convertPathData.js•36.1 kB
'use strict';
/**
* @typedef {import('../lib//types').PathDataItem} PathDataItem
*/
const { collectStylesheet, computeStyle } = require('../lib/style.js');
const { visit } = require('../lib/xast.js');
const { pathElems } = require('./_collections.js');
const { path2js, js2path } = require('./_path.js');
const { applyTransforms } = require('./applyTransforms.js');
const { cleanupOutData, toFixed } = require('../lib/svgo/tools');
exports.name = 'convertPathData';
exports.description =
'optimizes path data: writes in shorter form, applies transformations';
/** @type {(data: number[]) => number[]} */
let roundData;
/** @type {number | false} */
let precision;
/** @type {number} */
let error;
/** @type {number} */
let arcThreshold;
/** @type {number} */
let arcTolerance;
/**
* @typedef {{
* applyTransforms: boolean,
* applyTransformsStroked: boolean,
* makeArcs: {
* threshold: number,
* tolerance: number,
* },
* straightCurves: boolean,
* convertToQ: boolean,
* lineShorthands: boolean,
* convertToZ: boolean,
* curveSmoothShorthands: boolean,
* floatPrecision: number | false,
* transformPrecision: number,
* smartArcRounding: boolean,
* removeUseless: boolean,
* collapseRepeated: boolean,
* utilizeAbsolute: boolean,
* leadingZero: boolean,
* negativeExtraSpace: boolean,
* noSpaceAfterFlags: boolean,
* forceAbsolutePath: boolean,
* }} InternalParams
*/
/**
* @typedef {[number, number]} Point
*/
/**
* @typedef {{
* center: Point,
* radius: number
* }} Circle
*/
/**
* 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 https://www.w3.org/TR/SVG11/paths.html#PathData
*
* @author Kir Belevich
*
* @type {import('./plugins-types').Plugin<'convertPathData'>}
*/
exports.fn = (root, params) => {
const {
// TODO convert to separate plugin in v3
applyTransforms: _applyTransforms = true,
applyTransformsStroked = true,
makeArcs = {
threshold: 2.5, // coefficient of rounding error
tolerance: 0.5, // percentage of radius
},
straightCurves = true,
convertToQ = true,
lineShorthands = true,
convertToZ = true,
curveSmoothShorthands = true,
floatPrecision = 3,
transformPrecision = 5,
smartArcRounding = true,
removeUseless = true,
collapseRepeated = true,
utilizeAbsolute = true,
leadingZero = true,
negativeExtraSpace = true,
noSpaceAfterFlags = false, // a20 60 45 0 1 30 20 → a20 60 45 0130 20
forceAbsolutePath = false,
} = params;
/**
* @type {InternalParams}
*/
const newParams = {
applyTransforms: _applyTransforms,
applyTransformsStroked,
makeArcs,
straightCurves,
convertToQ,
lineShorthands,
convertToZ,
curveSmoothShorthands,
floatPrecision,
transformPrecision,
smartArcRounding,
removeUseless,
collapseRepeated,
utilizeAbsolute,
leadingZero,
negativeExtraSpace,
noSpaceAfterFlags,
forceAbsolutePath,
};
// invoke applyTransforms plugin
if (_applyTransforms) {
visit(
root,
// @ts-ignore
applyTransforms(root, {
transformPrecision,
applyTransformsStroked,
}),
);
}
const stylesheet = collectStylesheet(root);
return {
element: {
enter: (node) => {
if (pathElems.has(node.name) && node.attributes.d != null) {
const computedStyle = computeStyle(stylesheet, node);
precision = floatPrecision;
error =
precision !== false
? +Math.pow(0.1, precision).toFixed(precision)
: 1e-2;
roundData =
precision && precision > 0 && precision < 20 ? strongRound : round;
