820 lines
29 KiB
TypeScript
820 lines
29 KiB
TypeScript
/**
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* Copyright (c) 2026 The xterm.js authors. All rights reserved.
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* @license MIT
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*/
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import { IDisposable } from '@xterm/xterm';
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import { IApcHandler, IImageAddonOptions, IResetHandler, ITerminalExt, ImageLayer } from '../Types';
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import { ImageRenderer } from '../ImageRenderer';
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import { CELL_SIZE_DEFAULT } from '../ImageStorage';
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import { KittyImageStorage } from './KittyImageStorage';
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import Base64Decoder, { type DecodeStatus } from 'xterm-wasm-parts/lib/base64/Base64Decoder.wasm';
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import {
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KittyAction,
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KittyFormat,
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KittyCompression,
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IKittyCommand,
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IPendingTransmission,
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IKittyImageData,
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KittyPixelConstants,
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parseKittyCommand
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} from './KittyGraphicsTypes';
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const enum Constants {
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// Memory limit for base64 decoder (4MB, same as IIPHandler)
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DECODER_KEEP_DATA = 4194304,
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DECODER_INITIAL_DATA = 4194304, // 4MB
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// Local mirror of const enum (esbuild can't inline const enums from external packages)
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DECODER_OK = 0,
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// Maximum control data size
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MAX_CONTROL_DATA_SIZE = 512,
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// Semicolon codepoint
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SEMICOLON = 0x3B
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}
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const DECODER_OK = Constants.DECODER_OK as unknown as DecodeStatus.OK;
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// Kitty graphics protocol handler with streaming base64 decoding.
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export class KittyGraphicsHandler implements IApcHandler, IResetHandler, IDisposable {
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private _aborted = false;
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private _decodeError = false;
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private _activeDecoder: Base64Decoder | null = null;
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private readonly _maxEncodedBytes: number;
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private readonly _initialEncodedBytes: number;
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// Streaming related states
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// True while receiving control data (before semicolon).
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private _inControlData = true;
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// Buffer for control data.
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private _controlData = new Uint32Array(Constants.MAX_CONTROL_DATA_SIZE);
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private _controlLength = 0;
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// Pre-calculated encoded size limit
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private _encodedSizeLimit = 0;
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private _totalEncodedSize = 0;
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// Parsed command. These are the control data before semicolon.
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private _parsedCommand: IKittyCommand | null = null;
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// Storage related states
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private _pendingTransmissions: Map<number, IPendingTransmission> = new Map();
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// Tracks the pending key of the most recently started chunked upload.
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// Per spec, subsequent chunks only need m= (and optionally q=), without i=.
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// When a chunk arrives with no i=, this key is used to find the pending upload.
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private _lastPendingKey: number | undefined;
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constructor(
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private readonly _opts: IImageAddonOptions,
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private readonly _renderer: ImageRenderer,
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private readonly _kittyStorage: KittyImageStorage,
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private readonly _coreTerminal: ITerminalExt
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) {
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// Convert decoded size limit -> max encoded bytes.
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this._maxEncodedBytes = Math.ceil(this._opts.kittySizeLimit * 4 / 3);
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// ensure we preallocate more than configured limit while using 4mb initial size.
