2 * noVNC: HTML5 VNC client
3 * Copyright (C) 2019 The noVNC Authors
4 * Licensed under MPL 2.0 (see LICENSE.txt)
6 * See README.md for usage and integration instructions.
9 import * as Log
from './util/logging.js';
10 import Base64
from "./base64.js";
11 import { supportsImageMetadata
} from './util/browser.js';
13 export default class Display
{
17 this._renderQ
= []; // queue drawing actions for in-oder rendering
18 this._flushing
= false;
20 // the full frame buffer (logical canvas) size
24 this._prevDrawStyle
= "";
26 this._tile16x16
= null;
30 Log
.Debug(">> Display.constructor");
33 this._target
= target
;
36 throw new Error("Target must be set");
39 if (typeof this._target
=== 'string') {
40 throw new Error('target must be a DOM element');
43 if (!this._target
.getContext
) {
44 throw new Error("no getContext method");
47 this._targetCtx
= this._target
.getContext('2d');
49 // the visible canvas viewport (i.e. what actually gets seen)
50 this._viewportLoc
= { 'x': 0, 'y': 0, 'w': this._target
.width
, 'h': this._target
.height
};
52 // The hidden canvas, where we do the actual rendering
53 this._backbuffer
= document
.createElement('canvas');
54 this._drawCtx
= this._backbuffer
.getContext('2d');
56 this._damageBounds
= { left
: 0, top
: 0,
57 right
: this._backbuffer
.width
,
58 bottom
: this._backbuffer
.height
};
60 Log
.Debug("User Agent: " + navigator
.userAgent
);
62 // Check canvas features
63 if (!('createImageData' in this._drawCtx
)) {
64 throw new Error("Canvas does not support createImageData");
67 this._tile16x16
= this._drawCtx
.createImageData(16, 16);
68 Log
.Debug("<< Display.constructor");
70 // ===== PROPERTIES =====
73 this._clipViewport
= false;
75 // ===== EVENT HANDLERS =====
77 this.onflush
= () => {}; // A flush request has finished
80 // ===== PROPERTIES =====
82 get scale() { return this._scale
; }
87 get clipViewport() { return this._clipViewport
; }
88 set clipViewport(viewport
) {
89 this._clipViewport
= viewport
;
90 // May need to readjust the viewport dimensions
91 const vp
= this._viewportLoc
;
92 this.viewportChangeSize(vp
.w
, vp
.h
);
93 this.viewportChangePos(0, 0);
97 return this._fb_width
;
101 return this._fb_height
;
104 // ===== PUBLIC METHODS =====
106 viewportChangePos(deltaX
, deltaY
) {
107 const vp
= this._viewportLoc
;
108 deltaX
= Math
.floor(deltaX
);
109 deltaY
= Math
.floor(deltaY
);
111 if (!this._clipViewport
) {
112 deltaX
= -vp
.w
; // clamped later of out of bounds
116 const vx2
= vp
.x
+ vp
.w
- 1;
117 const vy2
= vp
.y
+ vp
.h
- 1;
121 if (deltaX
< 0 && vp
.x
+ deltaX
< 0) {
124 if (vx2
+ deltaX
>= this._fb_width
) {
125 deltaX
-= vx2
+ deltaX
- this._fb_width
+ 1;
128 if (vp
.y
+ deltaY
< 0) {
131 if (vy2
+ deltaY
>= this._fb_height
) {
132 deltaY
-= (vy2
+ deltaY
- this._fb_height
+ 1);
135 if (deltaX
=== 0 && deltaY
=== 0) {
138 Log
.Debug("viewportChange deltaX: " + deltaX
+ ", deltaY: " + deltaY
);
143 this._damage(vp
.x
, vp
.y
, vp
.w
, vp
.h
);
148 viewportChangeSize(width
, height
) {
150 if (!this._clipViewport
||
151 typeof(width
) === "undefined" ||
152 typeof(height
) === "undefined") {
154 Log
.Debug("Setting viewport to full display region");
155 width
= this._fb_width
;
156 height
= this._fb_height
;
159 width
= Math
.floor(width
);
160 height
= Math
.floor(height
);
162 if (width
> this._fb_width
) {
