tree: Fix transformation and support named nodes

src/lib/tree.typ

@@ -130,14 +130,16 @@
         children: children,
         content: content,
         drawables: none,
+        elements: none,
       )
 
       // Pre-Render the node
-      let (ctx: _, drawables, bounds) = process.many(ctx, draw.scope({
+      let (ctx: _, drawables, bounds, elements) = process.many(ctx, {
         draw.set-origin((0, 0))
         (draw-node)(node)
-      }))
+      })
       node.drawables = drawables
+      node.elements = elements
 
       if measure-content {
         if bounds != none {
@@ -197,12 +199,20 @@
 
             (ctx => {
               let (x, y) = node-position(node)
-              let translation = matrix.transform-translate(x, -y, 0)
+              let transform = matrix.transform-translate(x, y, 0)
+              transform = matrix.mul-mat(ctx.transform, transform)
+
+              // Update all the nodes anchors
+              for elem in node.elements.filter(elem => elem.at("name", default: none) != none) {
+                elem.anchors = util.transform-anchors(elem, transform)
+                ctx.nodes.insert(elem.name, elem)
+                ctx.groups.last().push(elem.name)
+              }
 
               return (
                 ctx: ctx,
                 drawables: drawable.apply-transform(
-                  translation, node.drawables),
+                  transform, node.drawables),
               )
             },)
           },

src/process.typ

@@ -64,6 +64,7 @@
     ctx: ctx,
     bounds: bounds,
     drawables: element.at("drawables", default: ()),
+    element: element,
   )
 }
 
@@ -74,6 +75,7 @@
 #let many(ctx, body) = {
   let drawables = ()
   let bounds = none
+  let elements = ()
 
   for el in body {
     let r = element(ctx, el)
@@ -85,6 +87,7 @@
       ctx = r.ctx
       drawables += r.drawables
     }
+    elements.push(r.element)
   }
-  return (ctx: ctx, bounds: bounds, drawables: drawables)
+  return (ctx: ctx, bounds: bounds, drawables: drawables, elements: elements)
 }

src/util.typ

@@ -412,3 +412,17 @@
   }
   return num
 }
+
+/// Returns a new anchor function that applies
+/// the given transformation on each anchor returned
+/// by the elements previous anchor function.
+#let transform-anchors(element, transform) = {
+  let next-resolver = element.anchors
+  return (key) => {
+    if key == () {
+      next-resolver(key)
+    } else {
+      matrix.mul4x4-vec3(transform, next-resolver(key))
+    }
+  }
+}