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Use a faster segment lookup (in case there are many segments)

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+ remove the "overflow safe" index computations - we shall really not exceed
2^30 track points in a single track...
This commit is contained in:
Martin Tůma 2021-11-07 12:11:53 +01:00
parent 933ecffe93
commit 7ddadf9811
1 changed files with 21 additions and 7 deletions
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28
src/GUI/graphitem.cpp
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@ -78,11 +78,25 @@ void GraphItem::setWidth(int width)
const GraphSegment *GraphItem::segment(qreal x, GraphType type) const const GraphSegment *GraphItem::segment(qreal x, GraphType type) const
{ {
for (int i = 0; i < _graph.size(); i++) int low = 0;
if (x <= _graph.at(i).last().x(type)) int high = _graph.size() - 1;
return &(_graph.at(i)); int mid = 0;
return 0; while (low <= high) {
mid = (high + low) / 2;
const GraphPoint &p = _graph.at(mid).last();
if (p.x(_type) > x)
high = mid - 1;
else if (p.x(_type) < x)
low = mid + 1;
else
return &(_graph.at(mid));
}
if (_graph.at(mid).last().x(type) < x)
return (mid == _graph.size() - 1) ? 0 : &(_graph.at(mid+1));
else
return &(_graph.at(mid));
} }
qreal GraphItem::yAtX(qreal x) const qreal GraphItem::yAtX(qreal x) const
@ -99,7 +113,7 @@ qreal GraphItem::yAtX(qreal x) const
return NAN; return NAN;
while (low <= high) { while (low <= high) {
mid = low + ((high - low) / 2); mid = (high + low) / 2;
const GraphPoint &p = seg->at(mid); const GraphPoint &p = seg->at(mid);
if (p.x(_type) > x) if (p.x(_type) > x)
high = mid - 1; high = mid - 1;
@ -137,7 +151,7 @@ qreal GraphItem::distanceAtTime(qreal time) const
return NAN; return NAN;
while (low <= high) { while (low <= high) {
mid = low + ((high - low) / 2); mid = (high + low) / 2;
const GraphPoint &p = seg->at(mid); const GraphPoint &p = seg->at(mid);
if (p.t() > time) if (p.t() > time)
high = mid - 1; high = mid - 1;
@ -175,7 +189,7 @@ qreal GraphItem::timeAtDistance(qreal distance) const
return NAN; return NAN;
while (low <= high) { while (low <= high) {
mid = low + ((high - low) / 2); mid = (high + low) / 2;
const GraphPoint &p = seg->at(mid); const GraphPoint &p = seg->at(mid);
if (p.s() > distance) if (p.s() > distance)
high = mid - 1; high = mid - 1;