Add native Crystal exploration port and reference tooling

src/game/rendering/pixels.ts

@@ -0,0 +1,36 @@
+import type { Palette } from "../world/types";
+
+/** Decode Game Boy planar pixels directly to RGBA; no display hardware emulation. */
+export function drawTile(
+  target: Uint8ClampedArray,
+  width: number,
+  height: number,
+  graphics: Uint8Array,
+  tile: number,
+  x: number,
+  y: number,
+  palette: Palette,
+  options: { transparent?: boolean; flipX?: boolean; flipY?: boolean } = {},
+) {
+  const offset = tile * 16;
+  if (offset < 0 || offset + 16 > graphics.length) return;
+  for (let row = 0; row < 8; row++) {
+    const sourceRow = options.flipY ? 7 - row : row;
+    const lo = graphics[offset + sourceRow * 2],
+      hi = graphics[offset + sourceRow * 2 + 1];
+    for (let col = 0; col < 8; col++) {
+      const bit = options.flipX ? col : 7 - col;
+      const index = ((lo >> bit) & 1) | (((hi >> bit) & 1) << 1);
+      if (options.transparent && index === 0) continue;
+      const px = x + col,
+        py = y + row;
+      if (px < 0 || py < 0 || px >= width || py >= height) continue;
+      const destination = (py * width + px) * 4,
+        color = palette[index];
+      target[destination] = color[0];
+      target[destination + 1] = color[1];
+      target[destination + 2] = color[2];
+      target[destination + 3] = 255;
+    }
+  }
+}