/**********************************************
    * Copyright (C) 2009 Lukas Laag
    * This file is part of Vectomatic.
    * 
    * Vectomatic is free software: you can redistribute it and/or modify
    * it under the terms of the GNU General Public License as published by
    * the Free Software Foundation, either version 3 of the License, or
    * (at your option) any later version.
    * 
   * Vectomatic is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   * 
   * You should have received a copy of the GNU General Public License
   * along with Vectomatic.  If not, see http://www.gnu.org/licenses/
   **********************************************/
  package org.vectomatic.common.model;
  
  import java.util.HashMap;
  import java.util.Map;
  import java.util.Set;
  
  import org.vectomatic.common.model.geometry.BoundingBox;
  import org.vectomatic.common.model.geometry.Point;
  import org.vectomatic.common.model.geometry.TransformMatrix;
  
  import com.google.gwt.user.client.rpc.IsSerializable;
  
  /**
   * Base class for geometric shapes
   * @author Lukas Laag
   */
  public abstract class Shape implements IsSerializable {
  	protected transient DrawingModel _model;
  	protected int _id;
  	protected float _r;
  	protected Point _s;
  	protected Point _t;
  	protected transient boolean _dirty;
  	protected transient TransformMatrix _m;
  	protected BoundingBox _bbox;
  	/**
  	 * A map of attribute, attribute values.
  	 */
  	protected Map<Attribute, IAttributeValue> _attributes;
  	
  	public Shape() {
  		_t = new Point();
  		_s = new Point(Point.UNIT);
  		_m = new TransformMatrix();
  		_attributes = new HashMap<Attribute, IAttributeValue>();
  		_dirty = true;
  	}
  	
  	public Shape(Shape shape) {
  		_t = new Point(shape._t);
  		_r = shape._r;
  		_s = new Point(shape._s);
  		_m = new TransformMatrix(shape._m);
  		_dirty = shape._dirty;
  		_bbox = new BoundingBox(shape._bbox);
  		_attributes = new HashMap<Attribute, IAttributeValue>(shape._attributes);
  	}
  	
  	public float getRotation() {
  		return _r;
  	}
  	
  	public void setRotation(float r) {
  		_r = r;
  		_dirty = true;
  	}
  	
  	public Point getScaling(Point s) {
  		_s.copyTo(s);
  		return s;
  	}
  	
  	public void setScaling(Point s) {
  		s.copyTo(_s);
  		_dirty = true;
  	}
  	
  	public Point getTranslation(Point t) {
  		_t.copyTo(t);
  		return t;
  	}
  	
  	public void setTranslation(Point t) {
  		t.copyTo(_t);
  		_dirty = true;
  	}
  	
  	public TransformMatrix getTransform() {
  		if (_dirty) {
  			updateTransform();
  		}
  		return _m;
 	}
 
 	public void setTransform(TransformMatrix m) {
 		m.copyTo(_m);
 		_s.x = (float)Math.sqrt(_m.m11 * _m.m11 + _m.m21 * _m.m21);
 		_s.y = (float)Math.sqrt(_m.m12 * _m.m12 + _m.m22 * _m.m22);
 		_r = (float)(Math.acos(_m.m11 / _s.x));
 		if (_m.m21 < 0f) {
 			_r = 2f * (float)Math.PI - _r;
 		}
 		if (_m.m11 * _m.m22 < 0f) {
 			_s.y = -_s.y;
 		}
 		float cos = (float)Math.cos(_r);
 		float sin = (float)Math.sin(_r);
 		float x1 = _bbox.getXCenter();
 		float y1 = _bbox.getYCenter();
 		_t.x = _m.m13 + _s.x * x1 * cos - _s.y * y1 * sin;
 		_t.y = _m.m23 + _s.x * x1 * sin + _s.y * y1 * cos;
 		_dirty = false;
 	}
 	
 	protected void updateTransform() {
 		// Compute the transform matrix
 		// T(_t) . R(_r) . S(_s) . T(- _bbox.center)
 		float cos = (float)Math.cos(_r);
 		float sin = (float)Math.sin(_r);
 		float x1 = _bbox.getXCenter();
 		float y1 = _bbox.getYCenter();
 		_m.m11 = _s.x * cos; _m.m12 = -_s.y * sin; _m.m13 = - _s.x * x1 * cos + _s.y * y1 * sin + _t.x;
 		_m.m21 = _s.x * sin; _m.m22 =  _s.y * cos; _m.m23 = - _s.x * x1 * sin - _s.y * y1 * cos + _t.y;
 		_dirty = false;
 	}
 	
 	
 	public BoundingBox getBoundingBox() {
 		return _bbox;
 	}
 	
 	public DrawingModel getModel() {
 		return _model;
 	}
 	
 	public void setModel(DrawingModel model) {
 		_model = model;
 	}
 	
 	public IAttributeValue getAttribute(Attribute attr) {
 		return _attributes.get(attr);
 	}
 	
 	public IAttributeValue setAttribute(Attribute attr, IAttributeValue value) {
 		return _attributes.put(attr, value);
 	}
 	
 	public IAttributeValue clearAttribute(Attribute attr) {
 		return _attributes.remove(attr);
 	}
 	
 	public Set<Attribute> getDefinedAttributes() {
 		return _attributes.keySet();
 	}
 	
 	public boolean definesAttribute(Attribute attr) {
 		return _attributes.containsKey(attr);
 	}
 	
 	public void copyAttributes(Shape src) {
 		_attributes.clear();
 		_attributes.putAll(src._attributes);
 	}
 	
 	public abstract void acceptVisitor(IShapeVisitor visitor);
 	
 	/**
 	 * Returns true if the specified shape has the same
 	 * geometrical and styling properties as this shape,
 	 * false otherwise.
 	 * @param shape
 	 * A shape
 	 * @return
 	 * True if the specified shape has the same
 	 * geometrical and styling properties as this shape,
 	 * false otherwise.
 	 */
 	public abstract boolean isSame(Shape shape);
 
 }