the proper nice okay working text rendering

agb-image-converter/src/font_loader.rs

@@ -25,9 +25,9 @@ pub fn load_font(font_data: &[u8], pixels_per_em: f32) -> TokenStream {
     let line_metrics = font.horizontal_line_metrics(pixels_per_em).unwrap();
 
     let line_height = line_metrics.new_line_size as i32;
-    let ascent = line_metrics.ascent as i32;
+    let mut ascent = line_metrics.ascent as i32;
 
-    let font = (0..128)
+    let letters: Vec<_> = (0..128)
         .map(|i| font.rasterize(char::from_u32(i).unwrap(), pixels_per_em))
         .map(|(metrics, bitmap)| {
             let width = metrics.width;
@@ -56,25 +56,37 @@ pub fn load_font(font_data: &[u8], pixels_per_em: f32) -> TokenStream {
                 advance_width: metrics.advance_width,
             }
         })
-        .map(|letter_data| {
+        .collect();
-            let data_raw = ByteString(&letter_data.rendered);
-            let height = letter_data.height as u8;
-            let width = letter_data.width as u8;
-            let xmin = letter_data.xmin as i8;
-            let ymin = letter_data.ymin as i8;
-            let advance_width = letter_data.advance_width.ceil() as u8;
 
-            quote!(
+    let maximum_above_line = letters
-                display::FontLetter::new(
+        .iter()
-                    #width,
+        .map(|x| (x.height as i32 + x.ymin))
-                    #height,
+        .max()
-                    #data_raw,
+        .unwrap();
-                    #xmin,
+
-                    #ymin,
+    if (ascent - maximum_above_line) < 0 {
-                    #advance_width,
+        ascent = maximum_above_line;
-                )
+    }
+
+    let font = letters.iter().map(|letter_data| {
+        let data_raw = ByteString(&letter_data.rendered);
+        let height = letter_data.height as u8;
+        let width = letter_data.width as u8;
+        let xmin = letter_data.xmin as i8;
+        let ymin = letter_data.ymin as i8;
+        let advance_width = letter_data.advance_width.ceil() as u8;
+
+        quote!(
+            display::FontLetter::new(
+                #width,
+                #height,
+                #data_raw,
+                #xmin,
+                #ymin,
+                #advance_width,
             )
-        });
+        )
+    });
 
     quote![
         display::Font::new(&[#(#font),*], #line_height, #ascent)

agb/examples/object_text_render.rs

@@ -8,19 +8,17 @@ use agb::{
             PaletteVram, Size,
         },
         palette16::Palette16,
-        Font, WIDTH,
+        Font, HEIGHT, WIDTH,
     },
     include_font,
     input::Button,
 };
-use agb_fixnum::Rect;
 
 extern crate alloc;
-use alloc::vec::Vec;
 
 use core::fmt::Write;
 
-const FONT: Font = include_font!("examples/font/pixelated.ttf", 8);
+const FONT: Font = include_font!("examples/font/yoster.ttf", 12);
 #[agb::entry]
 fn entry(gba: agb::Gba) -> ! {
     main(gba);
@@ -35,12 +33,11 @@ fn main(mut gba: agb::Gba) -> ! {
         let palette = Palette16::new(palette);
         let palette = PaletteVram::new(&palette).unwrap();
 
-        let mut wr = ObjectTextRender::new(&FONT, Size::S16x8, palette);
+        let mut wr = ObjectTextRender::new(&FONT, Size::S16x16, palette);
         let _ = writeln!(
             wr,
-            "{}",
+            "Woah! Hey there! I have a bunch of text I want to show you. However, you will find that the amount of text I can display is limited. Who'd have thought! Good thing that my text system supports scrolling! It only took around 20 jank versions to get here!"
-            "counts for three shoot dice for damage calculation\nmalfunctions all dice after use"
+        
-                .to_ascii_uppercase()
         );
 
         let vblank = agb::interrupt::VBlank::get();
@@ -52,25 +49,32 @@ fn main(mut gba: agb::Gba) -> ! {
         timer.set_enabled(true);
         timer.set_divider(agb::timer::Divider::Divider256);
 