163 width
= this._fb_width
;
165 if (height
> this._fb_height
) {
166 height
= this._fb_height
;
169 const vp
= this._viewportLoc
;
170 if (vp
.w
!== width
|| vp
.h
!== height
) {
174 const canvas
= this._target
;
175 canvas
.width
= width
;
176 canvas
.height
= height
;
178 // The position might need to be updated if we've grown
179 this.viewportChangePos(0, 0);
181 this._damage(vp
.x
, vp
.y
, vp
.w
, vp
.h
);
184 // Update the visible size of the target canvas
185 this._rescale(this._scale
);
190 if (this._scale
=== 0) {
193 return x
/ this._scale
+ this._viewportLoc
.x
;
197 if (this._scale
=== 0) {
200 return y
/ this._scale
+ this._viewportLoc
.y
;
203 resize(width
, height
) {
204 this._prevDrawStyle
= "";
206 this._fb_width
= width
;
207 this._fb_height
= height
;
209 const canvas
= this._backbuffer
;
210 if (canvas
.width
!== width
|| canvas
.height
!== height
) {
212 // We have to save the canvas data since changing the size will clear it
214 if (canvas
.width
> 0 && canvas
.height
> 0) {
215 saveImg
= this._drawCtx
.getImageData(0, 0, canvas
.width
, canvas
.height
);
218 if (canvas
.width
!== width
) {
219 canvas
.width
= width
;
221 if (canvas
.height
!== height
) {
222 canvas
.height
= height
;
226 this._drawCtx
.putImageData(saveImg
, 0, 0);
230 // Readjust the viewport as it may be incorrectly sized
232 const vp
= this._viewportLoc
;
233 this.viewportChangeSize(vp
.w
, vp
.h
);
234 this.viewportChangePos(0, 0);
237 // Track what parts of the visible canvas that need updating
238 _damage(x
, y
, w
, h
) {
239 if (x
< this._damageBounds
.left
) {
240 this._damageBounds
.left
= x
;
242 if (y
< this._damageBounds
.top
) {
243 this._damageBounds
.top
= y
;
245 if ((x
+ w
) > this._damageBounds
.right
) {
246 this._damageBounds
.right
= x
+ w
;
248 if ((y
+ h
) > this._damageBounds
.bottom
) {
249 this._damageBounds
.bottom
= y
+ h
;
253 // Update the visible canvas with the contents of the
256 if (this._renderQ
.length
!== 0 && !from_queue
) {
261 let x
= this._damageBounds
.left
;
262 let y
= this._damageBounds
.top
;
263 let w
= this._damageBounds
.right
- x
;
264 let h
= this._damageBounds
.bottom
- y
;
266 let vx
= x
- this._viewportLoc
.x
;
267 let vy
= y
- this._viewportLoc
.y
;
280 if ((vx
+ w
) > this._viewportLoc
.w
) {
281 w
= this._viewportLoc
.w
- vx
;
283 if ((vy
+ h
) > this._viewportLoc
.h
) {
284 h
= this._viewportLoc
.h
- vy
;
287 if ((w
> 0) && (h
> 0)) {
288 // FIXME: We may need to disable image smoothing here
289 // as well (see copyImage()), but we haven't
290 // noticed any problem yet.
291 this._targetCtx
.drawImage(this._backbuffer
,
296 this._damageBounds
.left
= this._damageBounds
.top
= 65535;
297 this._damageBounds
.right
= this._damageBounds
.bottom
= 0;
302 return this._renderQ
.length
> 0;
306 if (this._renderQ
.length
=== 0) {
309 this._flushing
= true;
313 fillRect(x
, y
, width
, height
, color
, from_queue
) {
314 if (this._renderQ
.length
!== 0 && !from_queue
) {
324 this._setFillColor(color
);
325 this._drawCtx
.fillRect(x
, y
, width
, height
);
326 this._damage(x
, y
, width
, height
);
330 copyImage(old_x
, old_y
, new_x
, new_y
, w
, h
, from_queue
) {
331 if (this._renderQ
.length
!== 0 && !from_queue
) {
342 // Due to this bug among others [1] we need to disable the image-smoothing to
343 // avoid getting a blur effect when copying data.
