Unbounded pages 🌌

src/eval/context.rs

@@ -95,6 +95,7 @@ impl EvalContext {
     pub fn start_page_group(&mut self, softness: Softness) {
         self.start_group(PageGroup {
             size: self.state.page.size,
+            expand: self.state.page.expand,
             padding: self.state.page.margins(),
             dirs: self.state.dirs,
             align: self.state.align,
@@ -124,7 +125,7 @@ impl EvalContext {
                     child: NodeStack {
                         dirs: group.dirs,
                         align: group.align,
-                        expansion: Gen::uniform(Expansion::Fill),
+                        expand: group.expand,
                         children,
                     }
                     .into(),
@@ -281,6 +282,7 @@ pub enum Softness {
 #[derive(Debug)]
 struct PageGroup {
     size: Size,
+    expand: Spec<Expansion>,
     padding: Sides<Linear>,
     dirs: LayoutDirs,
     align: ChildAlign,

src/eval/mod.rs

@@ -19,7 +19,7 @@ use std::rc::Rc;
 use crate::color::Color;
 use crate::diag::Pass;
 use crate::env::SharedEnv;
-use crate::geom::{Angle, Gen, Length, Relative};
+use crate::geom::{Angle, Length, Relative, Spec};
 use crate::layout::{self, Expansion, NodeSpacing, NodeStack};
 use crate::syntax::*;
 
@@ -137,7 +137,7 @@ impl Eval for Spanned<&NodeRaw> {
         ctx.push(NodeStack {
             dirs: ctx.state.dirs,
             align: ctx.state.align,
-            expansion: Gen::uniform(Expansion::Fit),
+            expand: Spec::uniform(Expansion::Fit),
             children,
         });
 

src/eval/state.rs

@@ -4,8 +4,9 @@ use fontdock::{fallback, FallbackTree, FontStretch, FontStyle, FontVariant, Font
 
 use super::Scope;
 use crate::geom::{
-    Align, ChildAlign, Dir, LayoutDirs, Length, Linear, Relative, Sides, Size,
+    Align, ChildAlign, Dir, LayoutDirs, Length, Linear, Relative, Sides, Size, Spec,
 };
+use crate::layout::Expansion;
 use crate::paper::{Paper, PaperClass, PAPER_A4};
 
 /// The evaluation state.
@@ -45,6 +46,8 @@ pub struct StatePage {
     pub class: PaperClass,
     /// The width and height of the page.
     pub size: Size,
+    /// Whether the expand the pages to the `size` or to fit the content.
+    pub expand: Spec<Expansion>,
     /// The amount of white space in the order [left, top, right, bottom]. If a
     /// side is set to `None`, the default for the paper class is used.
     pub margins: Sides<Option<Linear>>,
@@ -56,6 +59,7 @@ impl StatePage {
         Self {
             class: paper.class,
             size: paper.size(),
+            expand: Spec::uniform(Expansion::Fill),
             margins: Sides::uniform(None),
         }
     }

src/geom/length.rs

@@ -81,6 +81,16 @@ impl Length {
         Self { raw: self.raw.max(other.raw) }
     }
 
+    /// Whether the length is finite.
+    pub fn is_finite(self) -> bool {
+        self.raw.is_finite()
+    }
+
+    /// Whether the length is infinite.
+    pub fn is_infinite(self) -> bool {
+        self.raw.is_infinite()
+    }
+
     /// Whether the length is `NaN`.
     pub fn is_nan(self) -> bool {
         self.raw.is_nan()

src/geom/relative.rs

@@ -26,7 +26,12 @@ impl Relative {
 
     /// Resolve this relative to the given `length`.
     pub fn resolve(self, length: Length) -> Length {
-        self.get() * length
+        // Zero wins over infinity.
+        if self.0 == 0.0 {
+            Length::ZERO
+        } else {
+            self.get() * length
+        }
     }
 }
 

src/geom/size.rs

@@ -31,6 +31,16 @@ impl Size {
         self.width >= other.width && self.height >= other.height
     }
 
