initial commit

node_modules/svgo/plugins/convertTransform.js

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+'use strict';
+
+exports.type = 'perItem';
+
+exports.active = true;
+
+exports.description = 'collapses multiple transformations and optimizes it';
+
+exports.params = {
+    convertToShorts: true,
+    // degPrecision: 3, // transformPrecision (or matrix precision) - 2 by default
+    floatPrecision: 3,
+    transformPrecision: 5,
+    matrixToTransform: true,
+    shortTranslate: true,
+    shortScale: true,
+    shortRotate: true,
+    removeUseless: true,
+    collapseIntoOne: true,
+    leadingZero: true,
+    negativeExtraSpace: false
+};
+
+var cleanupOutData = require('../lib/svgo/tools').cleanupOutData,
+    transform2js = require('./_transforms.js').transform2js,
+    transformsMultiply = require('./_transforms.js').transformsMultiply,
+    matrixToTransform = require('./_transforms.js').matrixToTransform,
+    degRound,
+    floatRound,
+    transformRound;
+
+/**
+ * Convert matrices to the short aliases,
+ * convert long translate, scale or rotate transform notations to the shorts ones,
+ * convert transforms to the matrices and multiply them all into one,
+ * remove useless transforms.
+ *
+ * @see http://www.w3.org/TR/SVG/coords.html#TransformMatrixDefined
+ *
+ * @param {Object} item current iteration item
+ * @param {Object} params plugin params
+ * @return {Boolean} if false, item will be filtered out
+ *
+ * @author Kir Belevich
+ */
+exports.fn = function(item, params) {
+
+    if (item.elem) {
+
+        // transform
+        if (item.hasAttr('transform')) {
+            convertTransform(item, 'transform', params);
+        }
+
+        // gradientTransform
+        if (item.hasAttr('gradientTransform')) {
+            convertTransform(item, 'gradientTransform', params);
+        }
+
+        // patternTransform
+        if (item.hasAttr('patternTransform')) {
+            convertTransform(item, 'patternTransform', params);
+        }
+
+    }
+
+};
+
+/**
+ * Main function.
+ *
+ * @param {Object} item input item
+ * @param {String} attrName attribute name
+ * @param {Object} params plugin params
+ */
+function convertTransform(item, attrName, params) {
+    var data = transform2js(item.attr(attrName).value);
+    params = definePrecision(data, params);
+
+    if (params.collapseIntoOne && data.length > 1) {
+        data = [transformsMultiply(data)];
+    }
+
+    if (params.convertToShorts) {
+        data = convertToShorts(data, params);
+    } else {
+        data.forEach(roundTransform);
+    }
+
+    if (params.removeUseless) {
+        data = removeUseless(data);
+    }
+
+    if (data.length) {
+        item.attr(attrName).value = js2transform(data, params);
+    } else {
+        item.removeAttr(attrName);
+    }
+}
+
+/**
+ * Defines precision to work with certain parts.
+ * transformPrecision - for scale and four first matrix parameters (needs a better precision due to multiplying),
+ * floatPrecision - for translate including two last matrix and rotate parameters,
+ * degPrecision - for rotate and skew. By default it's equal to (rougly)
+ * transformPrecision - 2 or floatPrecision whichever is lower. Can be set in params.
+ *
+ * @param {Array} transforms input array
+ * @param {Object} params plugin params
+ * @return {Array} output array
+ */
+function definePrecision(data, params) {
+    /* jshint validthis: true */
+    var matrixData = data.reduce(getMatrixData, []),
+        significantDigits = params.transformPrecision;
+
+    // Clone params so it don't affect other elements transformations.
+    params = Object.assign({}, params);
+
+    // Limit transform precision with matrix one. Calculating with larger precision doesn't add any value.
+    if (matrixData.length) {
+        params.transformPrecision = Math.min(params.transformPrecision,
+            Math.max.apply(Math, matrixData.map(floatDigits)) || params.transformPrecision);
+
+        significantDigits = Math.max.apply(Math, matrixData.map(function(n) {
+            return String(n).replace(/\D+/g, '').length; // Number of digits in a number. 123.45 → 5
+        }));
+    }
+    // No sense in angle precision more then number of significant digits in matrix.
+    if (!('degPrecision' in params)) {
+        params.degPrecision = Math.max(0, Math.min(params.floatPrecision, significantDigits - 2));
+    }
+
+    floatRound = params.floatPrecision >= 1 && params.floatPrecision < 20 ?
+        smartRound.bind(this, params.floatPrecision) :
+        round;
+    degRound = params.degPrecision >= 1 && params.floatPrecision < 20 ?
+        smartRound.bind(this, params.degPrecision) :
+        round;
+    transformRound = params.transformPrecision >= 1 && params.floatPrecision < 20 ?
+        smartRound.bind(this, params.transformPrecision) :
+        round;
+
+    return params;
+}
+
+/**
+ * Gathers four first matrix parameters.
+ *
+ * @param {Array} a array of data
+ * @param {Object} transform
+ * @return {Array} output array
+ */
+function getMatrixData(a, b) {
+    return b.name == 'matrix' ? a.concat(b.data.slice(0, 4)) : a;
+}
+
+/**
+ * Returns number of digits after the point. 0.125 → 3
+ */
+function floatDigits(n) {
+    return (n = String(n)).slice(n.indexOf('.')).length - 1;
+}
+
+/**
+ * Convert transforms to the shorthand alternatives.
