Correct parsers
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7fe5d03a09
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9 changed files with 437 additions and 169 deletions
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@ -1,9 +1,70 @@
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const METABYTES = 13;
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export function unpackEdges(arrayBuffer: ArrayBuffer) {
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const dv = new DataView(arrayBuffer, METABYTES);
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const indices = new Uint32Array((arrayBuffer.byteLength - METABYTES) / 4);
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for (let i = 0; i < indices.length; i++) {
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indices[i] = dv.getUint32(i * 4, true);
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}
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return indices;
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}
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const DIMENSIONS = 3;
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const ONEBYTE = 1;
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const FOURBYTE = 4;
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const METABYTES = 13;
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const FOURBYTE = 4; // bytes count for metadata in PG_pointcloud (significant bits compression)
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export function unpackVertices(arrayBuffer: ArrayBuffer) {
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const dataView = new DataView(arrayBuffer);
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let ptr = ONEBYTE + 2 * FOURBYTE;
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const pointsCount = dataView.getUint32(ptr, true); // 1 + 4 + 4 = 9 bytes offset
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const posArray = new Float32Array(pointsCount * DIMENSIONS);
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ptr += FOURBYTE;
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class BitStream {
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let bytesCount;
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let significantBitsCount;
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let commonBits;
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let significantBits;
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for (let dim = 0; dim < 3; dim++) {
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ptr += ONEBYTE;
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bytesCount = dataView.getInt32(ptr, true) - 8;
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ptr += FOURBYTE;
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significantBitsCount = dataView.getUint32(ptr, true);
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ptr += FOURBYTE;
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commonBits = readCommonBits(dataView, ptr);
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ptr += FOURBYTE;
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significantBits = readSignificantBits(dataView, ptr, bytesCount);
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let value = 0.0;
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for (var j = dim, i = 0; i < pointsCount; j += DIMENSIONS, i++) {
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value = significantBits.readBits(significantBitsCount, 0) | commonBits;
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if (dim === 2) {
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value = value / 100; // z values in pc_patch from DB are multiplied by 100
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}
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posArray[j] = value;
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}
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ptr += bytesCount;
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}
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return posArray;
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}
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function readCommonBits(dataView: DataView, ptr: number) {
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const temp = new Int32Array(1);
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temp[0] = dataView.getInt32(ptr, false);
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const combits = new BitStream(new Uint8Array(temp.buffer));
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return combits.readBits(32, 0);
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}
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function readSignificantBits(
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dataView: DataView,
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ptr: number,
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bytesCount: number
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) {
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const temp = new Int32Array(bytesCount / 4);
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for (let i = ptr, j = 0; i < ptr + bytesCount; i += 4, j++) {
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temp[j] = dataView.getInt32(i);
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}
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const sigbits = new BitStream(new Uint8Array(temp.buffer));
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return sigbits;
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}
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export class BitStream {
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private a: Uint8Array;
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private position: number;
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private bitsPending: number;
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@ -15,114 +76,67 @@ class BitStream {
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}
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writeBits(bits: number, value: number) {
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if (bits === 0) return;
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if (bits === 0) {
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return;
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}
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value &= 0xffffffff >>> (32 - bits);
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while (bits > 0) {
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if (this.bitsPending === 0) {
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this.a[this.position++] = 0;
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this.bitsPending = 8;
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let bitsConsumed;
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if (this.bitsPending > 0) {
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if (this.bitsPending > bits) {
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this.a[this.position - 1] |= value << (this.bitsPending - bits);
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bitsConsumed = bits;
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this.bitsPending -= bits;
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} else if (this.bitsPending === bits) {
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this.a[this.position - 1] |= value;
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bitsConsumed = bits;
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this.bitsPending = 0;
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} else {
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this.a[this.position - 1] |= value >> (bits - this.bitsPending);
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bitsConsumed = this.bitsPending;
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this.bitsPending = 0;
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}
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const bitsToWrite = Math.min(this.bitsPending, bits);
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const shift = this.bitsPending - bitsToWrite;
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this.a[this.position - 1] |= (value >> (bits - bitsToWrite)) << shift;
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bits -= bitsToWrite;
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value &= (1 << bits) - 1;
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this.bitsPending -= bitsToWrite;
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} else {
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bitsConsumed = Math.min(8, bits);
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this.bitsPending = 8 - bitsConsumed;
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this.a[this.position++] =
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(value >> (bits - bitsConsumed)) << this.bitsPending;
