Add existing to tracked

node_modules/ktx-parse/src/read.ts

@@ -0,0 +1,226 @@
+import { BufferReader } from './buffer-reader.js';
+import { KTX2_ID } from './constants-internal.js';
+import { KHR_DF_SAMPLE_DATATYPE_SIGNED, type Supercompression, type VKFormat } from './constants.js';
+import type { KTX2BasicFormatSample, KTX2Container, KTX2DataFormatDescriptorBasicFormat } from './container.js';
+import { createDefaultContainer } from './create-default-container.js';
+import { decodeText } from './util.js';
+
+/**
+ * Parses a KTX 2.0 file, returning an unpacked {@link KTX2Container} instance with all associated
+ * data. The container's mip levels and other binary data are pointers into the original file, not
+ * copies, so the original file should not be overwritten after reading.
+ *
+ * @param data Bytes of KTX 2.0 file, as Uint8Array or Buffer.
+ */
+export function read(data: Uint8Array): KTX2Container {
+	///////////////////////////////////////////////////
+	// KTX 2.0 Identifier.
+	///////////////////////////////////////////////////
+
+	const id = new Uint8Array(data.buffer, data.byteOffset, KTX2_ID.length);
+	if (
+		id[0] !== KTX2_ID[0] || // '´'
+		id[1] !== KTX2_ID[1] || // 'K'
+		id[2] !== KTX2_ID[2] || // 'T'
+		id[3] !== KTX2_ID[3] || // 'X'
+		id[4] !== KTX2_ID[4] || // ' '
+		id[5] !== KTX2_ID[5] || // '2'
+		id[6] !== KTX2_ID[6] || // '0'
+		id[7] !== KTX2_ID[7] || // 'ª'
+		id[8] !== KTX2_ID[8] || // '\r'
+		id[9] !== KTX2_ID[9] || // '\n'
+		id[10] !== KTX2_ID[10] || // '\x1A'
+		id[11] !== KTX2_ID[11] // '\n'
+	) {
+		throw new Error('Missing KTX 2.0 identifier.');
+	}
+
+	const container = createDefaultContainer();
+
+	///////////////////////////////////////////////////
+	// Header.
+	///////////////////////////////////////////////////
+
+	const headerByteLength = 17 * Uint32Array.BYTES_PER_ELEMENT;
+	const headerReader = new BufferReader(data, KTX2_ID.length, headerByteLength, true);
+
+	container.vkFormat = headerReader._nextUint32() as VKFormat;
+	container.typeSize = headerReader._nextUint32();
+	container.pixelWidth = headerReader._nextUint32();
+	container.pixelHeight = headerReader._nextUint32();
+	container.pixelDepth = headerReader._nextUint32();
+	container.layerCount = headerReader._nextUint32();
+	container.faceCount = headerReader._nextUint32();
+	container.levelCount = headerReader._nextUint32();
+
+	container.supercompressionScheme = headerReader._nextUint32() as Supercompression;
+
+	const dfdByteOffset = headerReader._nextUint32();
+	const dfdByteLength = headerReader._nextUint32();
+	const kvdByteOffset = headerReader._nextUint32();
+	const kvdByteLength = headerReader._nextUint32();
+	const sgdByteOffset = headerReader._nextUint64();
+	const sgdByteLength = headerReader._nextUint64();
+
+	///////////////////////////////////////////////////
+	// Level Index.
+	///////////////////////////////////////////////////
+
+	const levelByteLength = Math.max(container.levelCount, 1) * 3 * 8;
+	const levelReader = new BufferReader(data, KTX2_ID.length + headerByteLength, levelByteLength, true);
+
+	for (let i = 0, il = Math.max(container.levelCount, 1); i < il; i++) {
+		container.levels.push({
+			levelData: new Uint8Array(data.buffer, data.byteOffset + levelReader._nextUint64(), levelReader._nextUint64()),
+			uncompressedByteLength: levelReader._nextUint64(),
+		});
+	}
+
+	///////////////////////////////////////////////////
+	// Data Format Descriptor (DFD).
