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Diffstat (limited to 'src/env/mod.rs')
| -rw-r--r-- | src/env/mod.rs | 243 |
1 files changed, 0 insertions, 243 deletions
diff --git a/src/env/mod.rs b/src/env/mod.rs deleted file mode 100644 index 84be3e81..00000000 --- a/src/env/mod.rs +++ /dev/null @@ -1,243 +0,0 @@ -//! Font and image loading. - -#[cfg(feature = "fs")] -mod fs; -mod image; - -pub use self::image::*; -#[cfg(feature = "fs")] -pub use fs::*; - -use std::collections::{hash_map::Entry, HashMap}; -use std::rc::Rc; - -use serde::{Deserialize, Serialize}; - -use crate::font::{Face, FaceInfo, FontVariant}; - -/// Handles font and image loading. -pub struct Env { - /// The loader that serves the font face and file buffers. - loader: Box<dyn Loader>, - /// Faces indexed by [`FaceId`]. `None` if not yet loaded. - faces: Vec<Option<Face>>, - /// Maps a family name to the ids of all faces that are part of the family. - families: HashMap<String, Vec<FaceId>>, - /// Loaded images indexed by [`ImageId`]. - images: Vec<Image>, - /// Maps from paths to loaded images. - paths: HashMap<String, ImageId>, - /// Callback for loaded font faces. - on_face_load: Option<Box<dyn Fn(FaceId, &Face)>>, - /// Callback for loaded images. - on_image_load: Option<Box<dyn Fn(ImageId, &Image)>>, -} - -impl Env { - /// Create an environment from a `loader`. - pub fn new(loader: impl Loader + 'static) -> Self { - let infos = loader.faces(); - - let mut faces = vec![]; - let mut families = HashMap::<String, Vec<FaceId>>::new(); - - for (i, info) in infos.iter().enumerate() { - let id = FaceId(i as u32); - faces.push(None); - families - .entry(info.family.to_lowercase()) - .and_modify(|vec| vec.push(id)) - .or_insert_with(|| vec![id]); - } - - Self { - loader: Box::new(loader), - faces, - families, - images: vec![], - paths: HashMap::new(), - on_face_load: None, - on_image_load: None, - } - } - - /// Create an empty environment for testing purposes. - pub fn blank() -> Self { - struct BlankLoader; - - impl Loader for BlankLoader { - fn faces(&self) -> &[FaceInfo] { - &[] - } - - fn load_face(&mut self, _: usize) -> Option<Buffer> { - None - } - - fn load_file(&mut self, _: &str) -> Option<Buffer> { - None - } - } - - Self::new(BlankLoader) - } - - /// Query for and load the font face from the given `family` that most - /// closely matches the given `variant`. - pub fn query_face(&mut self, family: &str, variant: FontVariant) -> Option<FaceId> { - // Check whether a family with this name exists. - let ids = self.families.get(family)?; - let infos = self.loader.faces(); - - let mut best = None; - let mut best_key = None; - - // Find the best matching variant of this font. - for &id in ids { - let current = infos[id.0 as usize].variant; - - // This is a perfect match, no need to search further. - if current == variant { - best = Some(id); - break; - } - - // If this is not a perfect match, we compute a key that we want to - // minimize among all variants. This key prioritizes style, then - // stretch distance and then weight distance. - let key = ( - current.style != variant.style, - current.stretch.distance(variant.stretch), - current.weight.distance(variant.weight), - ); - - if best_key.map_or(true, |b| key < b) { - best = Some(id); - best_key = Some(key); - } - } - - // Load the face if it's not already loaded. - let id = best?; - let idx = id.0 as usize; - let slot = &mut self.faces[idx]; - if slot.is_none() { - let index = infos[idx].index; - let buffer = self.loader.load_face(idx)?; - let face = Face::new(buffer, index)?; - if let Some(callback) = &self.on_face_load { - callback(id, &face); - } - *slot = Some(face); - } - - best - } - - /// Get a reference to a queried face. - /// - /// This panics if no face with this id was loaded. This function should - /// only be called with ids returned by [`query_face()`](Self::query_face). - #[track_caller] - pub fn face(&self, id: FaceId) -> &Face { - self.faces[id.0 as usize].as_ref().expect("font face was not loaded") - } - - /// Register a callback which is invoked when a font face was loaded. - pub fn on_face_load<F>(&mut self, f: F) - where - F: Fn(FaceId, &Face) + 'static, - { - self.on_face_load = Some(Box::new(f)); - } - - /// Load and decode an image file from a path. - pub fn load_image(&mut self, path: &str) -> Option<ImageId> { - Some(match self.paths.entry(path.to_string()) { - Entry::Occupied(entry) => *entry.get(), - Entry::Vacant(entry) => { - let buffer = self.loader.load_file(path)?; - let image = Image::parse(&buffer)?; - let id = ImageId(self.images.len() as u32); - if let Some(callback) = &self.on_image_load { - callback(id, &image); - } - self.images.push(image); - *entry.insert(id) - } - }) - } - - /// Get a reference to a loaded image. - /// - /// This panics if no image with this id was loaded. This function should - /// only be called with ids returned by [`load_image()`](Self::load_image). - #[track_caller] - pub fn image(&self, id: ImageId) -> &Image { - &self.images[id.0 as usize] - } - - /// Register a callback which is invoked when an image was loaded. - pub fn on_image_load<F>(&mut self, f: F) - where - F: Fn(ImageId, &Image) + 'static, - { - self.on_image_load = Some(Box::new(f)); - } -} - -/// Loads fonts and images from a remote or local source. -pub trait Loader { - /// Descriptions of all font faces this loader serves. - fn faces(&self) -> &[FaceInfo]; - - /// Load the font face with the given index in [`faces()`](Self::faces). - fn load_face(&mut self, idx: usize) -> Option<Buffer>; - - /// Load a file from a path. - fn load_file(&mut self, path: &str) -> Option<Buffer>; -} - -/// A shared byte buffer. -pub type Buffer = Rc<Vec<u8>>; - -/// A unique identifier for a loaded font face. -#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash, Serialize, Deserialize)] -pub struct FaceId(u32); - -impl FaceId { - /// A blank initialization value. - pub const MAX: Self = Self(u32::MAX); - - /// Create a face id from the raw underlying value. - /// - /// This should only be called with values returned by - /// [`into_raw`](Self::into_raw). - pub fn from_raw(v: u32) -> Self { - Self(v) - } - - /// Convert into the raw underlying value. - pub fn into_raw(self) -> u32 { - self.0 - } -} - -/// A unique identifier for a loaded image. -#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash, Serialize, Deserialize)] -pub struct ImageId(u32); - -impl ImageId { - /// Create an image id from the raw underlying value. - /// - /// This should only be called with values returned by - /// [`into_raw`](Self::into_raw). - pub fn from_raw(v: u32) -> Self { - Self(v) - } - - /// Convert into the raw underlying value. - pub fn into_raw(self) -> u32 { - self.0 - } -} |