package engine.rendering.lighting;

import org.lwjgl.util.vector.Vector3f;

public class ConeGenerator{

    private Vector3f[] positions;
    private short[] indices;

    public void create(int subdivisions){

        positions = new Vector3f[subdivisions + 1];

        positions[0] = new Vector3f(0, 0, 0);

        for(int i = 0; i < subdivisions; i++){
            positions[i + 1] = new Vector3f((float)Math.cos(Math.PI * 2 * i / subdivisions), (float)Math.sin(Math.PI * 2 * i / subdivisions), 1);
        }

        indices = new short[(subdivisions*2 - 2) * 3];

        int index = 0;
        for(int i = 1; i < subdivisions; i++){
            indices[index++] = 0; //Source point
            indices[index++] = (short)(i+1);
            indices[index++] = (short)i;
        }
        indices[index++] = 0; //Source point
        indices[index++] = 1;
        indices[index++] = (short)subdivisions;


        for(int i = 2; i < subdivisions; i++){
            indices[index++] = 1;
            indices[index++] = (short)i;
            indices[index++] = (short)(i+1);
        }

    }

    public Vector3f[] getPositions(){
        return positions;
    }

    public short[] getIndices(){
        return indices;
    }
}