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mightyscape-1.1-deprecated/extensions/fablabchemnitz/svgo-inkscape/node_modules/svgo/plugins/convertPathData.js
2020-08-30 12:36:33 +02:00

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'use strict';
exports.type = 'perItem';
exports.active = true;
exports.description = 'optimizes path data: writes in shorter form, applies transformations';
exports.params = {
applyTransforms: true,
applyTransformsStroked: true,
straightCurves: true,
lineShorthands: true,
curveSmoothShorthands: true,
floatPrecision: 3,
transformPrecision: 5,
removeUseless: true,
collapseRepeated: true,
utilizeAbsolute: true,
leadingZero: true,
negativeExtraSpace: true
};
var pathElems = require('./_collections.js').pathElems,
path2js = require('./_path.js').path2js,
js2path = require('./_path.js').js2path,
applyTransforms = require('./_path.js').applyTransforms,
cleanupOutData = require('../lib/svgo/tools').cleanupOutData,
precision,
error,
hasMarkerMid;
/**
* Convert absolute Path to relative,
* collapse repeated instructions,
* detect and convert Lineto shorthands,
* remove useless instructions like "l0,0",
* trim useless delimiters and leading zeros,
* decrease accuracy of floating-point numbers.
*
* @see http://www.w3.org/TR/SVG/paths.html#PathData
*
* @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.isElem(pathElems) && item.hasAttr('d')) {
precision = params.floatPrecision;
error = precision !== false ? +Math.pow(.1, precision).toFixed(precision) : 1e-2;
hasMarkerMid = item.hasAttr('marker-mid');
var data = path2js(item);
// TODO: get rid of functions returns
if (data.length) {
convertToRelative(data);
if (params.applyTransforms) {
data = applyTransforms(item, data, params);
}
data = filters(data, params);
if (params.utilizeAbsolute) {
data = convertToMixed(data, params);
}
js2path(item, data, params);
}
}
};
/**
* Convert absolute path data coordinates to relative.
*
* @param {Array} path input path data
* @param {Object} params plugin params
* @return {Array} output path data
*/
function convertToRelative(path) {
var point = [0, 0],
subpathPoint = [0, 0],
baseItem;
path.forEach(function(item, index) {
var instruction = item.instruction,
data = item.data;
// data !== !z
if (data) {
// already relative
// recalculate current point
if ('mcslqta'.indexOf(instruction) > -1) {
point[0] += data[data.length - 2];
point[1] += data[data.length - 1];
if (instruction === 'm') {
subpathPoint[0] = point[0];
subpathPoint[1] = point[1];
baseItem = item;
}
} else if (instruction === 'h') {
point[0] += data[0];
} else if (instruction === 'v') {
point[1] += data[0];
}
// convert absolute path data coordinates to relative
// if "M" was not transformed from "m"
// M → m
if (instruction === 'M') {
if (index > 0) instruction = 'm';
data[0] -= point[0];
data[1] -= point[1];
subpathPoint[0] = point[0] += data[0];
subpathPoint[1] = point[1] += data[1];
baseItem = item;
}
// L → l
// T → t
else if ('LT'.indexOf(instruction) > -1) {
instruction = instruction.toLowerCase();
// x y
// 0 1
data[0] -= point[0];
data[1] -= point[1];
point[0] += data[0];
point[1] += data[1];
// C → c
} else if (instruction === 'C') {
instruction = 'c';
// x1 y1 x2 y2 x y
// 0 1 2 3 4 5
data[0] -= point[0];
data[1] -= point[1];
data[2] -= point[0];
data[3] -= point[1];
data[4] -= point[0];
data[5] -= point[1];
point[0] += data[4];
point[1] += data[5];
// S → s
// Q → q
} else if ('SQ'.indexOf(instruction) > -1) {
instruction = instruction.toLowerCase();
// x1 y1 x y
// 0 1 2 3
data[0] -= point[0];
data[1] -= point[1];
data[2] -= point[0];
data[3] -= point[1];
point[0] += data[2];
point[1] += data[3];
// A → a
} else if (instruction === 'A') {
instruction = 'a';
// rx ry x-axis-rotation large-arc-flag sweep-flag x y
// 0 1 2 3 4 5 6
data[5] -= point[0];
data[6] -= point[1];
point[0] += data[5];
point[1] += data[6];
// H → h
} else if (instruction === 'H') {
instruction = 'h';
data[0] -= point[0];
point[0] += data[0];
// V → v
} else if (instruction === 'V') {
instruction = 'v';
data[0] -= point[1];
point[1] += data[0];
}
item.instruction = instruction;
item.data = data;
// store absolute coordinates for later use
item.coords = point.slice(-2);
}
// !data === z, reset current point
else if (instruction == 'z') {
if (baseItem) {
item.coords = baseItem.coords;
}
point[0] = subpathPoint[0];
point[1] = subpathPoint[1];
}
item.base = index > 0 ? path[index - 1].coords : [0, 0];
});
return path;
}
/**
* Main filters loop.
