diff options
Diffstat (limited to 'tiny_skia/src/text.rs')
| -rw-r--r-- | tiny_skia/src/text.rs | 431 |
1 files changed, 431 insertions, 0 deletions
diff --git a/tiny_skia/src/text.rs b/tiny_skia/src/text.rs new file mode 100644 index 00000000..f2935efa --- /dev/null +++ b/tiny_skia/src/text.rs @@ -0,0 +1,431 @@ +use crate::core::alignment; +use crate::core::text::Hit; +use crate::core::{Color, Font, Point, Rectangle, Size}; + +use rustc_hash::{FxHashMap, FxHashSet}; +use std::borrow::Cow; +use std::cell::RefCell; +use std::collections::hash_map; +use std::hash::{BuildHasher, Hash, Hasher}; +use std::sync::Arc; + +#[allow(missing_debug_implementations)] +pub struct Pipeline { + system: Option<System>, + glyph_cache: GlyphCache, +} + +#[ouroboros::self_referencing] +struct System { + fonts: cosmic_text::FontSystem, + + #[borrows(fonts)] + #[not_covariant] + measurement_cache: RefCell<Cache<'this>>, + + #[borrows(fonts)] + #[not_covariant] + render_cache: Cache<'this>, +} + +impl Pipeline { + pub fn new() -> Self { + Pipeline { + system: Some( + SystemBuilder { + fonts: cosmic_text::FontSystem::new_with_fonts( + [cosmic_text::fontdb::Source::Binary(Arc::new( + include_bytes!("../../wgpu/fonts/Iced-Icons.ttf") + .as_slice(), + ))] + .into_iter(), + ), + measurement_cache_builder: |_| RefCell::new(Cache::new()), + render_cache_builder: |_| Cache::new(), + } + .build(), + ), + glyph_cache: GlyphCache::new(), + } + } + + pub fn load_font(&mut self, bytes: Cow<'static, [u8]>) { + let heads = self.system.take().unwrap().into_heads(); + + let (locale, mut db) = heads.fonts.into_locale_and_db(); + + db.load_font_source(cosmic_text::fontdb::Source::Binary(Arc::new( + bytes.into_owned(), + ))); + + self.system = Some( + SystemBuilder { + fonts: cosmic_text::FontSystem::new_with_locale_and_db( + locale, db, + ), + measurement_cache_builder: |_| RefCell::new(Cache::new()), + render_cache_builder: |_| Cache::new(), + } + .build(), + ); + } + + pub fn draw( + &mut self, + content: &str, + bounds: Rectangle, + color: Color, + size: f32, + font: Font, + horizontal_alignment: alignment::Horizontal, + vertical_alignment: alignment::Vertical, + pixels: &mut tiny_skia::PixmapMut<'_>, + clip_mask: Option<&tiny_skia::ClipMask>, + ) { + self.system.as_mut().unwrap().with_mut(|fields| { + let key = Key { + bounds: { + let size = bounds.size(); + + // TODO: Reuse buffers from layouting + Size::new(size.width.ceil(), size.height.ceil()) + }, + content, + font, + size, + }; + + let (_, buffer) = fields.render_cache.allocate(fields.fonts, key); + + let (total_lines, max_width) = buffer + .layout_runs() + .enumerate() + .fold((0, 0.0), |(_, max), (i, buffer)| { + (i + 1, buffer.line_w.max(max)) + }); + + let total_height = total_lines as f32 * size * 1.2; + + let x = match horizontal_alignment { + alignment::Horizontal::Left => bounds.x, + alignment::Horizontal::Center => bounds.x - max_width / 2.0, + alignment::Horizontal::Right => bounds.x - max_width, + }; + + let y = match vertical_alignment { + alignment::Vertical::Top => bounds.y, + alignment::Vertical::Center => bounds.y - total_height / 2.0, + alignment::Vertical::Bottom => bounds.y - total_height, + }; + + let mut