Allow users of Text/TextBundle to choose from glyph_brush_layout's BuiltInLineBreaker options. (#7283)

# Objective
Currently, Text always uses the default linebreaking behaviour in glyph_brush_layout `BuiltInLineBreaker::Unicode` which breaks lines at word boundaries. However, glyph_brush_layout also supports breaking lines at any character by setting the linebreaker to `BuiltInLineBreaker::AnyChar`. Having text wrap character-by-character instead of at word boundaries is desirable in some cases - consider that consoles/terminals usually wrap this way.

As a side note, the default Unicode linebreaker does not seem to handle emergency cases, where there is no word boundary on a line to break at. In that case, the text runs out of bounds. Issue #1867 shows an example of this.

## Solution
Basically just copies how TextAlignment is exposed, but for a new enum TextLineBreakBehaviour.
This PR exposes glyph_brush_layout's two simple linebreaking options (Unicode, AnyChar) to users of Text via the enum TextLineBreakBehaviour (which just translates those 2 aforementioned options), plus a method 'with_linebreak_behaviour' on Text and TextBundle. 

## Changelog

Added `Text::with_linebreak_behaviour`
Added `TextBundle::with_linebreak_behaviour` 
`TextPipeline::queue_text` and `GlyphBrush::compute_glyphs` now need a TextLineBreakBehaviour argument, in order to pass through the new field.
Modified the `text2d` example to show both linebreaking behaviours. 


## Example
Here's what the modified example looks like
![image](https://user-images.githubusercontent.com/117271367/213589184-b1a54bf3-116c-4721-8cb6-1cb69edb3070.png)

crates/bevy_text/src/glyph_brush.rs

@@ -5,12 +5,13 @@ use bevy_render::texture::Image;
 use bevy_sprite::TextureAtlas;
 use bevy_utils::tracing::warn;
 use glyph_brush_layout::{
-    FontId, GlyphPositioner, Layout, SectionGeometry, SectionGlyph, SectionText, ToSectionText,
+    BuiltInLineBreaker, FontId, GlyphPositioner, Layout, SectionGeometry, SectionGlyph,
+    SectionText, ToSectionText,
 };
 
 use crate::{
-    error::TextError, Font, FontAtlasSet, FontAtlasWarning, GlyphAtlasInfo, TextAlignment,
-    TextSettings, YAxisOrientation,
+    error::TextError, BreakLineOn, Font, FontAtlasSet, FontAtlasWarning, GlyphAtlasInfo,
+    TextAlignment, TextSettings, YAxisOrientation,
 };
 
 pub struct GlyphBrush {
@@ -35,13 +36,18 @@ impl GlyphBrush {
         sections: &[S],
         bounds: Vec2,
         text_alignment: TextAlignment,
+        linebreak_behaviour: BreakLineOn,
     ) -> Result<Vec<SectionGlyph>, TextError> {
         let geom = SectionGeometry {
             bounds: (bounds.x, bounds.y),
             ..Default::default()
         };
+
+        let lbb: BuiltInLineBreaker = linebreak_behaviour.into();
+
         let section_glyphs = Layout::default()
             .h_align(text_alignment.into())
+            .line_breaker(lbb)
             .calculate_glyphs(&self.fonts, &geom, sections);
         Ok(section_glyphs)
     }

crates/bevy_text/src/pipeline.rs

@@ -10,8 +10,8 @@ use bevy_utils::HashMap;
 use glyph_brush_layout::{FontId, SectionText};
 
 use crate::{
-    error::TextError, glyph_brush::GlyphBrush, scale_value, Font, FontAtlasSet, FontAtlasWarning,
-    PositionedGlyph, TextAlignment, TextSection, TextSettings, YAxisOrientation,
+    error::TextError, glyph_brush::GlyphBrush, scale_value, BreakLineOn, Font, FontAtlasSet,
+    FontAtlasWarning, PositionedGlyph, TextAlignment, TextSection, TextSettings, YAxisOrientation,
 };
 
 #[derive(Default, Resource)]
@@ -45,6 +45,7 @@ impl TextPipeline {
         sections: &[TextSection],
         scale_factor: f64,
         text_alignment: TextAlignment,
+        linebreak_behaviour: BreakLineOn,
         bounds: Vec2,
         font_atlas_set_storage: &mut Assets<FontAtlasSet>,
         texture_atlases: &mut Assets<TextureAtlas>,
@@ -75,9 +76,9 @@ impl TextPipeline {
             })
             .collect::<Result<Vec<_>, _>>()?;
 
-        let section_glyphs = self
-            .brush
-            .compute_glyphs(&sections, bounds, text_alignment)?;
+        let section_glyphs =
+            self.brush
+                .compute_glyphs(&sections, bounds, text_alignment, linebreak_behaviour)?;
 
         if section_glyphs.is_empty() {
             return Ok(TextLayoutInfo::default());

crates/bevy_text/src/text.rs

@@ -14,6 +14,8 @@ pub struct Text {
     /// The text's internal alignment.
     /// Should not affect its position within a container.
     pub alignment: TextAlignment,
+    /// How the text should linebreak when running out of the bounds determined by max_size
+    pub linebreak_behaviour: BreakLineOn,
 }
 