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this._initialEncodedBytes = Math.min(Constants.DECODER_INITIAL_DATA, this._maxEncodedBytes);
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}
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public reset(): void {
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this._cleanupAllPending();
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if (this._activeDecoder) {
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this._activeDecoder.release();
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this._activeDecoder = null;
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}
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this._kittyStorage.reset();
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}
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public dispose(): void {
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this.reset();
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}
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private _removePendingEntry(key: number): void {
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this._pendingTransmissions.delete(key);
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if (this._lastPendingKey === key) {
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this._lastPendingKey = undefined;
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}
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}
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private _cleanupAllPending(): void {
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for (const pending of this._pendingTransmissions.values()) {
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pending.decoder.release();
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}
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this._pendingTransmissions.clear();
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this._lastPendingKey = undefined;
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}
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public start(): void {
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this._aborted = false;
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this._decodeError = false;
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this._inControlData = true;
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this._controlLength = 0;
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this._parsedCommand = null;
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// Pre-calculate encoded limit once: base64 is 4 bytes encoded → 3 bytes decoded
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this._encodedSizeLimit = this._maxEncodedBytes;
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this._totalEncodedSize = 0;
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this._activeDecoder = null;
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}
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public put(data: Uint32Array, start: number, end: number): void {
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if (this._aborted) return;
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if (!this._inControlData) {
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this._streamPayload(data, start, end);
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} else {
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// Scan for semicolon
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let controlEnd = end;
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for (let i = start; i < end; i++) {
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if (data[i] === Constants.SEMICOLON) {
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this._inControlData = false;
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controlEnd = i;
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break;
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}
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}
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// Copy control data
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const copyLength = controlEnd - start;
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if (this._controlLength + copyLength > Constants.MAX_CONTROL_DATA_SIZE) {
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this._aborted = true;
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return;
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}
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this._controlData.set(data.subarray(start, controlEnd), this._controlLength);
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this._controlLength += copyLength;
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if (!this._inControlData) {
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// Found semicolon - parse control data early for validation
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this._parsedCommand = parseKittyCommand(this._parseControlDataString());
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// Early validation: i+I conflict
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if (this._parsedCommand.id !== undefined && this._parsedCommand.imageNumber !== undefined) {
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this._sendResponse(this._parsedCommand.id, 'EINVAL:cannot specify both i and I keys', this._parsedCommand.quiet ?? 0);
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this._aborted = true;
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return;
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}
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// Delete action doesn't need payload - skip streaming
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if (this._parsedCommand.action === KittyAction.DELETE) {
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return;
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}
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// Stream remaining as payload
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const payloadStart = controlEnd + 1;
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if (payloadStart < end) {
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this._streamPayload(data, payloadStart, end);
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}
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}
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}
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}
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// Stream payload bytes into the base64 decoder.
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private _streamPayload(data: Uint32Array, start: number, end: number): void {
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if (this._aborted) return;
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// Check size limit (compare encoded bytes against pre-calculated limit)
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// Include cumulative size from pending transmission for multi-chunk images.
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// Per spec, subsequent chunks may omit i=, so fall back to _lastPendingKey.
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const pendingKey = this._parsedCommand?.id ?? this._lastPendingKey ?? 0;
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const pending = this._pendingTransmissions.get(pendingKey);
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const previousEncodedSize = pending?.totalEncodedSize ?? 0;
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this._totalEncodedSize += end - start;
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const cumulativeEncodedSize = previousEncodedSize + this._totalEncodedSize;
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if (cumulativeEncodedSize > this._encodedSizeLimit) {
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const decoderToRelease = this._activeDecoder ?? pending?.decoder;
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if (decoderToRelease) {
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decoderToRelease.release();
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}
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this._activeDecoder = null;
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if (pending) {
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this._removePendingEntry(pendingKey);
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}
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this._aborted = true;
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return;
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}
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if (this._decodeError) return;
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if (pending?.decoder && !this._activeDecoder) {
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this._activeDecoder = pending.decoder;
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}
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if (!this._activeDecoder) {
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this._activeDecoder = new Base64Decoder(Constants.DECODER_KEEP_DATA, this._maxEncodedBytes, this._initialEncodedBytes);
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this._activeDecoder.init();
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}
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if (this._activeDecoder.put(data.subarray(start, end)) !== DECODER_OK) {
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this._activeDecoder.release();
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this._activeDecoder = null;
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this._decodeError = true;
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if (pending) {
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this._removePendingEntry(pendingKey);
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}
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}
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}
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public end(success: boolean): boolean | Promise<boolean> {
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if (this._aborted || !success) {
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if (this._activeDecoder) {
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this._activeDecoder.release();
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this._activeDecoder = null;
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}
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return true;
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}
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// No semicolon = no payload (delete, capability query)
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if (this._inControlData) {
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return this._handleNoPayloadCommand();
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}
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// Use command parsed early in put() - i+I already validated there
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const cmd = this._parsedCommand!;
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// Delete action was handled by skipping payload - just execute
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if (cmd.action === KittyAction.DELETE) {
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return this._handleDelete(cmd);
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}
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// Per spec, subsequent chunks may omit i=, so fall back to _lastPendingKey.
