Entity:

Usage:
**bezier_line(X1,Y1, ... , Xn, Yn)**

This function will draw a cubic Bézier curve using the points
**X1,Y1,
... , Xn, Yn** . The Bezier line is a smooth line which is used to describe
curves (for example in CorelDraw). If you want to make such a line which
goes true **k+1** points then you need to give **3*k+1** points to
this predicate (that is, you need **2*(3*k+1)** arguments). You need
so many points because for every point you have to give also the vector
of the touching line in the left and in the right direction. This vectors
show the direction of the touching line but also their length shows how
close is the curve to the touching line in this point. For example, if
you gave as arguments the points **p1, p2, p3, p4** then you will connect
points **p1** and **p4** with a Bézier curve. The points **p2**
and **p3** will describe the lines which touch our curve in **p1**
and **p4** . More concretely the vector **p1, p2** gives the direction
of the touching line and its length gives how close is this curve to the
touching line in **p1** . It is analogous for the vector **p4, p3**
for the point **p4** . For users who are familiar with CorelDraw this
is easier. Anyway, in CorelDraw you change the position of these points
by the mouse and see the result directly.

This function draws lines by using the current pen .

See also:

Examples:

Music.pro