345 // 1. https://bugzilla.mozilla.org/show_bug.cgi?id=1194719
347 // We need to set these every time since all properties are reset
348 // when the the size is changed
349 this._drawCtx
.mozImageSmoothingEnabled
= false;
350 this._drawCtx
.webkitImageSmoothingEnabled
= false;
351 this._drawCtx
.msImageSmoothingEnabled
= false;
352 this._drawCtx
.imageSmoothingEnabled
= false;
354 this._drawCtx
.drawImage(this._backbuffer
,
357 this._damage(new_x
, new_y
, w
, h
);
361 imageRect(x
, y
, width
, height
, mime
, arr
) {
362 /* The internal logic cannot handle empty images, so bail early */
363 if ((width
=== 0) || (height
=== 0)) {
367 const img
= new Image();
368 img
.src
= "data: " + mime
+ ";base64," + Base64
.encode(arr
);
380 // start updating a tile
381 startTile(x
, y
, width
, height
, color
) {
384 if (width
=== 16 && height
=== 16) {
385 this._tile
= this._tile16x16
;
387 this._tile
= this._drawCtx
.createImageData(width
, height
);
390 const red
= color
[2];
391 const green
= color
[1];
392 const blue
= color
[0];
394 const data
= this._tile
.data
;
395 for (let i
= 0; i
< width
* height
* 4; i
+= 4) {
403 // update sub-rectangle of the current tile
404 subTile(x
, y
, w
, h
, color
) {
405 const red
= color
[2];
406 const green
= color
[1];
407 const blue
= color
[0];
411 const data
= this._tile
.data
;
412 const width
= this._tile
.width
;
413 for (let j
= y
; j
< yend
; j
++) {
414 for (let i
= x
; i
< xend
; i
++) {
415 const p
= (i
+ (j
* width
)) * 4;
424 // draw the current tile to the screen
426 this._drawCtx
.putImageData(this._tile
, this._tile_x
, this._tile_y
);
427 this._damage(this._tile_x
, this._tile_y
,
428 this._tile
.width
, this._tile
.height
);
431 blitImage(x
, y
, width
, height
, arr
, offset
, from_queue
) {
432 if (this._renderQ
.length
!== 0 && !from_queue
) {
433 // NB(directxman12): it's technically more performant here to use preallocated arrays,
434 // but it's a lot of extra work for not a lot of payoff -- if we're using the render queue,
435 // this probably isn't getting called *nearly* as much
436 const new_arr
= new Uint8Array(width
* height
* 4);
437 new_arr
.set(new Uint8Array(arr
.buffer
, 0, new_arr
.length
));
447 this._bgrxImageData(x
, y
, width
, height
, arr
, offset
);
451 blitRgbImage(x
, y
, width
, height
, arr
, offset
, from_queue
) {
452 if (this._renderQ
.length
!== 0 && !from_queue
) {
453 // NB(directxman12): it's technically more performant here to use preallocated arrays,
454 // but it's a lot of extra work for not a lot of payoff -- if we're using the render queue,
455 // this probably isn't getting called *nearly* as much
456 const new_arr
= new Uint8Array(width
* height
* 3);
457 new_arr
.set(new Uint8Array(arr
.buffer
, 0, new_arr
.length
));
467 this._rgbImageData(x
, y
, width
, height
, arr
, offset
);
471 blitRgbxImage(x
, y
, width
, height
, arr
, offset
, from_queue
) {
472 if (this._renderQ
.length
!== 0 && !from_queue
) {
473 // NB(directxman12): it's technically more performant here to use preallocated arrays,
474 // but it's a lot of extra work for not a lot of payoff -- if we're using the render queue,
475 // this probably isn't getting called *nearly* as much
476 const new_arr
= new Uint8Array(width
* height
* 4);
477 new_arr
.set(new Uint8Array(arr
.buffer
, 0, new_arr
.length
));
487 this._rgbxImageData(x
, y
, width
, height
, arr
, offset
);
491 drawImage(img
, x
, y
) {
492 this._drawCtx
.drawImage(img
, x
, y
);
493 this._damage(x
, y
, img
.width
, img
.height
);
496 autoscale(containerWidth
, containerHeight
) {
499 if (containerWidth
=== 0 || containerHeight
=== 0) {
504 const vp
= this._viewportLoc
;
505 const targetAspectRatio
= containerWidth
/ containerHeight
;
506 const fbAspectRatio
= vp
.w
/ vp
.h
;
508 if (fbAspectRatio
>= targetAspectRatio
) {
509 scaleRatio
= containerWidth
/ vp
.w
;
511 scaleRatio
= containerHeight
/ vp
.h
;
515 this._rescale(scaleRatio
);
518 // ===== PRIVATE METHODS =====
521 this._scale
= factor
;
522 const vp
= this._viewportLoc
;
524 // NB(directxman12): If you set the width directly, or set the
525 // style width to a number, the canvas is cleared.
526 // However, if you set the style width to a string
527 // ('NNNpx'), the canvas is scaled without clearing.
