static void
WriteTrace(TextWriter &writer, const ContestTraceVector &trace)
{
JSON::ArrayWriter array(writer);
const ContestTracePoint *previous = NULL;
for (auto i = trace.begin(), end = trace.end(); i != end; ++i) {
array.WriteElement(WritePoint, *i, previous);
previous = &*i;
}
}
void
TrailRenderer::Draw(Canvas &canvas, const WindowProjection &projection,
const ContestTraceVector &trace)
{
points.GrowDiscard(trace.size());
unsigned n = 0;
for (auto i = trace.begin(), end = trace.end(); i != end; ++i)
points[n++] = projection.GeoToScreen(i->get_location());
canvas.DrawPolyline(points.begin(), n);
}
