cione-comp-lib
Version:
`$ yarn add cione-comp-lib` 或者 `$ npm i cione-comp-lib -S`
413 lines (412 loc) • 12 kB
JavaScript
function earcut(data, holeIndices, dim) {
dim = dim || 2;
var hasHoles = holeIndices && holeIndices.length, outerLen = hasHoles ? holeIndices[0] * dim : data.length, outerNode = linkedList(data, 0, outerLen, dim, true), triangles = [];
if (!outerNode)
return triangles;
var minX, minY, maxX, maxY, x, y, size;
if (hasHoles)
outerNode = eliminateHoles(data, holeIndices, outerNode, dim);
if (data.length > 80 * dim) {
minX = maxX = data[0];
minY = maxY = data[1];
for (var i = dim; i < outerLen; i += dim) {
x = data[i];
y = data[i + 1];
if (x < minX)
minX = x;
if (y < minY)
minY = y;
if (x > maxX)
maxX = x;
if (y > maxY)
maxY = y;
}
size = Math.max(maxX - minX, maxY - minY);
}
earcutLinked(outerNode, triangles, dim, minX, minY, size);
return triangles;
}
function linkedList(data, start, end, dim, clockwise) {
var i, last;
if (clockwise === signedArea(data, start, end, dim) > 0) {
for (i = start; i < end; i += dim)
last = insertNode(i, data[i], data[i + 1], last);
} else {
for (i = end - dim; i >= start; i -= dim)
last = insertNode(i, data[i], data[i + 1], last);
}
if (last && equals(last, last.next)) {
removeNode(last);
last = last.next;
}
return last;
}
function filterPoints(start, end) {
if (!start)
return start;
if (!end)
end = start;
var p = start, again;
do {
again = false;
if (!p.steiner && (equals(p, p.next) || area(p.prev, p, p.next) === 0)) {
removeNode(p);
p = end = p.prev;
if (p === p.next)
return null;
again = true;
} else {
p = p.next;
}
} while (again || p !== end);
return end;
}
function earcutLinked(ear, triangles, dim, minX, minY, size, pass) {
if (!ear)
return;
if (!pass && size)
indexCurve(ear, minX, minY, size);
var stop = ear, prev, next;
while (ear.prev !== ear.next) {
prev = ear.prev;
next = ear.next;
if (size ? isEarHashed(ear, minX, minY, size) : isEar(ear)) {
triangles.push(prev.i / dim);
triangles.push(ear.i / dim);
triangles.push(next.i / dim);
removeNode(ear);
ear = next.next;
stop = next.next;
continue;
}
ear = next;
if (ear === stop) {
if (!pass) {
earcutLinked(filterPoints(ear), triangles, dim, minX, minY, size, 1);
} else if (pass === 1) {
ear = cureLocalIntersections(ear, triangles, dim);
earcutLinked(ear, triangles, dim, minX, minY, size, 2);
} else if (pass === 2) {
splitEarcut(ear, triangles, dim, minX, minY, size);
}
break;
}
}
}
function isEar(ear) {
var a = ear.prev, b = ear, c = ear.next;
if (area(a, b, c) >= 0)
return false;
var p = ear.next.next;
while (p !== ear.prev) {
if (pointInTriangle(a.x, a.y, b.x, b.y, c.x, c.y, p.x, p.y) && area(p.prev, p, p.next) >= 0)
return false;
p = p.next;
}
return true;
}
function isEarHashed(ear, minX, minY, size) {
var a = ear.prev, b = ear, c = ear.next;
if (area(a, b, c) >= 0)
return false;
var minTX = a.x < b.x ? a.x < c.x ? a.x : c.x : b.x < c.x ? b.x : c.x, minTY = a.y < b.y ? a.y < c.y ? a.y : c.y : b.y < c.y ? b.y : c.y, maxTX = a.x > b.x ? a.x > c.x ? a.x : c.x : b.x > c.x ? b.x : c.x, maxTY = a.y > b.y ? a.y > c.y ? a.y : c.y : b.y > c.y ? b.y : c.y;
var minZ = zOrder(minTX, minTY, minX, minY, size), maxZ = zOrder(maxTX, maxTY, minX, minY, size);
var p = ear.nextZ;
while (p && p.z <= maxZ) {
if (p !== ear.prev && p !== ear.next && pointInTriangle(a.x, a.y, b.x, b.y, c.x, c.y, p.x, p.y) && area(p.prev, p, p.next) >= 0)
return false;
p = p.nextZ;
}
p = ear.prevZ;
while (p && p.z >= minZ) {
if (p !== ear.prev && p !== ear.next && pointInTriangle(a.x, a.y, b.x, b.y, c.x, c.y, p.x, p.y) && area(p.prev, p, p.next) >= 0)
