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binary.js
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binary.js
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export default function(parent, x0, y0, x1, y1) {
var nodes = parent.children,
i, n = nodes.length,
sum, sums = new Array(n + 1);
for (sums[0] = sum = i = 0; i < n; ++i) {
sums[i + 1] = sum += nodes[i].value;
}
partition(0, n, parent.value, x0, y0, x1, y1);
function partition(i, j, value, x0, y0, x1, y1) {
if (i >= j - 1) {
var node = nodes[i];
node.x0 = x0, node.y0 = y0;
node.x1 = x1, node.y1 = y1;
return;
}
var valueOffset = sums[i],
valueTarget = (value / 2) + valueOffset,
k = i + 1,
hi = j - 1;
while (k < hi) {
var mid = k + hi >>> 1;
if (sums[mid] < valueTarget) k = mid + 1;
else hi = mid;
}
if ((valueTarget - sums[k - 1]) < (sums[k] - valueTarget) && i + 1 < k) --k;
var valueLeft = sums[k] - valueOffset,
valueRight = value - valueLeft;
if ((x1 - x0) > (y1 - y0)) {
var xk = (x0 * valueRight + x1 * valueLeft) / value;
partition(i, k, valueLeft, x0, y0, xk, y1);
partition(k, j, valueRight, xk, y0, x1, y1);
} else {
var yk = (y0 * valueRight + y1 * valueLeft) / value;
partition(i, k, valueLeft, x0, y0, x1, yk);
partition(k, j, valueRight, x0, yk, x1, y1);
}
}
}