-        wr.set_alignment(TextAlignment::Left);
+        wr.layout((WIDTH, 40).into(), TextAlignment::Left, 2);
-        wr.set_size((WIDTH / 3, 20).into());
+
-        wr.set_paragraph_spacing(2);
+        let mut line_done = false;
-        wr.layout();
+        let mut frame = 0;
 
         loop {
             vblank.wait_for_vblank();
             input.update();
             let oam = &mut unmanaged.iter();
-            wr.commit(oam, (WIDTH / 3, 0).into());
+            wr.commit(oam);
 
             let start = timer.value();
-            let line_done = !wr.next_letter_group();
+            if frame % 4 == 0 {
-            if line_done && input.is_just_pressed(Button::A) {
+                line_done = !wr.next_letter_group();
+            }
+            if line_done
+            && input.is_just_pressed(Button::A)
+            {
+                line_done = false;
                 wr.pop_line();
             }
-            wr.layout();
+            wr.update((0, HEIGHT - 40).into());
             let end = timer.value();
 
+            frame += 1;
+
             agb::println!(
                 "Took {} cycles, line done {}",
                 256 * (end.wrapping_sub(start) as u32),

agb/src/display/object/font.rs

@@ -1,9 +1,9 @@
 use core::fmt::Write;
 
-use agb_fixnum::{Rect, Vector2D};
+use agb_fixnum::Vector2D;
 use alloc::{collections::VecDeque, vec::Vec};
 
-use crate::display::{object::font::preprocess::Word, Font};
+use crate::display::Font;
 
 use self::{
     preprocess::{Line, Preprocessed, PreprocessedElement},
@@ -32,14 +32,6 @@ impl WhiteSpace {
     }
 }
 
-#[derive(Debug)]
-pub(crate) struct LetterGroup {
-    sprite: SpriteVram,
-    // the width of the letter group
-    width: u16,
-    left: i16,
-}
-
 pub struct BufferedRender<'font> {
     char_render: WordRender,
     preprocessor: Preprocessed,
@@ -50,7 +42,7 @@ pub struct BufferedRender<'font> {
 
 #[derive(Debug, Default)]
 struct Letters {
-    letters: VecDeque<LetterGroup>,
+    letters: VecDeque<SpriteVram>,
     number_of_groups: usize,
 }
 
@@ -69,12 +61,7 @@ struct TextAlignmentSettings {
 }
 
 impl TextAlignment {
-    fn settings(
+    fn settings(self, line: &Line, minimum_space_width: i32, width: i32) -> TextAlignmentSettings {
-        self,
-        line: &Line,
-        minimum_space_width: i32,
-        size: Vector2D<i32>,
-    ) -> TextAlignmentSettings {
         match self {
             TextAlignment::Left => TextAlignmentSettings {
                 space_width: minimum_space_width,
@@ -82,11 +69,11 @@ impl TextAlignment {
             },
             TextAlignment::Right => TextAlignmentSettings {
                 space_width: minimum_space_width,
-                start_x: size.x - line.width(),
+                start_x: width - line.width(),
             },
             TextAlignment::Center => TextAlignmentSettings {
                 space_width: minimum_space_width,
-                start_x: (size.x - line.width()) / 2,
+                start_x: (width - line.width()) / 2,
             },
         }
     }
@@ -143,7 +130,7 @@ impl BufferedRender<'_> {
 pub struct ObjectTextRender<'font> {
     buffer: BufferedRender<'font>,
     layout: LayoutCache,
-    settings: LayoutSettings,
+    number_of_objects: usize,
 }
 
 impl<'font> ObjectTextRender<'font> {
@@ -151,8 +138,14 @@ impl<'font> ObjectTextRender<'font> {
     pub fn new(font: &'font Font, sprite_size: Size, palette: PaletteVram) -> Self {
         Self {
             buffer: BufferedRender::new(font, sprite_size, palette),
-            layout: LayoutCache::new(),
+            number_of_objects: 0,
-            settings: Default::default(),
+            layout: LayoutCache {
+                positions: VecDeque::new(),
+                line_capacity: VecDeque::new(),
+                objects: Vec::new(),
+                objects_are_at_origin: (0, 0).into(),
+                area: (0, 0).into(),
+            },
         }
     }
 }
@@ -168,267 +161,222 @@ impl Write for ObjectTextRender<'_> {
 }
 
