reactivity base

src/render/primitive/mod.rs

@@ -8,23 +8,19 @@ pub use def::*;
 pub use format::*;
 pub use point::*;
 
-use crate::{render::data::PrimitiveInstance, UINode};
+use crate::{render::data::PrimitiveInstance, WidgetId, Widgets};
 use bytemuck::Pod;
 
-pub struct Painter {
-    pub region: UIRegion,
+#[derive(Default)]
+pub struct Primitives {
     pub instances: Vec<PrimitiveInstance>,
     pub data: Vec<u32>,
 }
 
-impl Default for Painter {
-    fn default() -> Self {
-        Self {
-            region: UIRegion::full(),
-            instances: Default::default(),
-            data: Default::default(),
-        }
-    }
+pub struct Painter<'a> {
+    nodes: &'a Widgets,
+    primitives: Primitives,
+    pub region: UIRegion,
 }
 
 /// NOTE: Self must have at least u32 alignment
@@ -32,19 +28,36 @@ pub trait PrimitiveData: Pod {
     const DISCRIM: u32;
 }
 
-impl Painter {
-    pub fn write<D: PrimitiveData>(&mut self, data: D) {
-        let ptr = self.data.len() as u32;
+impl<'a> Painter<'a> {
+    pub fn new(nodes: &'a Widgets) -> Self {
+        Self {
+            nodes,
+            primitives: Primitives::default(),
+            region: UIRegion::full(),
+        }
+    }
+    pub fn write<Data: PrimitiveData>(&mut self, data: Data) {
+        let ptr = self.primitives.data.len() as u32;
         let region = self.region;
-        self.instances.push(PrimitiveInstance { region, ptr });
-        self.data.push(D::DISCRIM);
-        self.data
+        self.primitives
+            .instances
+            .push(PrimitiveInstance { region, ptr });
+        self.primitives.data.push(Data::DISCRIM);
+        self.primitives
+            .data
             .extend_from_slice(bytemuck::cast_slice::<_, u32>(&[data]));
     }
-    pub fn draw_within(&mut self, node: &impl UINode, region: UIRegion) {
+    pub fn draw(&mut self, node: &WidgetId) {
+        self.nodes.get(node).draw(self);
+    }
+    pub fn draw_within(&mut self, node: &WidgetId, region: UIRegion) {
         let old = self.region;
         self.region.select(&region);
-        node.draw(self);
+        self.draw(node);
         self.region = old;
     }
+
+    pub fn finish(self) -> Primitives {
+        self.primitives
+    }
 }