bend.as

Papervision3d的源码

/**
 * Copyright (c) 2008 Bartek Drozdz (http://www.everydayflash.com)
 * 
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use,
 * copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following
 * conditions:
 * 
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */
package com.everydayflash.pv3d.modifiers {

	import org.papervision3d.objects.DisplayObject3D;
	import org.papervision3d.objects.parsers.Collada;
	import org.papervision3d.objects.primitives.Cone;
	import org.papervision3d.objects.primitives.Cube;
	import org.papervision3d.objects.primitives.Cylinder;
	import org.papervision3d.objects.primitives.Plane;
	import org.papervision3d.core.proto.MaterialObject3D;
	import org.papervision3d.core.geom.renderables.Vertex3D;
	import org.papervision3d.objects.primitives.Sphere;

	/**
	 * Bend modifier for Papervision3D objects 
	 * 
	 * Version 1.2. Features:
	 * 
	 * 1. Bends primitives only (no Collada objects)
	 * 2. Allows to constraint
	 * 3. Works with Tweener 
	 * 
	 * Author: Bartek Drozdz
	 * Version: 1.2
	 */
	public class Bend {
		
		private var target:DisplayObject3D;
		
		private var w:Number;
		private var h:Number;
		private var d:Number;
		private var mx:Number;
		private var my:Number;
		private var mz:Number;
		
		public static var X:int = 0;
		public static var Y:int = 1;
		public static var Z:int = 2;
		
		public static var NONE:int = 0;
		public static var LEFT:int = 1;
		public static var RIGHT:int = 2;
		public var constraint:int = NONE;
		
		private var base:Array;
		
		private var _force:Number;
		private var _offset:Number;
		public var U_AXIS:int;
		public var V_AXIS:int;
		
		/**
		 *  If this is set to true, the object will not be bended bu rather squeezed.
		 * 
		 * 	This feature is used here: http://www.everydayflash.com/blog/index.php/2008/06/11/bending-modifier-papervision3d/
		 * 	to make the shadow...
		 */
		public var shadowMode:Boolean = false;

		/**
		 * Creates a bend modifier for a DisplayObject3D.
		 * 
		 * @param	_target the DisplayObject3D to bend. Currently supported types are all primitives
		 * and any other DisplayObject3D that has all its vertices available in the 'geometry.vertices'
		 * array.
		 */
		public function Bend(_target:DisplayObject3D) {
			target = _target;
			_force = 0;
			_offset = .5;
			
			if (_target is Collada) throw new Error("Bend does not work with Collada objects.");
			
			freezeVertices();
		}
		
		public function freezeVertices():void {
			
			base = new Array();
			var vs:Array = target.geometry.vertices;
			var vc:int = vs.length;

			for (var i:int = 0; i < vc; i++) {
				var v:Vertex3D = vs[i] as Vertex3D;
				
				base.push([v.x, v.y, v.z]);
				
				if (i == 0) {
					mx = w = v.x;
					my = h = v.y;
					mz = d = v.z;
				} else  {
					mx = Math.min(mx, v.x);
					my = Math.min(my, v.y);
					mz = Math.min(mz, v.z);
					w = Math.max(w, v.x); 
					h = Math.max(h, v.y); 
					d = Math.max(d, v.z); 
				}
			}
			
			w = w - mx;
			h = h - my;
			d = d - mz;
			
			var maxe:Number = Math.max(d, Math.max(w, h));
			
			if (d == h && d == w) {			
				// This is a sphere, bending spheres look weird for any option
				U_AXIS = 2;
				V_AXIS = 2;
			} else if (maxe == w) {
				U_AXIS = 0;
				V_AXIS = 2;
			} else if (maxe == h) {
				U_AXIS = 1;
				V_AXIS = 2;
			} else if (maxe == d) {
				U_AXIS = 2;
				V_AXIS = 1;
			}
		}

