MeshCentral/public/mstsc/canvas.js

117 lines
3.1 KiB
JavaScript

/*
* Copyright (c) 2015 Sylvain Peyrefitte
*
* This file is part of mstsc.js.
*
* mstsc.js is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
(function() {
/**
* decompress bitmap from RLE algorithm
* @param bitmap {object} bitmap object of bitmap event of node-rdpjs
*/
function decompress (bitmap) {
var fName = null;
switch (bitmap.bitsPerPixel) {
case 15:
fName = 'bitmap_decompress_15';
break;
case 16:
fName = 'bitmap_decompress_16';
break;
case 24:
fName = 'bitmap_decompress_24';
break;
case 32:
fName = 'bitmap_decompress_32';
break;
default:
throw 'invalid bitmap data format';
}
var input = new Uint8Array(bitmap.data);
var inputPtr = Module._malloc(input.length);
var inputHeap = new Uint8Array(Module.HEAPU8.buffer, inputPtr, input.length);
inputHeap.set(input);
var output_width = bitmap.destRight - bitmap.destLeft + 1;
var output_height = bitmap.destBottom - bitmap.destTop + 1;
var ouputSize = output_width * output_height * 4;
var outputPtr = Module._malloc(ouputSize);
var outputHeap = new Uint8Array(Module.HEAPU8.buffer, outputPtr, ouputSize);
var res = Module.ccall(fName,
'number',
['number', 'number', 'number', 'number', 'number', 'number', 'number', 'number'],
[outputHeap.byteOffset, output_width, output_height, bitmap.width, bitmap.height, inputHeap.byteOffset, input.length]
);
var output = new Uint8ClampedArray(outputHeap.buffer, outputHeap.byteOffset, ouputSize);
Module._free(inputPtr);
Module._free(outputPtr);
return { width : output_width, height : output_height, data : output };
}
/**
* Un compress bitmap are reverse in y axis
*/
function reverse (bitmap) {
return { width : bitmap.width, height : bitmap.height, data : new Uint8ClampedArray(bitmap.data) };
}
/**
* Canvas renderer
* @param canvas {canvas} use for rendering
*/
function Canvas(canvas) {
this.canvas = canvas;
this.ctx = canvas.getContext("2d");
}
Canvas.prototype = {
/**
* update canvas with new bitmap
* @param bitmap {object}
*/
update : function (bitmap) {
var output = null;
if (bitmap.isCompress) {
output = decompress(bitmap);
}
else {
output = reverse(bitmap);
}
// use image data to use asm.js
var imageData = this.ctx.createImageData(output.width, output.height);
imageData.data.set(output.data);
this.ctx.putImageData(imageData, bitmap.destLeft, bitmap.destTop);
}
}
/**
* Module export
*/
Mstsc.Canvas = {
create : function (canvas) {
return new Canvas(canvas);
}
}
})();