 impl ObjectTextRender<'_> {
-    /// Remove a line from the render and shift everything up one line.
-    /// A full complete line must be rendered for this to do anything, incomplete lines won't be popped. Returns whether a line could be popped.
-    pub fn pop_line(&mut self) -> bool {
-        let width = self.layout.settings.area.x;
-        let space = self.buffer.font.letter(' ').advance_width as i32;
-        let Some(line) = self.buffer.preprocessor.lines(width, space).next() else {
-            return false;
-        };
-
-        let number_of_elements = line.number_of_letter_groups();
-        if self.layout.state.line_depth >= 1 && self.layout.objects.len() >= number_of_elements {
-            for _ in 0..number_of_elements {
-                // self.buffer.letters.letters.pop_front();
-                self.layout.objects.pop_front();
-            }
-            self.buffer.preprocessor.pop(&line);
-
-            self.layout.state.head_offset.y -= self.buffer.font.line_height();
-            for obj in self.layout.objects.iter_mut() {
-                obj.offset.y -= self.buffer.font.line_height() as i16;
-                let object_offset = obj.offset.change_base();
-                obj.object
-                    .set_position(self.layout.position + object_offset);
-            }
-
-            self.layout.state.line_depth -= 1;
-
-            true
-        } else {
-            false
-        }
-    }
-
-    /// On next update, the next unit of letters will be rendered. Returns whether the next element could be added.
-    /// Can only be called once per layout.
-    pub fn next_letter_group(&mut self) -> bool {
-        self.layout.next_letter_group(&self.buffer)
-    }
     /// Commits work already done to screen. You can commit to multiple places in the same frame.
-    pub fn commit(&mut self, oam: &mut OamIterator, position: Vector2D<i32>) {
+    pub fn commit(&mut self, oam: &mut OamIterator) {
-        self.layout.commit(oam, position);
+        for (object, slot) in self.layout.objects.iter().zip(oam) {
-    }
+            slot.set(object);
-    /// Updates the internal state based on the chosen render settings. Best
-    /// effort is made to reuse previous layouts, but a full rerender may be
-    /// required if certain settings are changed.
-    pub fn layout(&mut self) {
-        self.layout.update(
-            &mut self.buffer,
-            self.settings.area,
-            self.settings.alignment,
-            self.settings.paragraph_spacing,
-        );
-    }
-    /// Causes a change to the area that text is rendered. This will cause a relayout.
-    pub fn set_size(&mut self, size: Vector2D<i32>) {
-        self.settings.area = size;
-    }
-    /// Causes a change to the text alignment. This will cause a relayout.
-    pub fn set_alignment(&mut self, alignment: TextAlignment) {
-        self.settings.alignment = alignment;
-    }
-    /// Sets the paragraph spacing. This will cause a relayout.
-    pub fn set_paragraph_spacing(&mut self, paragraph_spacing: i32) {
-        self.settings.paragraph_spacing = paragraph_spacing;
-    }
-}
-
-struct LayoutObject {
-    object: ObjectUnmanaged,
-    offset: Vector2D<i16>,
-}
-
-struct LayoutCache {
-    objects: VecDeque<LayoutObject>,
-    state: LayoutCacheState,
-    settings: LayoutSettings,
-    desired_number_of_groups: usize,
-    position: Vector2D<i32>,
-}
-
-impl LayoutCache {
-    fn next_letter_group(&mut self, buffer: &BufferedRender) -> bool {
-        let width = self.settings.area.x;
-        let space = buffer.font.letter(' ').advance_width as i32;
-        let line_height = buffer.font.line_height();
-
-        if self.state.head_offset.y + line_height > self.settings.area.y {
-            return false;
-        }
-
-        if let Some((_line, mut line_elements)) = buffer
-            .preprocessor
-            .lines_element(width, space)
-            .nth(self.state.line_depth)
-        {
-            match line_elements.nth(self.state.line_element_depth) {
-                Some(PreprocessedElement::Word(_)) => {
-                    self.desired_number_of_groups += 1;
-                }
-                Some(PreprocessedElement::WhiteSpace(WhiteSpace::Space)) => {
-                    self.desired_number_of_groups += 1;
-                }
-                Some(PreprocessedElement::WhiteSpace(WhiteSpace::NewLine)) => {
-                    self.desired_number_of_groups += 1;
-                }
-                None => {
-                    if self.state.head_offset.y + line_height * 2 > self.settings.area.y {
-                        return false;
-                    }
-                    self.desired_number_of_groups += 1;
-                }
-            }
-        }
-
-        true
-    }
-
-    fn update_cache(&mut self, render: &BufferedRender) {
-        if self.state.rendered_groups >= self.desired_number_of_groups {
-            return;
-        }
-
-        let minimum_space_width = render.font.letter(' ').advance_width as i32;
-
-        let lines = render
-            .preprocessor
-            .lines_element(self.settings.area.x, minimum_space_width);
-
-        'outer: for (line, line_elements) in lines.skip(self.state.line_depth) {
-            let settings =
-                self.settings
-                    .alignment
-                    .settings(&line, minimum_space_width, self.settings.area);
-
-            if self.state.line_element_depth == 0 {
-                self.state.head_offset.x += settings.start_x;
-            }
-
-            for element in line_elements.skip(self.state.line_element_depth) {
-                match element {
-                    PreprocessedElement::Word(word) => {
-                        for letter in (word.sprite_index()
-                            ..(word.sprite_index() + word.number_of_sprites()))
-                            .skip(self.state.word_depth)
-                            .map(|x| &render.letters.letters[x])
-                        {
-                            let mut object = ObjectUnmanaged::new(letter.sprite.clone());
-                            self.state.head_offset.x += letter.left as i32;
-                            object
-                                .set_position(self.state.head_offset + self.position)
-                                .show();
-
-                            let layout_object = LayoutObject {
-                                object,
-                                offset: (
-                                    self.state.head_offset.x as i16,
-                                    self.state.head_offset.y as i16,
-                                )
-                                    .into(),
-                            };
-                            self.state.head_offset.x += letter.width as i32;
-                            self.objects.push_back(layout_object);
-                            self.state.rendered_groups += 1;
-                            self.state.word_depth += 1;
-                            if self.state.rendered_groups >= self.desired_number_of_groups {
-                                break 'outer;
-                            }
-                        }
-
-                        self.state.word_depth = 0;
-                        self.state.line_element_depth += 1;
-                    }
-                    PreprocessedElement::WhiteSpace(space_type) => {
-                        if space_type == WhiteSpace::NewLine {
-                            self.state.head_offset.y += self.settings.paragraph_spacing;
-                        }
-                        self.state.head_offset.x += settings.space_width;
-                        self.state.rendered_groups += 1;
-                        self.state.line_element_depth += 1;
-                        if self.state.rendered_groups >= self.desired_number_of_groups {
-                            break 'outer;
-                        }
-                    }
-                }
-            }
-
-            self.state.head_offset.y += render.font.line_height();
-            self.state.head_offset.x = 0;
-
-            self.state.line_element_depth = 0;
-            self.state.line_depth += 1;
         }
     }
 
