Create [name].js

adding serverless function to get thumbnails

api/thumbnail/[name].js

@@ -0,0 +1,77 @@
+import * as gridEngine from "../engine/engine.js";
+import { palette } from "../palette.js";
+
+async function drawGames(game) {
+
+  if (game.name.split('.').pop() != 'js') return {};
+  const src = await fetch(game.download_url).then(x => x.text());
+
+  let screen, bitmaps;
+  const setScreenSize = (w, h) => screen = new ImageData(w, h);
+  const { api, state } = gridEngine.init({
+    palette,
+    setBitmaps: bm => bitmaps = bm,
+    setScreenSize,
+    drawText: () => {}
+  });
+  api.setScreenSize = setScreenSize;
+  api.afterInput = () => {};
+  api.onInput = () => {};
+
+  try {
+    new Function(...Object.keys(api), src)(...Object.values(api));
+
+    if (!screen) throw new Error("never set screen size");
+    if (!bitmaps) throw new Error("never set legend");
+  } catch(e) {
+    console.error(`couldn't run ${game.name}: ${e}`);
+    return {};
+  }
+
+  screen.data.fill(255);
+  drawTiles(state, api, screen, bitmaps);
+  const canvas = document.createElement("canvas");
+  canvas.width = canvas.height = Math.max(screen.width, screen.height);
+  canvas.imageSmoothingEnabled = false;
+  canvas.getContext("2d").putImageData(screen, 0, 0);
+
+  return { name: game.name, download_url: canvas.toDataURL() };
+
+
+  function blitSprite(screen, sprite, tx, ty) {
+    const [_, { imageData: { data: bitmap } }] = sprite;
+    for (let x = 0; x < 16; x++)
+      for (let y = 0; y < 16; y++) {
+        const sx = tx*16 + x;
+        const sy = ty*16 + y;
+
+        if (bitmap[(y*16 + x)*4 + 3] < 255) continue;
+
+        screen.data[(sy*screen.width + sx)*4 + 0] = bitmap[(y*16 + x)*4 + 0];
+        screen.data[(sy*screen.width + sx)*4 + 1] = bitmap[(y*16 + x)*4 + 1];
+        screen.data[(sy*screen.width + sx)*4 + 2] = bitmap[(y*16 + x)*4 + 2];
+        screen.data[(sy*screen.width + sx)*4 + 3] = bitmap[(y*16 + x)*4 + 3];
+      }
+  }
+
+  function drawTiles(state, api, screen, bitmaps) {
+    const { dimensions, legend } = state;
+    const { width, height, maxTileDim } = dimensions;
+
+    const grid = api.getGrid();
+
+    for (const cell of grid) {
+      const zOrder = legend.map(x => x[0]);
+      cell.sort((a, b) => zOrder.indexOf(a.type) - zOrder.indexOf(b.type));
+
+      for (const { x, y, type } of cell) {
+        blitSprite(screen, bitmaps.find(x => x[0] == type), x, y);
+      }
+    }
+  }
+}
+
+export default async function handler(request, response) {
+  const { name } = req.query;
+  return response.status(200).json({ data: "test", name });
+}