEXT),
         InheritableFont {
             font: HandleOrPath::Path(fonts::REGULAR.to_owned()),
-            font_size: 14.0,
+            font_size: FontSize::Px(14.0),
         },
         overrides,
         Children::spawn((

crates/bevy_feathers/src/controls/radio.rs

@@ -16,6 +16,7 @@ use bevy_ecs::{
 use bevy_input_focus::tab_navigation::TabIndex;
 use bevy_picking::{hover::Hovered, PickingSystems};
 use bevy_reflect::{prelude::ReflectDefault, Reflect};
+use bevy_text::FontSize;
 use bevy_ui::{
     AlignItems, BorderRadius, Checked, Display, FlexDirection, InteractionDisabled, JustifyContent,
     Node, UiRect, Val,
@@ -73,7 +74,7 @@ pub fn radio<C: SpawnableList<ChildOf> + Send + Sync + 'static, B: Bundle>(
         ThemeFontColor(tokens::RADIO_TEXT),
         InheritableFont {
             font: HandleOrPath::Path(fonts::REGULAR.to_owned()),
-            font_size: 14.0,
+            font_size: FontSize::Px(14.0),
         },
         overrides,
         Children::spawn((

crates/bevy_feathers/src/controls/slider.rs

@@ -17,6 +17,7 @@ use bevy_ecs::{
 use bevy_input_focus::tab_navigation::TabIndex;
 use bevy_picking::PickingSystems;
 use bevy_reflect::{prelude::ReflectDefault, Reflect};
+use bevy_text::FontSize;
 use bevy_ui::{
     widget::Text, AlignItems, BackgroundGradient, ColorStop, Display, FlexDirection, Gradient,
     InteractionDisabled, InterpolationColorSpace, JustifyContent, LinearGradient, Node,
@@ -121,7 +122,7 @@ pub fn slider<B: Bundle>(props: SliderProps, overrides: B) -> impl Bundle {
             ThemeFontColor(tokens::SLIDER_TEXT),
             InheritableFont {
                 font: HandleOrPath::Path(fonts::MONO.to_owned()),
-                font_size: 12.0,
+                font_size: FontSize::Px(12.0),
             },
             children![(Text::new("10.0"), ThemedText, SliderValueText,)],
         )],

crates/bevy_feathers/src/font_styles.rs

@@ -9,7 +9,7 @@ use bevy_ecs::{
     system::{Commands, Query, Res},
 };
 use bevy_reflect::{prelude::ReflectDefault, Reflect};
-use bevy_text::{Font, TextFont};
+use bevy_text::{Font, FontSize, TextFont};
 
 use crate::{handle_or_path::HandleOrPath, theme::ThemedText};
 
@@ -22,23 +22,23 @@ pub struct InheritableFont {
     /// The font handle or path.
     pub font: HandleOrPath<Font>,
     /// The desired font size.
-    pub font_size: f32,
+    pub font_size: FontSize,
 }
 
 impl InheritableFont {
     /// Create a new `InheritableFont` from a handle.
     pub fn from_handle(handle: Handle<Font>) -> Self {
         Self {
             font: HandleOrPath::Handle(handle),
-            font_size: 16.0,
+            font_size: FontSize::Px(16.0),
         }
     }
 
     /// Create a new `InheritableFont` from a path.
     pub fn from_path(path: &str) -> Self {
         Self {
             font: HandleOrPath::Path(path.to_string()),
-            font_size: 16.0,
+            font_size: FontSize::Px(16.0),
         }
     }
 }

crates/bevy_sprite/src/text2d.rs

@@ -8,6 +8,8 @@ use bevy_camera::Camera;
 use bevy_color::Color;
 use bevy_derive::{Deref, DerefMut};
 use bevy_ecs::entity::EntityHashSet;
+use bevy_ecs::query::With;
+use bevy_ecs::system::Single;
 use bevy_ecs::{
     change_detection::{DetectChanges, Ref},
     component::Component,
@@ -21,10 +23,11 @@ use bevy_math::{FloatOrd, Vec2, Vec3};
 use bevy_reflect::{prelude::ReflectDefault, Reflect};
 use bevy_text::{
     ComputedTextBlock, CosmicFontSystem, Font, FontAtlasSet, FontHinting, LineBreak, LineHeight,
-    SwashCache, TextBounds, TextColor, TextError, TextFont, TextLayout, TextLayoutInfo,
+    RemSize, SwashCache, TextBounds, TextColor, TextError, TextFont, TextLayout, TextLayoutInfo,
     TextPipeline, TextReader, TextRoot, TextSpanAccess, TextWriter,
 };
 use bevy_transform::components::Transform;
+use bevy_window::{PrimaryWindow, Window};
 use core::any::TypeId;
 
