refactor drawing

implement shareable cache logic
improve caching
fix drawing bug

app/src/drawers/cache.ts

@@ -0,0 +1,35 @@
+import { BaseEntity } from "primitives/Entities";
+import { z } from "zod";
+
+export interface EntityCache<T> {
+  build: () => T;
+  get: () => T | undefined;
+  set: (id: string, cache: T) => void;
+  cleanup: (cache: T) => void;
+}
+
+export function handleEntityCache<
+  E extends z.output<typeof BaseEntity>,
+  C,
+  EC extends EntityCache<C>
+>(entity: E, cache: EC): C {
+  const cached = cache.get();
+
+  if (!entity.cache.valid) {
+    console.log("Invalid cache");
+    if (cached) {
+      cache.cleanup(cached);
+    }
+    return cache.build();
+  } else {
+    if (!cached) {
+      const nextCache = cache.build();
+
+      cache.set(entity.id, nextCache);
+
+      return nextCache;
+    } else {
+      return cached;
+    }
+  }
+}