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