# R2 - DrawSpline

void R2::DrawSpline(double x1,
double y1,
double x2,
double y2,
double x3,
double y3,
double x4,
double y4)

This method draws a spline.

## Parameters

double x1

The x-coordinate of the starting point of the spline.

double y1

The y-coordinate of the starting point of the spline.

double x2

The x-coordinate of the first control point of the spline.

double y2

The y-coordinate of the first control point of the spline.

double x3

The x-coordinate of the second control point of the spline.

double y3

The y-coordinate of the second control point of the spline.

double x4

The x-coordinate of the ending point of the spline.

double y4

The y-coordinate of the ending point of the spline.

## Notes

A line drawn from the starting point to the first control point
is tangential to the spline. A line drawn from from the ending point of the spline
to the second control point is also tangential to the spline. The starting and ending
points together with the tangents at these points completely determine the shape
of the spline.