-    fn update(
+    /// Force a relayout, must be called after writing.
+    pub fn layout(
         &mut self,
-        r: &mut BufferedRender<'_>,
         area: Vector2D<i32>,
         alignment: TextAlignment,
         paragraph_spacing: i32,
     ) {
-        r.process();
+        self.layout.create_positions(
-
+            self.buffer.font,
-        while !r.buffered_chars.is_empty()
+            &self.buffer.preprocessor,
-            && r.letters.number_of_groups <= self.desired_number_of_groups
+            &LayoutSettings {
-        {
+                area,
-            r.process();
+                alignment,
-        }
+                paragraph_spacing,
-
-        let settings = LayoutSettings {
-            area,
-            alignment,
-            paragraph_spacing,
-        };
-        if settings != self.settings {
-            self.reset(settings);
-        }
-
-        self.update_cache(r);
-    }
-
-    fn commit(&mut self, oam: &mut OamIterator, position: Vector2D<i32>) {
-        if self.position != position {
-            for (object, slot) in self.objects.iter_mut().zip(oam) {
-                let object_offset = object.offset.change_base();
-                object.object.set_position(position + object_offset);
-                slot.set(&object.object);
-            }
-            self.position = position;
-        } else {
-            for (object, slot) in self.objects.iter().zip(oam) {
-                slot.set(&object.object);
-            }
-        }
-    }
-
-    #[must_use]
-    fn new() -> Self {
-        Self {
-            objects: VecDeque::new(),
-            state: Default::default(),
-            settings: LayoutSettings {
-                area: (0, 0).into(),
-                alignment: TextAlignment::Right,
-                paragraph_spacing: -100,
             },
-            desired_number_of_groups: 0,
+        );
-            position: (0, 0).into(),
+    }
+
+    /// Removes one complete line.
+    pub fn pop_line(&mut self) -> bool {
+        let width = self.layout.area.x;
+        let space = self.buffer.font.letter(' ').advance_width as i32;
+        let line_height = self.buffer.font.line_height();
+        if let Some(line) = self.buffer.preprocessor.lines(width, space).next() {
+            // there is a line
+            if self.layout.objects.len() >= line.number_of_letter_groups() {
+                // we have enough rendered letter groups to count
+                self.number_of_objects -= line.number_of_letter_groups();
+                for _ in 0..line.number_of_letter_groups() {
+                    self.buffer.letters.letters.pop_front();
+                    self.layout.positions.pop_front();
+                }
+                self.layout.line_capacity.pop_front();
+                self.layout.objects.clear();
+                self.buffer.preprocessor.pop(&line);
+                for position in self.layout.positions.iter_mut() {
+                    position.y -= line_height as i16;
+                }
+                return true;
+            }
+        }
+        false
+    }
+
+    pub fn update(&mut self, position: Vector2D<i32>) {
+        if !self.buffer.buffered_chars.is_empty()
+            && self.buffer.letters.letters.len() <= self.number_of_objects + 5
+        {
+            self.buffer.process();
+        }
+
+        self.layout.update_objects_to_display_at_position(
+            position,
+            self.buffer.letters.letters.iter(),
+            self.number_of_objects,
+        );
+    }
+
+    pub fn next_letter_group(&mut self) -> bool {
+        if !self.can_render_another_element() {
+            return false;
+        }
+        self.number_of_objects += 1;
+        self.at_least_n_letter_groups(self.number_of_objects);
+
+        true
+    }
+
+    fn can_render_another_element(&self) -> bool {
+        let max_number_of_lines = (self.layout.area.y / self.buffer.font.line_height()) as usize;
+
+        let max_number_of_objects = self
+            .layout
+            .line_capacity
+            .iter()
+            .take(max_number_of_lines)
+            .sum::<usize>();
+
+        max_number_of_objects > self.number_of_objects
+    }
+
+    pub fn next_line(&mut self) -> bool {
+        let max_number_of_lines = (self.layout.area.y / self.buffer.font.line_height()) as usize;
+
+        // find current line
+
+        for (start, end) in self
+            .layout
+            .line_capacity
+            .iter()
+            .scan(0, |count, line_size| {
+                let start = *count;
+                *count += line_size;
+                Some((start, *count))
+            })
+            .take(max_number_of_lines)
+        {
+            if self.number_of_objects >= start && self.number_of_objects < end {
+                self.number_of_objects = end;
+                self.at_least_n_letter_groups(end);
+                return true;
+            }
+        }
+
+        false
+    }
+
+    fn at_least_n_letter_groups(&mut self, n: usize) {
+        while !self.buffer.buffered_chars.is_empty() && self.buffer.letters.letters.len() <= n {
+            self.buffer.process();
+        }
+    }
+}
+
+struct LayoutCache {
+    positions: VecDeque<Vector2D<i16>>,
+    line_capacity: VecDeque<usize>,
+    objects: Vec<ObjectUnmanaged>,
+    objects_are_at_origin: Vector2D<i32>,
+    area: Vector2D<i32>,
+}
+
+impl LayoutCache {
+    fn update_objects_to_display_at_position<'a>(
+        &mut self,
+        position: Vector2D<i32>,
+        letters: impl Iterator<Item = &'a SpriteVram>,
+        number_of_objects: usize,
+    ) {
+        let already_done = if position == self.objects_are_at_origin {
+            self.objects.len()
+        } else {
+            self.objects.clear();
+            0
+        };
+        self.objects.extend(
+            self.positions
+                .iter()
+                .zip(letters)
+                .take(number_of_objects)
+                .skip(already_done)
+                .map(|(offset, letter)| {
+                    let position = offset.change_base() + position;
+                    let mut object = ObjectUnmanaged::new(letter.clone());
+                    object.show().set_position(position);
+                    object
+                }),
+        );
+        self.objects.truncate(number_of_objects);
+        self.objects_are_at_origin = position;
+    }
+
+    fn create_positions(
+        &mut self,
+        font: &Font,
+        preprocessed: &Preprocessed,
+        settings: &LayoutSettings,
+    ) {
+        self.area = settings.area;
+        self.line_capacity.clear();
+        self.positions.clear();
+        for (line, line_positions) in Self::create_layout(font, preprocessed, settings) {
+            self.line_capacity.push_back(line.number_of_letter_groups());
+            self.positions
+                .extend(line_positions.map(|x| Vector2D::new(x.x as i16, x.y as i16)));
         }
     }
 
