add script to create png tiles for ocean

utils/ocean-tiles/README.md

@@ -39,3 +39,6 @@ for file in ./ocean_tiles*.png; do NUM=`echo $file | sed -e 's/.*ocean_tiles//'
 ```
 for i in {0..31}; do rm -r $i; done
 ```
+
+# createOceanTiles.js
+createOceanTiles is splitting the generated ocean tiles into 256x256 tiles, skipping the ones that are empty (aka all ocean).

utils/ocean-tiles/createOceanTiles.js

@@ -0,0 +1,81 @@
+/* @flow 
+ * this script takes black/withe tiles and sets their colors on the canvas
+ * its used to set the land area on the planet.
+ *
+ * The tiles it uses are explained in 3dmodels/ocean-tiles
+ *
+ * run this script with --expose-gc or you run out of RAM
+ */
+
+
+import sharp from 'sharp';
+import fs from 'fs';
+
+const CANVAS_SIZE = 256 * 256;
+const CANVAS_MIN_XY = -(CANVAS_SIZE / 2);
+const CANVAS_MAX_XY = (CANVAS_SIZE / 2) - 1;
+
+const TILEFOLDER = './ocean';
+const TILE_SIZE = 2048;
+const SMALL_TILE_SIZE = 256;
+
+
+async function createTiles() {
+  const targetfolder = './tmpfolder';
+  if (!fs.existsSync(targetfolder)) {
+    fs.mkdirSync(targetfolder);
+  }
+
+  for (let dx = 0; dx < CANVAS_SIZE / SMALL_TILE_SIZE; dx += 1) {
+    const dir = `${targetfolder}/${dx}`;
+    if (!fs.existsSync(dir)) {
+      fs.mkdirSync(dir);
+    }
+  }
+
+  for (let ty = 0; ty < CANVAS_SIZE / TILE_SIZE; ty += 1) {
+    for (let tx = 0; tx < CANVAS_SIZE / TILE_SIZE; tx += 1) {
+      const [ x, y ] = [tx, ty].map(z => z * TILE_SIZE / SMALL_TILE_SIZE);
+      const filename = `${TILEFOLDER}/${tx}/${ty}.png`;
+      console.log(`Checking tile ${filename}`);
+      if (!fs.existsSync(filename)) continue;
+      let tile = await sharp(filename).ensureAlpha().raw().toBuffer();
+      tile = new Uint32Array(tile.buffer);
+      for (let dxc = 0; dxc < TILE_SIZE / SMALL_TILE_SIZE; dxc += 1) {
+        for (let dyc = 0; dyc < TILE_SIZE / SMALL_TILE_SIZE; dyc += 1) {
+          const buffer = new Uint32Array(SMALL_TILE_SIZE * SMALL_TILE_SIZE);
+          let boff = (dxc + dyc * TILE_SIZE) * SMALL_TILE_SIZE;
+          let soff = 0;
+          let exists = false;
+          for (let column = 0; column < SMALL_TILE_SIZE; column += 1) {
+            for (let row = 0; row < SMALL_TILE_SIZE; row += 1) {
+              const mask = tile[boff++] & 0x00FFFFFF;
+              if (!mask && !exists) {
+                exists = true;
+              }
+              buffer[soff++] = (mask) ? 0xFFFFE3CA : 0xFFFFFFFF;
+            }
+            boff += TILE_SIZE - SMALL_TILE_SIZE;
+          }
+          if (exists) {
+            const filename = `${targetfolder}/${tx * TILE_SIZE / SMALL_TILE_SIZE + dxc}/${ty * TILE_SIZE / SMALL_TILE_SIZE + dyc}.png`
+            await sharp(
+              Buffer.from(
+                buffer.buffer,
+              ), {
+                raw: {
+                  width: SMALL_TILE_SIZE,
+                  height: SMALL_TILE_SIZE,
+                  channels: 4,
+                },
+              },
+            ).toFile(filename);
+          }
+        }
+      }
+      tile = null;
+    }
+  }
+}
+
+createTiles();