//::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
/** @author  Alekhya Chennupati, John Miller
 *  @version 1.2
 *  @date    May 15 11:58:34 EDT 2015
 *  @see     LICENSE (MIT style license file).
 */

package scalation.scala3d

import javafx.scene._

import javafx.application.Application
import javafx.event.{Event, EventHandler, EventTarget}
import javafx.scene.input.MouseEvent
import javafx.scene.paint.{Color, PhongMaterial}
import javafx.css.Styleable

import math.{acos, toDegrees}

//::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
/** The `Line3D` class is used to create lines in 3D.
 *  @param p1  the first endpoint of the line
 *  @param p2  the second endpoint of the line
 */
class Line3D (p1: Point3D, p2: Point3D)
      extends Cylinder (1.0, p1.distance (p2))
{
    private val DEBUG = true
    if (DEBUG) println(s"p1 = $p1, p2 = $p2")

    private val y_axis      = Point3D (0.0, 1.0, 0.0)
    private val translation = Translate (p2 midpoint p1)

    private val rot_axis    = (p2 subtract p1).crossProduct (y_axis)
    private val rot_angle   = acos (p2.subtract (p1).normalize ().dotProduct (y_axis))
    val rotation  = Rotate (-toDegrees (rot_angle), rot_axis)

    getTransforms ().add (translation)
    getTransforms ().add (rotation)

} // Line3D class


//::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
/** The `Line3Dep` class is used to create lines in 3D with endpoints (ep).
 *  @param p1  the first endpoint of the line
 *  @param p2  the second endpoint of the line
 *  @param sz  the size/radius of the endpoints
 */
class Line3Dep (p1: Point3D, p2: Point3D, sz: Double = 3.0)
      extends Line3D (p1, p2)
{
    private val sphere1 = new Sphere (sz)
    private val sphere2 = new Sphere (sz)
        
    sphere1.getTransforms ().add (Translate (p1))
    sphere2.getTransforms ().add (Translate (p2))
 
    //::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
    /** Get the two spheres serving as endpoints for the line.
     */
    def getSpheres = (sphere1, sphere2) 

} // Line3Dep class


//::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
/** The `Line3DHelper` class is used for displaying a line in 3D.
 */
case class Line3DHelper ()
     extends javafx.application.Application ()
{
    private val root        = new Group ()
    private val camera      = new Camera3D ()
    private var anchorX     = 0.0
    private var anchorY     = 0.0
    private var anchorAngle = 0.0

    def mkEventHandler [E <: Event] (f: E => Unit) = new EventHandler [E] { def handle (e: E) = f(e) }

    override def start (primaryStage: Stage)
    {
        println ("Line3DHelper: start")

        val line = new Line3Dep (Point3D.ZERO,
                                 Point3D (50.0, -100.0, 50.0), 2.0)
        val s = line.getSpheres
        root.getChildren ().addAll (new Group (line),
                                    new Group (s._1),
                                    new Group (s._2))

        try { 
            val scene = new Scene (root, 1024, 768, true)
            scene.setOnMousePressed (mkEventHandler ((event: MouseEvent) =>
            {
                anchorX = event.getSceneX ()
                anchorY = event.getSceneY ()
                anchorAngle = camera.getRotate ()
            }))
            scene.setOnMouseDragged (mkEventHandler ((event: MouseEvent) =>
            {
                camera.setRotate (anchorAngle + anchorX - event.getSceneX ())
            }))
            scene.setFill (paint.Color.YELLOW)
            primaryStage.setTitle ("scala3d Line3Dep demo")
            primaryStage.setScene (scene)
            primaryStage.show ()
            scene.setCamera (camera)
        } catch {
            case e: Exception => e.printStackTrace ()
        } // try
    } // start
    
} // Line3DHelper class


//::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
/** The `Line3DTest` class is used to test the `Line3D` and `Line3Dep` classes.
 *  run-main scalation.scala3d.Line3DTest
 */
object Line3DTest
{
    def main (args: Array [String])
    {
        javafx.application.Application.launch (classOf [Line3DHelper], args: _*)
    } // main

} // Line3DTest object