| public CreateCircle ( float radius, int sides ) : void | ||
| radius | float | The radius (half the width) of the circle. |
| sides | int | The number of sides on the circle (the more the detailed). |
| return | void | |
public void CreateCircle(float radius, int sides)
{
mVectors.Clear();
float max = 2 * (float)System.Math.PI;
float step = max / (float)sides;
for (float theta = 0; theta < max; theta += step)
{
mVectors.Add(new Vector2(radius * (float)System.Math.Cos((double)theta),
radius * (float)System.Math.Sin((double)theta)));
}
// then add the first vector again so it's a complete loop
mVectors.Add(new Vector2(radius * (float)System.Math.Cos(0),
radius * (float)System.Math.Sin(0)));
}
private void UpdatePoints()
{
mLinePrimitive.CreateCircle(Radius, 15);
if (mCircleOrigin == Geometry.CircleOrigin.TopLeft)
{
if (Rotation != 0)
{
Matrix matrix = Matrix.CreateRotationZ(-MathHelper.ToRadians(Rotation));
var vector = Radius * matrix.Right + Radius * matrix.Up;
mLinePrimitive.Shift(vector.X, vector.Y);
}
else
{
mLinePrimitive.Shift(Radius, Radius);
}
}
}
