Merge pull request #17 from typst/rects

Add rectangle function 🎛

8 files changed, 212 insertions, 34 deletions

diff --git a/src/export/pdf.rs b/src/export/pdf.rs
index 03c9ae95..e5124c21 100644
--- a/src/export/pdf.rs
+++ b/src/export/pdf.rs
@@ -13,9 +13,10 @@ use pdf_writer::{
 };
 use ttf_parser::{name_id, GlyphId};
 
+use crate::color::Color;
 use crate::env::{Env, ImageResource, ResourceId};
 use crate::geom::Length;
-use crate::layout::{Element, Frame};
+use crate::layout::{Element, Fill, Frame, Shape};
 
 /// Export a collection of frames into a _PDF_ document.
 ///
@@ -57,6 +58,7 @@ impl<'a> PdfExporter<'a> {
                         }
                         images.insert(image.res);
                     }
+                    Element::Geometry(_) => {}
                 }
             }
         }
@@ -127,6 +129,56 @@ impl<'a> PdfExporter<'a> {
     fn write_page(&mut self, id: Ref, page: &'a Frame) {
         let mut content = Content::new();
 
+        for (pos, element) in &page.elements {
+            match element {
+                Element::Image(image) => {
+                    let name = format!("Im{}", self.images.map(image.res));
+                    let size = image.size;
+                    let x = pos.x.to_pt() as f32;
+                    let y = (page.size.height - pos.y - size.height).to_pt() as f32;
+                    let w = size.width.to_pt() as f32;
+                    let h = size.height.to_pt() as f32;
+
+                    content.save_state();
+                    content.matrix(w, 0.0, 0.0, h, x, y);
+                    content.x_object(Name(name.as_bytes()));
+                    content.restore_state();
+                }
+
+                Element::Geometry(geometry) => {
+                    content.save_state();
+
+                    match geometry.fill {
+                        Fill::Color(Color::Rgba(c)) => {
+                            content.fill_rgb(
+                                c.r as f32 / 255.,
+                                c.g as f32 / 255.,
+                                c.b as f32 / 255.,
+                            );
+                        }
+                        Fill::Image(_) => todo!(),
+                    }
+
+                    let x = pos.x.to_pt() as f32;
+
+                    match &geometry.shape {
+                        Shape::Rect(r) => {
+                            let w = r.width.to_pt() as f32;
+                            let h = r.height.to_pt() as f32;
+                            let y = (page.size.height - pos.y - r.height).to_pt() as f32;
+                            if w > 0.0 && h > 0.0 {
+                                content.rect(x, y, w, h, false, true);
+                            }
+                        }
+                    }
+
+                    content.restore_state();
+                }
+
+                _ => {}
+            }
+        }
+
         // We only write font switching actions when the used face changes. To
         // do that, we need to remember the active face.
         let mut face = FaceId::MAX;
@@ -153,22 +205,6 @@ impl<'a> PdfExporter<'a> {
 
         drop(text);
 
-        for (pos, element) in &page.elements {
-            if let Element::Image(image) = element {
-                let name = format!("Im{}", self.images.map(image.res));
-                let size = image.size;
-                let x = pos.x.to_pt() as f32;
-                let y = (page.size.height - pos.y - size.height).to_pt() as f32;
-                let w = size.width.to_pt() as f32;
-                let h = size.height.to_pt() as f32;
-
-                content.save_state();
-                content.matrix(w, 0.0, 0.0, h, x, y);
-                content.x_object(Name(name.as_bytes()));
-                content.restore_state();
-            }
-        }
-
         self.writer.stream(id, &content.finish());
     }
 
diff --git a/src/layout/background.rs b/src/layout/background.rs
new file mode 100644
index 00000000..07248e02
--- /dev/null
+++ b/src/layout/background.rs
@@ -0,0 +1,37 @@
+use super::*;
+
+/// A node that represents a rectangular box.
+#[derive(Debug, Clone, PartialEq)]
+pub struct NodeBackground {
+    /// The background fill.
+    pub fill: Fill,
+    /// The child node to be filled in.
+    pub child: Node,
+}
+
+impl Layout for NodeBackground {
+    fn layout(&self, ctx: &mut LayoutContext, areas: &Areas) -> Layouted {
+        let mut layouted = self.child.layout(ctx, areas);
+
+        if let Some(first) = layouted.frames_mut().first_mut() {
+            first.elements.insert(
+                0,
+                (
+                    Point::ZERO,
+                    Element::Geometry(Geometry {
+                        shape: Shape::Rect(first.size),
+                        fill: self.fill.clone(),
+                    }),
+                ),
+            )
+        }
+
+        layouted
+    }
+}
+
+impl From<NodeBackground> for NodeAny {
+    fn from(background: NodeBackground) -> Self {
+        Self::new(background)
+    }
+}
diff --git a/src/layout/mod.rs b/src/layout/mod.rs
index 44960de7..30295841 100644
--- a/src/layout/mod.rs
+++ b/src/layout/mod.rs
@@ -1,5 +1,6 @@
 //! Layouting.
 