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const pendingKey = cmd.id ?? this._lastPendingKey ?? 0;
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const isMoreComing = cmd.more === 1;
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const pending = this._pendingTransmissions.get(pendingKey);
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if (isMoreComing) {
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if (this._activeDecoder) {
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if (pending) {
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pending.totalEncodedSize += this._totalEncodedSize;
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pending.decodeError = pending.decodeError || this._decodeError;
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} else {
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this._pendingTransmissions.set(pendingKey, {
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cmd: { ...cmd },
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decoder: this._activeDecoder,
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totalEncodedSize: this._totalEncodedSize,
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decodeError: this._decodeError
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});
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}
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this._lastPendingKey = pendingKey;
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this._activeDecoder = null;
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}
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return true;
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}
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// Final chunk received — clear the last pending key
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if (pending) {
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this._lastPendingKey = undefined;
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}
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let decodeError = this._decodeError;
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let finalCmd = cmd;
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let decoder = this._activeDecoder;
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if (pending) {
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finalCmd = pending.cmd;
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decoder = pending.decoder;
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decodeError = decodeError || pending.decodeError;
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this._pendingTransmissions.delete(pendingKey);
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}
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let imageBytes = new Uint8Array(0);
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if (decoder) {
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if (decoder.end() !== DECODER_OK) {
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decodeError = true;
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}
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imageBytes = decoder.data8;
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}
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this._activeDecoder = null;
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// Handle command first — handlers create Blob/ImageData from imageBytes,
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// which copies the data. Only then is it safe to release the decoder's
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// wasm memory that imageBytes points into.
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const result = this._handleCommandWithBytesAndCmd(finalCmd, imageBytes, decodeError);
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if (decoder) {
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decoder.release();
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}
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return result;
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}
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// Command handling
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private _parseControlDataString(): string {
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let str = '';
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for (let i = 0; i < this._controlLength; i++) {
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str += String.fromCodePoint(this._controlData[i]);
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}
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return str;
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}
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private _handleNoPayloadCommand(): boolean | Promise<boolean> {
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const cmd = parseKittyCommand(this._parseControlDataString());
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// Per spec: specifying both i and I is an error
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if (cmd.id !== undefined && cmd.imageNumber !== undefined) {
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this._sendResponse(cmd.id, 'EINVAL:cannot specify both i and I keys', cmd.quiet ?? 0);
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return true;
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}
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const action = cmd.action ?? 't';
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switch (action) {
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case KittyAction.DELETE:
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return this._handleDelete(cmd);
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case KittyAction.QUERY:
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this._sendResponse(cmd.id ?? 0, 'OK', cmd.quiet ?? 0);
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return true;
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case KittyAction.PLACEMENT:
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return this._handlePlacement(cmd);
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default:
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// TODO: Implement remaining actions when needed:
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// - a=f (frame): animation frame operations
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// - a=a (animation): animation control
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// - a=c (compose): compose images
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if (cmd.id !== undefined) {
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this._sendResponse(cmd.id, 'EINVAL:unsupported action', cmd.quiet ?? 0);
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}
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return true;
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}
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}
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private _handleCommandWithBytesAndCmd(cmd: IKittyCommand, bytes: Uint8Array, decodeError: boolean): boolean | Promise<boolean> {
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const action = cmd.action ?? 't';
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switch (action) {
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case KittyAction.TRANSMIT: {
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const result = this._handleTransmit(cmd, bytes, decodeError);
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// Only send response when _handleTransmit didn't already respond
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// (it handles unsupported transmission medium responses internally)
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if ((cmd.transmission ?? 'd') === 'd' && cmd.id !== undefined) {
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if (decodeError) {
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this._sendResponse(cmd.id, 'EINVAL:invalid base64 data', cmd.quiet ?? 0);
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} else if (bytes.length > 0) {
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this._sendResponse(cmd.id, 'OK', cmd.quiet ?? 0);
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}
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}
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return result;
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}
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case KittyAction.TRANSMIT_DISPLAY:
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return this._handleTransmitDisplay(cmd, bytes, decodeError);
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case KittyAction.QUERY:
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return this._handleQuery(cmd, bytes, decodeError);
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case KittyAction.PLACEMENT:
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// a=p ignores any payload — image data was already transmitted
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return this._handlePlacement(cmd);
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default:
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// TODO: Implement remaining actions when needed:
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// - a=f (frame): animation frame operations
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// - a=a (animation): animation control
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// - a=c (compose): compose images
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if (cmd.id !== undefined) {
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this._sendResponse(cmd.id, 'EINVAL:unsupported action', cmd.quiet ?? 0);
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}
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return true;
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}
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}
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private _handlePlacement(cmd: IKittyCommand): boolean | Promise<boolean> {
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if (cmd.id === undefined) {
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return true;
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}
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const id = cmd.id;
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const image = this._kittyStorage.getImage(id);
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if (!image) {
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this._sendResponse(id, 'ENOENT:image not found', cmd.quiet ?? 0, cmd.placementId);
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return true;
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}
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const result = this._displayImage(image, cmd);
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return result.then(success => {
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this._sendResponse(id, success ? 'OK' : 'EINVAL:image rendering failed', cmd.quiet ?? 0, cmd.placementId);
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return true;
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});
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}
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private _handleTransmit(cmd: IKittyCommand, bytes: Uint8Array, decodeError: boolean): boolean {
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// TODO: Support file-based transmission modes (t=f, t=t, t=s)
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// Currently only supports direct transmission (t=d, the default).