+    /// Whether both components are finite.
+    pub fn is_finite(self) -> bool {
+        self.width.is_finite() && self.height.is_finite()
+    }
+
+    /// Whether any of the two components is infinite.
+    pub fn is_infinite(self) -> bool {
+        self.width.is_infinite() || self.height.is_infinite()
+    }
+
     /// Whether any of the two components is `NaN`.
     pub fn is_nan(self) -> bool {
         self.width.is_nan() || self.height.is_nan()

src/layout/fixed.rs

@@ -14,10 +14,10 @@ pub struct NodeFixed {
 
 impl Layout for NodeFixed {
     fn layout(&self, ctx: &mut LayoutContext, areas: &Areas) -> Layouted {
-        let Area { rem, full } = areas.current;
+        let Areas { current, full, .. } = areas;
         let size = Size::new(
-            self.width.map(|w| w.resolve(full.width)).unwrap_or(rem.width),
-            self.height.map(|h| h.resolve(full.height)).unwrap_or(rem.height),
+            self.width.map(|w| w.resolve(full.width)).unwrap_or(current.width),
+            self.height.map(|h| h.resolve(full.height)).unwrap_or(current.height),
         );
 
         let areas = Areas::once(size);

src/layout/mod.rs

@@ -71,27 +71,13 @@ pub struct LayoutContext {
     pub env: SharedEnv,
 }
 
-/// An area into which content can be laid out.
-#[derive(Debug, Copy, Clone, PartialEq)]
-pub struct Area {
-    /// The remaining size of this area.
-    pub rem: Size,
-    /// The full size this area once had (used for relative sizing).
-    pub full: Size,
-}
-
-impl Area {
-    /// Create a new area.
-    pub fn new(size: Size) -> Self {
-        Self { rem: size, full: size }
-    }
-}
-
 /// A collection of areas to layout into.
 #[derive(Debug, Clone, PartialEq)]
 pub struct Areas {
-    /// The current area.
-    pub current: Area,
+    /// The remaining size of the current area.
+    pub current: Size,
+    /// The full size the current area once had (used for relative sizing).
+    pub full: Size,
     /// A stack of followup areas (the next area is the last element).
     pub backlog: Vec<Size>,
     /// The final area that is repeated when the backlog is empty.
@@ -102,7 +88,8 @@ impl Areas {
     /// Create a new length-1 sequence of areas with just one `area`.
     pub fn once(size: Size) -> Self {
         Self {
-            current: Area::new(size),
+            current: size,
+            full: size,
             backlog: vec![],
             last: None,
         }
@@ -111,7 +98,8 @@ impl Areas {
     /// Create a new sequence of areas that repeats `area` indefinitely.
     pub fn repeat(size: Size) -> Self {
         Self {
-            current: Area::new(size),
+            current: size,
+            full: size,
             backlog: vec![],
             last: Some(size),
         }
@@ -120,7 +108,8 @@ impl Areas {
     /// Advance to the next area if there is any.
     pub fn next(&mut self) {
         if let Some(size) = self.backlog.pop().or(self.last) {
-            self.current = Area::new(size);
+            self.current = size;
+            self.full = size;
         }
     }
 
@@ -130,11 +119,32 @@ impl Areas {
     pub fn in_full_last(&self) -> bool {
         self.backlog.is_empty()
             && self.last.map_or(true, |size| {
-                self.current.rem.is_nan() || size.is_nan() || self.current.rem == size
+                self.current.is_nan() || size.is_nan() || self.current == size
             })
     }
 }
 
+/// Whether to expand or shrink a node along an axis.
+#[derive(Debug, Copy, Clone, Eq, PartialEq)]
+pub enum Expansion {
+    /// Fit the content.
+    Fit,
+    /// Fill the available space.
+    Fill,
+}
+
+impl Expansion {
+    /// Resolve the expansion to either the `fit` or `fill` length.
+    ///
+    /// Prefers `fit` if `fill` is infinite.
+    pub fn resolve(self, fit: Length, fill: Length) -> Length {
+        match self {
+            Self::Fill if fill.is_finite() => fill,
+            _ => fit,
+        }
+    }
+}
+
 /// The result of layouting a node.
 #[derive(Debug, Clone, PartialEq)]
 pub enum Layouted {
@@ -158,15 +168,6 @@ impl Layouted {
     }
 }
 
