Nebula.java

package celestial;

import mainpkg.CPU;
import setup.MakeWorld;
import util.Methods;

import com.jme3.math.ColorRGBA;
import com.jme3.math.FastMath;
import com.jme3.math.Vector3f;
import com.jme3.renderer.queue.RenderQueue.Bucket;
import com.jme3.renderer.queue.RenderQueue.ShadowMode;
import com.jme3.scene.Geometry;
import com.jme3.scene.Node;
import com.jme3.scene.Spatial;
import com.jme3.scene.shape.Quad;

public class Nebula extends Node{

    float size;
    ColorRGBA template;

    public Nebula(Vector3f loc, float size, ColorRGBA col)
    {
        super();
        setLocalTranslation(loc);
        this.size = size;

        if(col != null)
            template = col; //predefined color
        else
            template = new ColorRGBA( //generates a random color
                FastMath.nextRandomFloat()*0.8f,
                FastMath.nextRandomFloat()*0.8f,
                FastMath.nextRandomFloat()*0.8f,
                0f
            );
    }

    public void disable(){
        //delete untill rebuilt again
        if(getChildren().size() > 0)
            detachAllChildren();
    }

    public void enable(){
        if(getChildren().size() == 0)
        {
            //construct the nebula
            for (int i = 0; i < size/50; i++) {
                float rand1 = FastMath.nextRandomFloat()*FastMath.pow((size/75f), 1.85f);
                float rand2 = FastMath.nextRandomFloat()*FastMath.pow((size/75f), 1.85f);
                float rand3 = FastMath.nextRandomFloat()*FastMath.pow((size/75f), 1.85f);
                Quad side = new Quad(size,size);
                Geometry plate = new Geometry("plane",side);
                plate.setMaterial(MakeWorld.nebula.get(FastMath.rand.nextInt(MakeWorld.nebula.size())).clone());
                plate.setQueueBucket(Bucket.Transparent);
                plate.setLocalTranslation(-size/2+rand1, -size/2+rand2, rand3);
                plate.setShadowMode(ShadowMode.Off);
                Node n = new Node();
                n.attachChild(plate);
                n.getLocalRotation().fromAngleAxis(i*36, Methods.randomVector3f());
                attachChild(n);
            }
        }
    }

    public void cycle(float tpf)
    {
        Node temp = new Node();
        for (Spatial plate : getChildren()) {

            //get both vectors (don't ask)
            Vector3f one = plate.getLocalRotation().getRotationColumn(2);
            temp.setLocalTranslation(((Geometry)((Node)plate).getChild(0)).getWorldTranslation());
            temp.lookAt(CPU.game.getCamera().getLocation().mult(0.7f), Vector3f.UNIT_Y);
            Vector3f two = temp.getLocalRotation().getRotationColumn(2);

            //calculate opacity
            float opacity = FastMath.abs(one.dot(two))*0.75f;

            //set opacity
            ((Geometry)((Node)plate).getChild(0)).getMaterial()
            .setColor("Color", new ColorRGBA(template.r,template.g,template.b,opacity));
        }
    }
}