+mod background;
 mod fixed;
 mod node;
 mod pad;
@@ -8,10 +9,12 @@ mod spacing;
 mod stack;
 mod text;
 
+use crate::color::Color;
 use crate::env::{Env, ResourceId};
 use crate::geom::*;
 use crate::shaping::Shaped;
 
+pub use background::*;
 pub use fixed::*;
 pub use node::*;
 pub use pad::*;
@@ -54,7 +57,7 @@ impl NodePages {
     pub fn layout(&self, ctx: &mut LayoutContext) -> Vec<Frame> {
         let areas = Areas::repeat(self.size);
         let layouted = self.child.layout(ctx, &areas);
-        layouted.frames()
+        layouted.into_frames()
     }
 }
 
@@ -157,9 +160,27 @@ pub enum Layouted {
 }
 
 impl Layouted {
-    /// Return all frames contained in this variant (zero, one or arbitrarily
-    /// many).
-    pub fn frames(self) -> Vec<Frame> {
+    /// Return a reference to all frames contained in this variant (zero, one or
+    /// arbitrarily many).
+    pub fn frames(&self) -> &[Frame] {
+        match self {
+            Self::Spacing(_) => &[],
+            Self::Frame(frame, _) => std::slice::from_ref(frame),
+            Self::Frames(frames, _) => frames,
+        }
+    }
+
+    /// Return a mutable reference to all frames contained in this variant.
+    pub fn frames_mut(&mut self) -> &mut [Frame] {
+        match self {
+            Self::Spacing(_) => &mut [],
+            Self::Frame(frame, _) => std::slice::from_mut(frame),
+            Self::Frames(frames, _) => frames,
+        }
+    }
+
+    /// Return all frames contained in this varian.
+    pub fn into_frames(self) -> Vec<Frame> {
         match self {
             Self::Spacing(_) => vec![],
             Self::Frame(frame, _) => vec![frame],
@@ -204,6 +225,37 @@ pub enum Element {
     Text(Shaped),
     /// An image.
     Image(Image),
+    /// Some shape that could hold another frame.
+    Geometry(Geometry),
+}
+
+/// The kind of graphic fill to be applied to a [`Shape`].
+#[derive(Debug, Clone, PartialEq)]
+pub enum Fill {
+    /// The fill is a color.
+    Color(Color),
+    /// The fill is an image.
+    Image(Image),
+}
+
+/// A shape with some kind of fill.
+#[derive(Debug, Clone, PartialEq)]
+pub struct Geometry {
+    /// The shape to draw.
+    pub shape: Shape,
+    /// How the shape looks on the inside.
+    //
+    //  TODO: This could be made into a Vec<Fill> or something such that
+    //        the user can compose multiple fills with alpha values less
+    //        than one to achieve cool effects.
+    pub fill: Fill,
+}
+
+/// Some shape.
+#[derive(Debug, Clone, PartialEq)]
+pub enum Shape {
+    /// A rectangle.
+    Rect(Size),
 }
 
 /// An image element.
diff --git a/src/layout/pad.rs b/src/layout/pad.rs
index f8a623e3..425fa41b 100644
--- a/src/layout/pad.rs
+++ b/src/layout/pad.rs
@@ -15,14 +15,8 @@ impl Layout for NodePad {
         let areas = shrink(areas, self.padding);
 
         let mut layouted = self.child.layout(ctx, &areas);
-        match &mut layouted {
-            Layouted::Spacing(_) => {}
-            Layouted::Frame(frame, _) => pad(frame, self.padding),
-            Layouted::Frames(frames, _) => {
-                for frame in frames {
-                    pad(frame, self.padding);
-                }
-            }
+        for frame in layouted.frames_mut() {
+            pad(frame, self.padding);
         }
 
         layouted
diff --git a/src/library/layout.rs b/src/library/layout.rs
index 0e04c507..2812a48f 100644
--- a/src/library/layout.rs
+++ b/src/library/layout.rs
@@ -1,9 +1,9 @@
 use std::fmt::{self, Display, Formatter};
 
-use crate::eval::Softness;
-use crate::layout::{Expansion, NodeFixed, NodeSpacing, NodeStack};
+use crate::layout::{Expansion, Fill, NodeFixed, NodeSpacing, NodeStack};
 use crate::paper::{Paper, PaperClass};
 use crate::prelude::*;
+use crate::{eval::Softness, layout::NodeBackground};
 
 /// `align`: Align content along the layouting axes.
 ///
@@ -175,6 +175,7 @@ impl Display for Alignment {
 /// # Named arguments
 /// - Width of the box:  `width`, of type `linear` relative to parent width.
 /// - Height of the box: `height`, of type `linear` relative to parent height.
+/// - Background color of the box: `color`, of type `color`.
 pub fn box_(ctx: &mut EvalContext, args: &mut Args) -> Value {
     let snapshot = ctx.state.clone();
 