return false;
p = p.prevZ;
}
return true;
}
function cureLocalIntersections(start, triangles, dim) {
var p = start;
do {
var a = p.prev, b = p.next.next;
if (!equals(a, b) && intersects(a, p, p.next, b) && locallyInside(a, b) && locallyInside(b, a)) {
triangles.push(a.i / dim);
triangles.push(p.i / dim);
triangles.push(b.i / dim);
removeNode(p);
removeNode(p.next);
p = start = b;
}
p = p.next;
} while (p !== start);
return p;
}
function splitEarcut(start, triangles, dim, minX, minY, size) {
var a = start;
do {
var b = a.next.next;
while (b !== a.prev) {
if (a.i !== b.i && isValidDiagonal(a, b)) {
var c = splitPolygon(a, b);
a = filterPoints(a, a.next);
c = filterPoints(c, c.next);
earcutLinked(a, triangles, dim, minX, minY, size);
earcutLinked(c, triangles, dim, minX, minY, size);
return;
}
b = b.next;
}
a = a.next;
} while (a !== start);
}
function eliminateHoles(data, holeIndices, outerNode, dim) {
var queue = [], i, len, start, end, list;
for (i = 0, len = holeIndices.length; i < len; i++) {
start = holeIndices[i] * dim;
end = i < len - 1 ? holeIndices[i + 1] * dim : data.length;
list = linkedList(data, start, end, dim, false);
if (list === list.next)
list.steiner = true;
queue.push(getLeftmost(list));
}
queue.sort(compareX);
for (i = 0; i < queue.length; i++) {
eliminateHole(queue[i], outerNode);
outerNode = filterPoints(outerNode, outerNode.next);
}
return outerNode;
}
function compareX(a, b) {
return a.x - b.x;
}
function eliminateHole(hole, outerNode) {
outerNode = findHoleBridge(hole, outerNode);
if (outerNode) {
var b = splitPolygon(outerNode, hole);
filterPoints(b, b.next);
}
}
function findHoleBridge(hole, outerNode) {
var p = outerNode, hx = hole.x, hy = hole.y, qx = -Infinity, m;
do {
if (hy <= p.y && hy >= p.next.y && p.next.y !== p.y) {
var x = p.x + (hy - p.y) * (p.next.x - p.x) / (p.next.y - p.y);
if (x <= hx && x > qx) {
qx = x;
if (x === hx) {
if (hy === p.y)
return p;
if (hy === p.next.y)
return p.next;
}
m = p.x < p.next.x ? p : p.next;
}
}
p = p.next;
} while (p !== outerNode);
if (!m)
return null;
if (hx === qx)
return m.prev;
var stop = m, mx = m.x, my = m.y, tanMin = Infinity, tan;
p = m.next;
while (p !== stop) {
if (hx >= p.x && p.x >= mx && hx !== p.x && pointInTriangle(hy < my ? hx : qx, hy, mx, my, hy < my ? qx : hx, hy, p.x, p.y)) {
tan = Math.abs(hy - p.y) / (hx - p.x);
if ((tan < tanMin || tan === tanMin && p.x > m.x) && locallyInside(p, hole)) {
m = p;
tanMin = tan;
}
}
p = p.next;
}
return m;
}
function indexCurve(start, minX, minY, size) {
var p = start;
do {
if (p.z === null)
p.z = zOrder(p.x, p.y, minX, minY, size);
p.prevZ = p.prev;
p.nextZ = p.next;
p = p.next;
} while (p !== start);
p.prevZ.nextZ = null;
p.prevZ = null;
sortLinked(p);
}
function sortLinked(list) {
var i, p, q, e, tail, numMerges, pSize, qSize, inSize = 1;
do {
p = list;
list = null;
tail = null;
numMerges = 0;
while (p) {
numMerges++;
q = p;
pSize = 0;
for (i = 0; i < inSize; i++) {
pSize++;
q = q.nextZ;
if (!q)
break;
}
qSize = inSize;
while (pSize > 0 || qSize > 0 && q) {
if (pSize !== 0 && (qSize === 0 || !q || p.z <= q.z)) {
e = p;
p = p.nextZ;
pSize--;
} else {
e = q;
q = q.nextZ;
qSize--;
}
if (tail)
tail.nextZ = e;
else
list = e;
e.prevZ = tail;
tail = e;
}
p = q;
}
tail.nextZ = null;
inSize *= 2;
} while (numMerges > 1);
return list;
}
function zOrder(x, y, minX, minY, size) {
x = 32767 * (x - minX) / size;
y = 32767 * (y - minY) / size;
x = (x | x << 8) & 16711935;
x = (x | x << 4) & 252645135;
x = (x | x << 2) & 858993459;
x = (x | x << 1) & 1431655765;
y = (y | y << 8) & 16711935;