if (makeArcs) {
arcThreshold = makeArcs.threshold;
arcTolerance = makeArcs.tolerance;
}
const hasMarkerMid = computedStyle['marker-mid'] != null;
const maybeHasStroke =
computedStyle.stroke &&
(computedStyle.stroke.type === 'dynamic' ||
computedStyle.stroke.value !== 'none');
const maybeHasLinecap =
computedStyle['stroke-linecap'] &&
(computedStyle['stroke-linecap'].type === 'dynamic' ||
computedStyle['stroke-linecap'].value !== 'butt');
const maybeHasStrokeAndLinecap = maybeHasStroke && maybeHasLinecap;
const isSafeToUseZ = maybeHasStroke
? computedStyle['stroke-linecap']?.type === 'static' &&
computedStyle['stroke-linecap'].value === 'round' &&
computedStyle['stroke-linejoin']?.type === 'static' &&
computedStyle['stroke-linejoin'].value === 'round'
: true;
var data = path2js(node);
// TODO: get rid of functions returns
if (data.length) {
convertToRelative(data);
data = filters(data, newParams, {
isSafeToUseZ,
maybeHasStrokeAndLinecap,
hasMarkerMid,
});
if (utilizeAbsolute) {
data = convertToMixed(data, newParams);
}
// @ts-ignore
js2path(node, data, newParams);
}
}
},
},
};
};
/**
* Convert absolute path data coordinates to relative.
*
* @type {(pathData: PathDataItem[]) => PathDataItem[]}
*/
const convertToRelative = (pathData) => {
let start = [0, 0];
let cursor = [0, 0];
let prevCoords = [0, 0];
for (let i = 0; i < pathData.length; i += 1) {
const pathItem = pathData[i];
let { command, args } = pathItem;
// moveto (x y)
if (command === 'm') {
// update start and cursor
cursor[0] += args[0];
cursor[1] += args[1];
start[0] = cursor[0];
start[1] = cursor[1];
}
if (command === 'M') {
// M → m
// skip first moveto
if (i !== 0) {
command = 'm';
}
args[0] -= cursor[0];
args[1] -= cursor[1];
// update start and cursor
cursor[0] += args[0];
cursor[1] += args[1];
start[0] = cursor[0];
start[1] = cursor[1];
}
// lineto (x y)
if (command === 'l') {
cursor[0] += args[0];
cursor[1] += args[1];
}
if (command === 'L') {
// L → l
command = 'l';
args[0] -= cursor[0];
args[1] -= cursor[1];
cursor[0] += args[0];
cursor[1] += args[1];
}
// horizontal lineto (x)
if (command === 'h') {
cursor[0] += args[0];
}
if (command === 'H') {
// H → h
command = 'h';
args[0] -= cursor[0];
cursor[0] += args[0];
}
// vertical lineto (y)
if (command === 'v') {
cursor[1] += args[0];
}
if (command === 'V') {
// V → v
command = 'v';
args[0] -= cursor[1];
cursor[1] += args[0];
}
// curveto (x1 y1 x2 y2 x y)
if (command === 'c') {
cursor[0] += args[4];
cursor[1] += args[5];
}
if (command === 'C') {
// C → c
command = 'c';
args[0] -= cursor[0];
args[1] -= cursor[1];
args[2] -= cursor[0];
args[3] -= cursor[1];
args[4] -= cursor[0];
args[5] -= cursor[1];
cursor[0] += args[4];
cursor[1] += args[5];
}
// smooth curveto (x2 y2 x y)
if (command === 's') {
cursor[0] += args[2];
cursor[1] += args[3];
}
if (command === 'S') {
// S → s
command = 's';
args[0] -= cursor[0];
args[1] -= cursor[1];
args[2] -= cursor[0];
args[3] -= cursor[1];
cursor[0] += args[2];
cursor[1] += args[3];
}
// quadratic Bézier curveto (x1 y1 x y)
if (command === 'q') {
cursor[0] += args[2];
cursor[1] += args[3];
}
if (command === 'Q') {
// Q → q
command = 'q';
args[0] -= cursor[0];
args[1] -= cursor[1];
args[2] -= cursor[0];
args[3] -= cursor[1];
