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- 'use strict';
-
- var regTransformTypes = /matrix|translate|scale|rotate|skewX|skewY/,
- regTransformSplit = /\s*(matrix|translate|scale|rotate|skewX|skewY)\s*\(\s*(.+?)\s*\)[\s,]*/,
- regNumericValues = /[-+]?(?:\d*\.\d+|\d+\.?)(?:[eE][-+]?\d+)?/g;
-
- /**
- * Convert transform string to JS representation.
- *
- * @param {String} transformString input string
- * @param {Object} params plugin params
- * @return {Array} output array
- */
- exports.transform2js = function(transformString) {
-
- // JS representation of the transform data
- var transforms = [],
- // current transform context
- current;
-
- // split value into ['', 'translate', '10 50', '', 'scale', '2', '', 'rotate', '-45', '']
- transformString.split(regTransformSplit).forEach(function(item) {
- /*jshint -W084 */
- var num;
-
- if (item) {
- // if item is a translate function
- if (regTransformTypes.test(item)) {
- // then collect it and change current context
- transforms.push(current = { name: item });
- // else if item is data
- } else {
- // then split it into [10, 50] and collect as context.data
- while (num = regNumericValues.exec(item)) {
- num = Number(num);
- if (current.data)
- current.data.push(num);
- else
- current.data = [num];
- }
- }
- }
- });
-
- // return empty array if broken transform (no data)
- return current && current.data ? transforms : [];
- };
-
- /**
- * Multiply transforms into one.
- *
- * @param {Array} input transforms array
- * @return {Array} output matrix array
- */
- exports.transformsMultiply = function(transforms) {
-
- // convert transforms objects to the matrices
- transforms = transforms.map(function(transform) {
- if (transform.name === 'matrix') {
- return transform.data;
- }
- return transformToMatrix(transform);
- });
-
- // multiply all matrices into one
- transforms = {
- name: 'matrix',
- data: transforms.length > 0 ? transforms.reduce(multiplyTransformMatrices) : []
- };
-
- return transforms;
-
- };
-
- /**
- * Do math like a schoolgirl.
- *
- * @type {Object}
- */
- var mth = exports.mth = {
-
- rad: function(deg) {
- return deg * Math.PI / 180;
- },
-
- deg: function(rad) {
- return rad * 180 / Math.PI;
- },
-
- cos: function(deg) {
- return Math.cos(this.rad(deg));
- },
-
- acos: function(val, floatPrecision) {
- return +(this.deg(Math.acos(val)).toFixed(floatPrecision));
- },
-
- sin: function(deg) {
- return Math.sin(this.rad(deg));
- },
-
- asin: function(val, floatPrecision) {
- return +(this.deg(Math.asin(val)).toFixed(floatPrecision));
- },
-
- tan: function(deg) {
- return Math.tan(this.rad(deg));
- },
-
- atan: function(val, floatPrecision) {
- return +(this.deg(Math.atan(val)).toFixed(floatPrecision));
- }
-
- };
-
- /**
- * Decompose matrix into simple transforms. See
- * http://frederic-wang.fr/decomposition-of-2d-transform-matrices.html
- *
- * @param {Object} data matrix transform object
- * @return {Object|Array} transforms array or original transform object
- */
- exports.matrixToTransform = function(transform, params) {
- var floatPrecision = params.floatPrecision,
- data = transform.data,
- transforms = [],
- sx = +Math.hypot(data[0], data[1]).toFixed(params.transformPrecision),
- sy = +((data[0] * data[3] - data[1] * data[2]) / sx).toFixed(params.transformPrecision),
- colsSum = data[0] * data[2] + data[1] * data[3],
- rowsSum = data[0] * data[1] + data[2] * data[3],
- scaleBefore = rowsSum != 0 || sx == sy;
-
- // [..., ..., ..., ..., tx, ty] → translate(tx, ty)
