planning

node_modules/geotiff/dist-node/dataslice.js

@@ -0,0 +1,105 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+class DataSlice {
+    constructor(arrayBuffer, sliceOffset, littleEndian, bigTiff) {
+        this._dataView = new DataView(arrayBuffer);
+        this._sliceOffset = sliceOffset;
+        this._littleEndian = littleEndian;
+        this._bigTiff = bigTiff;
+    }
+    get sliceOffset() {
+        return this._sliceOffset;
+    }
+    get sliceTop() {
+        return this._sliceOffset + this.buffer.byteLength;
+    }
+    get littleEndian() {
+        return this._littleEndian;
+    }
+    get bigTiff() {
+        return this._bigTiff;
+    }
+    get buffer() {
+        return this._dataView.buffer;
+    }
+    covers(offset, length) {
+        return this.sliceOffset <= offset && this.sliceTop >= offset + length;
+    }
+    readUint8(offset) {
+        return this._dataView.getUint8(offset - this._sliceOffset, this._littleEndian);
+    }
+    readInt8(offset) {
+        return this._dataView.getInt8(offset - this._sliceOffset, this._littleEndian);
+    }
+    readUint16(offset) {
+        return this._dataView.getUint16(offset - this._sliceOffset, this._littleEndian);
+    }
+    readInt16(offset) {
+        return this._dataView.getInt16(offset - this._sliceOffset, this._littleEndian);
+    }
+    readUint32(offset) {
+        return this._dataView.getUint32(offset - this._sliceOffset, this._littleEndian);
+    }
+    readInt32(offset) {
+        return this._dataView.getInt32(offset - this._sliceOffset, this._littleEndian);
+    }
+    readFloat32(offset) {
+        return this._dataView.getFloat32(offset - this._sliceOffset, this._littleEndian);
+    }
+    readFloat64(offset) {
+        return this._dataView.getFloat64(offset - this._sliceOffset, this._littleEndian);
+    }
+    readUint64(offset) {
+        const left = this.readUint32(offset);
+        const right = this.readUint32(offset + 4);
+        let combined;
+        if (this._littleEndian) {
+            combined = left + ((2 ** 32) * right);
+            if (!Number.isSafeInteger(combined)) {
+                throw new Error(`${combined} exceeds MAX_SAFE_INTEGER. `
+                    + 'Precision may be lost. Please report if you get this message to https://github.com/geotiffjs/geotiff.js/issues');
+            }
+            return combined;
+        }
+        combined = ((2 ** 32) * left) + right;
+        if (!Number.isSafeInteger(combined)) {
+            throw new Error(`${combined} exceeds MAX_SAFE_INTEGER. `
+                + 'Precision may be lost. Please report if you get this message to https://github.com/geotiffjs/geotiff.js/issues');
+        }
+        return combined;
+    }
+    // adapted from https://stackoverflow.com/a/55338384/8060591
+    readInt64(offset) {
+        let value = 0;
+        const isNegative = (this._dataView.getUint8(offset + (this._littleEndian ? 7 : 0)) & 0x80)
+            > 0;
+        let carrying = true;
+        for (let i = 0; i < 8; i++) {
+            let byte = this._dataView.getUint8(offset + (this._littleEndian ? i : 7 - i));
+            if (isNegative) {
+                if (carrying) {
+                    if (byte !== 0x00) {
+                        byte = ~(byte - 1) & 0xff;
+                        carrying = false;
+                    }
+                }
+                else {
+                    byte = ~byte & 0xff;
+                }
+            }
+            value += byte * (256 ** i);
+        }
+        if (isNegative) {
+            value = -value;
+        }
+        return value;
+    }
+    readOffset(offset) {
+        if (this._bigTiff) {
+            return this.readUint64(offset);
+        }
+        return this.readUint32(offset);
+    }
+}
+exports.default = DataSlice;
+//# sourceMappingURL=dataslice.js.map