core: use OnceCell for lazily-loaded Drawings in display objects

This saves one `usize` in the common case where there's no `Drawing`

Author: moulins

core/src/display_object/graphic.rs

@@ -15,7 +15,7 @@ use gc_arena::barrier::unlock;
 use gc_arena::{Collect, Gc, Lock, Mutation, RefLock};
 use ruffle_render::backend::ShapeHandle;
 use ruffle_render::commands::CommandHandler;
-use std::cell::{Ref, RefCell, RefMut};
+use std::cell::{OnceCell, Ref, RefCell, RefMut};
 use std::sync::Arc;
 
 #[derive(Clone, Collect, Copy)]
@@ -38,7 +38,8 @@ pub struct GraphicData<'gc> {
     class: Lock<Option<Avm2ClassObject<'gc>>>,
     avm2_object: Lock<Option<Avm2Object<'gc>>>,
     /// This is lazily allocated on demand, to make `GraphicData` smaller in the common case.
-    drawing: RefCell<Option<Box<Drawing>>>,
+    #[collect(require_static)]
+    drawing: OnceCell<Box<RefCell<Drawing>>>,
 }
 
 impl<'gc> Graphic<'gc> {
@@ -68,7 +69,7 @@ impl<'gc> Graphic<'gc> {
                 shared: Lock::new(Gc::new(context.gc(), shared)),
                 class: Lock::new(None),
                 avm2_object: Lock::new(None),
-                drawing: RefCell::new(None),
+                drawing: OnceCell::new(),
             },
         ))
     }
@@ -101,15 +102,13 @@ impl<'gc> Graphic<'gc> {
                 shared: Lock::new(Gc::new(context.gc(), shared)),
                 class: Lock::new(None),
                 avm2_object: Lock::new(None),
-                drawing: RefCell::new(None),
+                drawing: OnceCell::new(),
             },
         ))
     }
 
     pub fn drawing_mut(&self) -> RefMut<'_, Drawing> {
-        RefMut::map(self.0.drawing.borrow_mut(), |drawing| {
-            &mut **drawing.get_or_insert_with(Default::default)
-        })
+        self.0.drawing.get_or_init(Default::default).borrow_mut()
     }
 
     pub fn set_avm2_class(self, mc: &Mutation<'gc>, class: Avm2ClassObject<'gc>) {
@@ -143,8 +142,8 @@ impl<'gc> TDisplayObject<'gc> for Graphic<'gc> {
     }
 
     fn self_bounds(self) -> Rectangle<Twips> {
-        if let Some(drawing) = self.0.drawing.borrow().as_ref() {
-            drawing.self_bounds()
+        if let Some(drawing) = self.0.drawing.get() {
+            drawing.borrow().self_bounds()
         } else {
             self.0.shared.get().bounds
         }
@@ -200,8 +199,8 @@ impl<'gc> TDisplayObject<'gc> for Graphic<'gc> {
             return;
         }
 
-        if let Some(drawing) = &self.0.drawing.borrow().as_ref() {
-            drawing.render(context);
+        if let Some(drawing) = self.0.drawing.get() {
+            drawing.borrow().render(context);
         } else if let Some(render_handle) = self.0.shared.get().render_handle.clone() {
             context
                 .commands
@@ -223,8 +222,8 @@ impl<'gc> TDisplayObject<'gc> for Graphic<'gc> {
                 return false;
             };
             let point = local_matrix * point;
-            if let Some(drawing) = &self.0.drawing.borrow().as_ref() {
-                if drawing.hit_test(point, &local_matrix) {
+            if let Some(drawing) = self.0.drawing.get() {
+                if drawing.borrow().hit_test(point, &local_matrix) {
                     return true;
                 }
             } else {

core/src/display_object/movie_clip.rs

@@ -46,7 +46,7 @@ use ruffle_macros::istr;
 use ruffle_render::perspective_projection::PerspectiveProjection;
 use smallvec::SmallVec;
 use std::borrow::Cow;
-use std::cell::{Cell, Ref, RefCell, RefMut};
+use std::cell::{Cell, OnceCell, Ref, RefCell, RefMut};
 use std::cmp::max;
 use std::collections::HashMap;
 use std::sync::Arc;
@@ -165,7 +165,7 @@ pub struct MovieClipData<'gc> {
     flags: Cell<MovieClipFlags>,
     /// This is lazily allocated on demand, to make `MovieClipData` smaller in the common case.
     #[collect(require_static)]
-    drawing: RefCell<Option<Box<Drawing>>>,
+    drawing: OnceCell<Box<RefCell<Drawing>>>,
     avm2_enabled: Cell<bool>,
 
     /// Show a hand cursor when the clip is in button mode.
@@ -211,7 +211,7 @@ impl<'gc> MovieClipData<'gc> {
             clip_event_flags: Cell::new(ClipEventFlag::empty()),
             frame_scripts: RefLock::new(Vec::new()),
             flags: Cell::new(MovieClipFlags::empty()),
-            drawing: RefCell::new(None),
+            drawing: OnceCell::new(),
             avm2_enabled: Cell::new(true),
             avm2_use_hand_cursor: Cell::new(true),
             button_mode: Cell::new(false),
@@ -1945,13 +1945,11 @@ impl<'gc> MovieClip<'gc> {
     pub fn drawing_mut(&self, gc_context: &Mutation<'gc>) -> RefMut<'_, Drawing> {
         // We're about to change graphics, so invalidate on the next frame
         self.invalidate_cached_bitmap(gc_context);
-        RefMut::map(self.0.drawing.borrow_mut(), |drawing| {
-            &mut **drawing.get_or_insert_with(Default::default)
-        })
+        self.0.drawing.get_or_init(Default::default).borrow_mut()
     }
 
     pub fn drawing(&self) -> Option<Ref<'_, Drawing>> {
-        Ref::filter_map(self.0.drawing.borrow(), |d| d.as_deref()).ok()
+        self.0.drawing.get().map(|d| d.borrow())
     }
 
     pub fn is_button_mode(&self, context: &mut UpdateContext<'gc>) -> bool {