-/// Whether to expand or shrink a node along an axis.
-#[derive(Debug, Copy, Clone, Eq, PartialEq)]
-pub enum Expansion {
-    /// Fit the content.
-    Fit,
-    /// Fill the available space.
-    Fill,
-}
-
 /// A finished layout with elements at fixed positions.
 #[derive(Debug, Clone, PartialEq)]
 pub struct Frame {

src/layout/pad.rs

@@ -39,10 +39,8 @@ impl From<NodePad> for NodeAny {
 fn shrink(areas: &Areas, padding: Sides<Linear>) -> Areas {
     let shrink = |size| size - padding.resolve(size).size();
     Areas {
-        current: Area {
-            rem: shrink(areas.current.rem),
-            full: shrink(areas.current.full),
-        },
+        current: shrink(areas.current),
+        full: shrink(areas.full),
         backlog: areas.backlog.iter().copied().map(shrink).collect(),
         last: areas.last.map(shrink),
     }

src/layout/par.rs

@@ -74,7 +74,7 @@ impl<'a> ParLayouter<'a> {
     }
 
     fn push_spacing(&mut self, amount: Length) {
-        let cross_max = self.areas.current.rem.get(self.cross);
+        let cross_max = self.areas.current.get(self.cross);
         self.run_size.cross = (self.run_size.cross + amount).min(cross_max);
     }
 
@@ -84,7 +84,7 @@ impl<'a> ParLayouter<'a> {
         }
 
         let fits = {
-            let mut usable = self.areas.current.rem;
+            let mut usable = self.areas.current;
             *usable.get_mut(self.cross) -= self.run_size.cross;
             usable.fits(frame.size)
         };
@@ -92,7 +92,7 @@ impl<'a> ParLayouter<'a> {
         if !fits {
             self.finish_run();
 
-            while !self.areas.current.rem.fits(frame.size) {
+            while !self.areas.current.fits(frame.size) {
                 if self.areas.in_full_last() {
                     // TODO: Diagnose once the necessary spans exist.
                     let _ = warning!("cannot fit frame into any area");
@@ -112,10 +112,15 @@ impl<'a> ParLayouter<'a> {
     }
 
     fn finish_run(&mut self) {
-        let full_size = Gen::new(self.run_size.main, match self.par.cross_expansion {
-            Expansion::Fill => self.areas.current.full.get(self.cross),
-            Expansion::Fit => self.run_size.cross,
-        });
+        let full_size = {
+            let full = self.areas.full.switch(self.dirs);
+            Gen::new(
+                self.run_size.main,
+                self.par
+                    .cross_expansion
+                    .resolve(self.run_size.cross.min(full.cross), full.cross),
+            )
+        };
 
         let mut output = Frame::new(full_size.switch(self.dirs).to_size());
 
@@ -139,7 +144,7 @@ impl<'a> ParLayouter<'a> {
         self.lines.push((self.lines_size.main, output, self.run_ruler));
 
         let main_offset = full_size.main + self.par.line_spacing;
-        *self.areas.current.rem.get_mut(self.main) -= main_offset;
+        *self.areas.current.get_mut(self.main) -= main_offset;
         self.lines_size.main += main_offset;
         self.lines_size.cross = self.lines_size.cross.max(full_size.cross);
 

src/layout/stack.rs

@@ -11,7 +11,7 @@ pub struct NodeStack {
     /// How to align this stack in _its_ parent.
     pub align: ChildAlign,
     /// Whether to expand the axes to fill the area or to fit the content.
-    pub expansion: Gen<Expansion>,
+    pub expand: Spec<Expansion>,
     /// The nodes to be stacked.
     pub children: Vec<Node>,
 }
@@ -66,7 +66,7 @@ impl<'a> StackLayouter<'a> {
     }
 
     fn push_spacing(&mut self, amount: Length) {
-        let main_rest = self.areas.current.rem.get_mut(self.main);
+        let main_rest = self.areas.current.get_mut(self.main);
         let capped = amount.min(*main_rest);
         *main_rest -= capped;
         self.used.main += capped;
@@ -77,7 +77,7 @@ impl<'a> StackLayouter<'a> {
             self.finish_area();
         }
 
