feat: threads

app/render-worker.ts

@@ -0,0 +1,61 @@
+import type { Framebuffer } from "../engine/render/Framebuffer"
+import type { RenderConfig } from "../engine/render/RenderConfig"
+import { renderBand, type Scene } from "./renderScene"
+
+/** One-time setup: shared framebuffer + control/param buffers, the (cloned)
+ *  scene, this worker's row band, and its index into the per-worker times array. */
+type Init = {
+  colorSAB: SharedArrayBuffer
+  depthSAB: SharedArrayBuffer
+  width: number
+  height: number
+  scene: Scene
+  band: [number, number]
+  config: RenderConfig
+  skyStep: number
+  ctrlSAB: SharedArrayBuffer
+  camSAB: SharedArrayBuffer
+  vpSAB: SharedArrayBuffer
+  visSAB: SharedArrayBuffer
+  timesSAB: SharedArrayBuffer
+  index: number
+}
+
+const FRAME = 0
+const DONE = 1
+const VIS = 2
+
+const ctx = globalThis as unknown as {
+  addEventListener: (type: "message", handler: (e: { data: Init }) => void) => void
+}
+
+ctx.addEventListener("message", (e) => {
+  const m = e.data
+  const fb: Framebuffer = {
+    width: m.width,
+    height: m.height,
+    color: new Uint32Array(m.colorSAB),
+    depth: new Float32Array(m.depthSAB),
+  }
+  const ctrl = new Int32Array(m.ctrlSAB)
+  const cam = new Float64Array(m.camSAB)
+  const vp = new Float32Array(m.vpSAB)
+  const vis = new Int32Array(m.visSAB)
+  const times = new Float64Array(m.timesSAB)
+  const { scene, band, config, skyStep, index } = m
+
+  // Lock-free frame loop: block until main bumps the frame counter, render this
+  // band, record the band time, and signal done. No messages per frame.
+  let last = 0
+  for (;;) {
+    Atomics.wait(ctrl, FRAME, last)
+    last = Atomics.load(ctrl, FRAME)
+    const t0 = performance.now()
+    const camera = { position: { x: cam[0], y: cam[1], z: cam[2] }, yaw: cam[3], pitch: cam[4], fov: cam[5] }
+    const count = Atomics.load(ctrl, VIS)
+    const visible = [...vis.subarray(0, count)]
+    renderBand(fb, scene, camera, vp, visible, config, skyStep, cam[6], band[0], band[1])
+    times[index] = performance.now() - t0
+    Atomics.add(ctrl, DONE, 1)
+  }
+})