package nextrek.arse;

import nextrek.math.Vector;


/**
 * Represents the camera and it's view. It also allows a user to project a point given this camera's view.
 * 
 * This file was adapted from Mixare <http://www.mixare.org/>
 * 
 * @author Daniele Gobbetti <info@mixare.org>
 * @author Justin Wetherell <phishman3579@gmail.com>
 */
public class CameraModel {
    private static final float[] tmp1 = new float[3];
    private static final float[] tmp2 = new float[3];

	private int width = 0; 
	private int height = 0;
	private float viewAngle = 0F;
	private float distance = 0F;
	
	public static final float DEFAULT_VIEW_ANGLE = (float) Math.toRadians(45);
	
	public CameraModel(int width, int height) {
		this(width, height, true);
	}

	public CameraModel(int width, int height, boolean init) {
		set(width, height, init);
	}
	
	/**
	 * Set this objects parameters. This should be used instead of creating new objects.
	 * @param width Width of the model.
	 * @param height Height of the model.
	 * @param init Should initialize the internal transform and lco objects.
	 */
	public void set(int width, int height, boolean init) {
		this.width = width;
		this.height = height;
	}
	
	/**
	 * Width of the camera view.
	 * @return int representing the width of camera view.
	 */
	public int getWidth() {
	    return width;
	}
    
    /**
     * Height of the camera view.
     * @return int representing height of the camera view.
     */
    public int getHeight() {
        return height;
    }

	/**
	 * Set the View Angle of the camera model.
	 * @param viewAngle float representing the camera model.
	 */
	public void setViewAngle(float viewAngle) {
		this.viewAngle = viewAngle;
		this.distance = (this.width / 2) / (float) Math.tan(viewAngle / 2);
	}
	
	/**
	 * Set the View Angle of the camera model.
	 * @param width Width of the camera model.
	 * @param height Height of the camera model.
	 * @param viewAngle float representing the camera model.
	 */
	public void setViewAngle(int width, int height, float viewAngle) {
		this.viewAngle = viewAngle;
		this.distance = (width / 2) / (float) Math.tan(viewAngle / 2);
	}

	/**
	 * Project point from the origin Vector to the projected Vector.
	 * @param orgPoint Vector representing the origin.
	 * @param prjPoint Vector representing the projected point.
	 * @param addX Add X to the projected point.
	 * @param addY Add Y to the projected point.
	 */
	public void projectPoint(Vector orgPoint, Vector prjPoint, float addX, float addY) {
	    orgPoint.get(tmp1);
	    tmp2[0]=(distance * tmp1[0] / -tmp1[2]);
	    tmp2[1]=(distance * tmp1[1] / -tmp1[2]);
	    tmp2[2]=(tmp1[2]);
	    tmp2[0]=(tmp2[0] + addX + width / 2);
	    tmp2[1]=(-tmp2[1] + addY + height / 2);
	    prjPoint.set(tmp2);
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public String toString() {
		return "CAM(" + width + "," + height + "," + viewAngle + "," + distance + ")";
	}
}