| Current File : /home/tradevaly/www/node_modules/svgo/plugins/convertPathData.js |
'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,
makeArcs: {
threshold: 2.5, // coefficient of rounding error
tolerance: 0.5 // percentage of radius
},
straightCurves: true,
lineShorthands: true,
curveSmoothShorthands: true,
floatPrecision: 3,
transformPrecision: 5,
removeUseless: true,
collapseRepeated: true,
utilizeAbsolute: true,
leadingZero: true,
negativeExtraSpace: true,
noSpaceAfterFlags: true,
forceAbsolutePath: false
};
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,
roundData,
precision,
error,
arcThreshold,
arcTolerance,
hasMarkerMid,
hasStrokeLinecap;
/**
* 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;
roundData = precision > 0 && precision < 20 ? strongRound : round;
if (params.makeArcs) {
arcThreshold = params.makeArcs.threshold;
arcTolerance = params.makeArcs.tolerance;
}
hasMarkerMid = item.hasAttr('marker-mid');
var stroke = item.computedAttr('stroke'),
strokeLinecap = item.computedAttr('stroke');
hasStrokeLinecap = stroke && stroke != 'none' && strokeLinecap && strokeLinecap != 'butt';
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 stringify = data2Path.bind(null, params),
relSubpoint = [0, 0],
pathBase = [0, 0],
prev = {};
path = path.filter(function(item, index, path) {
var instruction = item.instruction,
data = item.data,
next = path[index + 1];
if (data) {
var sdata = data,
circle;
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];
}
}
// convert curves to arcs if possible
if (
params.makeArcs &&
(instruction == 'c' || instruction == 's') &&
isConvex(sdata) &&
(circle = findCircle(sdata))
) {
var r = roundData([circle.radius])[0],
angle = findArcAngle(sdata, circle),
sweep = sdata[5] * sdata[0] - sdata[4] * sdata[1] > 0 ? 1 : 0,
arc = {
instruction: 'a',
data: [r, r, 0, 0, sweep, sdata[4], sdata[5]],
coords: item.coords.slice(),
base: item.base
},
output = [arc],
// relative coordinates to adjust the found circle
relCenter = [circle.center[0] - sdata[4], circle.center[1] - sdata[5]],
relCircle = { center: relCenter, radius: circle.radius },
arcCurves = [item],
hasPrev = 0,
suffix = '',
nextLonghand;
if (
prev.instruction == 'c' && isConvex(prev.data) && isArcPrev(prev.data, circle) ||
prev.instruction == 'a' && prev.sdata && isArcPrev(prev.sdata, circle)
) {
arcCurves.unshift(prev);
arc.base = prev.base;
arc.data[5] = arc.coords[0] - arc.base[0];
arc.data[6] = arc.coords[1] - arc.base[1];
var prevData = prev.instruction == 'a' ? prev.sdata : prev.data;
var prevAngle = findArcAngle(prevData,
{
center: [prevData[4] + circle.center[0], prevData[5] + circle.center[1]],
radius: circle.radius
}
);
angle += prevAngle;
if (angle > Math.PI) arc.data[3] = 1;
hasPrev = 1;
}
// check if next curves are fitting the arc
for (var j = index; (next = path[++j]) && ~'cs'.indexOf(next.instruction);) {
var nextData = next.data;
if (next.instruction == 's') {
nextLonghand = makeLonghand({instruction: 's', data: next.data.slice() },
path[j - 1].data);
nextData = nextLonghand.data;
nextLonghand.data = nextData.slice(0, 2);
suffix = stringify([nextLonghand]);
}
if (isConvex(nextData) && isArc(nextData, relCircle)) {
angle += findArcAngle(nextData, relCircle);
if (angle - 2 * Math.PI > 1e-3) break; // more than 360°
if (angle > Math.PI) arc.data[3] = 1;
arcCurves.push(next);
if (2 * Math.PI - angle > 1e-3) { // less than 360°
arc.coords = next.coords;
arc.data[5] = arc.coords[0] - arc.base[0];
arc.data[6] = arc.coords[1] - arc.base[1];
} else {
// full circle, make a half-circle arc and add a second one
arc.data[5] = 2 * (relCircle.center[0] - nextData[4]);
arc.data[6] = 2 * (relCircle.center[1] - nextData[5]);
arc.coords = [arc.base[0] + arc.data[5], arc.base[1] + arc.data[6]];
arc = {
instruction: 'a',
data: [r, r, 0, 0, sweep,
next.coords[0] - arc.coords[0], next.coords[1] - arc.coords[1]],
coords: next.coords,
base: arc.coords
};
output.push(arc);
j++;
break;
}
relCenter[0] -= nextData[4];
relCenter[1] -= nextData[5];
} else break;
}
if ((stringify(output) + suffix).length < stringify(arcCurves).length) {
if (path[j] && path[j].instruction == 's') {
makeLonghand(path[j], path[j - 1].data);
