package cz.cuni.jagrlib.testing;

import cz.cuni.jagrlib.*;
import cz.cuni.jagrlib.iface.Trigger;
import cz.cuni.jagrlib.reg.*;

/**
 * Computes 3D-to-2D transformation matrix from interactive mouse/keyboard events.
 *
 * @version 0.24 $Rev: 183 $ $Date: 2006-02-08 01:24:54 +0100 (st, 08 II 2006) $ $Author: pepca $
 * @since   0.24
 * @see     <a href="../../../../../cz/cuni/jagrlib/testing/InteractiveProjection.java">InteractiveProjection.java</a>
 */
public class InteractiveProjection extends DefaultInputListener
{
  //==========================================================================
  //  Data:

  /** Zoom coefficient for one mouse-wheel "tick" minus 1.0d. */
  public static final double WHEEL_ZOOM = 0.03d;

  /** Actual window width in pixels. */
  protected int width  = 0;

  /** Actual window height in pixels. */
  protected int height = 0;

  /** Actual projection matrix. */
  protected TrMatrix proj = new TrMatrix( 4, 3 );

  protected double rotZ = 0.0d;

  protected double rotX = 0.0d;

  /** Actual result zoom factor. */
  protected double zoom = 1.0d;

  /** Zoom factor produces by the mouse-wheel. */
  protected double wheelZoom = 1.0d;

  /** Mouse-move processing is switched on? */
  protected boolean live = false;

  /** Actual translation component. */
  protected double[] transl = { 0.0d, 0.0d, 0.0d };

  //==========================================================================
  //  Support:

  /** Assembles the projection matrix and triggers the "redraw" action. */
  protected void updateMatrix ()
  {
    proj.identity( 4, 3 );
    proj.rotateAxis3D( 2, rotZ, null );
    proj.rotateAxis3D( 0, rotX + 0.5d * Math.PI, null );
    proj.scale3D( null, zoom * wheelZoom, null );
    proj.translate3D( transl, null );
    Trigger t = (Trigger)getInterface( PL_OUTPUT, IFACE+"Trigger" );
    if ( t != null ) t.fire( 0 );
  }

  //==========================================================================
  //  Interface InputListener:

  /**
   * Change the window shape.
   *
   * @param width Horizontal window size in pixels.
   * @param height Vertical window size in pixels.
   */
  @Override
  public void setWindowSize ( int width, int height )
  {
    this.width  = width;
    this.height = height;
    transl[0] = 0.5d * width;
    transl[1] = 0.5d * height;
    zoom = Math.min( transl[0], transl[1] );
    updateMatrix();
  }

  /**
   * Mouse button was pressed/released.
   *
   * @param when System time in milliseconds.
   * @param x Horizontal screen position in pixels.
   * @param y Vertical screen position in pixels.
   * @param button Button number (0, 1, etc.).
   * @param press Was it press or release?
   * @param flags Input system status (key shifts/alts, ..).
   */
  @Override
  public void mouseButton ( long when, int x, int y, int button, boolean press, int flags )
  {
    if ( button != 1 || press ) return;
    live = !live;
  }

  /**
   * Mouse pointer was moved.
   *
   * @param when System time in milliseconds.
   * @param x Horizontal screen position in pixels.
   * @param y Vertical screen position in pixels.
   * @param flags Input system status (key shifts/alts, ..).
   */
  @Override
  public void mouseMove ( long when, int x, int y, int flags )
  {
    if ( !live ) return;
    rotZ = ((double)x / width - 0.5d) * 2.0d * Math.PI;
    rotX = -((double)y / width - 0.5d) * 2.0d * Math.PI;
    updateMatrix();
  }

  /**
   * Mouse wheel was rotated.
   *
   * @param when System time in milliseconds.
   * @param x Horizontal screen position in pixels.
   * @param y Vertical screen position in pixels.
   * @param wheel Wheel number (0, 1, etc.).
   * @param amount Rotation angle (positive number means down - or towards the user).
   * @param flags Input system status (key shifts/alts, ..).
   */
  @Override
  public void mouseWheel ( long when, int x, int y, int wheel, int amount, int flags )
  {
    if ( amount == 0 ) return;
    wheelZoom *= 1.0d + WHEEL_ZOOM * amount;
    updateMatrix();
  }

  //==========================================================================
  //  Interface Property:

  public final static String MATRIX = "Matrix";

  /**
   * Sets the given property.
   *
   * @param  key Key string.
   * @param  value The new value.
   */
  public void set ( String key, Object value )
  {
    if ( key == null || value == null ) return;
      // MATRIX:
    if ( key.compareTo(MATRIX) == 0 )
    {
      if ( value != null && value instanceof TrMatrix )
        proj = (TrMatrix)value;
      return;
    }
  }

  /**
   * Gets the given property.
   *
   * @param  key Key string.
   * @return The actual value or <code>null</code>.
   */
  public Object get ( String key )
  {
    if ( key == null )
      return null;
    if ( key.compareTo(MATRIX) == 0 )
      return proj;
    return null;
  }

  //==========================================================================
  //  Module registration:

  /** Object name. */
  private final static String NAME = "InteractiveProjection";

  /** Object template identifier. */
  protected final static String TEMPLATE_NAME = "InputListenerToTrigger";

  /** Object description. */
  private final static String DESCRIPTION = "Computes projection matrix from interactive mouse events.";

  /** Object category. */
  protected final static String CATEGORY = C_3D + ".projection";

  /**
   * General-purpose registration routine.
   * Sets all plugs, strings, etc. to the given Template.
   */
  public static int setTemplate ( Template t, int ord )
  {
    if ( t != null && ord <= 0 )
    {
      t.setRegStrings( NAME, TEMPLATE_NAME, CATEGORY, DESCRIPTION );
        // Plugs:
      t.newInputPlug(     PL_INPUT,  IFACE+"InputListener" );
      t.newOptOutputPlug( PL_OUTPUT, IFACE+"Trigger" );
        // Property:
      t.propBegin( MATRIX, TYPE_OBJECT, "Projection matrix", false );
      t.propEnd();
    }
    return 1;
  }

  /**
   * Static registration instance for this class.
   * Automatically initialized in class-loading time.
   */
  public static final RegPiece reg;
  static
  {
    reg = new RegPiece();
    setTemplate( reg, 0 );
  }

}