planning

node_modules/geotiff/dist-module/compression/packbits.js

@@ -0,0 +1,26 @@
+import BaseDecoder from './basedecoder.js';
+
+export default class PackbitsDecoder extends BaseDecoder {
+  decodeBlock(buffer) {
+    const dataView = new DataView(buffer);
+    const out = [];
+
+    for (let i = 0; i < buffer.byteLength; ++i) {
+      let header = dataView.getInt8(i);
+      if (header < 0) {
+        const next = dataView.getUint8(i + 1);
+        header = -header;
+        for (let j = 0; j <= header; ++j) {
+          out.push(next);
+        }
+        i += 1;
+      } else {
+        for (let j = 0; j <= header; ++j) {
+          out.push(dataView.getUint8(i + j + 1));
+        }
+        i += header + 1;
+      }
+    }
+    return new Uint8Array(out).buffer;
+  }
+}