-    fn reset(&mut self, settings: LayoutSettings) {
+    fn create_layout<'a>(
-        self.objects.clear();
+        font: &Font,
-        self.state = LayoutCacheState {
+        preprocessed: &'a Preprocessed,
-            head_offset: (0, 0).into(),
+        settings: &'a LayoutSettings,
-            word_depth: 0,
+    ) -> impl Iterator<Item = (Line, impl Iterator<Item = Vector2D<i32>> + 'a)> + 'a {
-            rendered_groups: 0,
+        let minimum_space_width = font.letter(' ').advance_width as i32;
-            line_depth: 0,
+        let width = settings.area.x;
-            line_element_depth: 0,
+        let line_height = font.line_height();
-        };
+
-        self.settings = settings;
+        let mut head_position: Vector2D<i32> = (0, -line_height).into();
+
+        preprocessed
+            .lines_element(width, minimum_space_width)
+            .map(move |(line, line_elements)| {
+                let line_settings = settings
+                    .alignment
+                    .settings(&line, minimum_space_width, width);
+
+                head_position.y += line_height;
+                head_position.x = line_settings.start_x;
+
+                (
+                    line,
+                    line_elements.filter_map(move |element| match element.decode() {
+                        PreprocessedElement::LetterGroup { width } => {
+                            let this_position = head_position;
+                            head_position.x += width as i32;
+                            Some(this_position)
+                        }
+                        PreprocessedElement::WhiteSpace(space) => {
+                            match space {
+                                WhiteSpace::NewLine => {
+                                    head_position.y += settings.paragraph_spacing;
+                                }
+                                WhiteSpace::Space => head_position.x += line_settings.space_width,
+                            }
+                            None
+                        }
+                    }),
+                )
+            })
     }
 }
 
