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#include <mbgl/algorithm/generate_clip_ids_impl.hpp>
#include <mbgl/algorithm/covered_by_children.hpp>
#include <mbgl/util/std.hpp>
#include <list>
#include <vector>
#include <bitset>
#include <cassert>
#include <iostream>
#include <algorithm>
#include <iterator>
namespace mbgl {
namespace algorithm {
ClipIDGenerator::Leaf::Leaf(ClipID& clip_) : clip(clip_) {
}
void ClipIDGenerator::Leaf::add(const CanonicalTileID& p) {
// Ensure that no already present child is a parent of the new p.
for (const auto& child : children) {
if (p.isChildOf(child)) {
return;
}
}
children.emplace(p);
}
bool ClipIDGenerator::Leaf::operator==(const Leaf& other) const {
return children == other.children;
}
std::map<UnwrappedTileID, ClipID> ClipIDGenerator::getStencils() const {
std::map<UnwrappedTileID, ClipID> stencils;
// Merge everything.
for (auto& pair : pool) {
auto& id = pair.first;
auto& leaf = pair.second;
auto res = stencils.emplace(id, leaf.clip);
if (!res.second) {
// Merge with the existing ClipID when there was already an element with the
// same tile ID.
res.first->second |= leaf.clip;
}
}
for (auto it = stencils.begin(); it != stencils.end(); ++it) {
auto& childId = it->first;
auto& childClip = it->second;
// Loop through all preceding stencils, and find all parents.
for (auto parentIt = std::reverse_iterator<decltype(it)>(it);
parentIt != stencils.rend(); ++parentIt) {
auto& parentId = parentIt->first;
if (childId.isChildOf(parentId)) {
// Once we have a parent, we add the bits that this ID hasn't set yet.
const auto& parentClip = parentIt->second;
const auto mask = ~(childClip.mask & parentClip.mask);
childClip.reference |= mask & parentClip.reference;
childClip.mask |= parentClip.mask;
}
}
}
// Remove tiles that are entirely covered by children.
util::erase_if(stencils, [&](const auto& stencil) {
return algorithm::coveredByChildren(stencil.first, stencils);
});
return stencils;
}
} // namespace algorithm
} // namespace mbgl
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