*
* @param {Array} path input path data
* @param {Object} params plugin params
* @return {Array} output path data
*/
function filters(path, params) {
var relSubpoint = [0, 0],
pathBase = [0, 0],
prev = {};
path = path.filter(function(item, index) {
var instruction = item.instruction,
data = item.data;
if (data) {
var sdata;
if (instruction === 's') {
sdata = [0, 0].concat(data);
if ('cs'.indexOf(prev.instruction) > -1) {
var pdata = prev.data,
n = pdata.length;
// (-x, -y) of the prev tangent point relative to the current point
sdata[0] = pdata[n - 2] - pdata[n - 4];
sdata[1] = pdata[n - 1] - pdata[n - 3];
}
}
// Rounding relative coordinates, taking in account accummulating error
// to get closer to absolute coordinates. Sum of rounded value remains same:
// l .25 3 .25 2 .25 3 .25 2 -> l .3 3 .2 2 .3 3 .2 2
if (precision !== false) {
if ('mltqsc'.indexOf(instruction) > -1) {
for (var i = data.length; i--;) {
data[i] += item.base[i % 2] - relSubpoint[i % 2];
}
} else if (instruction == 'h') {
data[0] += item.base[0] - relSubpoint[0];
} else if (instruction == 'v') {
data[0] += item.base[1] - relSubpoint[1];
} else if (instruction == 'a') {
data[5] += item.base[0] - relSubpoint[0];
data[6] += item.base[1] - relSubpoint[1];
}
roundData(data);
if (instruction == 'h') relSubpoint[0] += data[0];
else if (instruction == 'v') relSubpoint[1] += data[0];
else {
relSubpoint[0] += data[data.length - 2];
relSubpoint[1] += data[data.length - 1];
}
roundData(relSubpoint);
if (instruction.toLowerCase() == 'm') {
pathBase[0] = relSubpoint[0];
pathBase[1] = relSubpoint[1];
}
}
// convert straight curves into lines segments
if (params.straightCurves) {
// c
if (
instruction === 'c' &&
isCurveStraightLine(
[ 0, data[0], data[2], data[4] ],
[ 0, data[1], data[3], data[5] ]
)
) {
instruction = 'l';
data = data.slice(-2);
}
// s
else if (
instruction === 's' &&
isCurveStraightLine(
[ 0, sdata[0], sdata[2], sdata[4] ],
[ 0, sdata[1], sdata[3], sdata[5] ]
)
) {
instruction = 'l';
data = data.slice(-2);
}
// q
else if (
instruction === 'q' &&
isCurveStraightLine(
[ 0, data[0], data[2] ],
[ 0, data[1], data[3] ]
)
) {
// save the original one for the future potential q + t conversion
item.original = {
instruction: instruction,
data: data
};
instruction = 'l';
data = data.slice(-2);
}
else if (instruction === 't') {
// q (original) + t
if (
prev.original &&
prev.original.instruction === 'q'
) {
if (isCurveStraightLine(
[ prev.original.data[0], prev.original.data[2], data[0] ],
[ prev.original.data[1], prev.original.data[3], data[1] ]
)) {
instruction = 'l';
data = data.slice(-2);
} else {
prev.instruction = 'q';
prev.data = prev.original.data;
}
}
// [^qt] + t
else if ('qt'.indexOf(prev.instruction) < 0) {
instruction = 'l';
data = data.slice(-2);
}
}
// a
else if (
instruction === 'a' &&
(data[0] === 0 || data[1] === 0)
) {
instruction = 'l';
data = data.slice(-2);
}
}
// horizontal and vertical line shorthands
// l 50 0 → h 50
// l 0 50 → v 50
if (
params.lineShorthands &&
instruction === 'l'
) {
if (data[1] === 0) {
instruction = 'h';
data.pop();
} else if (data[0] === 0) {
instruction = 'v';
data.shift();
}
}
// collapse repeated commands
// h 20 h 30 -> h 50
if (
params.collapseRepeated &&
!hasMarkerMid &&
('mhv'.indexOf(instruction) > -1) &&
prev.instruction &&
instruction == prev.instruction.toLowerCase() &&
(
(instruction != 'h' && instruction != 'v') ||
(prev.data[0] >= 0) == (item.data[0] >= 0)
)) {
prev.data[0] += data[0];
if (instruction != 'h' && instruction != 'v') {
prev.data[1] += data[1];
}
prev.coords = item.coords;
if (prev.original) prev.original = null;
path[index] = prev;
return false;
}
// convert curves into smooth shorthands
if (params.curveSmoothShorthands && prev.instruction) {
// curveto
if (instruction === 'c') {
// c + c → c + s
if (
prev.instruction === 'c' &&
data[0] === -(prev.data[2] - prev.data[4]) &&
data[1] === -(prev.data[3] - prev.data[5])
) {
instruction = 's';
data = data.slice(2);
}
// s + c → s + s
else if (
prev.instruction === 's' &&
data[0] === -(prev.data[0] - prev.data[2]) &&
data[1] === -(prev.data[1] - prev.data[3])
) {
instruction = 's';
data = data.slice(2);
}
// [^cs] + c → [^cs] + s