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// - t=f (file): Payload is base64-encoded file path. Terminal reads image from that path.
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// - t=t (temp file): Payload is base64-encoded path in temp directory. Terminal reads, deletes.
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// - t=s: Payload is base64-encoded POSIX shm name. Terminal reads from shared memory.
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// These modes require filesystem/IPC access not available in browsers. For Node.js/Electron:
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// 1. Check cmd.transmission (t key) before treating bytes as image data
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// 2. For t=f/t/s: decode bytes as UTF-8 string (the path/name), then read file contents
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// 3. For t=d: treat bytes as image data (current behavior)
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// When implementing, also update _handleQuery to accept these transmission mediums.
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const transmission = cmd.transmission ?? 'd';
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if (transmission !== 'd') {
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if (cmd.id !== undefined) {
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this._sendResponse(cmd.id, 'EINVAL:unsupported transmission medium', cmd.quiet ?? 0);
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}
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return true;
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}
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if (decodeError || bytes.length === 0) return true;
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this._kittyStorage.storeImage(cmd.id, {
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data: new Blob([bytes as BlobPart]),
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width: cmd.width ?? 0,
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height: cmd.height ?? 0,
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format: (cmd.format ?? KittyFormat.RGBA) as 24 | 32 | 100,
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compression: cmd.compression ?? ''
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});
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return true;
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}
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private _handleTransmitDisplay(cmd: IKittyCommand, bytes: Uint8Array, decodeError: boolean): boolean | Promise<boolean> {
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if (decodeError) {
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if (cmd.id !== undefined) {
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this._sendResponse(cmd.id, 'EINVAL:invalid base64 data', cmd.quiet ?? 0);
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}
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return true;
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}
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this._handleTransmit(cmd, bytes, decodeError);
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const id = cmd.id ?? this._kittyStorage.lastImageId;
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const image = this._kittyStorage.getImage(id);
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if (image) {
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const result = this._displayImage(image, cmd);
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if (cmd.id !== undefined) {
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return result.then(success => {
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this._sendResponse(id, success ? 'OK' : 'EINVAL:image rendering failed', cmd.quiet ?? 0);
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return true;
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});
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}
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return result.then(() => true);
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}
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return true;
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}
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private _handleQuery(cmd: IKittyCommand, bytes: Uint8Array, decodeError: boolean): boolean {
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const id = cmd.id ?? 0;
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const quiet = cmd.quiet ?? 0;
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// Per spec: reject unsupported transmission mediums (only t=d is supported atm)
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// TODO: When filesystem support is added (Node.js/Electron), update this to accept
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// t=f (file), t=t (temp file), and t=s (shared memory) and respond OK for queries.