@@ -438,12 +386,3 @@ struct LayoutSettings {
     alignment: TextAlignment,
     paragraph_spacing: i32,
 }
-
-#[derive(Default)]
-struct LayoutCacheState {
-    head_offset: Vector2D<i32>,
-    word_depth: usize,
-    rendered_groups: usize,
-    line_depth: usize,
-    line_element_depth: usize,
-}

agb/src/display/object/font/preprocess.rs

@@ -6,52 +6,47 @@ use crate::display::Font;
 
 use super::WhiteSpace;
 
-#[derive(Debug, PartialEq, Eq, Clone, Copy)]
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub(crate) struct PreprocessedElementEncoded(u8);
+
+impl PreprocessedElementEncoded {
+    pub(crate) fn decode(self) -> PreprocessedElement {
+        match self.0 {
+            255 => PreprocessedElement::WhiteSpace(WhiteSpace::NewLine),
+            254 => PreprocessedElement::WhiteSpace(WhiteSpace::Space),
+            width => PreprocessedElement::LetterGroup { width },
+        }
+    }
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+
 pub(crate) enum PreprocessedElement {
-    Word(Word),
+    LetterGroup { width: u8 },
     WhiteSpace(WhiteSpace),
 }
 
-#[test_case]
+impl PreprocessedElement {
-fn check_size_of_preprocessed_element_is_correct(_: &mut crate::Gba) {
+    fn encode(self) -> PreprocessedElementEncoded {
-    assert_eq!(
+        PreprocessedElementEncoded(match self {
-        core::mem::size_of::<PreprocessedElement>(),
+            PreprocessedElement::LetterGroup { width } => width,
-        core::mem::size_of::<Word>()
+            PreprocessedElement::WhiteSpace(space) => match space {
-    );
+                WhiteSpace::NewLine => 255,
-}
+                WhiteSpace::Space => 254,
-
+            },
-#[derive(Debug, PartialEq, Eq, Clone, Copy)]
+        })
-#[repr(align(4))]
-pub(crate) struct Word {
-    pixels: u8,
-    number_of_sprites: NonZeroU8,
-    index: u16,
-}
-
-impl Word {
-    pub fn pixels(self) -> i32 {
-        self.pixels.into()
-    }
-    pub fn number_of_sprites(self) -> usize {
-        self.number_of_sprites.get().into()
-    }
-    pub fn sprite_index(self) -> usize {
-        self.index.into()
     }
 }
 
 #[derive(Default, Debug)]
 pub(crate) struct Preprocessed {
-    widths: VecDeque<PreprocessedElement>,
+    widths: VecDeque<PreprocessedElementEncoded>,
     preprocessor: Preprocessor,
 }
 