		/**
		 * Resets all the vertices to the original positions.
		 */
		public function reset():void {
			var vs:Array = target.geometry.vertices;
			var vc:int = vs.length;
			
			for (var i:int = 0; i < vc; i++) {
				var v:Vertex3D = vs[i] as Vertex3D;
				v.x = base[i][0] as Number;
				v.y = base[i][1] as Number;
				v.z = base[i][2] as Number;
			}
		}
		
		/**
		 * Bends a primitive in a 'most wanted' way.
		 * 
		 * The primitives in PV3D are build in different way, so ex. bending a cube on some axes 
		 * can give regualr results while bengind a cylinder on the same axes can be weird. This method
		 * check the type of the primitive and bends it along thie optimal axes for that type.
		 * 
		 * If you have special needs use rather the 'bend' method below.
		 * 
		 * @param	force the force of the bending, 0 to restore original, 2 or -2 for 360 degrees bend
		 * @param	offset Value between 0 and 1. 
		 *          If its 0.5 the bending is centered on the object, values 0 and 1 bend around one of the edges.
		 */
		public function quickBend(force:Number, offset:Number):void {
			bend(U_AXIS, V_AXIS, force, offset);
		}
		
		/**
		 * Use static X, Y and Z fields to specify the axis and paxis arguments.
		 * 
		 * The axis and paxis arguments can be combined in severl adifferent ways, some of those 
		 * combinations result in really interesting shapes! :) Play with those to see.
		 * 
		 * If you need to bend a primitive in just a regular way, use the 'quickBend' method above.
		 * 
		 * @param   axis the axis along which to bend. 
		 * @param	paxis the axis where the point around which the bending occurs is located
		 * @param	force the force of the bending, 0 to restore original, 2 or -2 for 360 degrees bend
		 * @param	offset Value between 0 and 1. 
		 *          If its 0.5 the bending is centered on the object, values 0 and 1 bend around one of the edges.
		 */
		public function bend(uaxis:int, vaxis:int, force:Number, offset:Number):void {
			reset();
			if (force == 0) {
				return;
			}
			
			offset = Math.max(0, offset);
			offset = Math.min(1, offset);
			
			_bend(uaxis, vaxis, force, offset);
		}
		
		private function _bend(uaxis:int, vaxis:int, force:Number, offset:Number):void {
				
			var pto:Number;
			var ptd:Number;
				
			if (uaxis == 0) {
				pto = mx;
				ptd = w;
			} else if (uaxis == 1) {
				pto = my;
				ptd = h;
			} else if (uaxis == 2) {
				pto = mz;
				ptd = d;
			}
				
			var vs:Array = target.geometry.vertices;
			var vc:int = vs.length;
			
			var distance:Number = pto + ptd * offset;
			var radius:Number = ptd / Math.PI / force;
			var angle:Number = Math.PI * 2 * (ptd / (radius * Math.PI * 2));
			
			for (var i:int = 0; i < vc; i++) {
				var v:Vertex3D = vs[i] as Vertex3D;
				var portion:Number = (base[i][uaxis] - pto) / ptd;
				var fa:Number = ((Math.PI / 2) - angle * offset) + (angle * portion);
				
				if (constraint == LEFT && portion <= offset) continue;
				if (constraint == RIGHT && portion >= offset) continue;

				var op:Number = Math.sin(fa) * (radius + base[i][vaxis]) - radius;
				var ow:Number = distance - Math.cos(fa) * (radius + base[i][vaxis]);
				
				if (!shadowMode) {
					if (vaxis == X) v.x = op;
					else if (vaxis == Y) v.y = op;
					else if (vaxis == Z) v.z = op;
				}
				
				if(uaxis == X) v.x = ow;
				else if (uaxis == Y) v.y = ow;
				else if(uaxis == Z) v.z = ow;
			}
		}
		
		public function get force():Number {
			return _force;
		}
		
		public function set force(f:Number):void {
			_force = f;
			bend(U_AXIS, V_AXIS, _force, _offset);
		}
		
		public function get offset():Number {
			return _offset;
		}
		
		public function set offset(o:Number):void {
			_offset = o;
			bend(U_AXIS, V_AXIS, _force, _offset);
		}
	}
}