MeshCentral/public/novnc/core/display.js
2023-07-05 13:20:10 +03:00

526 lines
16 KiB
JavaScript

/*
* noVNC: HTML5 VNC client
* Copyright (C) 2019 The noVNC Authors
* Licensed under MPL 2.0 (see LICENSE.txt)
*
* See README.md for usage and integration instructions.
*/
import * as Log from './util/logging.js';
import Base64 from "./base64.js";
import { toSigned32bit } from './util/int.js';
export default class Display {
constructor(target) {
this._drawCtx = null;
this._renderQ = []; // queue drawing actions for in-oder rendering
this._flushing = false;
// the full frame buffer (logical canvas) size
this._fbWidth = 0;
this._fbHeight = 0;
this._prevDrawStyle = "";
Log.Debug(">> Display.constructor");
// The visible canvas
this._target = target;
if (!this._target) {
throw new Error("Target must be set");
}
if (typeof this._target === 'string') {
throw new Error('target must be a DOM element');
}
if (!this._target.getContext) {
throw new Error("no getContext method");
}
this._targetCtx = this._target.getContext('2d');
// the visible canvas viewport (i.e. what actually gets seen)
this._viewportLoc = { 'x': 0, 'y': 0, 'w': this._target.width, 'h': this._target.height };
// The hidden canvas, where we do the actual rendering
this._backbuffer = document.createElement('canvas');
this._drawCtx = this._backbuffer.getContext('2d');
this._damageBounds = { left: 0, top: 0,
right: this._backbuffer.width,
bottom: this._backbuffer.height };
Log.Debug("User Agent: " + navigator.userAgent);
Log.Debug("<< Display.constructor");
// ===== PROPERTIES =====
this._scale = 1.0;
this._clipViewport = false;
// ===== EVENT HANDLERS =====
this.onflush = () => {}; // A flush request has finished
}
// ===== PROPERTIES =====
get scale() { return this._scale; }
set scale(scale) {
this._rescale(scale);
}
get clipViewport() { return this._clipViewport; }
set clipViewport(viewport) {
this._clipViewport = viewport;
// May need to readjust the viewport dimensions
const vp = this._viewportLoc;
this.viewportChangeSize(vp.w, vp.h);
this.viewportChangePos(0, 0);
}
get width() {
return this._fbWidth;
}
get height() {
return this._fbHeight;
}
// ===== PUBLIC METHODS =====
viewportChangePos(deltaX, deltaY) {
const vp = this._viewportLoc;
deltaX = Math.floor(deltaX);
deltaY = Math.floor(deltaY);
if (!this._clipViewport) {
deltaX = -vp.w; // clamped later of out of bounds
deltaY = -vp.h;
}
const vx2 = vp.x + vp.w - 1;
const vy2 = vp.y + vp.h - 1;
// Position change
if (deltaX < 0 && vp.x + deltaX < 0) {
deltaX = -vp.x;
}
if (vx2 + deltaX >= this._fbWidth) {
deltaX -= vx2 + deltaX - this._fbWidth + 1;
}
if (vp.y + deltaY < 0) {
deltaY = -vp.y;
}
if (vy2 + deltaY >= this._fbHeight) {
deltaY -= (vy2 + deltaY - this._fbHeight + 1);
}
if (deltaX === 0 && deltaY === 0) {
return;
}
Log.Debug("viewportChange deltaX: " + deltaX + ", deltaY: " + deltaY);
vp.x += deltaX;
vp.y += deltaY;
this._damage(vp.x, vp.y, vp.w, vp.h);
this.flip();
}
viewportChangeSize(width, height) {
if (!this._clipViewport ||
typeof(width) === "undefined" ||
typeof(height) === "undefined") {
Log.Debug("Setting viewport to full display region");
width = this._fbWidth;
height = this._fbHeight;
}
width = Math.floor(width);
height = Math.floor(height);
if (width > this._fbWidth) {
width = this._fbWidth;
}
if (height > this._fbHeight) {
height = this._fbHeight;
}
const vp = this._viewportLoc;
if (vp.w !== width || vp.h !== height) {
vp.w = width;
vp.h = height;
const canvas = this._target;
canvas.width = width;
canvas.height = height;
// The position might need to be updated if we've grown