- if (data[4] || data[5]) {
- transforms.push({ name: 'translate', data: data.slice(4, data[5] ? 6 : 5) });
- }
-
- // [sx, 0, tan(a)·sy, sy, 0, 0] → skewX(a)·scale(sx, sy)
- if (!data[1] && data[2]) {
- transforms.push({ name: 'skewX', data: [mth.atan(data[2] / sy, floatPrecision)] });
-
- // [sx, sx·tan(a), 0, sy, 0, 0] → skewY(a)·scale(sx, sy)
- } else if (data[1] && !data[2]) {
- transforms.push({ name: 'skewY', data: [mth.atan(data[1] / data[0], floatPrecision)] });
- sx = data[0];
- sy = data[3];
-
- // [sx·cos(a), sx·sin(a), sy·-sin(a), sy·cos(a), x, y] → rotate(a[, cx, cy])·(scale or skewX) or
- // [sx·cos(a), sy·sin(a), sx·-sin(a), sy·cos(a), x, y] → scale(sx, sy)·rotate(a[, cx, cy]) (if !scaleBefore)
- } else if (!colsSum || (sx == 1 && sy == 1) || !scaleBefore) {
- if (!scaleBefore) {
- sx = (data[0] < 0 ? -1 : 1) * Math.hypot(data[0], data[2]);
- sy = (data[3] < 0 ? -1 : 1) * Math.hypot(data[1], data[3]);
- transforms.push({ name: 'scale', data: [sx, sy] });
- }
- var angle = Math.min(Math.max(-1, data[0] / sx), 1),
- rotate = [mth.acos(angle, floatPrecision) * ((scaleBefore ? 1 : sy) * data[1] < 0 ? -1 : 1)];
-
- if (rotate[0]) transforms.push({ name: 'rotate', data: rotate });
-
- if (rowsSum && colsSum) transforms.push({
- name: 'skewX',
- data: [mth.atan(colsSum / (sx * sx), floatPrecision)]
- });
-
- // rotate(a, cx, cy) can consume translate() within optional arguments cx, cy (rotation point)
- if (rotate[0] && (data[4] || data[5])) {
- transforms.shift();
- var cos = data[0] / sx,
- sin = data[1] / (scaleBefore ? sx : sy),
- x = data[4] * (scaleBefore || sy),
- y = data[5] * (scaleBefore || sx),
- denom = (Math.pow(1 - cos, 2) + Math.pow(sin, 2)) * (scaleBefore || sx * sy);
- rotate.push(((1 - cos) * x - sin * y) / denom);
- rotate.push(((1 - cos) * y + sin * x) / denom);
- }
-
- // Too many transformations, return original matrix if it isn't just a scale/translate
- } else if (data[1] || data[2]) {
- return transform;
- }
-
- if (scaleBefore && (sx != 1 || sy != 1) || !transforms.length) transforms.push({
- name: 'scale',
- data: sx == sy ? [sx] : [sx, sy]
- });
-
- return transforms;
- };
-
- /**
- * Convert transform to the matrix data.
- *
- * @param {Object} transform transform object
- * @return {Array} matrix data
- */
- function transformToMatrix(transform) {
-
- if (transform.name === 'matrix') return transform.data;
-
- var matrix;
-
- switch (transform.name) {
- case 'translate':
- // [1, 0, 0, 1, tx, ty]
- matrix = [1, 0, 0, 1, transform.data[0], transform.data[1] || 0];
- break;
- case 'scale':
- // [sx, 0, 0, sy, 0, 0]
- matrix = [transform.data[0], 0, 0, transform.data[1] || transform.data[0], 0, 0];
- break;
- case 'rotate':
- // [cos(a), sin(a), -sin(a), cos(a), x, y]
- var cos = mth.cos(transform.data[0]),
- sin = mth.sin(transform.data[0]),
- cx = transform.data[1] || 0,
- cy = transform.data[2] || 0;
-
- matrix = [cos, sin, -sin, cos, (1 - cos) * cx + sin * cy, (1 - cos) * cy - sin * cx];
- break;
- case 'skewX':
- // [1, 0, tan(a), 1, 0, 0]
- matrix = [1, 0, mth.tan(transform.data[0]), 1, 0, 0];
- break;
- case 'skewY':
- // [1, tan(a), 0, 1, 0, 0]
- matrix = [1, mth.tan(transform.data[0]), 0, 1, 0, 0];
- break;
- }
-
- return matrix;
-
- }
-
- /**
- * Applies transformation to an arc. To do so, we represent ellipse as a matrix, multiply it
- * by the transformation matrix and use a singular value decomposition to represent in a form
- * rotate(θ)·scale(a b)·rotate(φ). This gives us new ellipse params a, b and θ.