 #[derive(Debug, Default)]
 struct Preprocessor {
-    current_word_width: i32,
-    number_of_sprites: usize,
     width_in_sprite: i32,
-    total_number_of_sprites: usize,
 }
 
 impl Preprocessor {
@@ -60,37 +55,32 @@ impl Preprocessor {
         font: &Font,
         character: char,
         sprite_width: i32,
-        widths: &mut VecDeque<PreprocessedElement>,
+        widths: &mut VecDeque<PreprocessedElementEncoded>,
     ) {
         match character {
             space @ (' ' | '\n') => {
-                if self.current_word_width != 0 {
+                if self.width_in_sprite != 0 {
-                    self.number_of_sprites += 1;
+                    widths.push_back(
-                    self.total_number_of_sprites += 1;
+                        PreprocessedElement::LetterGroup {
-                    widths.push_back(PreprocessedElement::Word(Word {
+                            width: self.width_in_sprite as u8,
-                        pixels: self.current_word_width.try_into().expect("word too wide"),
+                        }
-                        number_of_sprites: NonZeroU8::new(
+                        .encode(),
-                            self.number_of_sprites.try_into().expect("word too wide"),
+                    );
-                        )
-                        .unwrap(),
-                        index: (self.total_number_of_sprites - self.number_of_sprites)
-                            .try_into()
-                            .expect("out of range"),
-                    }));
-                    self.current_word_width = 0;
-                    self.number_of_sprites = 0;
                     self.width_in_sprite = 0;
                 }
-                widths.push_back(PreprocessedElement::WhiteSpace(WhiteSpace::from_char(
+                widths.push_back(
-                    space,
+                    PreprocessedElement::WhiteSpace(WhiteSpace::from_char(space)).encode(),
-                )));
+                );
             }
             letter => {
                 let letter = font.letter(letter);
-                self.current_word_width += letter.advance_width as i32 + letter.xmin as i32;
                 if self.width_in_sprite + letter.width as i32 > sprite_width {
-                    self.number_of_sprites += 1;
+                    widths.push_back(
-                    self.total_number_of_sprites += 1;
+                        PreprocessedElement::LetterGroup {
+                            width: self.width_in_sprite as u8,
+                        }
+                        .encode(),
+                    );
                     self.width_in_sprite = 0;
                 }
                 if self.width_in_sprite != 0 {
@@ -105,7 +95,7 @@ impl Preprocessor {
 pub(crate) struct Lines<'preprocess> {
     minimum_space_width: i32,
     layout_width: i32,
-    data: &'preprocess VecDeque<PreprocessedElement>,
+    data: &'preprocess VecDeque<PreprocessedElementEncoded>,
     current_start_idx: usize,
 }
 
@@ -150,35 +140,58 @@ impl<'pre> Iterator for Lines<'pre> {
         }
 
         let mut line_idx_length = 0;
-        let mut current_line_width = 0;
+        let mut current_line_width_pixels = 0;
-        let mut additional_space_count = 0;
+        let mut spaces_after_last_word_count = 0usize;
+        let mut start_of_current_word = usize::MAX;
+        let mut length_of_current_word_pixels = 0;
+        let mut length_of_current_word = 0;
         let mut number_of_spaces = 0;
         let mut number_of_words = 0;
         let mut number_of_letter_groups = 0;
 