+	///////////////////////////////////////////////////
+
+	const dfdReader = new BufferReader(data, dfdByteOffset, dfdByteLength, true);
+
+	dfdReader._skip(4); // totalSize
+	const vendorId = dfdReader._nextUint16();
+	const descriptorType = dfdReader._nextUint16();
+	const versionNumber = dfdReader._nextUint16();
+	const descriptorBlockSize = dfdReader._nextUint16();
+	const colorModel = dfdReader._nextUint8();
+	const colorPrimaries = dfdReader._nextUint8();
+	const transferFunction = dfdReader._nextUint8();
+	const flags = dfdReader._nextUint8();
+
+	const texelBlockDimension = [
+		dfdReader._nextUint8(),
+		dfdReader._nextUint8(),
+		dfdReader._nextUint8(),
+		dfdReader._nextUint8(),
+	] as KTX2DataFormatDescriptorBasicFormat['texelBlockDimension'];
+
+	const bytesPlane = [
+		dfdReader._nextUint8(),
+		dfdReader._nextUint8(),
+		dfdReader._nextUint8(),
+		dfdReader._nextUint8(),
+		dfdReader._nextUint8(),
+		dfdReader._nextUint8(),
+		dfdReader._nextUint8(),
+		dfdReader._nextUint8(),
+	] as KTX2DataFormatDescriptorBasicFormat['bytesPlane'];
+
+	const samples = [] as KTX2BasicFormatSample[];
+
+	const dfd: KTX2DataFormatDescriptorBasicFormat = {
+		vendorId,
+		descriptorType,
+		versionNumber,
+		colorModel,
+		colorPrimaries,
+		transferFunction,
+		flags,
+		texelBlockDimension,
+		bytesPlane,
+		samples,
+	};
+
+	const sampleStart = 6;
+	const sampleWords = 4;
+	const numSamples = (descriptorBlockSize / 4 - sampleStart) / sampleWords;
+
+	for (let i = 0; i < numSamples; i++) {
+		const sample = {
+			bitOffset: dfdReader._nextUint16(),
+			bitLength: dfdReader._nextUint8(),
+			channelType: dfdReader._nextUint8(),
+			samplePosition: [dfdReader._nextUint8(), dfdReader._nextUint8(), dfdReader._nextUint8(), dfdReader._nextUint8()],
+			sampleLower: Number.NEGATIVE_INFINITY,
+			sampleUpper: Number.POSITIVE_INFINITY,
+		};
+
+		if (sample.channelType & KHR_DF_SAMPLE_DATATYPE_SIGNED) {
+			sample.sampleLower = dfdReader._nextInt32();
+			sample.sampleUpper = dfdReader._nextInt32();
+		} else {
+			sample.sampleLower = dfdReader._nextUint32();
+			sample.sampleUpper = dfdReader._nextUint32();
+		}
+
+		dfd.samples[i] = sample;
+	}
+
+	container.dataFormatDescriptor.length = 0;
+	container.dataFormatDescriptor.push(dfd);
+
+	///////////////////////////////////////////////////
+	// Key/Value Data (KVD).
+	///////////////////////////////////////////////////
+
+	const kvdReader = new BufferReader(data, kvdByteOffset, kvdByteLength, true);
+
+	while (kvdReader._offset < kvdByteLength) {
+		const keyValueByteLength = kvdReader._nextUint32();
+		const keyData = kvdReader._scan(keyValueByteLength);
+		const key = decodeText(keyData);
+
+		container.keyValue[key] = kvdReader._nextUint8Array(keyValueByteLength - keyData.byteLength - 1);
+
+		if (key.match(/^ktx/i)) {
+			const text = decodeText(container.keyValue[key] as Uint8Array);
+			container.keyValue[key] = text.substring(0, text.lastIndexOf('\x00'));
+		}
+
+		const kvPadding = keyValueByteLength % 4 ? 4 - (keyValueByteLength % 4) : 0; // align(4)
+		// 4-byte alignment.
+		kvdReader._skip(kvPadding);
+	}
+
+	///////////////////////////////////////////////////
+	// Supercompression Global Data (SGD).
+	///////////////////////////////////////////////////
+
+	if (sgdByteLength <= 0) return container;
+
+	const sgdReader = new BufferReader(data, sgdByteOffset, sgdByteLength, true);
+
+	const endpointCount = sgdReader._nextUint16();
+	const selectorCount = sgdReader._nextUint16();
+	const endpointsByteLength = sgdReader._nextUint32();
+	const selectorsByteLength = sgdReader._nextUint32();
+	const tablesByteLength = sgdReader._nextUint32();
+	const extendedByteLength = sgdReader._nextUint32();
+
+	const imageDescs = [];
+	for (let i = 0, il = Math.max(container.levelCount, 1); i < il; i++) {
+		imageDescs.push({
+			imageFlags: sgdReader._nextUint32(),
+			rgbSliceByteOffset: sgdReader._nextUint32(),
+			rgbSliceByteLength: sgdReader._nextUint32(),
+			alphaSliceByteOffset: sgdReader._nextUint32(),
+			alphaSliceByteLength: sgdReader._nextUint32(),
+		});
+	}
+
+	const endpointsByteOffset = sgdByteOffset + sgdReader._offset;
+	const selectorsByteOffset = endpointsByteOffset + endpointsByteLength;
+	const tablesByteOffset = selectorsByteOffset + selectorsByteLength;
+	const extendedByteOffset = tablesByteOffset + tablesByteLength;
+
+	const endpointsData = new Uint8Array(data.buffer, data.byteOffset + endpointsByteOffset, endpointsByteLength);
+	const selectorsData = new Uint8Array(data.buffer, data.byteOffset + selectorsByteOffset, selectorsByteLength);
+	const tablesData = new Uint8Array(data.buffer, data.byteOffset + tablesByteOffset, tablesByteLength);
+	const extendedData = new Uint8Array(data.buffer, data.byteOffset + extendedByteOffset, extendedByteLength);
+
+	container.globalData = {
+		endpointCount,
+		selectorCount,
+		imageDescs,
+		endpointsData,
+		selectorsData,
+		tablesData,
+		extendedData,
+	};
+
+	return container;
+}