cursor[0] += args[2];
cursor[1] += args[3];
}
// smooth quadratic Bézier curveto (x y)
if (command === 't') {
cursor[0] += args[0];
cursor[1] += args[1];
}
if (command === 'T') {
// T → t
command = 't';
args[0] -= cursor[0];
args[1] -= cursor[1];
cursor[0] += args[0];
cursor[1] += args[1];
}
// elliptical arc (rx ry x-axis-rotation large-arc-flag sweep-flag x y)
if (command === 'a') {
cursor[0] += args[5];
cursor[1] += args[6];
}
if (command === 'A') {
// A → a
command = 'a';
args[5] -= cursor[0];
args[6] -= cursor[1];
cursor[0] += args[5];
cursor[1] += args[6];
}
// closepath
if (command === 'Z' || command === 'z') {
// reset cursor
cursor[0] = start[0];
cursor[1] = start[1];
}
pathItem.command = command;
pathItem.args = args;
// store absolute coordinates for later use
// base should preserve reference from other element
// @ts-ignore
pathItem.base = prevCoords;
// @ts-ignore
pathItem.coords = [cursor[0], cursor[1]];
// @ts-ignore
prevCoords = pathItem.coords;
}
return pathData;
};
/**
* Main filters loop.
*
* @type {(
* path: PathDataItem[],
* params: InternalParams,
* aux: { isSafeToUseZ: boolean, maybeHasStrokeAndLinecap: boolean, hasMarkerMid: boolean }
* ) => PathDataItem[]}
*/
function filters(
path,
params,
{ isSafeToUseZ, maybeHasStrokeAndLinecap, hasMarkerMid },
) {
const stringify = data2Path.bind(null, params);
const relSubpoint = [0, 0];
const pathBase = [0, 0];
/** @type {any} */
let prev = {};
/** @type {Point | undefined} */
let prevQControlPoint;
path = path.filter(function (item, index, path) {
const qControlPoint = prevQControlPoint;
prevQControlPoint = undefined;
let command = item.command;
let data = item.args;
let next = path[index + 1];
if (command !== 'Z' && command !== 'z') {
var sdata = data,
circle;
if (command === 's') {
sdata = [0, 0].concat(data);
const pdata = prev.args;
const 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 &&
(command == 'c' || command == '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,
/**
* @type {PathDataItem}
*/
arc = {
command: 'a',
args: [r, r, 0, 0, sweep, sdata[4], sdata[5]],
// @ts-ignore
coords: item.coords.slice(),
// @ts-ignore
base: item.base,
},
/**
* @type {PathDataItem[]}
*/
output = [arc],
// relative coordinates to adjust the found circle
/**
* @type {Point}
*/
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.command == 'c' &&
isConvex(prev.args) &&
isArcPrev(prev.args, circle)) ||
(prev.command == 'a' && prev.sdata && isArcPrev(prev.sdata, circle))
) {
arcCurves.unshift(prev);
// @ts-ignore
arc.base = prev.base;
// @ts-ignore
arc.args[5] = arc.coords[0] - arc.base[0];
// @ts-ignore
arc.args[6] = arc.coords[1] - arc.base[1];
var prevData = prev.command == 'a' ? prev.sdata : prev.args;
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.args[3] = 1;
hasPrev = 1;
}
// check if next curves are fitting the arc
for (
var j = index;
(next = path[++j]) && (next.command === 'c' || next.command === 's');
) {
var nextData = next.args;
if (next.command == 's') {
nextLonghand = makeLonghand(
{ command: 's', args: next.args.slice() },
path[j - 1].args,
);
nextData = nextLonghand.args;
nextLonghand.args = 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.args[3] = 1;
arcCurves.push(next);
if (2 * Math.PI - angle > 1e-3) {
// less than 360°