swash = cosmic_text::SwashCache::new(fields.fonts); + + for run in buffer.layout_runs() { + for glyph in run.glyphs { + if let Some((buffer, placement)) = self + .glyph_cache + .allocate(glyph.cache_key, color, &mut swash) + { + let pixmap = tiny_skia::PixmapRef::from_bytes( + buffer, + placement.width, + placement.height, + ) + .expect("Create glyph pixel map"); + + pixels.draw_pixmap( + x as i32 + glyph.x_int + placement.left, + y as i32 - glyph.y_int - placement.top + + run.line_y as i32, + pixmap, + &tiny_skia::PixmapPaint::default(), + tiny_skia::Transform::identity(), + clip_mask, + ); + } + } + } + }); + } + + pub fn trim_cache(&mut self) { + self.system + .as_mut() + .unwrap() + .with_render_cache_mut(|cache| cache.trim()); + + self.glyph_cache.trim(); + } + + pub fn measure( + &self, + content: &str, + size: f32, + font: Font, + bounds: Size, + ) -> (f32, f32) { + self.system.as_ref().unwrap().with(|fields| { + let mut measurement_cache = fields.measurement_cache.borrow_mut(); + + let (_, paragraph) = measurement_cache.allocate( + fields.fonts, + Key { + content, + size, + font, + bounds, + }, + ); + + let (total_lines, max_width) = paragraph + .layout_runs() + .enumerate() + .fold((0, 0.0), |(_, max), (i, buffer)| { + (i + 1, buffer.line_w.max(max)) + }); + + (max_width, size * 1.2 * total_lines as f32) + }) + } + + pub fn hit_test( + &self, + content: &str, + size: f32, + font: Font, + bounds: Size, + point: Point, + _nearest_only: bool, + ) -> Option<Hit> { + self.system.as_ref().unwrap().with(|fields| { + let mut measurement_cache = fields.measurement_cache.borrow_mut(); + + let (_, paragraph) = measurement_cache.allocate( + fields.fonts, + Key { + content, + size, + font, + bounds, + }, + ); + + let cursor = paragraph.hit(point.x, point.y)?; + + Some(Hit::CharOffset(cursor.index)) + }) + } + + pub fn trim_measurement_cache(&mut self) { + self.system + .as_mut() + .unwrap() + .with_measurement_cache_mut(|cache| cache.borrow_mut().trim()); + } +} + +fn to_family(font: Font) -> cosmic_text::Family<'static> { + match font { + Font::Name(name) => cosmic_text::Family::Name(name), + Font::SansSerif => cosmic_text::Family::SansSerif, + Font::Serif => cosmic_text::Family::Serif, + Font::Cursive => cosmic_text::Family::Cursive, + Font::Fantasy => cosmic_text::Family::Fantasy, + Font::Monospace => cosmic_text::Family::Monospace, + } +} + +#[derive(Debug, Clone, Default)] +struct GlyphCache { + entries: FxHashMap< + (cosmic_text::CacheKey, [u8; 3]), + (Vec<u32>, cosmic_text::Placement), + >, + recently_used: FxHashSet<(cosmic_text::CacheKey, [u8; 3])>, + trim_count: usize, +} + +impl GlyphCache { + fn new() -> Self { + GlyphCache::default() + } + + fn allocate( + &mut self, + cache_key: cosmic_text::CacheKey, + color: Color, + swash: &mut cosmic_text::SwashCache<'_>, + ) -> Option<(&[u8], cosmic_text::Placement)> { + let [r, g, b, _a] = color.into_rgba8(); + let key = (cache_key, [r, g, b]); + + if let hash_map::Entry::Vacant(entry) = self.entries.entry(key) { + // TODO: Outline support + let image = swash.get_image_uncached(cache_key)?; + + let glyph_size = image.placement.width as usize + * image.placement.height as usize; + + if glyph_size == 0 { + return None; + } + + let mut buffer = vec![0u32; glyph_size]; + + match image.content { + cosmic_text::SwashContent::Mask => { + let mut i = 0; + + // TODO: Blend alpha + + for _y in 0..image.placement.height { + for _x in 0..image.placement.width { + buffer[i] = tiny_skia::ColorU8::from_rgba( + b, + g, + r, + image.data[i], + ) + .premultiply() + .get(); + + i += 1; + } + } + } + cosmic_text::SwashContent::Color => { + let mut i = 0; + + for _y in 0..image.placement.height { + for _x in 0..image.placement.width { + // TODO: Blend alpha + buffer[i >> 2] = tiny_skia::ColorU8::from_rgba( + image.data[i + 2], + image.data[i + 1], + image.data[i], + image.data[i + 3], + ) + .premultiply() + .get(); + + i += 4; + } + } + } + cosmic_text::SwashContent::SubpixelMask => { + // TODO + } + } + + entry.insert((buffer, image.placement)); + } + + self.recently_used.insert(key); + + self.entries.get(&key).map(|(buffer, placement)| { + (bytemuck::cast_slice(buffer.as_slice()), *placement) + }) + } + + pub fn trim(&mut self) { + if self.trim_count > 300 { + self.entries + .retain(|key, _| self.recently_used.contains(key)); + + self.recently_used.clear(); + + self.trim_count = 0; + } else { + self.trim_count += 1; + } + } +} + +struct Cache<'a> { + entries: FxHashMap<KeyHash, cosmic_text::Buffer<'a>>, + recently_used: FxHashSet<KeyHash>, + hasher: HashBuilder, + trim_count: usize, +} + +#[cfg(not(target_arch = "wasm32"))] +type HashBuilder = twox_hash::RandomXxHashBuilder64; + +#[cfg(target_arch = "wasm32")] +type HashBuilder = std::hash::BuildHasherDefault<twox_hash::XxHash64>; + +impl<'a> Cache<'a> { + const TRIM_INTERVAL: usize = 300; + + fn new() -> Self { + Self { + entries: FxHashMap::default(), + recently_used: FxHashSet::default(), + hasher: HashBuilder::default(), + trim_count: 0, + } + } + + fn allocate( + &mut self, + fonts: &'a cosmic_text::FontSystem, + key: Key<'_>, + ) -> (KeyHash, &mut cosmic_text::Buffer<'a>) { + let hash = { + let mut hasher = self.hasher.build_hasher(); + + key.content.hash(&mut hasher); + key.size.to_bits().hash(&mut hasher); + key.font.hash(&mut hasher); + key.bounds.width.to_bits().hash(&mut hasher); + key.bounds.height.to_bits().hash(&mut hasher); + + hasher.finish() + }; + + if let hash_map::Entry::Vacant(entry) = self.entries.entry(hash) { + let metrics = cosmic_text::Metrics::new(key.size, key.size * 1.2); + let mut buffer = cosmic_text::Buffer::new(fonts, metrics); + + buffer.set_size( + key.bounds.width, + key.bounds.height.max(key.size * 1.2), + ); + buffer.set_text( + key.content, + cosmic_text::Attrs::new() + .family(to_family(key.font)) + .monospaced(matches!(key.font, Font::Monospace)), + ); + + let _ = entry.insert(buffer); + } + + let _ = self.recently_used.insert(hash); + + (hash, self.entries.get_mut(&hash).unwrap()) + } + + fn trim(&mut self) { + if self.trim_count >= Self::TRIM_INTERVAL { + self.entries + .retain(|key, _| self.recently_used.contains(key)); + + self.recently_used.clear(); + + self.trim_count = 0; + } else { + self.trim_count += 1; + } + } +} + +#[derive(Debug, Clone, Copy)] +struct Key<'a> { + content: &'a str, + size: f32, + font: Font, + bounds: Size, +} + +type KeyHash = u64; |