         while let Some(next) = self.data.get(self.current_start_idx + line_idx_length) {
-            match next {
+            match next.decode() {
-                PreprocessedElement::Word(word) => {
+                PreprocessedElement::LetterGroup { width } => {
-                    let additional_space_width =
+                    if start_of_current_word == usize::MAX {
-                        additional_space_count as i32 * self.minimum_space_width;
+                        start_of_current_word = line_idx_length;
-                    let width = word.pixels();
+                    }
-                    if width + current_line_width + additional_space_width > self.layout_width {
+                    length_of_current_word_pixels += width as i32;
+                    length_of_current_word += 1;
+                    if current_line_width_pixels
+                        + length_of_current_word_pixels
+                        + spaces_after_last_word_count as i32 * self.minimum_space_width
+                        >= self.layout_width
+                    {
+                        line_idx_length = start_of_current_word;
                         break;
                     }
-                    number_of_letter_groups += word.number_of_sprites.get() as usize;
-                    number_of_words += 1;
-                    current_line_width += width + additional_space_width;
-                    number_of_spaces += additional_space_count;
                 }
-                PreprocessedElement::WhiteSpace(space) => match space {
+                PreprocessedElement::WhiteSpace(space) => {
-                    WhiteSpace::NewLine => {
+                    if start_of_current_word != usize::MAX {
-                        line_idx_length += 1;
+                        // flush word
-                        break;
+                        current_line_width_pixels += length_of_current_word_pixels
+                            + spaces_after_last_word_count as i32 * self.minimum_space_width;
+                        number_of_spaces += spaces_after_last_word_count;
+                        number_of_words += 1;
+                        number_of_letter_groups += length_of_current_word;
+
+                        // reset parser
+                        length_of_current_word_pixels = 0;
+                        length_of_current_word = 0;
+                        start_of_current_word = usize::MAX;
+                        spaces_after_last_word_count = 0;
                     }
-                    WhiteSpace::Space => {
+
-                        additional_space_count += 1;
+                    match space {
+                        WhiteSpace::NewLine => {
+                            line_idx_length += 1;
+                            break;
+                        }
+                        WhiteSpace::Space => {
+                            spaces_after_last_word_count += 1;
+                        }
                     }
-                },
+                }
             };
 
             line_idx_length += 1;
@@ -187,7 +200,7 @@ impl<'pre> Iterator for Lines<'pre> {
         self.current_start_idx += line_idx_length;
 
         Some(Line {
-            width: current_line_width,
+            width: current_line_width_pixels,
             number_of_text_elements: line_idx_length,
             number_of_spaces,
             number_of_words,
@@ -226,7 +239,7 @@ impl Preprocessed {
         &self,
         layout_width: i32,
         minimum_space_width: i32,
-    ) -> impl Iterator<Item = (Line, impl Iterator<Item = PreprocessedElement> + '_)> {
+    ) -> impl Iterator<Item = (Line, impl Iterator<Item = PreprocessedElementEncoded> + '_)> {
         let mut idx = 0;
         self.lines(layout_width, minimum_space_width).map(move |x| {
             let length = x.number_of_text_elements;

agb/src/display/object/font/renderer.rs

@@ -1,14 +1,10 @@
 use crate::display::{
-    object::{DynamicSprite, PaletteVram, Size},
+    object::{DynamicSprite, PaletteVram, Size, SpriteVram},
     Font,
 };
 
-use super::LetterGroup;
-
 struct WorkingLetter {
     dynamic: DynamicSprite,
-    // the x offset of the current letter with respect to the start of the current letter group
-    x_position: i32,
     // where to render the letter from x_min to x_max
     x_offset: i32,
 }
@@ -17,13 +13,11 @@ impl WorkingLetter {
     fn new(size: Size) -> Self {
         Self {
             dynamic: DynamicSprite::new(size),
-            x_position: 0,
             x_offset: 0,
         }
     }
 
     fn reset(&mut self) {
-        self.x_position = 0;
         self.x_offset = 0;
     }
 }
@@ -64,7 +58,7 @@ impl WordRender {
     }
 
     #[must_use]
-    pub(crate) fn finalise_letter(&mut self) -> Option<LetterGroup> {
+    pub(crate) fn finalise_letter(&mut self) -> Option<SpriteVram> {
         if self.working.x_offset == 0 {
             return None;
         }
@@ -72,19 +66,13 @@ impl WordRender {
         let mut new_sprite = DynamicSprite::new(self.config.sprite_size);
         core::mem::swap(&mut self.working.dynamic, &mut new_sprite);
         let sprite = new_sprite.to_vram(self.config.palette.clone());
-
-        let group = LetterGroup {
-            sprite,
-            width: self.working.x_offset as u16,
-            left: self.working.x_position as i16,
-        };
         self.working.reset();
 
-        Some(group)
+        Some(sprite)
     }
 
     #[must_use]
-    pub(crate) fn render_char(&mut self, font: &Font, c: char) -> Option<LetterGroup> {
+    pub(crate) fn render_char(&mut self, font: &Font, c: char) -> Option<SpriteVram> {
         let font_letter: &crate::display::FontLetter = font.letter(c);
 
         // uses more than the sprite can hold
@@ -96,9 +84,7 @@ impl WordRender {
             None
         };
 
-        if self.working.x_offset == 0 {
+        if self.working.x_offset != 0 {
-            self.working.x_position = font_letter.xmin as i32;
-        } else {
             self.working.x_offset += font_letter.xmin as i32;
         }