else if (
'cs'.indexOf(prev.instruction) === -1 &&
data[0] === 0 &&
data[1] === 0
) {
instruction = 's';
data = data.slice(2);
}
}
// quadratic Bézier curveto
else if (instruction === 'q') {
// q + q → q + t
if (
prev.instruction === 'q' &&
data[0] === (prev.data[2] - prev.data[0]) &&
data[1] === (prev.data[3] - prev.data[1])
) {
instruction = 't';
data = data.slice(2);
}
// t + q → t + t
else if (
prev.instruction === 't' &&
data[2] === prev.data[0] &&
data[3] === prev.data[1]
) {
instruction = 't';
data = data.slice(2);
}
}
}
// remove useless non-first path segments
if (params.removeUseless) {
// l 0,0 / h 0 / v 0 / q 0,0 0,0 / t 0,0 / c 0,0 0,0 0,0 / s 0,0 0,0
if (
(
'lhvqtcs'.indexOf(instruction) > -1
) &&
data.every(function(i) { return i === 0; })
) {
path[index] = prev;
return false;
}
// a 25,25 -30 0,1 0,0
if (
instruction === 'a' &&
data[5] === 0 &&
data[6] === 0
) {
path[index] = prev;
return false;
}
}
item.instruction = instruction;
item.data = data;
prev = item;
} else {
// z resets coordinates
relSubpoint[0] = pathBase[0];
relSubpoint[1] = pathBase[1];
if (prev.instruction == 'z') return false;
prev = item;
}
return true;
});
return path;
}
/**
* Writes data in shortest form using absolute or relative coordinates.
*
* @param {Array} data input path data
* @return {Boolean} output
*/
function convertToMixed(path, params) {
var prev = path[0];
path = path.filter(function(item, index) {
if (index == 0) return true;
if (!item.data) {
prev = item;
return true;
}
var instruction = item.instruction,
data = item.data,
adata = data && data.slice(0);
if ('mltqsc'.indexOf(instruction) > -1) {
for (var i = adata.length; i--;) {
adata[i] += item.base[i % 2];
}
} else if (instruction == 'h') {
adata[0] += item.base[0];
} else if (instruction == 'v') {
adata[0] += item.base[1];
} else if (instruction == 'a') {
adata[5] += item.base[0];
adata[6] += item.base[1];
}
roundData(adata);
var absoluteDataStr = cleanupOutData(adata, params),
relativeDataStr = cleanupOutData(data, params);
// Convert to absolute coordinates if it's shorter.
// v-20 -> V0
// Don't convert if it fits following previous instruction.
// l20 30-10-50 instead of l20 30L20 30
if (
absoluteDataStr.length < relativeDataStr.length &&
!(
params.negativeExtraSpace &&
instruction == prev.instruction &&
prev.instruction.charCodeAt(0) > 96 &&
absoluteDataStr.length == relativeDataStr.length - 1 &&
(data[0] < 0 || 0 < data[0] && data[0] < 1 && prev.data[prev.data.length - 1] % 1)
)
) {
item.instruction = instruction.toUpperCase();
item.data = adata;
}
prev = item;
return true;
});
return path;
}
/**
* Decrease accuracy of floating-point numbers
* in path data keeping a specified number of decimals.
* Smart rounds values like 2.349 to 2.35.
*
* @param {Array} data input data array
* @param {Number} fixed number of decimals
* @return {Array} output data array
*/
function roundData(data) {
function round(data) {
for (var i = data.length; i--;) {
data[i] = +data[i].toFixed(precision);
}
return data;
}
function strongRound(data) {
for (var i = data.length; i--;) {
var rounded = +data[i].toFixed(precision - 1);
data[i] = +Math.abs(rounded - data[i]).toFixed(precision) > error ?
+data[i].toFixed(precision) :
rounded;
}
return data;
}
roundData = precision > 0 ? strongRound : round; // jshint ignore: line
return roundData(data);
}
/**
* Checks if a curve is a straight line by measuring distance
* from middle points to the line formed by end points.
*
* @param {Array} xs array of curve points x-coordinates
* @param {Array} ys array of curve points y-coordinates
* @return {Boolean}
*/
function isCurveStraightLine(xs, ys) {
// Get line equation a·x + b·y + c = 0 coefficients a, b, c by start and end points.
var i = xs.length - 1,
a = ys[0] - ys[i], // y1 y2
b = xs[i] - xs[0], // x2 x1
c = xs[0] * ys[i] - xs[i] * ys[0], // x1·y2 x2·y1
d = 1 / (a * a + b * b); // same part for all points
if (!isFinite(d)) return false; // curve that ends at start point isn't the case
// Distance from point (x0, y0) to the line is sqrt((c a·x0 b·y0)² / (a² + b²))
while (--i) {
if (Math.sqrt(Math.pow(c - a * xs[i] - b * ys[i], 2) * d) > error)
return false;
}
return true;
}