diff --git a/index.js b/index.js
index 152d512..209c69a 100644
--- a/index.js
+++ b/index.js
@@ -223,7 +223,7 @@ function makeTerrain(x, y) {
 function makeChunk(x, y) {
     const terrain = makeTerrain(x, y);
 
-    const chunk = new Uint8Array(16 * 16 * 256);
+    const data = new Uint8Array(16 * 16 * 256);
 
     for (let i = 0; i < 16; i++) {
         for (let j = 0; j < 16; j++) {
@@ -233,19 +233,25 @@ function makeChunk(x, y) {
             // everything below is dirt
             const offset = i * (16 * 256) + j * 256;
             const stoneHeight = Math.min(62, height);
-            chunk.set(Array(stoneHeight).fill(BlockType.STONE), offset);
+            data.set(Array(stoneHeight).fill(BlockType.STONE), offset);
             if (stoneHeight < height) {
-                chunk.set(Array(height - 1 - stoneHeight).fill(BlockType.DIRT), offset + stoneHeight);
-                chunk[offset + height - 1] = BlockType.GRASS;
+                data.set(Array(height - 1 - stoneHeight).fill(BlockType.DIRT), offset + stoneHeight);
+                data[offset + height - 1] = BlockType.GRASS;
             }
-            chunk.set(Array(256 - height).fill(BlockType.AIR), offset + height);
+            data.set(Array(256 - height).fill(BlockType.AIR), offset + height);
         }
     }
 
-    return chunk;
+    return {
+        position: {x, y},
+        data,
+    };
 }
 
-function makeChunkMesh(chunk, z0, x0) {
+function makeChunkMesh(chunk) {
+    const {x: z0, y: x0} = chunk.position;
+    const {data} = chunk;
+
     const blockPos = i => {
         const x = Math.floor(i / (16 * 256));
         const y = Math.floor((i - 16 * 258 * x) / 256);
@@ -282,20 +288,20 @@ function makeChunkMesh(chunk, z0, x0) {
                 const bi = blockIndex(i, j, k);
 
                 const upTexture = (() => {
-                    switch (chunk[bi - 1]) {
+                    switch (data[bi - 1]) {
                         case BlockType.GRASS: return [0, 15];
                         case BlockType.DIRT: return [2, 15];
                         case BlockType.STONE: return [3, 15];
                     }
                 })();
 
-                if (chunk[bi] == BlockType.AIR) {
+                if (data[bi] == BlockType.AIR) {
                     faces.push(makeFace('+y', upTexture, [x0 + j, k - 0.5, z0 + i]));
                     break;
                 }
 
                 const sideTexture = (() => {
-                    switch (chunk[bi]) {
+                    switch (data[bi]) {
                         case BlockType.GRASS: return [1, 15];
                         case BlockType.DIRT: return [2, 15];
                         case BlockType.STONE: return [3, 15];
@@ -303,7 +309,7 @@ function makeChunkMesh(chunk, z0, x0) {
                 })();
 
                 for ({ pos, dir } of sideNeighbors(i, j)) {
-                    if (chunk[blockIndex(...pos, k)] == BlockType.AIR) {
+                    if (data[blockIndex(...pos, k)] == BlockType.AIR) {
                         faces.push(makeFace(dir, sideTexture, faceDir(dir, x0 + j, k, z0 + i)));
                     }
                 }
@@ -328,15 +334,14 @@ function makeChunkMesh(chunk, z0, x0) {
 
 function makeWorldBuffers(gl) {
     const chunkFaces = [].concat(
-        makeChunkMesh(makeChunk(0, -16), 0, -16),
-        makeChunkMesh(makeChunk(16, -16), 16, -16),
-        makeChunkMesh(makeChunk(0, 0), 0, 0),
-        makeChunkMesh(makeChunk(16, 0), 16, 0),
-        makeChunkMesh(makeChunk(16, 16), 16, 16),
-        makeChunkMesh(makeChunk(0, 16), 0, 16),
+        makeChunkMesh(makeChunk(0, -16)),
+        makeChunkMesh(makeChunk(16, -16)),
+        makeChunkMesh(makeChunk(0, 0)),
+        makeChunkMesh(makeChunk(16, 0)),
+        makeChunkMesh(makeChunk(16, 16)),
+        makeChunkMesh(makeChunk(0, 16)),
     );
 
-
     return makeBuffersFromFraces(gl, chunkFaces);
 }