// @ts-ignore
arc.coords = next.coords;
// @ts-ignore
arc.args[5] = arc.coords[0] - arc.base[0];
// @ts-ignore
arc.args[6] = arc.coords[1] - arc.base[1];
} else {
// full circle, make a half-circle arc and add a second one
arc.args[5] = 2 * (relCircle.center[0] - nextData[4]);
arc.args[6] = 2 * (relCircle.center[1] - nextData[5]);
// @ts-ignore
arc.coords = [
// @ts-ignore
arc.base[0] + arc.args[5],
// @ts-ignore
arc.base[1] + arc.args[6],
];
arc = {
command: 'a',
args: [
r,
r,
0,
0,
sweep,
// @ts-ignore
next.coords[0] - arc.coords[0],
// @ts-ignore
next.coords[1] - arc.coords[1],
],
// @ts-ignore
coords: next.coords,
// @ts-ignore
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].command == 's') {
makeLonghand(path[j], path[j - 1].args);
}
if (hasPrev) {
var prevArc = output.shift();
// @ts-ignore
roundData(prevArc.args);
// @ts-ignore
relSubpoint[0] += prevArc.args[5] - prev.args[prev.args.length - 2];
// @ts-ignore
relSubpoint[1] += prevArc.args[6] - prev.args[prev.args.length - 1];
prev.command = 'a';
// @ts-ignore
prev.args = prevArc.args;
// @ts-ignore
item.base = prev.coords = prevArc.coords;
}
// @ts-ignore
arc = output.shift();
if (arcCurves.length == 1) {
// @ts-ignore
item.sdata = sdata.slice(); // preserve curve data for future checks
} else if (arcCurves.length - 1 - hasPrev > 0) {
// filter out consumed next items
path.splice(index + 1, arcCurves.length - 1 - hasPrev, ...output);
}
if (!arc) return false;
command = 'a';
data = arc.args;
// @ts-ignore
item.coords = arc.coords;
}
}
// Rounding relative coordinates, taking in account accumulating 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 (
command === 'm' ||
command === 'l' ||
command === 't' ||
command === 'q' ||
command === 's' ||
command === 'c'
) {
for (var i = data.length; i--; ) {
// @ts-ignore
data[i] += item.base[i % 2] - relSubpoint[i % 2];
}
} else if (command == 'h') {
// @ts-ignore
data[0] += item.base[0] - relSubpoint[0];
} else if (command == 'v') {
// @ts-ignore
data[0] += item.base[1] - relSubpoint[1];
} else if (command == 'a') {
// @ts-ignore
data[5] += item.base[0] - relSubpoint[0];
// @ts-ignore
data[6] += item.base[1] - relSubpoint[1];
}
roundData(data);
if (command == 'h') relSubpoint[0] += data[0];
else if (command == 'v') relSubpoint[1] += data[0];
else {
relSubpoint[0] += data[data.length - 2];
relSubpoint[1] += data[data.length - 1];
}
roundData(relSubpoint);
if (command === 'M' || command === 'm') {
pathBase[0] = relSubpoint[0];
pathBase[1] = relSubpoint[1];
}
}
// round arc radius more accurately
// eg m 0 0 a 1234.567 1234.567 0 0 1 10 0 -> m 0 0 a 1235 1235 0 0 1 10 0
const sagitta = command === 'a' ? calculateSagitta(data) : undefined;
if (params.smartArcRounding && sagitta !== undefined && precision) {
for (let precisionNew = precision; precisionNew >= 0; precisionNew--) {
const radius = toFixed(data[0], precisionNew);
const sagittaNew = /** @type {number} */ (
calculateSagitta([radius, radius, ...data.slice(2)])
);
if (Math.abs(sagitta - sagittaNew) < error) {
data[0] = radius;
data[1] = radius;
} else {
break;
}
}
}
// convert straight curves into lines segments
if (params.straightCurves) {
if (
(command === 'c' && isCurveStraightLine(data)) ||
(command === 's' && isCurveStraightLine(sdata))
) {
