/// Fills \a buffer with the ends points for the lines that connect
/// technologies in \a techs
void FillArcBuffer(GG::GL2DVertexBuffer& buffer, const std::set<std::string>& techs) {
for (std::set<std::string>::const_iterator it = techs.begin(); it != techs.end(); ++it) {
const std::vector<TechTreeLayout::Edge*> edges = m_layout.GetOutEdges(*it);
//prerequisite edge
for (std::vector<TechTreeLayout::Edge*>::const_iterator edge = edges.begin();
edge != edges.end(); edge++)
{
std::vector<std::pair<double, double> > points;
const std::string& from = (*edge)->GetTechFrom();
const std::string& to = (*edge)->GetTechTo();
// Do not show lines leading to techs
// we are not showing
if (techs.find(to) == techs.end()) {
continue;
}
// Remember what edges we are showing so
// we can eventually highlight them
m_edges_to_show[from].insert(to);
if (!GetTech(from) || !GetTech(to)) {
ErrorLogger() << "TechTreeArcs::FillArcBuffer missing arc endpoint tech " << from << "->" << to;
continue;
}
(*edge)->ReadPoints(points);
// To be able to draw all the lines in one call,
// we will draw the with GL_LINES, which means all
// vertices except the first and the last must occur twice
for (unsigned i = 0; i < points.size() - 1; ++i){
buffer.store(points[i].first, points[i].second);
buffer.store(points[i+1].first, points[i+1].second);
}
}
}
buffer.createServerBuffer();
}