 impl Default for Text {
@@ -21,6 +23,7 @@ impl Default for Text {
         Self {
             sections: Default::default(),
             alignment: TextAlignment::Left,
+            linebreak_behaviour: BreakLineOn::WordBoundary,
         }
     }
 }
@@ -170,3 +173,26 @@ impl Default for TextStyle {
         }
     }
 }
+
+/// Determines how lines will be broken when preventing text from running out of bounds.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Reflect, Serialize, Deserialize)]
+#[reflect(Serialize, Deserialize)]
+pub enum BreakLineOn {
+    /// Uses the [Unicode Line Breaking Algorithm](https://www.unicode.org/reports/tr14/).
+    /// Lines will be broken up at the nearest suitable word boundary, usually a space.
+    /// This behaviour suits most cases, as it keeps words intact across linebreaks.
+    WordBoundary,
+    /// Lines will be broken without discrimination on any character that would leave bounds.
+    /// This is closer to the behaviour one might expect from text in a terminal.
+    /// However it may lead to words being broken up across linebreaks.
+    AnyCharacter,
+}
+
+impl From<BreakLineOn> for glyph_brush_layout::BuiltInLineBreaker {
+    fn from(val: BreakLineOn) -> Self {
+        match val {
+            BreakLineOn::WordBoundary => glyph_brush_layout::BuiltInLineBreaker::UnicodeLineBreaker,
+            BreakLineOn::AnyCharacter => glyph_brush_layout::BuiltInLineBreaker::AnyCharLineBreaker,
+        }
+    }
+}

crates/bevy_text/src/text2d.rs

@@ -186,6 +186,7 @@ pub fn update_text2d_layout(
                 &text.sections,
                 scale_factor,
                 text.alignment,
+                text.linebreak_behaviour,
                 text_bounds,
                 &mut font_atlas_set_storage,
                 &mut texture_atlases,

crates/bevy_ui/src/widget/text.rs

@@ -120,6 +120,7 @@ pub fn text_system(
                 &text.sections,
                 scale_factor,
                 text.alignment,
+                text.linebreak_behaviour,
                 node_size,
                 &mut font_atlas_set_storage,
                 &mut texture_atlases,

examples/2d/text2d.rs

@@ -5,7 +5,10 @@
 //! For an example on how to render text as part of a user interface, independent from the world
 //! viewport, you may want to look at `2d/contributors.rs` or `ui/text.rs`.
 
-use bevy::{prelude::*, text::Text2dBounds};
+use bevy::{
+    prelude::*,
+    text::{BreakLineOn, Text2dBounds},
+};
 
 fn main() {
     App::new()
@@ -29,7 +32,7 @@ struct AnimateScale;
 fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
     let font = asset_server.load("fonts/FiraSans-Bold.ttf");
     let text_style = TextStyle {
-        font,
+        font: font.clone(),
         font_size: 60.0,
         color: Color::WHITE,
     };
@@ -56,12 +59,17 @@ fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
     // Demonstrate changing scale
     commands.spawn((
         Text2dBundle {
-            text: Text::from_section("scale", text_style.clone()).with_alignment(text_alignment),
+            text: Text::from_section("scale", text_style).with_alignment(text_alignment),
             ..default()
         },
         AnimateScale,
     ));
     // Demonstrate text wrapping
+    let slightly_smaller_text_style = TextStyle {
+        font,
+        font_size: 42.0,
+        color: Color::WHITE,
+    };
     let box_size = Vec2::new(300.0, 200.0);
     let box_position = Vec2::new(0.0, -250.0);
     commands
@@ -76,8 +84,14 @@ fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
         })
         .with_children(|builder| {
             builder.spawn(Text2dBundle {
-                text: Text::from_section("this text wraps in the box", text_style)
-                    .with_alignment(TextAlignment::Left),
+                text: Text {
+                    sections: vec![TextSection::new(
+                        "this text wraps in the box\n(Unicode linebreaks)",
+                        slightly_smaller_text_style.clone(),
+                    )],
+                    alignment: TextAlignment::Left,
+                    linebreak_behaviour: BreakLineOn::WordBoundary,
+                },
                 text_2d_bounds: Text2dBounds {
                     // Wrap text in the rectangle
                     size: box_size,
@@ -87,6 +101,38 @@ fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
                 ..default()
             });
         });
+
+    let other_box_size = Vec2::new(300.0, 200.0);
+    let other_box_position = Vec2::new(320.0, -250.0);
+    commands
+        .spawn(SpriteBundle {
+            sprite: Sprite {
+                color: Color::rgb(0.20, 0.3, 0.70),
+                custom_size: Some(Vec2::new(other_box_size.x, other_box_size.y)),
+                ..default()
+            },
+            transform: Transform::from_translation(other_box_position.extend(0.0)),
+            ..default()
+        })
+        .with_children(|builder| {
+            builder.spawn(Text2dBundle {
+                text: Text {
+                    sections: vec![TextSection::new(
+                        "this text wraps in the box\n(AnyCharacter linebreaks)",
+                        slightly_smaller_text_style.clone(),
+                    )],
+                    alignment: TextAlignment::Left,
+                    linebreak_behaviour: BreakLineOn::AnyCharacter,
+                },
+                text_2d_bounds: Text2dBounds {
+                    // Wrap text in the rectangle
+                    size: other_box_size,
+                },
+                // ensure the text is drawn on top of the box
+                transform: Transform::from_translation(Vec3::Z),
+                ..default()
+            });
+        });
 }
 
 fn animate_translation(