@@ -182,6 +183,7 @@ pub fn box_(ctx: &mut EvalContext, args: &mut Args) -> Value {
     let height = args.get(ctx, "height");
     let main = args.get(ctx, "main-dir");
     let cross = args.get(ctx, "cross-dir");
+    let color = args.get(ctx, "color");
 
     ctx.set_dirs(Gen::new(main, cross));
 
@@ -199,11 +201,21 @@ pub fn box_(ctx: &mut EvalContext, args: &mut Args) -> Value {
     let fill_if = |c| if c { Expansion::Fill } else { Expansion::Fit };
     let expand = Spec::new(fill_if(width.is_some()), fill_if(height.is_some()));
 
-    ctx.push(NodeFixed {
+    let fixed_node = NodeFixed {
         width,
         height,
         child: NodeStack { dirs, align, expand, children }.into(),
-    });
+    };
+
+    if let Some(color) = color {
+        ctx.push(NodeBackground {
+            fill: Fill::Color(color),
+            child: Node::Any(fixed_node.into()),
+        })
+    } else {
+        ctx.push(fixed_node);
+    }
+
 
     ctx.state = snapshot;
     Value::None
diff --git a/tests/library/ref/box.png b/tests/library/ref/box.png
new file mode 100644
index 00000000..37fd7d27
--- /dev/null
+++ b/tests/library/ref/box.png
diff --git a/tests/library/typ/box.typ b/tests/library/typ/box.typ
new file mode 100644
index 00000000..03e5da54
--- /dev/null
+++ b/tests/library/typ/box.typ
@@ -0,0 +1,23 @@
+#[page "a5", flip: true]
+
+// Rectangle with width, should have paragraph height
+#[box width: 2cm, color: #9650D6][aa]
+
+Sometimes there is no box
+
+// Rectangle with height, should span line
+#[box height: 2cm, width: 100%, color: #734CED][bb]
+
+// Empty rectangle with width and height
+#[box width: 6cm, height: 12pt, color: #CB4CED]
+
+// This empty rectangle should not be displayed
+#[box width: 2in, color: #ff0000]
+
+// This one should be
+#[box height: 15mm, width: 100%, color: #494DE3]
+
+// These are in a row!
+#[box width: 2in, height: 10pt, color: #D6CD67]
+#[box width: 2in, height: 10pt, color: #EDD466]
+#[box width: 2in, height: 10pt, color: #E3BE62]
diff --git a/tests/typeset.rs b/tests/typeset.rs
index 807d55d9..d431abfe 100644
--- a/tests/typeset.rs
+++ b/tests/typeset.rs
@@ -20,7 +20,7 @@ use typst::eval::{Args, EvalContext, Scope, State, Value, ValueFunc};
 use typst::export::pdf;
 use typst::font::FsIndexExt;
 use typst::geom::{Length, Point, Sides, Size, Spec};
-use typst::layout::{Element, Expansion, Frame, Image};
+use typst::layout::{Element, Expansion, Fill, Frame, Geometry, Image, Shape};
 use typst::library;
 use typst::parse::{LineMap, Scanner};
 use typst::pretty::{Pretty, Printer};
@@ -409,6 +409,9 @@ fn draw(frames: &[Frame], env: &Env, pixel_per_pt: f32) -> Canvas {
                 Element::Image(image) => {
                     draw_image(&mut canvas, pos, env, image);
                 }
+                Element::Geometry(geom) => {
+                    draw_geometry(&mut canvas, pos, env, geom);
+                }
             }
         }
 
@@ -444,6 +447,27 @@ fn draw_text(canvas: &mut Canvas, pos: Point, env: &Env, shaped: &Shaped) {
     }
 }
 
+fn draw_geometry(canvas: &mut Canvas, pos: Point, _: &Env, element: &Geometry) {
+    let x = pos.x.to_pt() as f32;
+    let y = pos.y.to_pt() as f32;
+
+    let mut paint = Paint::default();
+
+    match &element.fill {
+        Fill::Color(c) => match c {
+            typst::color::Color::Rgba(c) => paint.set_color_rgba8(c.r, c.g, c.b, c.a),
+        },
+        Fill::Image(_) => todo!(),
+    };
+
+    match &element.shape {
+        Shape::Rect(s) => {
+            let (w, h) = (s.width.to_pt() as f32, s.height.to_pt() as f32);
+            canvas.fill_rect(Rect::from_xywh(x, y, w, h).unwrap(), &paint);
+        }
+    };
+}
+
 fn draw_image(canvas: &mut Canvas, pos: Point, env: &Env, element: &Image) {
     let img = &env.resources.loaded::<ImageResource>(element.res);