source: Dev/trunk/src/client/dojox/math/curves.js

// AMD-ID "dojox/math/curves"
define(["dojo", "dojox"], function(dojo, dojox) {
dojo.getObject("math.curves", true, dojox);

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;
        }
});

return dojox.math.curves;
});