this.viewportChangePos(0, 0);
this._damage(vp.x, vp.y, vp.w, vp.h);
this.flip();
// Update the visible size of the target canvas
this._rescale(this._scale);
}
}
absX(x) {
if (this._scale === 0) {
return 0;
}
return toSigned32bit(x / this._scale + this._viewportLoc.x);
}
absY(y) {
if (this._scale === 0) {
return 0;
}
return toSigned32bit(y / this._scale + this._viewportLoc.y);
}
resize(width, height) {
this._prevDrawStyle = "";
this._fbWidth = width;
this._fbHeight = height;
const canvas = this._backbuffer;
if (canvas.width !== width || canvas.height !== height) {
// We have to save the canvas data since changing the size will clear it
let saveImg = null;
if (canvas.width > 0 && canvas.height > 0) {
saveImg = this._drawCtx.getImageData(0, 0, canvas.width, canvas.height);
}
if (canvas.width !== width) {
canvas.width = width;
}
if (canvas.height !== height) {
canvas.height = height;
}
if (saveImg) {
this._drawCtx.putImageData(saveImg, 0, 0);
}
}
// Readjust the viewport as it may be incorrectly sized
// and positioned
const vp = this._viewportLoc;
this.viewportChangeSize(vp.w, vp.h);
this.viewportChangePos(0, 0);
}
getImageData() {
return this._drawCtx.getImageData(0, 0, this.width, this.height);
}
toDataURL(type, encoderOptions) {
return this._backbuffer.toDataURL(type, encoderOptions);
}
toBlob(callback, type, quality) {
return this._backbuffer.toBlob(callback, type, quality);
}
// Track what parts of the visible canvas that need updating
_damage(x, y, w, h) {
if (x < this._damageBounds.left) {
this._damageBounds.left = x;
}
if (y < this._damageBounds.top) {
this._damageBounds.top = y;
}
if ((x + w) > this._damageBounds.right) {
this._damageBounds.right = x + w;
}
if ((y + h) > this._damageBounds.bottom) {
this._damageBounds.bottom = y + h;
}
}
// Update the visible canvas with the contents of the
// rendering canvas
flip(fromQueue) {
if (this._renderQ.length !== 0 && !fromQueue) {
this._renderQPush({
'type': 'flip'
});
} else {
let x = this._damageBounds.left;
let y = this._damageBounds.top;
let w = this._damageBounds.right - x;
let h = this._damageBounds.bottom - y;
let vx = x - this._viewportLoc.x;
let vy = y - this._viewportLoc.y;
if (vx < 0) {
w += vx;
x -= vx;
vx = 0;
}
if (vy < 0) {
h += vy;
y -= vy;
vy = 0;
}
if ((vx + w) > this._viewportLoc.w) {
w = this._viewportLoc.w - vx;
}
if ((vy + h) > this._viewportLoc.h) {
h = this._viewportLoc.h - vy;
}
if ((w > 0) && (h > 0)) {
// FIXME: We may need to disable image smoothing here
// as well (see copyImage()), but we haven't
// noticed any problem yet.
this._targetCtx.drawImage(this._backbuffer,
x, y, w, h,
vx, vy, w, h);
}
this._damageBounds.left = this._damageBounds.top = 65535;
this._damageBounds.right = this._damageBounds.bottom = 0;
}
}
pending() {
return this._renderQ.length > 0;
}
flush() {
if (this._renderQ.length === 0) {
this.onflush();
} else {
this._flushing = true;
}
}
fillRect(x, y, width, height, color, fromQueue) {
if (this._renderQ.length !== 0 && !fromQueue) {
this._renderQPush({
'type': 'fill',
'x': x,
'y': y,
'width': width,
'height': height,
'color': color
});
} else {
this._setFillColor(color);
this._drawCtx.fillRect(x, y, width, height);
this._damage(x, y, width, height);
}
}
copyImage(oldX, oldY, newX, newY, w, h, fromQueue) {
if (this._renderQ.length !== 0 && !fromQueue) {
this._renderQPush({
'type': 'copy',
'oldX': oldX,
'oldY': oldY,
'x': newX,
'y': newY,
'width': w,
'height': h,
});
} else {
// Due to this bug among others [1] we need to disable the image-smoothing to
// avoid getting a blur effect when copying data.