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}
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bits -= bitsConsumed;
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if (bits > 0) {
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this.writeBits(bits, value);
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}
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}
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readBits(bits: number, bitBuffer = 0) {
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if (bits === 0) return bitBuffer;
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while (bits > 0) {
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if (this.bitsPending === 0) {
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this.bitsPending = 8;
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}
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const byte = this.a[this.position - (this.bitsPending === 8 ? 0 : 1)];
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const bitsToRead = Math.min(this.bitsPending, bits);
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const shift = this.bitsPending - bitsToRead;
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bitBuffer =
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(bitBuffer << bitsToRead) | ((byte >> shift) & ((1 << bitsToRead) - 1));
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bits -= bitsToRead;
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this.bitsPending -= bitsToRead;
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if (this.bitsPending === 0) this.position++;
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readBits(bits: number, bitBuffer: number): number {
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if (typeof bitBuffer === "undefined") {
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bitBuffer = 0;
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}
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return bitBuffer;
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if (bits === 0) {
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return bitBuffer;
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}
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let partial;
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let bitsConsumed;
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if (this.bitsPending > 0) {
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const byte = this.a[this.position - 1] & (0xff >> (8 - this.bitsPending));
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bitsConsumed = Math.min(this.bitsPending, bits);
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this.bitsPending -= bitsConsumed;
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partial = byte >> this.bitsPending;
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} else {
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bitsConsumed = Math.min(8, bits);
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this.bitsPending = 8 - bitsConsumed;
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partial = this.a[this.position++] >> this.bitsPending;
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}
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bits -= bitsConsumed;
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bitBuffer = (bitBuffer << bitsConsumed) | partial;
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return bits > 0 ? this.readBits(bits, bitBuffer) : bitBuffer;
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}
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seekTo(bitPos: number) {
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this.position = Math.floor(bitPos / 8);
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this.bitsPending = bitPos % 8 ? 8 - (bitPos % 8) : 0;
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if (this.bitsPending > 0) this.position++;
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}
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}
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export function unpackVertices(arrayBuffer: ArrayBuffer) {
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const dataView = new DataView(arrayBuffer);
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let ptr = ONEBYTE + 2 * FOURBYTE;
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// Read the number of points
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const pointsCount = dataView.getUint32(ptr, true);
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ptr += FOURBYTE;
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// Initialize position array
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const posArray = new Float32Array(pointsCount * DIMENSIONS);
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for (let dim = 0; dim < DIMENSIONS; dim++) {
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ptr += ONEBYTE; // Skip unused byte
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const bytesCount = dataView.getInt32(ptr, true) - 8;
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ptr += FOURBYTE;
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const significantBitsCount = dataView.getUint32(ptr, true);
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ptr += FOURBYTE;
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const commonBits = readCommonBits(dataView, ptr);
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ptr += FOURBYTE;
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const significantBits = readSignificantBits(dataView, ptr, bytesCount);
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ptr += bytesCount;
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// Read vertex data
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for (let i = 0, j = dim; i < pointsCount; i++, j += DIMENSIONS) {
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let value = significantBits.readBits(significantBitsCount) | commonBits;
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if (dim === 2) value /= 100; // Adjust Z values
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posArray[j] = value;
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this.position = (bitPos / 8) | 0;
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this.bitsPending = bitPos % 8;
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if (this.bitsPending > 0) {
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this.bitsPending = 8 - this.bitsPending;
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this.position++;
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}
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}
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return posArray;
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}
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export function unpackEdges(arrayBuffer: ArrayBuffer) {
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const dv = new DataView(arrayBuffer, METABYTES);
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const indices = new Uint32Array((arrayBuffer.byteLength - METABYTES) / 4);
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for (let i = 0; i < indices.length; i++) {
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indices[i] = dv.getUint32(i * 4, true);
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}
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return indices;
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}
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function readSignificantBits(
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dataView: DataView,
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ptr: number,
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bytesCount: number
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) {
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const temp = new Int32Array(bytesCount / 4);
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for (let i = 0; i < temp.length; i++, ptr += 4) {
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temp[i] = dataView.getInt32(ptr);
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}
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return new BitStream(new Uint8Array(temp.buffer));
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}
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function readCommonBits(dataView: DataView, ptr: number) {
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const temp = new Int32Array(1);
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temp[0] = dataView.getInt32(ptr, false);
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const combits = new BitStream(new Uint8Array(temp.buffer));
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return combits.readBits(32);
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}
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