feat: rewrite some systems

packages/scripts/src/core/blitz/readRoughnessMetallic.ts

@@ -0,0 +1,27 @@
+import { writeFile } from "fs/promises";
+import sharp from "sharp";
+import { readTexture } from "./readTexture";
+
+export async function readRoughnessMetallic(path: string) {
+  const raw = await readTexture(path);
+  const blitz = sharp(raw.data, { raw: raw });
+  const metallicness = await blitz?.extractChannel(1).raw().toBuffer();
+  const roughness = await blitz?.extractChannel(3).raw().toBuffer();
+
+  const combined = Buffer.alloc(raw.width * raw.height * 3);
+
+  for (let i = 0; i < raw.width * raw.height; i++) {
+    combined[i * 3 + 1] = roughness?.[i] ?? 0;
+    combined[i * 3 + 2] = metallicness?.[i] ?? 0;
+  }
+
+  const image = await sharp(combined, {
+    raw: { width: raw.width, height: raw.height, channels: 3 },
+  })
+    .jpeg()
+    .toBuffer();
+
+  writeFile("test.rm.jpg", image);
+
+  return image;
+}