[bevy_text] Add offset to TextSection

This makes it possible to shift text (such as for animations), while
still laying it out with ab_glyph.

Author: zmbush

crates/bevy_text/src/pipeline.rs

@@ -56,6 +56,12 @@ impl TextPipeline {
         y_axis_orientation: YAxisOrientation,
     ) -> Result<TextLayoutInfo, TextError> {
         let mut scaled_fonts = Vec::with_capacity(sections.len());
+        let glyph_offsets: Vec<_> = sections
+            .iter()
+            .flat_map(|section| {
+                std::iter::repeat(section.offset).take(section.value.chars().count())
+            })
+            .collect();
         let sections = sections
             .iter()
             .map(|section| {
@@ -77,9 +83,17 @@ impl TextPipeline {
             })
             .collect::<Result<Vec<_>, _>>()?;
 
-        let section_glyphs =
-            self.brush
-                .compute_glyphs(&sections, bounds, text_alignment, linebreak_behavior)?;
+        let section_glyphs: Vec<_> = self
+            .brush
+            .compute_glyphs(&sections, bounds, text_alignment, linebreak_behavior)?
+            .into_iter()
+            .zip(glyph_offsets)
+            .map(|(mut g, offset)| {
+                g.glyph.position.x += offset.x;
+                g.glyph.position.y += offset.y;
+                g
+            })
+            .collect();
 
         if section_glyphs.is_empty() {
             return Ok(TextLayoutInfo::default());

crates/bevy_text/src/text.rs

@@ -1,6 +1,7 @@
 use bevy_asset::Handle;
 use bevy_color::Color;
 use bevy_ecs::{prelude::Component, reflect::ReflectComponent};
+use bevy_math::Vec2;
 use bevy_reflect::prelude::*;
 use bevy_utils::default;
 use serde::{Deserialize, Serialize};
@@ -106,10 +107,21 @@ impl Text {
     }
 }
 
-#[derive(Debug, Default, Clone, Reflect)]
+#[derive(Debug, Clone, Reflect)]
 pub struct TextSection {
     pub value: String,
     pub style: TextStyle,
+    pub offset: Vec2,
+}
+
+impl Default for TextSection {
+    fn default() -> Self {
+        Self {
+            value: Default::default(),
+            style: Default::default(),
+            offset: Vec2::new(0., 0.),
+        }
+    }
 }
 
 impl TextSection {
@@ -118,14 +130,18 @@ impl TextSection {
         Self {
             value: value.into(),
             style,
+
+            ..Default::default()
         }
     }
 
     /// Create an empty [`TextSection`] from a style. Useful when the value will be set dynamically.
     pub const fn from_style(style: TextStyle) -> Self {
         Self {
-            value: String::new(),
             style,
+
+            value: String::new(),
+            offset: Vec2::new(0., 0.),
         }
     }
 }

examples/asset/multi_asset_sync.rs

@@ -189,6 +189,7 @@ fn setup_ui(mut commands: Commands) {
                                 color: Color::BLACK,
                                 ..Default::default()
                             },
+                            ..Default::default()
                         }],
                         justify: JustifyText::Right,
                         ..Default::default()

examples/input/text_input.rs

@@ -43,6 +43,7 @@ fn setup_scene(mut commands: Commands, asset_server: Res<AssetServer>) {
                     font: font.clone_weak(),
                     ..default()
                 },
+                ..default()
             },
             TextSection {
                 value: "false\n".to_string(),
@@ -51,13 +52,15 @@ fn setup_scene(mut commands: Commands, asset_server: Res<AssetServer>) {
                     font_size: 30.0,
                     ..default()
                 },
+                ..default()
             },
             TextSection {
                 value: "IME Active: ".to_string(),
                 style: TextStyle {
                     font: font.clone_weak(),
                     ..default()
                 },
+                ..default()
             },
             TextSection {
                 value: "false\n".to_string(),
@@ -66,6 +69,7 @@ fn setup_scene(mut commands: Commands, asset_server: Res<AssetServer>) {
                     font_size: 30.0,
                     ..default()
                 },
+                ..default()
             },
             TextSection {
                 value: "click to toggle IME, press return to start a new line\n\n".to_string(),
@@ -74,6 +78,7 @@ fn setup_scene(mut commands: Commands, asset_server: Res<AssetServer>) {
                     font_size: 18.0,
                     ..default()
                 },
+                ..default()
             },
             TextSection {
                 value: "".to_string(),
@@ -82,6 +87,7 @@ fn setup_scene(mut commands: Commands, asset_server: Res<AssetServer>) {
                     font_size: 25.0,
                     ..default()
                 },
+                ..default()
             },
         ])
         .with_style(Style {

examples/stress_tests/many_glyphs.rs

@@ -52,6 +52,7 @@ fn setup(mut commands: Commands) {
                 font_size: 4.,
                 ..default()
             },
+            ..default()
         }],
         justify: JustifyText::Left,
         linebreak_behavior: BreakLineOn::AnyCharacter,

examples/stress_tests/text_pipeline.rs

@@ -49,6 +49,7 @@ fn spawn(mut commands: Commands, asset_server: Res<AssetServer>) {
                         font_size: (4 + i % 10) as f32,
                         color: BLUE.into(),
                     },
+                    ..default()
                 },
                 TextSection {
                     value: "pipeline".repeat(i),
@@ -57,6 +58,7 @@ fn spawn(mut commands: Commands, asset_server: Res<AssetServer>) {
                         font_size: (4 + i % 11) as f32,
                         color: YELLOW.into(),
                     },
+                    ..default()
                 },
             ]
         })

examples/tools/gamepad_viewer.rs

@@ -321,14 +321,17 @@ fn setup_sticks(
                             TextSection {
                                 value: format!("{:.3}", 0.),
                                 style: style.clone(),
+                                ..default()
                             },
                             TextSection {
                                 value: ", ".to_string(),
                                 style: style.clone(),
+                                ..default()
                             },
                             TextSection {
                                 value: format!("{:.3}", 0.),
                                 style,
+                                ..default()
                             },
                         ]),
                         text_anchor: Anchor::BottomCenter,
@@ -424,10 +427,12 @@ fn setup_connected(mut commands: Commands) {
                 TextSection {
                     value: "Connected Gamepads:\n".to_string(),
                     style: text_style.clone(),
+                    ..default()
                 },
                 TextSection {
                     value: "None".to_string(),
                     style: text_style,
+                    ..default()
                 },
             ]),
             style: Style {

examples/ui/text_wrap_debug.rs

@@ -124,6 +124,7 @@ fn spawn(mut commands: Commands, asset_server: Res<AssetServer>) {
                     sections: vec![TextSection {
                         value: message.clone(),
                         style: text_style.clone(),
+                        ..Default::default()
                     }],
                     justify: JustifyText::Left,
                     linebreak_behavior,