minor refactoring

crates/egui/src/context.rs

@@ -1782,7 +1782,7 @@ impl ContextImpl {
 
         let shapes = viewport
             .graphics
-            .drain(self.memory.areas().order(), self.memory.layer_transforms());
+            .drain(self.memory.areas().order(), &self.memory.layer_transforms);
 
         if viewport.input.wants_repaint() {
             self.request_repaint(ended_viewport_id);
@@ -2078,7 +2078,13 @@ impl Context {
     ///
     /// Can be used to implement pan and zoom (see relevant demo).
     pub fn set_transform_layer(&self, layer_id: LayerId, transform: TSTransform) {
-        self.memory_mut(|m| m.layer_transforms_mut().insert(layer_id, transform));
+        self.memory_mut(|m| {
+            if transform == TSTransform::IDENTITY {
+                m.layer_transforms.remove(&layer_id)
+            } else {
+                m.layer_transforms.insert(layer_id, transform)
+            }
+        });
     }
 
     /// Top-most layer at the given position.
@@ -2106,13 +2112,12 @@ impl Context {
     ///
     /// See also [`Response::contains_pointer`].
     pub fn rect_contains_pointer(&self, layer_id: LayerId, rect: Rect) -> bool {
-        let rect = if let Some(transform) =
-            self.memory(|m| m.layer_transforms().get(&layer_id).cloned())
-        {
-            transform * rect
-        } else {
-            rect
-        };
+        let rect =
+            if let Some(transform) = self.memory(|m| m.layer_transforms.get(&layer_id).cloned()) {
+                transform * rect
+            } else {
+                rect
+            };
         if !rect.is_positive() {
             return false;
         }
@@ -2155,7 +2160,7 @@ impl Context {
         self.write(|ctx| {
             let transform = ctx
                 .memory
-                .layer_transforms()
+                .layer_transforms
                 .get(&layer_id)
                 .cloned()
                 .unwrap_or_default();

crates/egui/src/memory.rs

@@ -88,10 +88,12 @@ pub struct Memory {
     #[cfg_attr(feature = "persistence", serde(skip))]
     everything_is_visible: bool,
 
+    /// Transforms per layer
+    pub layer_transforms: HashMap<LayerId, TSTransform>,
+
     // -------------------------------------------------
     // Per-viewport:
     areas: ViewportIdMap<Areas>,
-    layer_transforms: HashMap<LayerId, TSTransform>,
 
     #[cfg_attr(feature = "persistence", serde(skip))]
     pub(crate) interactions: ViewportIdMap<Interaction>,
@@ -610,16 +612,6 @@ impl Memory {
         self.areas.entry(self.viewport_id).or_default()
     }
 
-    /// Access layer transformations.
-    pub fn layer_transforms(&self) -> &HashMap<LayerId, TSTransform> {
-        &self.layer_transforms
-    }
-
-    /// Access layer transformations.
-    pub fn layer_transforms_mut(&mut self) -> &mut HashMap<LayerId, TSTransform> {
-        &mut self.layer_transforms
-    }
-
     /// Top-most layer at the given position.
     pub fn layer_id_at(&self, pos: Pos2, resize_interact_radius_side: f32) -> Option<LayerId> {
         self.areas()

crates/epaint/src/shape.rs

@@ -384,9 +384,10 @@ impl Shape {
             Self::Text(text_shape) => {
                 text_shape.pos = transform * text_shape.pos;
                 let mut galley = (*text_shape.galley).clone();
-                let scale_transform = TSTransform::from_scaling(transform.scaling);
                 for row in &mut galley.rows {
-                    row.visuals.mesh.transform(scale_transform);
+                    for v in &mut row.visuals.mesh.vertices {
+                        v.pos = Pos2::new(transform.scaling * v.pos.x, transform.scaling * v.pos.y);
+                    }
                 }
 
                 text_shape.galley = Arc::new(galley);