y = (y | y << 4) & 252645135;
y = (y | y << 2) & 858993459;
y = (y | y << 1) & 1431655765;
return x | y << 1;
}
function getLeftmost(start) {
var p = start, leftmost = start;
do {
if (p.x < leftmost.x)
leftmost = p;
p = p.next;
} while (p !== start);
return leftmost;
}
function pointInTriangle(ax, ay, bx, by, cx, cy, px, py) {
return (cx - px) * (ay - py) - (ax - px) * (cy - py) >= 0 && (ax - px) * (by - py) - (bx - px) * (ay - py) >= 0 && (bx - px) * (cy - py) - (cx - px) * (by - py) >= 0;
}
function isValidDiagonal(a, b) {
return a.next.i !== b.i && a.prev.i !== b.i && !intersectsPolygon(a, b) && locallyInside(a, b) && locallyInside(b, a) && middleInside(a, b);
}
function area(p, q, r) {
return (q.y - p.y) * (r.x - q.x) - (q.x - p.x) * (r.y - q.y);
}
function equals(p1, p2) {
return p1.x === p2.x && p1.y === p2.y;
}
function intersects(p1, q1, p2, q2) {
if (equals(p1, q1) && equals(p2, q2) || equals(p1, q2) && equals(p2, q1))
return true;
return area(p1, q1, p2) > 0 !== area(p1, q1, q2) > 0 && area(p2, q2, p1) > 0 !== area(p2, q2, q1) > 0;
}
function intersectsPolygon(a, b) {
var p = a;
do {
if (p.i !== a.i && p.next.i !== a.i && p.i !== b.i && p.next.i !== b.i && intersects(p, p.next, a, b))
return true;
p = p.next;
} while (p !== a);
return false;
}
function locallyInside(a, b) {
return area(a.prev, a, a.next) < 0 ? area(a, b, a.next) >= 0 && area(a, a.prev, b) >= 0 : area(a, b, a.prev) < 0 || area(a, a.next, b) < 0;
}
function middleInside(a, b) {
var p = a, inside = false, px = (a.x + b.x) / 2, py = (a.y + b.y) / 2;
do {
if (p.y > py !== p.next.y > py && p.next.y !== p.y && px < (p.next.x - p.x) * (py - p.y) / (p.next.y - p.y) + p.x)
inside = !inside;
p = p.next;
} while (p !== a);
return inside;
}
function splitPolygon(a, b) {
var a2 = new Node(a.i, a.x, a.y), b2 = new Node(b.i, b.x, b.y), an = a.next, bp = b.prev;
a.next = b;
b.prev = a;
a2.next = an;
an.prev = a2;
b2.next = a2;
a2.prev = b2;
bp.next = b2;
b2.prev = bp;
return b2;
}
function insertNode(i, x, y, last) {
var p = new Node(i, x, y);
if (!last) {
p.prev = p;
p.next = p;
} else {
p.next = last.next;
p.prev = last;
last.next.prev = p;
last.next = p;
}
return p;
}
function removeNode(p) {
p.next.prev = p.prev;
p.prev.next = p.next;
if (p.prevZ)
p.prevZ.nextZ = p.nextZ;
if (p.nextZ)
p.nextZ.prevZ = p.prevZ;
}
function Node(i, x, y) {
this.i = i;
this.x = x;
this.y = y;
this.prev = null;
this.next = null;
this.z = null;
this.prevZ = null;
this.nextZ = null;
this.steiner = false;
}
earcut.deviation = function(data, holeIndices, dim, triangles) {
var hasHoles = holeIndices && holeIndices.length;
var outerLen = hasHoles ? holeIndices[0] * dim : data.length;
var polygonArea = Math.abs(signedArea(data, 0, outerLen, dim));
if (hasHoles) {
for (var i = 0, len = holeIndices.length; i < len; i++) {
var start = holeIndices[i] * dim;
var end = i < len - 1 ? holeIndices[i + 1] * dim : data.length;
polygonArea -= Math.abs(signedArea(data, start, end, dim));
}
}
var trianglesArea = 0;
for (i = 0; i < triangles.length; i += 3) {
var a = triangles[i] * dim;
var b = triangles[i + 1] * dim;
var c = triangles[i + 2] * dim;
trianglesArea += Math.abs((data[a] - data[c]) * (data[b + 1] - data[a + 1]) - (data[a] - data[b]) * (data[c + 1] - data[a + 1]));
}
return polygonArea === 0 && trianglesArea === 0 ? 0 : Math.abs((trianglesArea - polygonArea) / polygonArea);
};
function signedArea(data, start, end, dim) {
var sum = 0;
for (var i = start, j = end - dim; i < end; i += dim) {
sum += (data[j] - data[i]) * (data[i + 1] + data[j + 1]);
j = i;
}
return sum;
}
export { earcut as default };