+ *
+ * @param {Array} transforms input array
+ * @param {Object} params plugin params
+ * @return {Array} output array
+ */
+function convertToShorts(transforms, params) {
+
+    for(var i = 0; i < transforms.length; i++) {
+
+        var transform = transforms[i];
+
+        // convert matrix to the short aliases
+        if (
+            params.matrixToTransform &&
+            transform.name === 'matrix'
+        ) {
+            var decomposed = matrixToTransform(transform, params);
+            if (decomposed != transform &&
+                js2transform(decomposed, params).length <= js2transform([transform], params).length) {
+
+                transforms.splice.apply(transforms, [i, 1].concat(decomposed));
+            }
+            transform = transforms[i];
+        }
+
+        // fixed-point numbers
+        // 12.754997 → 12.755
+        roundTransform(transform);
+
+        // convert long translate transform notation to the shorts one
+        // translate(10 0) → translate(10)
+        if (
+            params.shortTranslate &&
+            transform.name === 'translate' &&
+            transform.data.length === 2 &&
+            !transform.data[1]
+        ) {
+            transform.data.pop();
+        }
+
+        // convert long scale transform notation to the shorts one
+        // scale(2 2) → scale(2)
+        if (
+            params.shortScale &&
+            transform.name === 'scale' &&
+            transform.data.length === 2 &&
+            transform.data[0] === transform.data[1]
+        ) {
+            transform.data.pop();
+        }
+
+        // convert long rotate transform notation to the short one
+        // translate(cx cy) rotate(a) translate(-cx -cy) → rotate(a cx cy)
+        if (
+            params.shortRotate &&
+            transforms[i - 2] &&
+            transforms[i - 2].name === 'translate' &&
+            transforms[i - 1].name === 'rotate' &&
+            transforms[i].name === 'translate' &&
+            transforms[i - 2].data[0] === -transforms[i].data[0] &&
+            transforms[i - 2].data[1] === -transforms[i].data[1]
+        ) {
+            transforms.splice(i - 2, 3, {
+                name: 'rotate',
+                data: [
+                    transforms[i - 1].data[0],
+                    transforms[i - 2].data[0],
+                    transforms[i - 2].data[1]
+                ]
+            });
+
+            // splice compensation
+            i -= 2;
+
+            transform = transforms[i];
+        }
+
+    }
+
+    return transforms;
+
+}
+
+/**
+ * Remove useless transforms.
+ *
+ * @param {Array} transforms input array
+ * @return {Array} output array
+ */
+function removeUseless(transforms) {
+
+    return transforms.filter(function(transform) {
+
+        // translate(0), rotate(0[, cx, cy]), skewX(0), skewY(0)
+        if (
+            ['translate', 'rotate', 'skewX', 'skewY'].indexOf(transform.name) > -1 &&
+            (transform.data.length == 1 || transform.name == 'rotate') &&
+            !transform.data[0] ||
+
+            // translate(0, 0)
+            transform.name == 'translate' &&
+            !transform.data[0] &&
+            !transform.data[1] ||
+
+            // scale(1)
+            transform.name == 'scale' &&
+            transform.data[0] == 1 &&
+            (transform.data.length < 2 || transform.data[1] == 1) ||
+
+            // matrix(1 0 0 1 0 0)
+            transform.name == 'matrix' &&
+            transform.data[0] == 1 &&
+            transform.data[3] == 1 &&
+            !(transform.data[1] || transform.data[2] || transform.data[4] || transform.data[5])
+        ) {
+            return false;
+        }
+
+        return true;
+
+    });
+
+}
+
+/**
+ * Convert transforms JS representation to string.
+ *
+ * @param {Array} transformJS JS representation array
+ * @param {Object} params plugin params
+ * @return {String} output string
+ */
+function js2transform(transformJS, params) {
+
+    var transformString = '';
+
+    // collect output value string
+    transformJS.forEach(function(transform) {
+        roundTransform(transform);
+        transformString += (transformString && ' ') + transform.name + '(' + cleanupOutData(transform.data, params) + ')';
+    });
+
+    return transformString;
+
+}
+
+function roundTransform(transform) {
+    switch (transform.name) {
+        case 'translate':
+            transform.data = floatRound(transform.data);
+            break;
+        case 'rotate':
+            transform.data = degRound(transform.data.slice(0, 1)).concat(floatRound(transform.data.slice(1)));
+            break;
+        case 'skewX':
+        case 'skewY':
+            transform.data = degRound(transform.data);
+            break;
+        case 'scale':
+            transform.data = transformRound(transform.data);
+            break;
+        case 'matrix':
+            transform.data = transformRound(transform.data.slice(0, 4)).concat(floatRound(transform.data.slice(4)));
+            break;
+    }
+    return transform;
+}
+
+/**
+ * Rounds numbers in array.
+ *
+ * @param {Array} data input data array
+ * @return {Array} output data array
+ */
+function round(data) {
+    return data.map(Math.round);
+}
+
+/**
+ * Decrease accuracy of floating-point numbers
+ * in transforms keeping a specified number of decimals.
+ * Smart rounds values like 2.349 to 2.35.
+ *
+ * @param {Number} fixed number of decimals
+ * @param {Array} data input data array
+ * @return {Array} output data array
+ */
+function smartRound(precision, data) {
+    for (var i = data.length, tolerance = +Math.pow(.1, precision).toFixed(precision); i--;) {
+        if (data[i].toFixed(precision) != data[i]) {
+            var rounded = +data[i].toFixed(precision - 1);
+            data[i] = +Math.abs(rounded - data[i]).toFixed(precision + 1) >= tolerance ?
+                +data[i].toFixed(precision) :
+                rounded;
+        }
+    }
+    return data;
+}