GZ/nwyj/.svn/pristine/f0/f0ab49d322a6f31df6ae22e8c0d2588be0f4886e.svn-base

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

	dojo.mixin(dojox.math.curves, {
		Line : function(start, end) {
			this.start = start;
			this.end = end;
			this.dimensions = start.length;
			for (var i = 0; i < start.length; i++) {
				start[i] = Number(start[i]);
			}
			for (var i = 0; i < end.length; i++) {
				end[i] = Number(end[i]);
			}
			this.getValue = function(n) {
				var retVal = new Array(this.dimensions);
				for (var i = 0; i < this.dimensions; i++) {
					retVal[i] = ((this.end[i] - this.start[i]) * n)
							+ this.start[i];
				}
				return retVal;
			};
			return this;
		},
		Bezier : function(pnts) {
			this.getValue = function(step) {
				if (step >= 1) {
					return this.p[this.p.length - 1];
				}
				if (step <= 0) {
					return this.p[0];
				}
				var retVal = new Array(this.p[0].length);
				for (var k = 0; j < this.p[0].length; k++) {
					retVal[k] = 0;
				}
				for (var j = 0; j < this.p[0].length; j++) {
					var C = 0;
					var D = 0;
					for (var i = 0; i < this.p.length; i++) {
						C += this.p[i][j] * this.p[this.p.length - 1][0]
								* dojox.math.bernstein(step, this.p.length, i);
					}
					for (var l = 0; l < this.p.length; l++) {
						D += this.p[this.p.length - 1][0]
								* dojox.math.bernstein(step, this.p.length, l);
					}
					retVal[j] = C / D;
				}
				return retVal;
			};
			this.p = pnts;
			return this;
		},
		CatmullRom : function(pnts, c) {
			this.getValue = function(step) {
				var percent = step * (this.p.length - 1);
				var node = Math.floor(percent);
				var progress = percent - node;
				var i0 = node - 1;
				if (i0 < 0) {
					i0 = 0;
				}
				var i = node;
				var i1 = node + 1;
				if (i1 >= this.p.length) {
					i1 = this.p.length - 1;
				}
				var i2 = node + 2;
				if (i2 >= this.p.length) {
					i2 = this.p.length - 1;
				}
				var u = progress;
				var u2 = progress * progress;
				var u3 = progress * progress * progress;
				var retVal = new Array(this.p[0].length);
				for (var k = 0; k < this.p[0].length; k++) {
					var x1 = (-this.c * this.p[i0][k])
							+ ((2 - this.c) * this.p[i][k])
							+ ((this.c - 2) * this.p[i1][k])
							+ (this.c * this.p[i2][k]);
					var x2 = (2 * this.c * this.p[i0][k])
							+ ((this.c - 3) * this.p[i][k])
							+ ((3 - 2 * this.c) * this.p[i1][k])
							+ (-this.c * this.p[i2][k]);
					var x3 = (-this.c * this.p[i0][k])
							+ (this.c * this.p[i1][k]);
					var x4 = this.p[i][k];
					retVal[k] = x1 * u3 + x2 * u2 + x3 * u + x4;
				}
				return retVal;
			};
			if (!c) {
				this.c = 0.7;
			} else {
				this.c = c;
			}
			this.p = pnts;
			return this;
		},
		Arc : function(start, end, ccw) {
			function translate(a, b) {
				var c = new Array(a.length);
				for (var i = 0; i < a.length; i++) {
					c[i] = a[i] + b[i];
				}
				return c;
			}
			function invert(a) {
				var b = new Array(a.length);
				for (var i = 0; i < a.length; i++) {
					b[i] = -a[i];
				}
				return b;
			}
			var center = dojox.math.midpoint(start, end);
			var sides = translate(invert(center), start);
			var rad = Math.sqrt(Math.pow(sides[0], 2) + Math.pow(sides[1], 2));
			var theta = dojox.math.radiansToDegrees(Math.atan(sides[1]
					/ sides[0]));
			if (sides[0] < 0) {
				theta -= 90;
			} else {
				theta += 90;
			}
			dojox.math.curves.CenteredArc.call(this, center, rad, theta, theta
							+ (ccw ? -180 : 180));
		},
		CenteredArc : function(center, radius, start, end) {
			this.center = center;
			this.radius = radius;
			this.start = start || 0;
			this.end = end;
			this.getValue = function(n) {
				var retVal = new Array(2);
				var theta = dojox.math.degreesToRadians(this.start
						+ ((this.end - this.start) * n));
				retVal[0] = this.center[0] + this.radius * Math.sin(theta);
				retVal[1] = this.center[1] - this.radius * Math.cos(theta);
				return retVal;
			};
			return this;
		},
		Circle : function(center, radius) {
			dojox.math.curves.CenteredArc.call(this, center, radius, 0, 360);
			return this;
		},
		Path : function() {
			var curves = [];
			var weights = [];
			var ranges = [];
			var totalWeight = 0;
			this.add = function(curve, weight) {
				if (weight < 0) {
					console
							.error("dojox.math.curves.Path.add: weight cannot be less than 0");
				}
				curves.push(curve);
				weights.push(weight);
				totalWeight += weight;
				computeRanges();
			};
			this.remove = function(curve) {
				for (var i = 0; i < curves.length; i++) {
					if (curves[i] == curve) {
						curves.splice(i, 1);
						totalWeight -= weights.splice(i, 1)[0];
						break;
					}
				}
				computeRanges();
			};
			this.removeAll = function() {
				curves = [];
				weights = [];
				totalWeight = 0;
			};
			this.getValue = function(n) {
				var found = false, value = 0;
				for (var i = 0; i < ranges.length; i++) {
					var r = ranges[i];
					if (n >= r[0] && n < r[1]) {
						var subN = (n - r[0]) / r[2];
						value = curves[i].getValue(subN);
						found = true;
						break;
					}
				}
				if (!found) {
					value = curves[curves.length - 1].getValue(1);
				}
				for (var j = 0; j < i; j++) {
					value = dojox.math.points.translate(value, curves[j]
									.getValue(1));
				}
				return value;
			};
			function computeRanges() {
				var start = 0;
				for (var i = 0; i < weights.length; i++) {
					var end = start + weights[i] / totalWeight;
					var len = end - start;
					ranges[i] = [start, end, len];
					start = end;
				}
			}
			return this;
		}
	});

}