if (next && next.command == 's') makeLonghand(next, data); // fix up next curve
command = 'l';
data = data.slice(-2);
} else if (command === 'q' && isCurveStraightLine(data)) {
if (next && next.command == 't') makeLonghand(next, data); // fix up next curve
command = 'l';
data = data.slice(-2);
} else if (
command === 't' &&
prev.command !== 'q' &&
prev.command !== 't'
) {
command = 'l';
data = data.slice(-2);
} else if (
command === 'a' &&
(data[0] === 0 ||
data[1] === 0 ||
(sagitta !== undefined && sagitta < error))
) {
command = 'l';
data = data.slice(-2);
}
}
// degree-lower c to q when possible
// m 0 12 C 4 4 8 4 12 12 → M 0 12 Q 6 0 12 12
if (params.convertToQ && command == 'c') {
const x1 =
// @ts-ignore
0.75 * (item.base[0] + data[0]) - 0.25 * item.base[0];
const x2 =
// @ts-ignore
0.75 * (item.base[0] + data[2]) - 0.25 * (item.base[0] + data[4]);
if (Math.abs(x1 - x2) < error * 2) {
const y1 =
// @ts-ignore
0.75 * (item.base[1] + data[1]) - 0.25 * item.base[1];
const y2 =
// @ts-ignore
0.75 * (item.base[1] + data[3]) - 0.25 * (item.base[1] + data[5]);
if (Math.abs(y1 - y2) < error * 2) {
const newData = data.slice();
newData.splice(
0,
4,
// @ts-ignore
x1 + x2 - item.base[0],
// @ts-ignore
y1 + y2 - item.base[1],
);
roundData(newData);
const originalLength = cleanupOutData(data, params).length,
newLength = cleanupOutData(newData, params).length;
if (newLength < originalLength) {
command = 'q';
data = newData;
if (next && next.command == 's') makeLonghand(next, data); // fix up next curve
}
}
}
}
// horizontal and vertical line shorthands
// l 50 0 → h 50
// l 0 50 → v 50
if (params.lineShorthands && command === 'l') {
if (data[1] === 0) {
command = 'h';
data.pop();
} else if (data[0] === 0) {
command = 'v';
data.shift();
}
}
// collapse repeated commands
// h 20 h 30 -> h 50
if (
params.collapseRepeated &&
hasMarkerMid === false &&
(command === 'm' || command === 'h' || command === 'v') &&
prev.command &&
command == prev.command.toLowerCase() &&
((command != 'h' && command != 'v') ||
prev.args[0] >= 0 == data[0] >= 0)
) {
prev.args[0] += data[0];
if (command != 'h' && command != 'v') {
prev.args[1] += data[1];
}
// @ts-ignore
prev.coords = item.coords;
path[index] = prev;
return false;
}
// convert curves into smooth shorthands
if (params.curveSmoothShorthands && prev.command) {
// curveto
if (command === 'c') {
// c + c → c + s
if (
prev.command === 'c' &&
Math.abs(data[0] - -(prev.args[2] - prev.args[4])) < error &&
Math.abs(data[1] - -(prev.args[3] - prev.args[5])) < error
) {
command = 's';
data = data.slice(2);
}
// s + c → s + s
else if (
prev.command === 's' &&
Math.abs(data[0] - -(prev.args[0] - prev.args[2])) < error &&
Math.abs(data[1] - -(prev.args[1] - prev.args[3])) < error
) {
command = 's';
data = data.slice(2);
}
// [^cs] + c → [^cs] + s
else if (
prev.command !== 'c' &&
prev.command !== 's' &&
Math.abs(data[0]) < error &&
Math.abs(data[1]) < error
) {
command = 's';
data = data.slice(2);
}
}
// quadratic Bézier curveto
else if (command === 'q') {
// q + q → q + t
if (
prev.command === 'q' &&
Math.abs(data[0] - (prev.args[2] - prev.args[0])) < error &&
Math.abs(data[1] - (prev.args[3] - prev.args[1])) < error
) {
command = 't';
data = data.slice(2);
}
// t + q → t + t
else if (prev.command === 't') {