//
// 1. https://bugzilla.mozilla.org/show_bug.cgi?id=1194719
//
// We need to set these every time since all properties are reset
// when the the size is changed
this._drawCtx.mozImageSmoothingEnabled = false;
this._drawCtx.webkitImageSmoothingEnabled = false;
this._drawCtx.msImageSmoothingEnabled = false;
this._drawCtx.imageSmoothingEnabled = false;
this._drawCtx.drawImage(this._backbuffer,
oldX, oldY, w, h,
newX, newY, w, h);
this._damage(newX, newY, w, h);
}
}
imageRect(x, y, width, height, mime, arr) {
/* The internal logic cannot handle empty images, so bail early */
if ((width === 0) || (height === 0)) {
return;
}
const img = new Image();
img.src = "data: " + mime + ";base64," + Base64.encode(arr);
this._renderQPush({
'type': 'img',
'img': img,
'x': x,
'y': y,
'width': width,
'height': height
});
}
blitImage(x, y, width, height, arr, offset, fromQueue) {
if (this._renderQ.length !== 0 && !fromQueue) {
// NB(directxman12): it's technically more performant here to use preallocated arrays,
// but it's a lot of extra work for not a lot of payoff -- if we're using the render queue,
// this probably isn't getting called *nearly* as much
const newArr = new Uint8Array(width * height * 4);
newArr.set(new Uint8Array(arr.buffer, 0, newArr.length));
this._renderQPush({
'type': 'blit',
'data': newArr,
'x': x,
'y': y,
'width': width,
'height': height,
});
} else {
// NB(directxman12): arr must be an Type Array view
let data = new Uint8ClampedArray(arr.buffer,
arr.byteOffset + offset,
width * height * 4);
let img = new ImageData(data, width, height);
this._drawCtx.putImageData(img, x, y);
this._damage(x, y, width, height);
}
}
drawImage(img, x, y) {
this._drawCtx.drawImage(img, x, y);
this._damage(x, y, img.width, img.height);
}
autoscale(containerWidth, containerHeight) {
let scaleRatio;
if (containerWidth === 0 || containerHeight === 0) {
scaleRatio = 0;
} else {
const vp = this._viewportLoc;
const targetAspectRatio = containerWidth / containerHeight;
const fbAspectRatio = vp.w / vp.h;
if (fbAspectRatio >= targetAspectRatio) {
scaleRatio = containerWidth / vp.w;
} else {
scaleRatio = containerHeight / vp.h;
}
}
this._rescale(scaleRatio);
}
// ===== PRIVATE METHODS =====
_rescale(factor) {
this._scale = factor;
const vp = this._viewportLoc;
// NB(directxman12): If you set the width directly, or set the
// style width to a number, the canvas is cleared.
// However, if you set the style width to a string
// ('NNNpx'), the canvas is scaled without clearing.
const width = factor * vp.w + 'px';
const height = factor * vp.h + 'px';
if ((this._target.style.width !== width) ||
(this._target.style.height !== height)) {
this._target.style.width = width;
this._target.style.height = height;
}
}
_setFillColor(color) {
const newStyle = 'rgb(' + color[0] + ',' + color[1] + ',' + color[2] + ')';
if (newStyle !== this._prevDrawStyle) {
this._drawCtx.fillStyle = newStyle;
this._prevDrawStyle = newStyle;
}
}
_renderQPush(action) {
this._renderQ.push(action);
if (this._renderQ.length === 1) {
// If this can be rendered immediately it will be, otherwise
// the scanner will wait for the relevant event
this._scanRenderQ();
}
}
_resumeRenderQ() {
// "this" is the object that is ready, not the
// display object
this.removeEventListener('load', this._noVNCDisplay._resumeRenderQ);
this._noVNCDisplay._scanRenderQ();
}
_scanRenderQ() {
let ready = true;
while (ready && this._renderQ.length > 0) {
const a = this._renderQ[0];
switch (a.type) {
case 'flip':
this.flip(true);
break;
case 'copy':
this.copyImage(a.oldX, a.oldY, a.x, a.y, a.width, a.height, true);
break;
case 'fill':
this.fillRect(a.x, a.y, a.width, a.height, a.color, true);
break;
case 'blit':
this.blitImage(a.x, a.y, a.width, a.height, a.data, 0, true);
break;
case 'img':
if (a.img.complete) {
if (a.img.width !== a.width || a.img.height !== a.height) {
Log.Error("Decoded image has incorrect dimensions. Got " +
a.img.width + "x" + a.img.height + ". Expected " +
a.width + "x" + a.height + ".");
return;
}
this.drawImage(a.img, a.x, a.y);
} else {
a.img._noVNCDisplay = this;
a.img.addEventListener('load', this._resumeRenderQ);
// We need to wait for this image to 'load'
// to keep things in-order
ready = false;
}
break;
}
if (ready) {
this._renderQ.shift();
}
}
if (this._renderQ.length === 0 && this._flushing) {
this._flushing = false;
this.onflush();
}
}
}