Refactor layouting a bit

Notably:
- Handle aspect ratio in fixed node
- Inline constraint inflation into pad node

3 files changed, 25 insertions, 27 deletions

diff --git a/src/library/elements.rs b/src/library/elements.rs
index f90363bb..6e71626a 100644
--- a/src/library/elements.rs
+++ b/src/library/elements.rs
@@ -64,18 +64,19 @@ fn rect_impl(
     body: Template,
 ) -> Value {
     Value::Template(Template::from_inline(move |state| {
-        let mut stack = body.to_stack(state);
-        stack.aspect = aspect;
-
-        let mut node = FixedNode { width, height, child: stack.into() }.into();
+        let mut node = LayoutNode::new(FixedNode {
+            width,
+            height,
+            aspect,
+            child: body.to_stack(state).into(),
+        });
 
         if let Some(fill) = fill {
-            node = BackgroundNode {
+            node = LayoutNode::new(BackgroundNode {
                 shape: BackgroundShape::Rect,
                 fill: Paint::Color(fill),
                 child: node,
-            }
-            .into();
+            });
         }
 
         node
@@ -120,27 +121,22 @@ fn ellipse_impl(
         // perfectly into the ellipse.
         const PAD: f64 = 0.5 - SQRT_2 / 4.0;
 
-        let mut stack = body.to_stack(state);
-        stack.aspect = aspect;
-
-        let mut node = FixedNode {
+        let mut node = LayoutNode::new(FixedNode {
             width,
             height,
-            child: PadNode {
+            aspect,
+            child: LayoutNode::new(PadNode {
                 padding: Sides::splat(Relative::new(PAD).into()),
-                child: stack.into(),
-            }
-            .into(),
-        }
-        .into();
+                child: body.to_stack(state).into(),
+            }),
+        });
 
         if let Some(fill) = fill {
-            node = BackgroundNode {
+            node = LayoutNode::new(BackgroundNode {
                 shape: BackgroundShape::Ellipse,
                 fill: Paint::Color(fill),
                 child: node,
-            }
-            .into();
+            });
         }
 
         node
diff --git a/src/library/layout.rs b/src/library/layout.rs
index b1510cb6..91e2e7f3 100644
--- a/src/library/layout.rs
+++ b/src/library/layout.rs
@@ -145,8 +145,12 @@ pub fn boxed(_: &mut EvalContext, args: &mut Arguments) -> TypResult<Value> {
     let height = args.named("height")?;
     let body: Template = args.eat().unwrap_or_default();
     Ok(Value::Template(Template::from_inline(move |state| {
-        let child = body.to_stack(state).into();
-        FixedNode { width, height, child }
+        FixedNode {
+            width,
+            height,
+            aspect: None,
+            child: body.to_stack(state).into(),
+        }
     })))
 }
 
@@ -190,10 +194,7 @@ pub fn stack(_: &mut EvalContext, args: &mut Arguments) -> TypResult<Value> {
     Ok(Value::Template(Template::from_block(move |state| {
         let children = children
             .iter()
-            .map(|child| {
-                let child = child.to_stack(state).into();
-                StackChild::Any(child, state.aligns)
-            })
+            .map(|child| StackChild::Any(child.to_stack(state).into(), state.aligns))
             .collect();
 
         let mut dirs = Gen::new(None, dir).unwrap_or(state.dirs);
@@ -204,7 +205,7 @@ pub fn stack(_: &mut EvalContext, args: &mut Arguments) -> TypResult<Value> {
             dirs.cross = state.dirs.main;
         }
 
-        StackNode { dirs, aspect: None, children }
+        StackNode { dirs, children }
     })))
 }
 
diff --git a/src/library/mod.rs b/src/library/mod.rs
index dd1574f3..44f1f01f 100644
--- a/src/library/mod.rs
+++ b/src/library/mod.rs
@@ -21,6 +21,7 @@ use crate::diag::TypResult;
 use crate::eval::{Arguments, EvalContext, Scope, Str, Template, Value};
 use crate::font::{FontFamily, FontStretch, FontStyle, FontWeight, VerticalFontMetric};
 use crate::geom::*;
+use crate::layout::LayoutNode;
 use crate::syntax::Spanned;
 
 /// Construct a scope containing all standard library definitions.