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const transmission = cmd.transmission ?? 'd';
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if (transmission !== 'd') {
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this._sendResponse(id, 'EINVAL:unsupported transmission medium', quiet);
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return true;
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}
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// Check decode error first (invalid base64)
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if (decodeError) {
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this._sendResponse(id, 'EINVAL:invalid base64 data', quiet);
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return true;
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}
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// Capability query (no payload) - just respond OK
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if (bytes.length === 0) {
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this._sendResponse(id, 'OK', quiet);
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return true;
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}
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const format = cmd.format ?? KittyFormat.RGBA;
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if (format === KittyFormat.PNG) {
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this._sendResponse(id, 'OK', quiet);
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} else {
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const width = cmd.width ?? 0;
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const height = cmd.height ?? 0;
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if (!width || !height) {
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this._sendResponse(id, 'EINVAL:width and height required for raw pixel data', quiet);
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return true;
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}
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const bytesPerPixel = format === KittyFormat.RGBA ? KittyPixelConstants.BYTES_PER_PIXEL_RGBA : KittyPixelConstants.BYTES_PER_PIXEL_RGB;
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const expectedBytes = width * height * bytesPerPixel;
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if (bytes.length < expectedBytes) {
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this._sendResponse(id, `EINVAL:insufficient pixel data`, quiet);
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return true;
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}
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this._sendResponse(id, 'OK', quiet);
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}
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return true;
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}
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private _handleDelete(cmd: IKittyCommand): boolean {
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// Per spec: default delete selector is 'a' (delete all visible placements)
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const selector = cmd.deleteSelector ?? 'a';
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// TODO: Distinguish lowercase (delete placements only) from uppercase
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// (delete placements + free stored image data). Currently both variants
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// free everything since we don't separate stored data from placements.
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switch (selector) {
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case 'a':
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case 'A':
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this._cleanupAllPending();
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this._kittyStorage.deleteAll();
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break;
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case 'i':
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case 'I':
|
||
// TODO: When placement id tracking is implemented (see TODO in
|
||
// KittyImageStorage), d=i with p=<pid> should delete only that
|
||
// specific placement, while d=i without p should delete all
|
||
// placements for the image.
|
||
if (cmd.id !== undefined) {
|
||
const pending = this._pendingTransmissions.get(cmd.id);
|
||
if (pending) {
|
||
pending.decoder.release();
|
||
}
|
||
this._removePendingEntry(cmd.id);
|
||
this._kittyStorage.deleteById(cmd.id);
|
||
}
|
||
break;
|
||
default:
|
||
// Unsupported selectors (c, n, p, q, r, x, y, z, f) — ignore for now
|
||
break;
|
||
}
|
||
return true;
|
||
}
|
||
|
||
private _sendResponse(id: number, message: string, quiet: number, placementId?: number): void {
|
||
const isOk = message === 'OK';
|
||
if (isOk && quiet >= 1) return;
|
||
if (!isOk && quiet >= 2) return;
|
||
|
||
const pPart = placementId ? `,p=${placementId}` : '';
|
||
const response = `\x1b_Gi=${id}${pPart};${message}\x1b\\`;
|
||
this._coreTerminal._core.coreService.triggerDataEvent(response);
|
||
}
|
||
|
||
// Image display
|
||
|
||
private _displayImage(image: IKittyImageData, cmd: IKittyCommand): Promise<boolean> {
|
||
return this._decodeAndDisplay(image, cmd)
|
||
.then(() => true)
|
||
.catch(() => false);
|
||
}
|
||
|
||
private async _decodeAndDisplay(image: IKittyImageData, cmd: IKittyCommand): Promise<void> {
|
||
let bitmap: ImageBitmap | undefined = await this._createBitmap(image);
|
||
|
||
try {
|
||
const cropX = Math.max(0, cmd.x ?? 0);
|
||
const cropY = Math.max(0, cmd.y ?? 0);
|
||
const cropW = cmd.sourceWidth || (bitmap.width - cropX);
|
||
const cropH = cmd.sourceHeight || (bitmap.height - cropY);
|
||
|
||
const maxCropW = Math.max(0, bitmap.width - cropX);
|
||
const maxCropH = Math.max(0, bitmap.height - cropY);
|
||
const finalCropW = Math.max(0, Math.min(cropW, maxCropW));
|
||
const finalCropH = Math.max(0, Math.min(cropH, maxCropH));
|
||
|
||
if (finalCropW === 0 || finalCropH === 0) {
|
||
throw new Error('invalid source rectangle');
|
||
}
|
||
|
||
if (cropX !== 0 || cropY !== 0 || finalCropW !== bitmap.width || finalCropH !== bitmap.height) {
|
||
const cropped = await createImageBitmap(bitmap, cropX, cropY, finalCropW, finalCropH);
|
||
bitmap.close();
|
||
bitmap = cropped;
|
||
}
|
||
|
||
const cw = this._renderer.dimensions?.css.cell.width || CELL_SIZE_DEFAULT.width;
|
||
const ch = this._renderer.dimensions?.css.cell.height || CELL_SIZE_DEFAULT.height;
|
||
|
||
// Per spec: c/r default to image's natural cell dimensions.