-        while !self.areas.current.rem.fits(frame.size) {
+        while !self.areas.current.fits(frame.size) {
             if self.areas.in_full_last() {
                 // TODO: Diagnose once the necessary spans exist.
                 let _ = warning!("cannot fit frame into any area");
@@ -90,7 +90,7 @@ impl<'a> StackLayouter<'a> {
         let size = frame.size.switch(self.dirs);
         self.frames.push((self.used.main, frame, align));
 
-        *self.areas.current.rem.get_mut(self.main) -= size.main;
+        *self.areas.current.get_mut(self.main) -= size.main;
         self.used.main += size.main;
         self.used.cross = self.used.cross.max(size.cross);
         self.ruler = align.main;
@@ -98,16 +98,11 @@ impl<'a> StackLayouter<'a> {
 
     fn finish_area(&mut self) {
         let full_size = {
-            let full = self.areas.current.full.switch(self.dirs);
+            let expand = self.stack.expand.switch(self.dirs);
+            let full = self.areas.full.switch(self.dirs);
             Gen::new(
-                match self.stack.expansion.main {
-                    Expansion::Fill => full.main,
-                    Expansion::Fit => self.used.main.min(full.main),
-                },
-                match self.stack.expansion.cross {
-                    Expansion::Fill => full.cross,
-                    Expansion::Fit => self.used.cross.min(full.cross),
-                },
+                expand.main.resolve(self.used.main.min(full.main), full.main),
+                expand.cross.resolve(self.used.cross.min(full.cross), full.cross),
             )
         };
 

src/library/insert.rs

@@ -55,8 +55,11 @@ struct NodeImage {
 
 impl Layout for NodeImage {
     fn layout(&self, _: &mut LayoutContext, areas: &Areas) -> Layouted {
-        let Area { rem, full } = areas.current;
-        let pixel_ratio = (self.dimensions.0 as f64) / (self.dimensions.1 as f64);
+        let Areas { current, full, .. } = areas;
+
+        let pixel_width = self.dimensions.0 as f64;
+        let pixel_height = self.dimensions.1 as f64;
+        let pixel_ratio = pixel_width / pixel_height;
 
         let width = self.width.map(|w| w.resolve(full.width));
         let height = self.height.map(|w| w.resolve(full.height));
@@ -66,12 +69,15 @@ impl Layout for NodeImage {
             (Some(width), None) => Size::new(width, width / pixel_ratio),
             (None, Some(height)) => Size::new(height * pixel_ratio, height),
             (None, None) => {
-                let ratio = rem.width / rem.height;
-                if ratio < pixel_ratio {
-                    Size::new(rem.width, rem.width / pixel_ratio)
-                } else {
+                let ratio = current.width / current.height;
+                if ratio < pixel_ratio && current.width.is_finite() {
+                    Size::new(current.width, current.width / pixel_ratio)
+                } else if current.height.is_finite() {
                     // TODO: Fix issue with line spacing.
-                    Size::new(rem.height * pixel_ratio, rem.height)
+                    Size::new(current.height * pixel_ratio, current.height)
+                } else {
+                    // Totally unbounded area, we have to make up something.
+                    Size::new(Length::pt(pixel_width), Length::pt(pixel_height))
                 }
             }
         };

src/library/layout.rs

@@ -197,13 +197,12 @@ pub fn box_(ctx: &mut EvalContext, args: &mut Args) -> Value {
     let children = ctx.end_content_group();
 
