Improved MSTSC.js support.

public/mstsc/canvas.js

@@ -0,0 +1,116 @@
+/*
+ * 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);
+		}
+	}
+})();