|
||
// If only one of c/r is specified, compute the other from image aspect ratio.
|
||
let imgCols: number;
|
||
let imgRows: number;
|
||
if (cmd.columns !== undefined && cmd.rows !== undefined) {
|
||
imgCols = cmd.columns;
|
||
imgRows = cmd.rows;
|
||
} else if (cmd.columns !== undefined) {
|
||
imgCols = cmd.columns;
|
||
imgRows = Math.max(1, Math.ceil((bitmap.height / bitmap.width) * (imgCols * cw) / ch));
|
||
} else if (cmd.rows !== undefined) {
|
||
imgRows = cmd.rows;
|
||
imgCols = Math.max(1, Math.ceil((bitmap.width / bitmap.height) * (imgRows * ch) / cw));
|
||
} else {
|
||
imgCols = Math.ceil(bitmap.width / cw);
|
||
imgRows = Math.ceil(bitmap.height / ch);
|
||
}
|
||
|
||
let w = bitmap.width;
|
||
let h = bitmap.height;
|
||
|
||
// Scale bitmap to fit placement rectangle when c/r are specified
|
||
if (cmd.columns !== undefined || cmd.rows !== undefined) {
|
||
w = Math.round(imgCols * cw);
|
||
h = Math.round(imgRows * ch);
|
||
}
|
||
|
||
if (w * h > this._opts.pixelLimit) {
|
||
throw new Error('image exceeds pixel limit');
|
||
}
|
||
|
||
// Save cursor position before addImage modifies it
|
||
const buffer = this._coreTerminal._core.buffer;
|
||
const savedX = buffer.x;
|
||
const savedY = buffer.y;
|
||
const savedYbase = buffer.ybase;
|
||
|
||
// Determine layer based on z-index: negative = behind text, 0+ = on top.
|
||
// When z<0 we always use the bottom layer even without allowTransparency —
|
||
// the image will simply be hidden behind the opaque text background, which
|
||
// is the correct behavior (client asked for "behind text").
|
||
const wantsBottom = cmd.zIndex !== undefined && cmd.zIndex < 0;
|
||
const layer: ImageLayer = wantsBottom ? 'bottom' : 'top';
|
||
|
||
if (w !== bitmap.width || h !== bitmap.height) {
|
||
const scaled = await createImageBitmap(bitmap, { resizeWidth: w, resizeHeight: h });
|
||
bitmap.close();
|
||
bitmap = scaled;
|
||
}
|
||
|
||
// Per spec: X/Y are pixel offsets within the first cell, so clamp to cell dimensions
|
||
const xOffset = Math.min(Math.max(0, cmd.xOffset ?? 0), cw - 1);
|
||
const yOffset = Math.min(Math.max(0, cmd.yOffset ?? 0), ch - 1);
|
||
if (xOffset !== 0 || yOffset !== 0) {
|
||
// Per spec: X/Y is not added to c/r area. When c/r are explicit, the
|
||
// total placement area remains c*cw × r*ch pixels and the offset image
|
||
// is clipped to fit. When c/r are unset, the padded canvas determines
|
||
// the natural cell dimensions.
