wp/nwyj/.svn/pristine/e3/e3f1afe537de50bf0eba741ab5b609b1acaf70c2.svn-base

if (!dojo._hasResource["dojox.gfx3d.vector"]) { // _hasResource checks added by
												// build. Do not use
												// _hasResource directly in your
												// code.
	dojo._hasResource["dojox.gfx3d.vector"] = true;
	dojo.provide("dojox.gfx3d.vector");

	dojo.mixin(dojox.gfx3d.vector, {
		sum : function() {
			// summary: sum of the vectors
			var v = {
				x : 0,
				y : 0,
				z : 0
			};
			dojo.forEach(arguments, function(item) {
						v.x += item.x;
						v.y += item.y;
						v.z += item.z;
					});
			return v;
		},

		center : function() {
			// summary: center of the vectors
			var l = arguments.length;
			if (l == 0) {
				return {
					x : 0,
					y : 0,
					z : 0
				};
			}
			var v = dojox.gfx3d.vector.sum(arguments);
			return {
				x : v.x / l,
				y : v.y / l,
				z : v.z / l
			};
		},

		substract : function(/* Pointer */a, /* Pointer */b) {
			return {
				x : a.x - b.x,
				y : a.y - b.y,
				z : a.z - b.z
			};
		},

		_crossProduct : function(x, y, z, u, v, w) {
			// summary: applies a cross product of two vectorss, (x, y, z) and
			// (u, v, w)
			// x: Number: an x coordinate of a point
			// y: Number: a y coordinate of a point
			// z: Number: a z coordinate of a point
			// u: Number: an x coordinate of a point
			// v: Number: a y coordinate of a point
			// w: Number: a z coordinate of a point
			return {
				x : y * w - z * v,
				y : z * u - x * w,
				z : x * v - y * u
			}; // Object
		},

		crossProduct : function(/* Number||Point */a, /* Number||Point */b, /*
																			 * Number,
																			 * optional
																			 */
				c, /* Number, optional */d, /* Number, optional */e, /*
																		 * Number,
																		 * optional
																		 */
				f) {
			// summary: applies a matrix to a point
			// matrix: dojox.gfx3d.matrix.Matrix3D: a 3D matrix object to be
			// applied
			// a: Number: an x coordinate of a point
			// b: Number: a y coordinate of a point
			// c: Number: a z coordinate of a point
			// d: Number: an x coordinate of a point
			// e: Number: a y coordinate of a point
			// f: Number: a z coordinate of a point
			if (arguments.length == 6 && dojo.every(arguments, function(item) {
						return typeof item == "number";
					})) {
				return dojox.gfx3d.vector._crossProduct(a, b, c, d, e, f); // Object
			}
			// branch
			// a: Object: a point
			// b: Object: a point
			// c: null
			// d: null
			// e: null
			// f: null
			return dojox.gfx3d.vector._crossProduct(a.x, a.y, a.z, b.x, b.y,
					b.z); // Object
		},

		_dotProduct : function(x, y, z, u, v, w) {
			// summary: applies a cross product of two vectorss, (x, y, z) and
			// (u, v, w)
			// x: Number: an x coordinate of a point
			// y: Number: a y coordinate of a point
			// z: Number: a z coordinate of a point
			// u: Number: an x coordinate of a point
			// v: Number: a y coordinate of a point
			// w: Number: a z coordinate of a point
			return x * u + y * v + z * w; // Number
		},
		dotProduct : function(/* Number||Point */a, /* Number||Point */b, /*
																			 * Number,
																			 * optional
																			 */
				c, /* Number, optional */d, /* Number, optional */e, /*
																		 * Number,
																		 * optional
																		 */
				f) {
			// summary: applies a matrix to a point
			// matrix: dojox.gfx3d.matrix.Matrix3D: a 3D matrix object to be
			// applied
			// a: Number: an x coordinate of a point
			// b: Number: a y coordinate of a point
			// c: Number: a z coordinate of a point
			// d: Number: an x coordinate of a point
			// e: Number: a y coordinate of a point
			// f: Number: a z coordinate of a point
			if (arguments.length == 6 && dojo.every(arguments, function(item) {
						return typeof item == "number";
					})) {
				return dojox.gfx3d.vector._dotProduct(a, b, c, d, e, f); // Object
			}
			// branch
			// a: Object: a point
			// b: Object: a point
			// c: null
			// d: null
			// e: null
			// f: null
			return dojox.gfx3d.vector._dotProduct(a.x, a.y, a.z, b.x, b.y, b.z); // Object
		},

		normalize : function(/* Point||Array */a, /* Point */b, /* Point */c) {
			// summary: find the normal of the implicit surface
			// a: Object: a point
			// b: Object: a point
			// c: Object: a point
			var l, m, n;
			if (a instanceof Array) {
				l = a[0];
				m = a[1];
				n = a[2];
			} else {
				l = a;
				m = b;
				n = c;
			}

			var u = dojox.gfx3d.vector.substract(m, l);
			var v = dojox.gfx3d.vector.substract(n, l);
			return dojox.gfx3d.vector.crossProduct(u, v);
		}
	});

}