Add interpolation when using the pen tool quickly

js/drawingtools/BaseTool.js

@@ -55,4 +55,41 @@
 	ns.BaseTool.prototype.removeCanvasOverlays = function () {
 		$(".canvas-overlay").remove();
 	};
+
+	/**
+	 * Bresenham line algorihtm: Get an array of pixels from
+	 * start and end coordinates.
+	 *
+	 * http://en.wikipedia.org/wiki/Bresenham's_line_algorithm
+	 * http://stackoverflow.com/questions/4672279/bresenham-algorithm-in-javascript
+	 *
+	 * @private
+	 */
+	ns.BaseTool.prototype.getLinePixels_ = function(x0, x1, y0, y1) {
+		
+		var pixels = [];
+		var dx = Math.abs(x1-x0);
+	   	var dy = Math.abs(y1-y0);
+	   	var sx = (x0 < x1) ? 1 : -1;
+	   	var sy = (y0 < y1) ? 1 : -1;
+	   	var err = dx-dy;
+
+	   	while(true){
+
+	    	// Do what you need to for this
+	    	pixels.push({"col": x0, "row": y0});
+
+		    if ((x0==x1) && (y0==y1)) break;
+		    var e2 = 2*err;
+		    if (e2>-dy){
+		    	err -= dy;
+		    	x0  += sx;
+		    }
+		    if (e2 < dx) {
+		    	err += dx;
+		    	y0  += sy;
+		    }
+	    }
+	    return pixels;
+     };
 })();