function drawPolygon2(context, polygon, matrix, fx, fy) {
context.beginPath();
var vertex = Vertex.transform(polygon.vertex(0), matrix);
context.moveTo(fx(vertex), -1 * fy(vertex));
for (var i = 1; i < polygon.count(); ++i) {
vertex = Vertex.transform(polygon.vertex(i), matrix);
context.lineTo(fx(vertex), -1 * fy(vertex));
}
context.closePath();
context.stroke();
}