CurveTo() with from mousedown to the mouseX, mouse Y

Anybody got a method of drawing a line from the mouse down point to the mouses current position.

But taking into account the direction the mouse is moving in to make the curve look more natural and directional.

This is what i have currently which is basic and rubbish:, startY);, Main.gameStage.mouseY/3,Main.gameStage.mouseX, Main.gameStage.mouseY);