Shape refactor (#705)

* More introspection stats about vertices/indices etc

* more serde derive

* #[inline] to Shape constructors

* Introduce RectShape

* Introduce CircleShape

* Introduce PathShape

* More serde derive

* impl Copy for RectShape and CircleShape

* Simplify some code

* More serde derive

* Add helpers for appending more input or output

* Serde derives for RawInput

* Rename Fonts::from_definitions to Fonts::new

* Add Output::take

* refactor EguiGlium slightly

* Derive PartialEq for RawInput

* Improve egui::util::History interface

* tweaks

* Improve History filter: add minimum length

* Calculate galley bounding rect

* tessellator: cull line segments and paths

* tessellator: cull meshes

* Fix bug in History bandwidth estimator

egui_demo_lib/src/apps/demo/drag_and_drop.rs

@@ -65,7 +65,7 @@ pub fn drop_target<R>(
 
     ui.painter().set(
         where_to_put_background,
-        Shape::Rect {
+        epaint::RectShape {
             corner_radius: style.corner_radius,
             fill,
             stroke,

egui_demo_lib/src/frame_history.rs

@@ -6,9 +6,10 @@ pub struct FrameHistory {
 
 impl Default for FrameHistory {
     fn default() -> Self {
-        let max_age: f64 = 1.0;
+        let max_age: f32 = 1.0;
+        let max_len = (max_age * 300.0).round() as usize;
         Self {
-            frame_times: History::from_max_len_age((max_age * 300.0).round() as usize, max_age),
+            frame_times: History::new(0..max_len, max_age),
         }
     }
 }
@@ -73,12 +74,12 @@ impl FrameHistory {
         let to_screen = emath::RectTransform::from_to(graph_rect, rect);
 
         let mut shapes = Vec::with_capacity(3 + 2 * history.len());
-        shapes.push(Shape::Rect {
+        shapes.push(Shape::Rect(epaint::RectShape {
             rect,
             corner_radius: style.corner_radius,
             fill: ui.visuals().extreme_bg_color,
             stroke: ui.style().noninteractive().bg_stroke,
-        });
+        }));
 
         let rect = rect.shrink(4.0);
         let color = ui.visuals().text_color();