- * SVD is being done with the formulae provided by Wolffram|Alpha (svd {{m0, m2}, {m1, m3}})
- *
- * @param {Array} arc [a, b, rotation in deg]
- * @param {Array} transform transformation matrix
- * @return {Array} arc transformed input arc
- */
- exports.transformArc = function(arc, transform) {
-
- var a = arc[0],
- b = arc[1],
- rot = arc[2] * Math.PI / 180,
- cos = Math.cos(rot),
- sin = Math.sin(rot),
- h = Math.pow(arc[5] * cos + arc[6] * sin, 2) / (4 * a * a) +
- Math.pow(arc[6] * cos - arc[5] * sin, 2) / (4 * b * b);
- if (h > 1) {
- h = Math.sqrt(h);
- a *= h;
- b *= h;
- }
- var ellipse = [a * cos, a * sin, -b * sin, b * cos, 0, 0],
- m = multiplyTransformMatrices(transform, ellipse),
- // Decompose the new ellipse matrix
- lastCol = m[2] * m[2] + m[3] * m[3],
- squareSum = m[0] * m[0] + m[1] * m[1] + lastCol,
- root = Math.hypot(m[0] - m[3], m[1] + m[2]) * Math.hypot(m[0] + m[3], m[1] - m[2]);
-
- if (!root) { // circle
- arc[0] = arc[1] = Math.sqrt(squareSum / 2);
- arc[2] = 0;
- } else {
- var majorAxisSqr = (squareSum + root) / 2,
- minorAxisSqr = (squareSum - root) / 2,
- major = Math.abs(majorAxisSqr - lastCol) > 1e-6,
- sub = (major ? majorAxisSqr : minorAxisSqr) - lastCol,
- rowsSum = m[0] * m[2] + m[1] * m[3],
- term1 = m[0] * sub + m[2] * rowsSum,
- term2 = m[1] * sub + m[3] * rowsSum;
- arc[0] = Math.sqrt(majorAxisSqr);
- arc[1] = Math.sqrt(minorAxisSqr);
- arc[2] = ((major ? term2 < 0 : term1 > 0) ? -1 : 1) *
- Math.acos((major ? term1 : term2) / Math.hypot(term1, term2)) * 180 / Math.PI;
- }
-
- if ((transform[0] < 0) !== (transform[3] < 0)) {
- // Flip the sweep flag if coordinates are being flipped horizontally XOR vertically
- arc[4] = 1 - arc[4];
- }
-
- return arc;
-
- };
-
- /**
- * Multiply transformation matrices.
- *
- * @param {Array} a matrix A data
- * @param {Array} b matrix B data
- * @return {Array} result
- */
- function multiplyTransformMatrices(a, b) {
-
- return [
- a[0] * b[0] + a[2] * b[1],
- a[1] * b[0] + a[3] * b[1],
- a[0] * b[2] + a[2] * b[3],
- a[1] * b[2] + a[3] * b[3],
- a[0] * b[4] + a[2] * b[5] + a[4],
- a[1] * b[4] + a[3] * b[5] + a[5]
- ];
-
- }
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