typst/src/library/graphics/transform.rs
2022-05-25 13:59:06 +02:00

117 lines
3.3 KiB
Rust

use crate::geom::Transform;
use crate::library::prelude::*;
/// Move a node without affecting layout.
#[derive(Debug, Hash)]
pub struct MoveNode {
/// The offset by which to move the node.
pub delta: Spec<Relative<RawLength>>,
/// The node whose contents should be moved.
pub child: LayoutNode,
}
#[node]
impl MoveNode {
fn construct(_: &mut Machine, args: &mut Args) -> TypResult<Content> {
let dx = args.named("dx")?.unwrap_or_default();
let dy = args.named("dy")?.unwrap_or_default();
Ok(Content::inline(Self {
delta: Spec::new(dx, dy),
child: args.expect("body")?,
}))
}
}
impl Layout for MoveNode {
fn layout(
&self,
ctx: &mut Context,
regions: &Regions,
styles: StyleChain,
) -> TypResult<Vec<Arc<Frame>>> {
let mut frames = self.child.layout(ctx, regions, styles)?;
let delta = self.delta.resolve(styles);
for frame in &mut frames {
let delta = delta.zip(frame.size).map(|(d, s)| d.relative_to(s));
Arc::make_mut(frame).translate(delta.to_point());
}
Ok(frames)
}
}
/// Transform a node without affecting layout.
#[derive(Debug, Hash)]
pub struct TransformNode<const T: TransformKind> {
/// Transformation to apply to the contents.
pub transform: Transform,
/// The node whose contents should be transformed.
pub child: LayoutNode,
}
/// Rotate a node without affecting layout.
pub type RotateNode = TransformNode<ROTATE>;
/// Scale a node without affecting layout.
pub type ScaleNode = TransformNode<SCALE>;
#[node]
impl<const T: TransformKind> TransformNode<T> {
/// The origin of the transformation.
#[property(resolve)]
pub const ORIGIN: Spec<Option<RawAlign>> = Spec::default();
fn construct(_: &mut Machine, args: &mut Args) -> TypResult<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(Content::inline(Self {
transform,
child: args.expect("body")?,
}))
}
}
impl<const T: TransformKind> Layout for TransformNode<T> {
fn layout(
&self,
ctx: &mut Context,
regions: &Regions,
styles: StyleChain,
) -> TypResult<Vec<Arc<Frame>>> {
let origin = styles.get(Self::ORIGIN).unwrap_or(Align::CENTER_HORIZON);
let mut frames = self.child.layout(ctx, regions, styles)?;
for frame in &mut frames {
let Spec { 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));
Arc::make_mut(frame).transform(transform);
}
Ok(frames)
}
}
/// Kinds of transformations.
pub type TransformKind = usize;
/// A rotational transformation.
const ROTATE: TransformKind = 1;
/// A scale transformation.
const SCALE: TransformKind = 2;