     let fill_if = |c| if c { Expansion::Fill } else { Expansion::Fit };
-    let expansion =
-        Spec::new(fill_if(width.is_some()), fill_if(height.is_some())).switch(dirs);
+    let expand = Spec::new(fill_if(width.is_some()), fill_if(height.is_some()));
 
     ctx.push(NodeFixed {
         width,
         height,
-        child: NodeStack { dirs, align, expansion, children }.into(),
+        child: NodeStack { dirs, align, expand, children }.into(),
     });
 
     ctx.state = snapshot;
@@ -271,6 +270,7 @@ pub fn page(ctx: &mut EvalContext, args: &mut Args) -> Value {
         if let Some(paper) = Paper::from_name(&name.v) {
             ctx.state.page.class = paper.class;
             ctx.state.page.size = paper.size();
+            ctx.state.page.expand = Spec::uniform(Expansion::Fill);
         } else {
             ctx.diag(error!(name.span, "invalid paper name"));
         }
@@ -279,11 +279,13 @@ pub fn page(ctx: &mut EvalContext, args: &mut Args) -> Value {
     if let Some(width) = args.get(ctx, "width") {
         ctx.state.page.class = PaperClass::Custom;
         ctx.state.page.size.width = width;
+        ctx.state.page.expand.horizontal = Expansion::Fill;
     }
 
     if let Some(height) = args.get(ctx, "height") {
         ctx.state.page.class = PaperClass::Custom;
         ctx.state.page.size.height = height;
+        ctx.state.page.expand.vertical = Expansion::Fill;
     }
 
     if let Some(margins) = args.get(ctx, "margins") {
@@ -307,8 +309,9 @@ pub fn page(ctx: &mut EvalContext, args: &mut Args) -> Value {
     }
 
     if args.get(ctx, "flip").unwrap_or(false) {
-        let size = &mut ctx.state.page.size;
-        std::mem::swap(&mut size.width, &mut size.height);
+        let page = &mut ctx.state.page;
+        std::mem::swap(&mut page.size.width, &mut page.size.height);
+        std::mem::swap(&mut page.expand.horizontal, &mut page.expand.vertical);
     }
 
     let main = args.get(ctx, "main-dir");

tests/typ/func-hv.typ

@@ -12,13 +12,13 @@ Add [h 10pt] [h 10pt] up
 // Relative to font size.
 Relative [h 100%] spacing
 
+// Missing spacing.
+// Error: 1:11-1:11 missing argument: spacing
+Totally [h] ignored
+
 // Swapped axes.
-[page main-dir: rtl, cross-dir: ttb][
+[page main-dir: rtl, cross-dir: ttb, height: 80pt][
     1 [h 1cm] 2
 
     3 [v 1cm] 4 [v -1cm] 5
 ]
-
-// Missing spacing.
-// Error: 1:11-1:11 missing argument: spacing
-Totally [h] ignored

tests/typ/func-image.typ

@@ -14,7 +14,7 @@
 [image "res/rhino.png"]
 
 // Fit to height of page.
-[page width: 270pt][
+[page height: 40pt][
     [image "res/rhino.png"]
 ]
 
@@ -29,7 +29,7 @@
 
 // Make sure the bounding-box of the image is correct.
 [align bottom, right][
-    [image "res/tiger.jpg"]
+    [image "res/tiger.jpg", width: 60pt]
 ]
 
 ---

tests/typ/func-page.typ

@@ -1,28 +1,36 @@
 // Test configuring page sizes and margins.
 
-// Set width.
-[page width: 50pt][High]
-
-// Set height.
-[page height: 50pt][Wide]
+// Set width and height.
+[page width: 120pt, height: 120pt]
+[page width: 40pt][High]
+[page height: 40pt][Wide]
 
 // Set all margins at once.
-[page margins: 40pt][
+[page margins: 30pt][
     [align top, left][TL]
     [align bottom, right][BR]
 ]
 
 // Set individual margins.
+[page height: 40pt]
 [page left: 0pt   | align left][Left]
 [page right: 0pt  | align right][Right]
 [page top: 0pt    | align top][Top]
 [page bottom: 0pt | align bottom][Bottom]
 
