core/decoders/raw.js

   1 /*
   2  * noVNC: HTML5 VNC client
   3  * Copyright (C) 2012 Joel Martin
   4  * Copyright (C) 2018 Samuel Mannehed for Cendio AB
   5  * Copyright (C) 2018 Pierre Ossman for Cendio AB
   6  * Licensed under MPL 2.0 (see LICENSE.txt)
   7  *
   8  * See README.md for usage and integration instructions.
   9  *
  10  */
  11
  12 export default class RawDecoder {
  13     constructor() {
  14         this._lines = 0;
  15     }
  16
  17     decodeRect(x, y, width, height, sock, display, depth) {
  18         if (this._lines === 0) {
  19             this._lines = height;
  20         }
  21
  22         const pixelSize = depth == 8 ? 1 : 4;
  23         const bytesPerLine = width * pixelSize;
  24
  25         if (sock.rQwait("RAW", bytesPerLine)) {
  26             return false;
  27         }
  28
  29         const cur_y = y + (height - this._lines);
  30         const curr_height = Math.min(this._lines,
  31                                      Math.floor(sock.rQlen / bytesPerLine));
  32         let data = sock.rQ;
  33         let index = sock.rQi;
  34
  35         // Convert data if needed
  36         if (depth == 8) {
  37             const pixels = width * curr_height;
  38             const newdata = new Uint8Array(pixels * 4);
  39             for (let i = 0; i < pixels; i++) {
  40                 newdata[i * 4 + 0] = ((data[index + i] >> 0) & 0x3) * 255 / 3;
  41                 newdata[i * 4 + 1] = ((data[index + i] >> 2) & 0x3) * 255 / 3;
  42                 newdata[i * 4 + 2] = ((data[index + i] >> 4) & 0x3) * 255 / 3;
  43                 newdata[i * 4 + 4] = 0;
  44             }
  45             data = newdata;
  46             index = 0;
  47         }
  48
  49         display.blitImage(x, cur_y, width, curr_height, data, index);
  50         sock.rQskipBytes(curr_height * bytesPerLine);
  51         this._lines -= curr_height;
  52         if (this._lines > 0) {
  53             return false;
  54         }
  55
  56         return true;
  57     }
  58 }