|
||
const canvasW = (cmd.columns !== undefined) ? Math.round(imgCols * cw) : bitmap.width + xOffset;
|
||
const canvasH = (cmd.rows !== undefined) ? Math.round(imgRows * ch) : bitmap.height + yOffset;
|
||
const offsetCanvas = ImageRenderer.createCanvas(window.document, canvasW, canvasH);
|
||
const offsetCtx = offsetCanvas.getContext('2d');
|
||
if (!offsetCtx) {
|
||
throw new Error('Failed to create offset canvas context');
|
||
}
|
||
offsetCtx.drawImage(bitmap, xOffset, yOffset);
|
||
|
||
const offsetBitmap = await createImageBitmap(offsetCanvas);
|
||
offsetCanvas.width = offsetCanvas.height = 0;
|
||
bitmap.close();
|
||
bitmap = offsetBitmap;
|
||
w = bitmap.width;
|
||
h = bitmap.height;
|
||
if (w * h > this._opts.pixelLimit) {
|
||
throw new Error('image exceeds pixel limit');
|
||
}
|
||
if (cmd.columns === undefined) {
|
||
imgCols = Math.ceil(bitmap.width / cw);
|
||
}
|
||
if (cmd.rows === undefined) {
|
||
imgRows = Math.ceil(bitmap.height / ch);
|
||
}
|
||
}
|
||
|
||
const zIndex = cmd.zIndex ?? 0;
|
||
this._kittyStorage.addImage(image.id, bitmap, true, layer, zIndex);
|
||
bitmap = undefined; // ownership transferred to storage
|
||
|
||
// Kitty cursor movement
|
||
// Per spec: cursor placed at first column after last image column,
|
||
// on the last row of the image. C=1 means don't move cursor.
|
||
if (cmd.cursorMovement === 1) {
|
||
// C=1: restore cursor to position before image was placed
|
||
const scrolled = buffer.ybase - savedYbase;
|
||
buffer.x = savedX;
|
||
// Can't restore cursor to scrollback?
|
||
buffer.y = Math.max(savedY - scrolled, 0);
|
||
} else {
|
||
// Default (C=0): advance cursor horizontally past the image
|
||
// addImage already positioned cursor on the last row via lineFeeds
|
||
buffer.x = Math.min(savedX + imgCols, this._coreTerminal.cols);
|
||
}
|
||
} catch (e) {
|
||
bitmap?.close();
|
||
throw e;
|
||
}
|
||
}
|
||
|
||
// Create ImageBitmap from already-decoded image data.
|
||
private async _createBitmap(image: IKittyImageData): Promise<ImageBitmap> {
|
||
let bytes: Uint8Array = new Uint8Array(await image.data.arrayBuffer());
|
||
|
||
if (image.compression === KittyCompression.ZLIB) {
|
||
bytes = await this._decompressZlib(bytes);
|
||
}
|
||
|
||
if (image.format === KittyFormat.PNG) {
|
||
const blob = new Blob([bytes as BlobPart], { type: 'image/png' });
|
||
if (!window.createImageBitmap) {
|
||
const url = URL.createObjectURL(blob);
|
||
const img = new Image();
|
||
return new Promise<ImageBitmap>((resolve, reject) => {
|
||
img.addEventListener('load', () => {
|
||
URL.revokeObjectURL(url);
|
||
const canvas = ImageRenderer.createCanvas(window.document, img.width, img.height);
|
||
canvas.getContext('2d')?.drawImage(img, 0, 0);
|
||
createImageBitmap(canvas).then(resolve).catch(reject);
|
||
});
|
||
img.addEventListener('error', () => {
|
||
URL.revokeObjectURL(url);
|
||
reject(new Error('Failed to load image'));
|
||
});
|
||
img.src = url;
|
||
});
|
||
}
|
||
return createImageBitmap(blob);
|
||
}
|
||
|
||
// Raw pixel data
|
||
const width = image.width;
|
||
const height = image.height;
|
||
|
||
if (!width || !height) {
|
||
throw new Error('Width and height required for raw pixel data');
|
||
}
|
||
|
||
const bytesPerPixel = image.format === KittyFormat.RGBA ? KittyPixelConstants.BYTES_PER_PIXEL_RGBA : KittyPixelConstants.BYTES_PER_PIXEL_RGB;
|
||
const expectedBytes = width * height * bytesPerPixel;
|
||
|
||
if (bytes.length < expectedBytes) {
|
||
throw new Error('Insufficient pixel data');
|
||
}
|
||
|
||
const pixelCount = width * height;
|
||
|
||
if (image.format === KittyFormat.RGBA) {
|
||
// RGBA: use bytes directly — no copy needed
|
||
return createImageBitmap(new ImageData(new Uint8ClampedArray(bytes.buffer as ArrayBuffer, bytes.byteOffset, pixelCount * KittyPixelConstants.BYTES_PER_PIXEL_RGBA), width, height));
|
||
}
|
||
|
||
// RGB→RGBA: interleave alpha using uint32 block processing (4 pixels per iteration).
