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Diffstat (limited to 'crates/typst-library/src/visualize/image.rs')
| -rw-r--r-- | crates/typst-library/src/visualize/image.rs | 197 |
1 files changed, 197 insertions, 0 deletions
diff --git a/crates/typst-library/src/visualize/image.rs b/crates/typst-library/src/visualize/image.rs new file mode 100644 index 00000000..b169cc4d --- /dev/null +++ b/crates/typst-library/src/visualize/image.rs @@ -0,0 +1,197 @@ +use std::ffi::OsStr; +use std::path::Path; + +use typst::image::{Image, ImageFormat, RasterFormat, VectorFormat}; +use typst::util::Bytes; + +use crate::meta::{Figurable, LocalName}; +use crate::prelude::*; +use crate::text::families; + +/// A raster or vector graphic. +/// +/// Supported formats are PNG, JPEG, GIF and SVG. +/// +/// _Note:_ Work on SVG export is ongoing and there might be visual inaccuracies +/// in the resulting PDF. Make sure to double-check embedded SVG images. If you +/// have an issue, also feel free to report it on [GitHub][gh-svg]. +/// +/// ## Example { #example } +/// ```example +/// #figure( +/// image("molecular.jpg", width: 80%), +/// caption: [ +/// A step in the molecular testing +/// pipeline of our lab. +/// ], +/// ) +/// ``` +/// +/// [gh-svg]: https://github.com/typst/typst/issues?q=is%3Aopen+is%3Aissue+label%3Asvg +/// +/// Display: Image +/// Category: visualize +#[element(Layout, LocalName, Figurable)] +pub struct ImageElem { + /// Path to an image file. + #[required] + #[parse( + let Spanned { v: path, span } = + args.expect::<Spanned<EcoString>>("path to image file")?; + let id = vm.location().join(&path).at(span)?; + let data = vm.world().file(id).at(span)?; + path + )] + pub path: EcoString, + + /// The raw file data. + #[internal] + #[required] + #[parse(data)] + pub data: Bytes, + + /// The width of the image. + pub width: Smart<Rel<Length>>, + + /// The height of the image. + pub height: Smart<Rel<Length>>, + + /// A text describing the image. + pub alt: Option<EcoString>, + + /// How the image should adjust itself to a given area. + #[default(ImageFit::Cover)] + pub fit: ImageFit, +} + +impl Layout for ImageElem { + #[tracing::instrument(name = "ImageElem::layout", skip_all)] + fn layout( + &self, + vt: &mut Vt, + styles: StyleChain, + regions: Regions, + ) -> SourceResult<Fragment> { + let ext = Path::new(self.path().as_str()) + .extension() + .and_then(OsStr::to_str) + .unwrap_or_default() + .to_lowercase(); + + let format = match ext.as_str() { + "png" => ImageFormat::Raster(RasterFormat::Png), + "jpg" | "jpeg" => ImageFormat::Raster(RasterFormat::Jpg), + "gif" => ImageFormat::Raster(RasterFormat::Gif), + "svg" | "svgz" => ImageFormat::Vector(VectorFormat::Svg), + _ => bail!(self.span(), "unknown image format"), + }; + + let image = Image::with_fonts( + self.data(), + format, + vt.world, + families(styles).next().as_ref().map(|f| f.as_str()), + self.alt(styles), + ) + .at(self.span())?; + + let sizing = Axes::new(self.width(styles), self.height(styles)); + let region = sizing + .zip(regions.base()) + .map(|(s, r)| s.map(|v| v.resolve(styles).relative_to(r))) + .unwrap_or(regions.base()); + + let expand = sizing.as_ref().map(Smart::is_custom) | regions.expand; + let region_ratio = region.x / region.y; + + // Find out whether the image is wider or taller than the target size. + let pxw = image.width() as f64; + let pxh = image.height() as f64; + let px_ratio = pxw / pxh; + let wide = px_ratio > region_ratio; + + // The space into which the image will be placed according to its fit. + let target = if expand.x && expand.y { + region + } else if expand.x || (!expand.y && wide && region.x.is_finite()) { + Size::new(region.x, region.y.min(region.x.safe_div(px_ratio))) + } else if region.y.is_finite() { + Size::new(region.x.min(region.y * px_ratio), region.y) + } else { + Size::new(Abs::pt(pxw), Abs::pt(pxh)) + }; + + // Compute the actual size of the fitted image. + let fit = self.fit(styles); + let fitted = match fit { + ImageFit::Cover | ImageFit::Contain => { + if wide == (fit == ImageFit::Contain) { + Size::new(target.x, target.x / px_ratio) + } else { + Size::new(target.y * px_ratio, target.y) + } + } + ImageFit::Stretch => target, + }; + + // First, place the image in a frame of exactly its size and then resize + // the frame to the target size, center aligning the image in the + // process. + let mut frame = Frame::new(fitted); + frame.push(Point::zero(), FrameItem::Image(image, fitted, self.span())); + frame.resize(target, Align::CENTER_HORIZON); + + // Create a clipping group if only part of the image should be visible. + if fit == ImageFit::Cover && !target.fits(fitted) { + frame.clip(); + } + + // Apply metadata. + frame.meta(styles, false); + + Ok(Fragment::frame(frame)) + } +} + +impl LocalName for ImageElem { + fn local_name(&self, lang: Lang, _: Option<Region>) -> &'static str { + match lang { + Lang::ALBANIAN => "Figurë", + Lang::ARABIC => "شكل", + Lang::BOKMÅL => "Figur", + Lang::CHINESE => "图", + Lang::CZECH => "Obrázek", + Lang::DANISH => "Figur", + Lang::DUTCH => "Figuur", + Lang::FILIPINO => "Pigura", + Lang::FRENCH => "Figure", + Lang::GERMAN => "Abbildung", + Lang::ITALIAN => "Figura", + Lang::NYNORSK => "Figur", + Lang::POLISH => "Rysunek", + Lang::PORTUGUESE => "Figura", + Lang::RUSSIAN => "Рисунок", + Lang::SLOVENIAN => "Slika", + Lang::SPANISH => "Figura", + Lang::SWEDISH => "Figur", + Lang::TURKISH => "Şekil", + Lang::UKRAINIAN => "Рисунок", + Lang::VIETNAMESE => "Hình", + Lang::ENGLISH | _ => "Figure", + } + } +} + +impl Figurable for ImageElem {} + +/// How an image should adjust itself to a given area. +#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash, Cast)] +pub enum ImageFit { + /// The image should completely cover the area. This is the default. + Cover, + /// The image should be fully contained in the area. + Contain, + /// The image should be stretched so that it exactly fills the area, even if + /// this means that the image will be distorted. + Stretch, +} |