}
if (hasPrev) {
var prevArc = output.shift();
roundData(prevArc.data);
relSubpoint[0] += prevArc.data[5] - prev.data[prev.data.length - 2];
relSubpoint[1] += prevArc.data[6] - prev.data[prev.data.length - 1];
prev.instruction = 'a';
prev.data = prevArc.data;
item.base = prev.coords = prevArc.coords;
}
arc = output.shift();
if (arcCurves.length == 1) {
item.sdata = sdata.slice(); // preserve curve data for future checks
} else if (arcCurves.length - 1 - hasPrev > 0) {
// filter out consumed next items
path.splice.apply(path, [index + 1, arcCurves.length - 1 - hasPrev].concat(output));
}
if (!arc) return false;
instruction = 'a';
data = arc.data;
item.coords = arc.coords;
}
}
// 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) {
if (
instruction === 'c' &&
isCurveStraightLine(data) ||
instruction === 's' &&
isCurveStraightLine(sdata)
) {
if (next && next.instruction == 's')
makeLonghand(next, data); // fix up next curve
instruction = 'l';
data = data.slice(-2);
}
else if (
instruction === 'q' &&
isCurveStraightLine(data)
) {
if (next && next.instruction == 't')
makeLonghand(next, data); // fix up next curve
instruction = 'l';
data = data.slice(-2);
}
else if (
instruction === 't' &&
prev.instruction !== 'q' &&
prev.instruction !== 't'
) {
instruction = 'l';
data = data.slice(-2);
}
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;
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 && !hasStrokeLinecap) {
// 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 or forceAbsolutePath is true.
// v-20 -> V0
// Don't convert if it fits following previous instruction.
// l20 30-10-50 instead of l20 30L20 30
if (
params.forceAbsolutePath || (
absoluteDataStr.length < relativeDataStr.length &&
!(
params.negativeExtraSpace &&
instruction == prev.instruction &&
prev.instruction.charCodeAt(0) > 96 &&
absoluteDataStr.length == relativeDataStr.length - 1 &&
(data[0] < 0 || /^0\./.test(data[0]) && prev.data[prev.data.length - 1] % 1)
))
) {
item.instruction = instruction.toUpperCase();
item.data = adata;
}
prev = item;
return true;
});
return path;
}
/**
* Checks if curve is convex. Control points of such a curve must form
* a convex quadrilateral with diagonals crosspoint inside of it.
*
* @param {Array} data input path data
* @return {Boolean} output
*/
function isConvex(data) {
var center = getIntersection([0, 0, data[2], data[3], data[0], data[1], data[4], data[5]]);
return center &&
(data[2] < center[0] == center[0] < 0) &&
(data[3] < center[1] == center[1] < 0) &&
(data[4] < center[0] == center[0] < data[0]) &&
(data[5] < center[1] == center[1] < data[1]);
}
/**
* Computes lines equations by two points and returns their intersection point.
*
* @param {Array} coords 8 numbers for 4 pairs of coordinates (x,y)
* @return {Array|undefined} output coordinate of lines' crosspoint
*/
function getIntersection(coords) {
// Prev line equation parameters.
var a1 = coords[1] - coords[3], // y1 - y2
b1 = coords[2] - coords[0], // x2 - x1
c1 = coords[0] * coords[3] - coords[2] * coords[1], // x1 * y2 - x2 * y1
// Next line equation parameters
a2 = coords[5] - coords[7], // y1 - y2
b2 = coords[6] - coords[4], // x2 - x1
c2 = coords[4] * coords[7] - coords[5] * coords[6], // x1 * y2 - x2 * y1
denom = (a1 * b2 - a2 * b1);
if (!denom) return; // parallel lines havn't an intersection
var cross = [
(b1 * c2 - b2 * c1) / denom,
(a1 * c2 - a2 * c1) / -denom
];
if (
!isNaN(cross[0]) && !isNaN(cross[1]) &&
isFinite(cross[0]) && isFinite(cross[1])
) {
return cross;
}
}
/**
* Decrease accuracy of floating-point numbers
* in path data keeping a specified number of decimals.
* Smart rounds values like 2.3491 to 2.35 instead of 2.349.
* Doesn't apply "smartness" if the number precision fits already.
*
* @param {Array} data input data array
* @return {Array} output data array
*/
function strongRound(data) {
for (var i = data.length; i-- > 0;) {
if (data[i].toFixed(precision) != data[i]) {
var rounded = +data[i].toFixed(precision - 1);
data[i] = +Math.abs(rounded - data[i]).toFixed(precision + 1) >= error ?
+data[i].toFixed(precision) :
rounded;
}
}
return data;
}
/**
* Simple rounding function if precision is 0.