|
||
// 3 uint32 reads + 4 uint32 writes per 4 pixels vs 28 byte reads/writes — ~6x faster.
|
||
// Assumes little-endian (all modern browsers/Node.js).
|
||
const data = new Uint8ClampedArray(pixelCount * KittyPixelConstants.BYTES_PER_PIXEL_RGBA);
|
||
const src32 = new Uint32Array(bytes.buffer, bytes.byteOffset, Math.floor(bytes.byteLength / 4));
|
||
const dst32 = new Uint32Array(data.buffer);
|
||
const alignedPixels = pixelCount & ~3; // round down to multiple of 4
|
||
|
||
let srcOffset = 0;
|
||
let dstOffset = 0;
|
||
for (let i = 0; i < alignedPixels; i += 4) {
|
||
const b0 = src32[srcOffset++];
|
||
const b1 = src32[srcOffset++];
|
||
const b2 = src32[srcOffset++];
|
||
// Little-endian: pixel bytes are [R,G,B] → uint32 ABGR layout
|
||
dst32[dstOffset++] = 0xFF000000 | b0;
|
||
dst32[dstOffset++] = 0xFF000000 | (b0 >>> 24) | (b1 << 8);
|
||
dst32[dstOffset++] = 0xFF000000 | (b1 >>> 16) | (b2 << 16);
|
||
dst32[dstOffset++] = 0xFF000000 | (b2 >>> 8);
|
||
}
|
||
|
||
// Handle remaining 1–3 pixels
|
||
let srcByte = alignedPixels * KittyPixelConstants.BYTES_PER_PIXEL_RGB;
|
||
let dstByte = alignedPixels * KittyPixelConstants.BYTES_PER_PIXEL_RGBA;
|
||
for (let i = alignedPixels; i < pixelCount; i++) {
|
||
data[dstByte] = bytes[srcByte];
|
||
data[dstByte + 1] = bytes[srcByte + 1];
|
||
data[dstByte + 2] = bytes[srcByte + 2];
|
||
data[dstByte + 3] = KittyPixelConstants.ALPHA_OPAQUE;
|
||
srcByte += KittyPixelConstants.BYTES_PER_PIXEL_RGB;
|
||
dstByte += KittyPixelConstants.BYTES_PER_PIXEL_RGBA;
|
||
}
|
||
|
||
return createImageBitmap(new ImageData(data, width, height));
|
||
}
|
||
|
||
private async _decompressZlib(compressed: Uint8Array): Promise<Uint8Array> {
|
||
try {
|
||
return await this._decompress(compressed, 'deflate');
|
||
} catch {
|
||
return await this._decompress(compressed, 'deflate-raw');
|
||
}
|
||
}
|
||
|
||
private async _decompress(compressed: Uint8Array, format: 'deflate' | 'deflate-raw'): Promise<Uint8Array> {
|
||
const ds = new DecompressionStream(format);
|
||
const writer = ds.writable.getWriter();
|
||
writer.write(compressed as BufferSource);
|
||
writer.close();
|
||
|
||
const chunks: Uint8Array[] = [];
|
||
const reader = ds.readable.getReader();
|
||
|
||
while (true) {
|
||
const { done, value } = await reader.read();
|
||
if (done) break;
|
||
chunks.push(value);
|
||
}
|
||
|
||
const totalLength = chunks.reduce((sum, chunk) => sum + chunk.length, 0);
|
||
const result = new Uint8Array(totalLength);
|
||
let offset = 0;
|
||
for (const chunk of chunks) {
|
||
result.set(chunk, offset);
|
||
offset += chunk.length;
|
||
}
|
||
return result;
|
||
}
|
||
|
||
public get images(): ReadonlyMap<number, IKittyImageData> {
|
||
return this._kittyStorage.images;
|
||
}
|
||
|
||
public get _kittyIdToStorageId(): ReadonlyMap<number, number> {
|
||
return this._kittyStorage.kittyIdToStorageId;
|
||
}
|
||
|
||
public get pendingTransmissions(): ReadonlyMap<number, IPendingTransmission> {
|
||
return this._pendingTransmissions;
|
||
}
|
||
}
|