const predictedControlPoint = reflectPoint(
// @ts-ignore
qControlPoint,
// @ts-ignore
item.base,
);
const realControlPoint = [
// @ts-ignore
data[0] + item.base[0],
// @ts-ignore
data[1] + item.base[1],
];
if (
Math.abs(predictedControlPoint[0] - realControlPoint[0]) <
error &&
Math.abs(predictedControlPoint[1] - realControlPoint[1]) < error
) {
command = 't';
data = data.slice(2);
}
}
}
}
// remove useless non-first path segments
if (params.removeUseless && !maybeHasStrokeAndLinecap) {
// 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 (
(command === 'l' ||
command === 'h' ||
command === 'v' ||
command === 'q' ||
command === 't' ||
command === 'c' ||
command === 's') &&
data.every(function (i) {
return i === 0;
})
) {
path[index] = prev;
return false;
}
// a 25,25 -30 0,1 0,0
if (command === 'a' && data[5] === 0 && data[6] === 0) {
path[index] = prev;
return false;
}
}
// convert going home to z
// m 0 0 h 5 v 5 l -5 -5 -> m 0 0 h 5 v 5 z
if (
params.convertToZ &&
(isSafeToUseZ || next?.command === 'Z' || next?.command === 'z') &&
(command === 'l' || command === 'h' || command === 'v')
) {
if (
// @ts-ignore
Math.abs(pathBase[0] - item.coords[0]) < error &&
// @ts-ignore
Math.abs(pathBase[1] - item.coords[1]) < error
) {
command = 'z';
data = [];
}
}
item.command = command;
item.args = data;
} else {
// z resets coordinates
relSubpoint[0] = pathBase[0];
relSubpoint[1] = pathBase[1];
if (prev.command === 'Z' || prev.command === 'z') return false;
}
if (
(command === 'Z' || command === 'z') &&
params.removeUseless &&
isSafeToUseZ &&
// @ts-ignore
Math.abs(item.base[0] - item.coords[0]) < error / 10 &&
// @ts-ignore
Math.abs(item.base[1] - item.coords[1]) < error / 10
)
return false;
if (command === 'q') {
// @ts-ignore
prevQControlPoint = [data[0] + item.base[0], data[1] + item.base[1]];
} else if (command === 't') {
if (qControlPoint) {
// @ts-ignore
prevQControlPoint = reflectPoint(qControlPoint, item.base);
} else {
// @ts-ignore
prevQControlPoint = item.coords;
}
}
prev = item;
return true;
});
return path;
}
/**
* Writes data in shortest form using absolute or relative coordinates.
*
* @type {(path: PathDataItem[], params: InternalParams) => PathDataItem[]}
*/
function convertToMixed(path, params) {
var prev = path[0];
path = path.filter(function (item, index) {
if (index == 0) return true;
if (item.command === 'Z' || item.command === 'z') {
prev = item;
return true;
}
var command = item.command,
data = item.args,
adata = data.slice(),
rdata = data.slice();
if (
command === 'm' ||
command === 'l' ||
command === 't' ||
command === 'q' ||
command === 's' ||
command === 'c'
) {
for (var i = adata.length; i--; ) {
// @ts-ignore
adata[i] += item.base[i % 2];
}
} else if (command == 'h') {
// @ts-ignore
adata[0] += item.base[0];
} else if (command == 'v') {
// @ts-ignore
adata[0] += item.base[1];
} else if (command == 'a') {
// @ts-ignore
adata[5] += item.base[0];
// @ts-ignore
adata[6] += item.base[1];
}
roundData(adata);
roundData(rdata);
var absoluteDataStr = cleanupOutData(adata, params),
relativeDataStr = cleanupOutData(rdata, params);
// Convert to absolute coordinates if it's shorter or forceAbsolutePath is true.
// v-20 -> V0
// Don't convert if it fits following previous command.