*
* @param {Array} data input data array
* @return {Array} output data array
*/
function round(data) {
for (var i = data.length; i-- > 0;) {
data[i] = Math.round(data[i]);
}
return 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(data) {
// Get line equation a·x + b·y + c = 0 coefficients a, b (c = 0) by start and end points.
var i = data.length - 2,
a = -data[i + 1], // y1 − y2 (y1 = 0)
b = data[i], // x2 − x1 (x1 = 0)
d = 1 / (a * a + b * b); // same part for all points
if (i <= 1 || !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 -= 2) >= 0) {
if (Math.sqrt(Math.pow(a * data[i] + b * data[i + 1], 2) * d) > error)
return false;
}
return true;
}
/**
* Converts next curve from shorthand to full form using the current curve data.
*
* @param {Object} item curve to convert
* @param {Array} data current curve data
*/
function makeLonghand(item, data) {
switch (item.instruction) {
case 's': item.instruction = 'c'; break;
case 't': item.instruction = 'q'; break;
}
item.data.unshift(data[data.length - 2] - data[data.length - 4], data[data.length - 1] - data[data.length - 3]);
return item;
}
/**
* Returns distance between two points
*
* @param {Array} point1 first point coordinates
* @param {Array} point2 second point coordinates
* @return {Number} distance
*/
function getDistance(point1, point2) {
return Math.hypot(point1[0] - point2[0], point1[1] - point2[1]);
}
/**
* Returns coordinates of the curve point corresponding to the certain t
* a·(1 - t)³·p1 + b·(1 - t)²·t·p2 + c·(1 - t)·t²·p3 + d·t³·p4,
* where pN are control points and p1 is zero due to relative coordinates.
*
* @param {Array} curve array of curve points coordinates
* @param {Number} t parametric position from 0 to 1
* @return {Array} Point coordinates
*/
function getCubicBezierPoint(curve, t) {
var sqrT = t * t,
cubT = sqrT * t,
mt = 1 - t,
sqrMt = mt * mt;
return [
3 * sqrMt * t * curve[0] + 3 * mt * sqrT * curve[2] + cubT * curve[4],
3 * sqrMt * t * curve[1] + 3 * mt * sqrT * curve[3] + cubT * curve[5]
];
}
/**
* Finds circle by 3 points of the curve and checks if the curve fits the found circle.
*
* @param {Array} curve
* @return {Object|undefined} circle
*/
function findCircle(curve) {
var midPoint = getCubicBezierPoint(curve, 1/2),
m1 = [midPoint[0] / 2, midPoint[1] / 2],
m2 = [(midPoint[0] + curve[4]) / 2, (midPoint[1] + curve[5]) / 2],
center = getIntersection([
m1[0], m1[1],
m1[0] + m1[1], m1[1] - m1[0],
m2[0], m2[1],
m2[0] + (m2[1] - midPoint[1]), m2[1] - (m2[0] - midPoint[0])
]),
radius = center && getDistance([0, 0], center),
tolerance = Math.min(arcThreshold * error, arcTolerance * radius / 100);
if (center && radius < 1e15 &&
[1/4, 3/4].every(function(point) {
return Math.abs(getDistance(getCubicBezierPoint(curve, point), center) - radius) <= tolerance;
}))
return { center: center, radius: radius};
}
/**
* Checks if a curve fits the given circle.
*
* @param {Object} circle
* @param {Array} curve
* @return {Boolean}
*/
function isArc(curve, circle) {
var tolerance = Math.min(arcThreshold * error, arcTolerance * circle.radius / 100);
return [0, 1/4, 1/2, 3/4, 1].every(function(point) {
return Math.abs(getDistance(getCubicBezierPoint(curve, point), circle.center) - circle.radius) <= tolerance;
});
}
/**
* Checks if a previous curve fits the given circle.
*
* @param {Object} circle
* @param {Array} curve
* @return {Boolean}
*/
function isArcPrev(curve, circle) {
return isArc(curve, {
center: [circle.center[0] + curve[4], circle.center[1] + curve[5]],
radius: circle.radius
});
}
/**
* Finds angle of a curve fitting the given arc.
* @param {Array} curve
* @param {Object} relCircle
* @return {Number} angle
*/
function findArcAngle(curve, relCircle) {
var x1 = -relCircle.center[0],
y1 = -relCircle.center[1],
x2 = curve[4] - relCircle.center[0],
y2 = curve[5] - relCircle.center[1];
return Math.acos(
(x1 * x2 + y1 * y2) /
Math.sqrt((x1 * x1 + y1 * y1) * (x2 * x2 + y2 * y2))
);
}
/**
* Converts given path data to string.
*
* @param {Object} params
* @param {Array} pathData
* @return {String}
*/
function data2Path(params, pathData) {
return pathData.reduce(function(pathString, item) {
var strData = '';
if (item.data) {
strData = cleanupOutData(roundData(item.data.slice()), params);
}
return pathString + item.instruction + strData;
}, '');
}