planning

node_modules/geotiff/dist-node/predictor.js

@@ -0,0 +1,77 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.applyPredictor = void 0;
+function decodeRowAcc(row, stride) {
+    let length = row.length - stride;
+    let offset = 0;
+    do {
+        for (let i = stride; i > 0; i--) {
+            row[offset + stride] += row[offset];
+            offset++;
+        }
+        length -= stride;
+    } while (length > 0);
+}
+function decodeRowFloatingPoint(row, stride, bytesPerSample) {
+    let index = 0;
+    let count = row.length;
+    const wc = count / bytesPerSample;
+    while (count > stride) {
+        for (let i = stride; i > 0; --i) {
+            row[index + stride] += row[index];
+            ++index;
+        }
+        count -= stride;
+    }
+    const copy = row.slice();
+    for (let i = 0; i < wc; ++i) {
+        for (let b = 0; b < bytesPerSample; ++b) {
+            row[(bytesPerSample * i) + b] = copy[((bytesPerSample - b - 1) * wc) + i];
+        }
+    }
+}
+function applyPredictor(block, predictor, width, height, bitsPerSample, planarConfiguration) {
+    if (!predictor || predictor === 1) {
+        return block;
+    }
+    for (let i = 0; i < bitsPerSample.length; ++i) {
+        if (bitsPerSample[i] % 8 !== 0) {
+            throw new Error('When decoding with predictor, only multiple of 8 bits are supported.');
+        }
+        if (bitsPerSample[i] !== bitsPerSample[0]) {
+            throw new Error('When decoding with predictor, all samples must have the same size.');
+        }
+    }
+    const bytesPerSample = bitsPerSample[0] / 8;
+    const stride = planarConfiguration === 2 ? 1 : bitsPerSample.length;
+    for (let i = 0; i < height; ++i) {
+        // Last strip will be truncated if height % stripHeight != 0
+        if (i * stride * width * bytesPerSample >= block.byteLength) {
+            break;
+        }
+        let row;
+        if (predictor === 2) { // horizontal prediction
+            switch (bitsPerSample[0]) {
+                case 8:
+                    row = new Uint8Array(block, i * stride * width * bytesPerSample, stride * width * bytesPerSample);
+                    break;
+                case 16:
+                    row = new Uint16Array(block, i * stride * width * bytesPerSample, stride * width * bytesPerSample / 2);
+                    break;
+                case 32:
+                    row = new Uint32Array(block, i * stride * width * bytesPerSample, stride * width * bytesPerSample / 4);
+                    break;
+                default:
+                    throw new Error(`Predictor 2 not allowed with ${bitsPerSample[0]} bits per sample.`);
+            }
+            decodeRowAcc(row, stride, bytesPerSample);
+        }
+        else if (predictor === 3) { // horizontal floating point
+            row = new Uint8Array(block, i * stride * width * bytesPerSample, stride * width * bytesPerSample);
+            decodeRowFloatingPoint(row, stride, bytesPerSample);
+        }
+    }
+    return block;
+}
+exports.applyPredictor = applyPredictor;
+//# sourceMappingURL=predictor.js.map