528 const width
= factor
* vp
.w
+ 'px';
529 const height
= factor
* vp
.h
+ 'px';
531 if ((this._target
.style
.width
!== width
) ||
532 (this._target
.style
.height
!== height
)) {
533 this._target
.style
.width
= width
;
534 this._target
.style
.height
= height
;
538 _setFillColor(color
) {
539 const newStyle
= 'rgb(' + color
[2] + ',' + color
[1] + ',' + color
[0] + ')';
540 if (newStyle
!== this._prevDrawStyle
) {
541 this._drawCtx
.fillStyle
= newStyle
;
542 this._prevDrawStyle
= newStyle
;
546 _rgbImageData(x
, y
, width
, height
, arr
, offset
) {
547 const img
= this._drawCtx
.createImageData(width
, height
);
548 const data
= img
.data
;
549 for (let i
= 0, j
= offset
; i
< width
* height
* 4; i
+= 4, j
+= 3) {
551 data
[i
+ 1] = arr
[j
+ 1];
552 data
[i
+ 2] = arr
[j
+ 2];
553 data
[i
+ 3] = 255; // Alpha
555 this._drawCtx
.putImageData(img
, x
, y
);
556 this._damage(x
, y
, img
.width
, img
.height
);
559 _bgrxImageData(x
, y
, width
, height
, arr
, offset
) {
560 const img
= this._drawCtx
.createImageData(width
, height
);
561 const data
= img
.data
;
562 for (let i
= 0, j
= offset
; i
< width
* height
* 4; i
+= 4, j
+= 4) {
563 data
[i
] = arr
[j
+ 2];
564 data
[i
+ 1] = arr
[j
+ 1];
565 data
[i
+ 2] = arr
[j
];
566 data
[i
+ 3] = 255; // Alpha
568 this._drawCtx
.putImageData(img
, x
, y
);
569 this._damage(x
, y
, img
.width
, img
.height
);
572 _rgbxImageData(x
, y
, width
, height
, arr
, offset
) {
573 // NB(directxman12): arr must be an Type Array view
575 if (supportsImageMetadata
) {
576 img
= new ImageData(new Uint8ClampedArray(arr
.buffer
, arr
.byteOffset
, width
* height
* 4), width
, height
);
578 img
= this._drawCtx
.createImageData(width
, height
);
579 img
.data
.set(new Uint8ClampedArray(arr
.buffer
, arr
.byteOffset
, width
* height
* 4));
581 this._drawCtx
.putImageData(img
, x
, y
);
582 this._damage(x
, y
, img
.width
, img
.height
);
585 _renderQ_push(action
) {
586 this._renderQ
.push(action
);
587 if (this._renderQ
.length
=== 1) {
588 // If this can be rendered immediately it will be, otherwise
589 // the scanner will wait for the relevant event
590 this._scan_renderQ();
595 // "this" is the object that is ready, not the
597 this.removeEventListener('load', this._noVNC_display
._resume_renderQ
);
598 this._noVNC_display
._scan_renderQ();
603 while (ready
&& this._renderQ
.length
> 0) {
604 const a
= this._renderQ
[0];
610 this.copyImage(a
.old_x
, a
.old_y
, a
.x
, a
.y
, a
.width
, a
.height
, true);
613 this.fillRect(a
.x
, a
.y
, a
.width
, a
.height
, a
.color
, true);
616 this.blitImage(a
.x
, a
.y
, a
.width
, a
.height
, a
.data
, 0, true);
619 this.blitRgbImage(a
.x
, a
.y
, a
.width
, a
.height
, a
.data
, 0, true);
622 this.blitRgbxImage(a
.x
, a
.y
, a
.width
, a
.height
, a
.data
, 0, true);
625 /* IE tends to set "complete" prematurely, so check dimensions */
626 if (a
.img
.complete
&& (a
.img
.width
!== 0) && (a
.img
.height
!== 0)) {
627 if (a
.img
.width
!== a
.width
|| a
.img
.height
!== a
.height
) {
628 Log
.Error("Decoded image has incorrect dimensions. Got " +
629 a
.img
.width
+ "x" + a
.img
.height
+ ". Expected " +
630 a
.width
+ "x" + a
.height
+ ".");
633 this.drawImage(a
.img
, a
.x
, a
.y
);
635 a
.img
._noVNC_display
= this;
636 a
.img
.addEventListener('load', this._resume_renderQ
);
637 // We need to wait for this image to 'load'
638 // to keep things in-order
645 this._renderQ
.shift();
649 if (this._renderQ
.length
=== 0 && this._flushing
) {
650 this._flushing
= false;