diff options
| author | Laurenz <laurmaedje@gmail.com> | 2020-10-03 11:09:32 +0200 |
|---|---|---|
| committer | Laurenz <laurmaedje@gmail.com> | 2020-10-03 11:09:32 +0200 |
| commit | 730715c064294337ee9befc3b9332d45eb74818f (patch) | |
| tree | e8bad130d43b3eefcb065365b223c3bdbd997026 /src/layout/text.rs | |
| parent | dc8d5d2f1eadb19d0351fa214400d7ec7ba31a20 (diff) | |
Rename text layouting to shaping ✏
Diffstat (limited to 'src/layout/text.rs')
| -rw-r--r-- | src/layout/text.rs | 156 |
1 files changed, 0 insertions, 156 deletions
diff --git a/src/layout/text.rs b/src/layout/text.rs deleted file mode 100644 index 7dd557c9..00000000 --- a/src/layout/text.rs +++ /dev/null @@ -1,156 +0,0 @@ -//! Layouting of continous pieces of text into boxes. -//! -//! The layouter picks the most suitable font for each individual character. -//! When the primary layouting axis horizontally inversed, the word is spelled -//! backwards. Vertical word layout is not yet supported. - -use fontdock::{FaceId, FaceQuery, FontStyle}; -use ttf_parser::GlyphId; - -use super::elements::{LayoutElement, Shaped}; -use super::*; -use crate::font::FontLoader; -use crate::geom::Size; -use crate::style::TextStyle; - -/// Layouts text into a box. -pub async fn layout_text(text: &str, ctx: TextContext<'_>) -> BoxLayout { - TextLayouter::new(text, ctx).layout().await -} - -/// Performs the text layouting. -#[derive(Debug)] -struct TextLayouter<'a> { - ctx: TextContext<'a>, - text: &'a str, - shaped: Shaped, - elements: LayoutElements, - start: f64, - width: f64, -} - -/// The context for text layouting. -#[derive(Debug)] -pub struct TextContext<'a> { - /// The font loader to retrieve fonts from when typesetting text with - /// `layout_text`. - pub loader: &'a mut FontLoader, - /// The style for text: Font selection with classes, weights and variants, - /// font sizes, spacing and so on. - pub style: &'a TextStyle, - /// The direction into which the word is laid out. For now, only horizontal - /// directions are supported. - pub dir: Dir, - /// The alignment of the _resulting_ layout. This does not effect the line - /// layouting itself, but rather how the finished layout will be positioned - /// in a parent layout. - pub align: LayoutAlign, -} - -impl<'a> TextLayouter<'a> { - fn new(text: &'a str, ctx: TextContext<'a>) -> Self { - Self { - text, - shaped: Shaped::new(FaceId::MAX, ctx.style.font_size()), - elements: LayoutElements::new(), - start: 0.0, - width: 0.0, - ctx, - } - } - - async fn layout(mut self) -> BoxLayout { - // If the primary axis is negative, we layout the characters reversed. - if self.ctx.dir.is_positive() { - for c in self.text.chars() { - self.layout_char(c).await; - } - } else { - for c in self.text.chars().rev() { - self.layout_char(c).await; - } - } - - // Flush the last buffered parts of the word. - if !self.shaped.text.is_empty() { - let pos = Size::new(self.start, 0.0); - self.elements.push(pos, LayoutElement::Text(self.shaped)); - } - - BoxLayout { - size: Size::new(self.width, self.ctx.style.font_size()), - align: self.ctx.align, - elements: self.elements, - } - } - - async fn layout_char(&mut self, c: char) { - let (index, glyph, char_width) = match self.select_font(c).await { - Some(selected) => selected, - // TODO: Issue warning about missing character. - None => return, - }; - - // Flush the buffer and issue a font setting action if the font differs - // from the last character's one. - if self.shaped.face != index { - if !self.shaped.text.is_empty() { - let pos = Size::new(self.start, 0.0); - let shaped = std::mem::replace( - &mut self.shaped, - Shaped::new(FaceId::MAX, self.ctx.style.font_size()), - ); - - self.elements.push(pos, LayoutElement::Text(shaped)); - self.start = self.width; - } - - self.shaped.face = index; - } - - self.shaped.text.push(c); - self.shaped.glyphs.push(glyph); - self.shaped.offsets.push(self.width - self.start); - - self.width += char_width; - } - - async fn select_font(&mut self, c: char) -> Option<(FaceId, GlyphId, f64)> { - let mut variant = self.ctx.style.variant; - - if self.ctx.style.bolder { - variant.weight = variant.weight.thicken(300); - } - - if self.ctx.style.italic { - variant.style = match variant.style { - FontStyle::Normal => FontStyle::Italic, - FontStyle::Italic => FontStyle::Normal, - FontStyle::Oblique => FontStyle::Normal, - } - } - - let query = FaceQuery { - fallback: self.ctx.style.fallback.iter(), - variant, - c, - }; - - if let Some((id, owned_face)) = self.ctx.loader.query(query).await { - let face = owned_face.get(); - - // Determine the width of the char. - let units_per_em = face.units_per_em().unwrap_or(1000) as f64; - let ratio = 1.0 / units_per_em; - let to_raw = |x| ratio * x as f64; - - let glyph = face.glyph_index(c)?; - let glyph_width = face.glyph_hor_advance(glyph)?; - let char_width = to_raw(glyph_width) * self.ctx.style.font_size(); - - Some((id, glyph, char_width)) - } else { - None - } - } -} |
