typst/library/src/layout/transform.rs
2022-11-24 17:41:41 +01:00

111 lines
3.2 KiB
Rust

use typst::geom::Transform;
use crate::prelude::*;
/// Move content without affecting layout.
#[derive(Debug, Hash)]
pub struct MoveNode {
/// The offset by which to move the content.
pub delta: Axes<Rel<Length>>,
/// The content that should be moved.
pub child: Content,
}
#[node(LayoutInline)]
impl MoveNode {
fn construct(_: &Vm, args: &mut Args) -> SourceResult<Content> {
let dx = args.named("dx")?.unwrap_or_default();
let dy = args.named("dy")?.unwrap_or_default();
Ok(Self {
delta: Axes::new(dx, dy),
child: args.expect("body")?,
}
.pack())
}
}
impl LayoutInline for MoveNode {
fn layout_inline(
&self,
world: Tracked<dyn World>,
regions: &Regions,
styles: StyleChain,
) -> SourceResult<Frame> {
let mut frame = self.child.layout_inline(world, regions, styles)?;
let delta = self.delta.resolve(styles);
let delta = delta.zip(frame.size()).map(|(d, s)| d.relative_to(s));
frame.translate(delta.to_point());
Ok(frame)
}
}
/// Transform content without affecting layout.
#[derive(Debug, Hash)]
pub struct TransformNode<const T: TransformKind> {
/// Transformation to apply to the content.
pub transform: Transform,
/// The content that should be transformed.
pub child: Content,
}
/// Rotate content without affecting layout.
pub type RotateNode = TransformNode<ROTATE>;
/// Scale content without affecting layout.
pub type ScaleNode = TransformNode<SCALE>;
#[node(LayoutInline)]
impl<const T: TransformKind> TransformNode<T> {
/// The origin of the transformation.
#[property(resolve)]
pub const ORIGIN: Axes<Option<GenAlign>> = Axes::default();
fn construct(_: &Vm, args: &mut Args) -> SourceResult<Content> {
let transform = match T {
ROTATE => {
let angle = args.named_or_find("angle")?.unwrap_or_default();
Transform::rotate(angle)
}
SCALE | _ => {
let all = args.find()?;
let sx = args.named("x")?.or(all).unwrap_or(Ratio::one());
let sy = args.named("y")?.or(all).unwrap_or(Ratio::one());
Transform::scale(sx, sy)
}
};
Ok(Self { transform, child: args.expect("body")? }.pack())
}
}
impl<const T: TransformKind> LayoutInline for TransformNode<T> {
fn layout_inline(
&self,
world: Tracked<dyn World>,
regions: &Regions,
styles: StyleChain,
) -> SourceResult<Frame> {
let mut frame = self.child.layout_inline(world, regions, styles)?;
let origin = styles.get(Self::ORIGIN).unwrap_or(Align::CENTER_HORIZON);
let Axes { x, y } = origin.zip(frame.size()).map(|(o, s)| o.position(s));
let transform = Transform::translate(x, y)
.pre_concat(self.transform)
.pre_concat(Transform::translate(-x, -y));
frame.transform(transform);
Ok(frame)
}
}
/// Kinds of transformations.
///
/// The move transformation is handled separately.
pub type TransformKind = usize;
/// A rotational transformation.
const ROTATE: TransformKind = 1;
/// A scale transformation.
const SCALE: TransformKind = 2;