webgpu demo

interfaces/Catcrafts-Demo.cppm

@@ -0,0 +1,36 @@
+/*
+catcrafts.net
+Copyright (C) 2026 Catcrafts
+
+The source code of this website is made available for viewing purposes only.
+No permission is granted to copy, modify, distribute, or create derivative works.
+*/
+
+export module Catcrafts:Demo;
+import Crafter.Graphics;
+import std;
+using namespace Crafter;
+
+export namespace Catcrafts {
+    // DOM element id that the ray-traced WebGPU demo renders into. The
+    // blog post embeds a <div> with this id; MountDemo() reparents the
+    // Crafter.Graphics render canvas into it via WebGPU::SetCanvasMount.
+    inline constexpr std::string_view kDemoMountId = "webgpu-demo";
+
+    // Build the ray-tracing pipeline + scene once and start the render
+    // loop plumbing. Runs the window's StartInit()/FinishInit(), so call
+    // it from main() right after the Window is constructed and before the
+    // page chrome / routes are built. The canvas starts detached + hidden;
+    // nothing is traced until MountDemo() is called.
+    void SetupDemo(Window& window);
+
+    // Reparent the render canvas into #webgpu-demo and begin tracing. Call
+    // only after the element exists in the DOM (i.e. right after the post's
+    // innerHTML has been set). Idempotent.
+    void MountDemo();
+
+    // Stop tracing and detach + hide the canvas, leaving a plain DOM page.
+    // Call before any route re-render that would replace #webgpu-demo.
+    // Safe to call when the demo is not mounted.
+    void UnmountDemo();
+}