/**

Circle.

*
@author Martin Simons
@version $Id$

*/

public class Circle

extends Mesh

{

/**
The center.

*/

private Vector3f center;



/**
The radius.

*/

private float radius;



/**
The samples.

*/

private int samples;



/**
Constructs a new instance of this class.

*
@param radius

*/

public Circle(float radius)

{

this(Vector3f.ZERO, radius, 16);

}



/**
Constructs a new instance of this class.

*
@param radius
@param samples

*/

public Circle(float radius, int samples)

{

this(Vector3f.ZERO, radius, samples);

}



/**
Constructs a new instance of this class.

*
@param center
@param radius
@param samples

*/

public Circle(Vector3f center, float radius, int samples)

{

super();

this.center = center;

this.radius = radius;

this.samples = samples;



setMode(Mode.Lines);

updateGeometry();

}



protected void updateGeometry()

{

FloatBuffer positions = BufferUtils.createFloatBuffer(samples * 3);

FloatBuffer normals = BufferUtils.createFloatBuffer(samples * 3);

short[] indices = new short[samples * 2];



float rate = FastMath.TWO_PI / (float) samples;

float angle = 0;

for (int i = 0; i < samples; i++)

{

float x = FastMath.cos(angle) + center.x;

float z = FastMath.sin(angle) + center.z;



positions.put(x * radius).put(center.y).put(z * radius);

normals.put(new float[] { 0, 1, 0 });

indices = (short) i;

if (i < samples - 1)

indices = (short) (i + 1);

else

indices = 0;



angle += rate;

}



setBuffer(Type.Position, 3, positions);

setBuffer(Type.Normal, 3, normals);

setBuffer(Type.Index, 2, indices);



setBuffer(Type.TexCoord, 2, new float[] { 0, 0, 1, 1 });



updateBound();

}