 // Ensure that specific margins override general margins.
-[page margins: 0pt, left: 40pt][Overriden]
+[page margins: 0pt, left: 20pt][Overriden]
 
-// Flip the page.
-[page "a10", flip: true][Flipped]
+---
+// Test flipping.
+
+// Flipped predefined paper.
+[page "a11", flip: true][Flipped A11]
+
+// Flipped custom page size.
+[page width: 40pt, height: 120pt]
+[page flip: true]
+Wide
 
 ---
 // Test a combination of pages with bodies and normal content.
@@ -40,7 +48,7 @@ Sixth
 ---
 // Test changing the layouting directions of pages.
 
-[page main-dir: btt, cross-dir: rtl]
+[page height: 50pt, main-dir: btt, cross-dir: rtl]
 
 Right to left!
 

tests/typ/headings.typ

@@ -8,15 +8,12 @@
 ####### Seven
 
 ---
-// Is a heading.
+// Heading vs. no heading.
 
 /**/ # Heading
 {[## Heading]}
 [box][### Heading]
 
----
-// Is no heading.
-
 \# No heading
 
 Text with # hashtag

tests/typeset.rs

@@ -18,8 +18,8 @@ use typst::env::{Env, ImageResource, ResourceLoader, SharedEnv};
 use typst::eval::{Args, EvalContext, State, Value, ValueFunc};
 use typst::export::pdf;
 use typst::font::FontLoader;
-use typst::geom::{Length, Point, Sides, Size};
-use typst::layout::{Element, Frame, Image};
+use typst::geom::{Length, Point, Sides, Size, Spec};
+use typst::layout::{Element, Expansion, Frame, Image};
 use typst::parse::{LineMap, Scanner};
 use typst::shaping::Shaped;
 use typst::syntax::{Location, Pos, SpanVec, Spanned, WithSpan};
@@ -153,12 +153,12 @@ fn test(
 
     let env = env.borrow();
     if !frames.is_empty() {
-        let canvas = draw(&frames, &env, 2.0);
-        canvas.pixmap.save_png(png_path).unwrap();
-
         let pdf_data = pdf::export(&frames, &env);
         fs::write(pdf_path, pdf_data).unwrap();
 
+        let canvas = draw(&frames, &env, 2.0);
+        canvas.pixmap.save_png(png_path).unwrap();
+
         if let Some(ref_path) = ref_path {
             if let Ok(ref_pixmap) = Pixmap::load_png(ref_path) {
                 if canvas.pixmap != ref_pixmap {
@@ -184,7 +184,11 @@ fn test_part(i: usize, src: &str, env: &SharedEnv) -> (bool, Vec<Frame>) {
     let (compare_ref, ref_diags) = parse_metadata(src, &map);
 
     let mut state = State::default();
-    state.page.size = Size::uniform(Length::pt(120.0));
+
+    // We want to have "unbounded" pages, so we allow them to be infinitely
+    // large and fit them to match their content.
+    state.page.size = Size::new(Length::pt(120.0), Length::raw(f64::INFINITY));
+    state.page.expand = Spec::new(Expansion::Fill, Expansion::Fit);
     state.page.margins = Sides::uniform(Some(Length::pt(10.0).into()));
 
     pub fn dump(_: &mut EvalContext, args: &mut Args) -> Value {
@@ -283,6 +287,10 @@ fn draw(frames: &[Frame], env: &Env, pixel_per_pt: f32) -> Canvas {
 
     let pixel_width = (pixel_per_pt * width.to_pt() as f32) as u32;
     let pixel_height = (pixel_per_pt * height.to_pt() as f32) as u32;
+    if pixel_width > 4000 || pixel_height > 4000 {
+        panic!("overlarge image: {} by {}", pixel_width, pixel_height);
+    }
+
     let mut canvas = Canvas::new(pixel_width, pixel_height).unwrap();
     canvas.scale(pixel_per_pt, pixel_per_pt);
     canvas.pixmap.fill(Color::BLACK);