 /// The top-level 2D text component.
@@ -45,7 +48,7 @@ use core::any::TypeId;
 /// # use bevy_color::Color;
 /// # use bevy_color::palettes::basic::BLUE;
 /// # use bevy_ecs::world::World;
-/// # use bevy_text::{Font, Justify, TextLayout, TextFont, TextColor, TextSpan};
+/// # use bevy_text::{Font, FontSize, Justify, TextLayout, TextFont, TextColor, TextSpan};
 /// # use bevy_sprite::Text2d;
 /// #
 /// # let font_handle: Handle<Font> = Default::default();
@@ -59,7 +62,7 @@ use core::any::TypeId;
 ///     Text2d::new("hello world!"),
 ///     TextFont {
 ///         font: font_handle.clone().into(),
-///         font_size: 60.0,
+///         font_size: FontSize::Px(60.0),
 ///         ..Default::default()
 ///     },
 ///     TextColor(BLUE.into()),
@@ -77,6 +80,8 @@ use core::any::TypeId;
 ///     parent.spawn((TextSpan::new("!"), TextColor(BLUE.into())));
 /// });
 /// ```
+///
+/// Viewport-based `FontSize` variants for `Text2d` are resolved based on the primary window’s logical size.
 #[derive(Component, Clone, Debug, Default, Deref, DerefMut, Reflect)]
 #[reflect(Component, Default, Debug, Clone)]
 #[require(
@@ -161,6 +166,7 @@ impl Default for Text2dShadow {
 /// [`ResMut<Assets<Image>>`](Assets<Image>) -- This system only adds new [`Image`] assets.
 /// It does not modify or observe existing ones.
 pub fn update_text2d_layout(
+    mut last_logical_viewport_size: Local<Vec2>,
     mut target_scale_factors: Local<Vec<(f32, RenderLayers)>>,
     // Text2d entities from the previous frame which need to be reprocessed, usually because the font hadn't loaded yet.
     mut reprocess_queue: Local<EntityHashSet>,
@@ -182,7 +188,17 @@ pub fn update_text2d_layout(
     mut text_reader: Text2dReader,
     mut font_system: ResMut<CosmicFontSystem>,
     mut swash_cache: ResMut<SwashCache>,
+    rem_size: Res<RemSize>,
+    primary_window: Option<Single<&Window, With<PrimaryWindow>>>,
 ) {
+    let logical_viewport_size = primary_window
+        .map(|window| window.resolution.size())
+        .unwrap_or(Vec2::splat(1000.));
+
+    let viewport_size_changed = *last_logical_viewport_size == logical_viewport_size;
+
+    *last_logical_viewport_size = logical_viewport_size;
+
     target_scale_factors.clear();
     target_scale_factors.extend(
         camera_query
@@ -225,7 +241,7 @@ pub fn update_text2d_layout(
         let text_changed = scale_factor != text_layout_info.scale_factor
             || block.is_changed()
             || hinting.is_changed()
-            || computed.needs_rerender()
+            || computed.needs_rerender(viewport_size_changed, rem_size.is_changed())
             || (!reprocess_queue.is_empty() && reprocess_queue.remove(&entity));
 
         if !(text_changed || bounds.is_changed()) {
@@ -252,6 +268,8 @@ pub fn update_text2d_layout(
                 &mut computed,
                 &mut font_system,
                 *hinting,
+                logical_viewport_size,
+                rem_size.0,
             ) {
                 Err(TextError::NoSuchFont | TextError::DegenerateScaleFactor) => {
                     // There was an error processing the text layout.
@@ -375,6 +393,7 @@ mod tests {
             .init_resource::<CosmicFontSystem>()
             .init_resource::<SwashCache>()
             .init_resource::<TextIterScratch>()
+            .init_resource::<RemSize>()
             .add_systems(
                 Update,
                 (

crates/bevy_text/src/lib.rs

@@ -60,9 +60,9 @@ pub use text_access::*;
 pub mod prelude {
     #[doc(hidden)]
     pub use crate::{
-        Font, FontHinting, FontSmoothing, FontSource, FontStyle, FontWeight, FontWidth, Justify,
-        LineBreak, Strikethrough, StrikethroughColor, TextColor, TextError, TextFont, TextLayout,
-        TextSpan, Underline, UnderlineColor,
+        Font, FontHinting, FontSize, FontSmoothing, FontSource, FontStyle, FontWeight, FontWidth,
+        Justify, LineBreak, Strikethrough, StrikethroughColor, TextColor, TextError, TextFont,
+        TextLayout, TextSpan, Underline, UnderlineColor,
     };
 }
 
@@ -94,6 +94,7 @@ impl Plugin for TextPlugin {
             .init_resource::<CosmicFontSystem>()
             .init_resource::<SwashCache>()
             .init_resource::<TextIterScratch>()
+            .init_resource::<RemSize>()
             .add_systems(
                 PostUpdate,
                 load_font_assets_into_fontdb_system.after(AssetEventSystems),