// l20 30-10-50 instead of l20 30L20 30
if (
params.forceAbsolutePath ||
(absoluteDataStr.length < relativeDataStr.length &&
!(
params.negativeExtraSpace &&
command == prev.command &&
prev.command.charCodeAt(0) > 96 &&
absoluteDataStr.length == relativeDataStr.length - 1 &&
(data[0] < 0 ||
(Math.floor(data[0]) === 0 &&
!Number.isInteger(data[0]) &&
prev.args[prev.args.length - 1] % 1))
))
) {
// @ts-ignore
item.command = command.toUpperCase();
item.args = 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.
*
* @type {(data: number[]) => boolean}
*/
function isConvex(data) {
var center = getIntersection([
0,
0,
data[2],
data[3],
data[0],
data[1],
data[4],
data[5],
]);
return (
center != null &&
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.
*
* @type {(coords: number[]) => undefined | Point}
*/
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 haven't an intersection
/**
* @type {Point}
*/
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.
*
* @type {(data: number[]) => number[]}
*/
function strongRound(data) {
const precisionNum = precision || 0;
for (let i = data.length; i-- > 0; ) {
const fixed = toFixed(data[i], precisionNum);
if (fixed !== data[i]) {
const rounded = toFixed(data[i], precisionNum - 1);
data[i] =
toFixed(Math.abs(rounded - data[i]), precisionNum + 1) >= error
? fixed
: rounded;
}
}
return data;
}
/**
* Simple rounding function if precision is 0.
*
* @type {(data: number[]) => number[]}
*/
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.
*
* @type {(data: number[]) => 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;
}
/**
* Calculates the sagitta of an arc if possible.
*
* @type {(data: number[]) => number | undefined}
* @see https://wikipedia.org/wiki/Sagitta_(geometry)#Formulas
*/
function calculateSagitta(data) {
if (data[3] === 1) return undefined;
const [rx, ry] = data;
if (Math.abs(rx - ry) > error) return undefined;
const chord = Math.sqrt(data[5] ** 2 + data[6] ** 2);
if (chord > rx * 2) return undefined;
return rx - Math.sqrt(rx ** 2 - 0.25 * chord ** 2);
}
/**
* Converts next curve from shorthand to full form using the current curve data.
*
* @type {(item: PathDataItem, data: number[]) => PathDataItem}
*/
function makeLonghand(item, data) {
switch (item.command) {
case 's':
item.command = 'c';
break;
case 't':
item.command = 'q';
break;
}
item.args.unshift(
data[data.length - 2] - data[data.length - 4],
data[data.length - 1] - data[data.length - 3],
);
return item;
}
/**
* Returns distance between two points
*
* @type {(point1: Point, point2: Point) => number}
*/
function getDistance(point1, point2) {
return Math.sqrt((point1[0] - point2[0]) ** 2 + (point1[1] - point2[1]) ** 2);
}
/**
* Reflects point across another point.
*
* @param {Point} controlPoint
* @param {Point} base
* @returns {Point}
*/
function reflectPoint(controlPoint, base) {
return [2 * base[0] - controlPoint[0], 2 * base[1] - controlPoint[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.
*
* @type {(curve: number[], t: number) => Point}
*/
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.
*
* @type {(curve: number[]) => 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),
// @ts-ignore
tolerance = Math.min(arcThreshold * error, (arcTolerance * radius) / 100);
if (
center &&
// @ts-ignore
radius < 1e15 &&
[1 / 4, 3 / 4].every(function (point) {
return (
Math.abs(
// @ts-ignore
getDistance(getCubicBezierPoint(curve, point), center) - radius,
) <= tolerance
);
})
)
// @ts-ignore
return { center: center, radius: radius };
}
/**
* Checks if a curve fits the given circle.
*
* @type {(curve: number[], circle: Circle) => 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.
*
* @type {(curve: number[], circle: Circle) => 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.
* @type {(curve: number[], relCircle: Circle) => number}
*/
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.
*
* @type {(params: InternalParams, pathData: PathDataItem[]) => string}
*/
function data2Path(params, pathData) {
return pathData.reduce(function (pathString, item) {
var strData = '';
if (item.args) {
strData = cleanupOutData(roundData(item.args.slice()), params);
}
return pathString + item.command + strData;
}, '');
}