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MapLibreParticleLab/src/mbgl/renderer/style_diff.cpp

79 lines
2.5 KiB
C++

#include <mbgl/renderer/style_diff.hpp>
#include <mbgl/style/layer_impl.hpp>
#include <mbgl/util/immutable.hpp>
#include <mbgl/util/variant.hpp>
#include <mbgl/util/longest_common_subsequence.hpp>
namespace mbgl {
template <class T, class Eq>
StyleDifference<T> diff(const Immutable<std::vector<T>>& a,
const Immutable<std::vector<T>>& b,
const Eq& eq) {
StyleDifference<T> result;
if (a == b) {
return result;
}
std::vector<T> lcs;
longest_common_subsequence(a->begin(), a->end(), b->begin(), b->end(), std::back_inserter(lcs), eq);
auto aIt = a->begin();
auto bIt = b->begin();
auto lIt = lcs.begin();
while (aIt != a->end() || bIt != b->end()) {
if (aIt != a->end() && (lIt == lcs.end() || !eq(*lIt, *aIt))) {
result.removed.emplace((*aIt)->id, *aIt);
aIt++;
} else if (bIt != b->end() && (lIt == lcs.end() || !eq(*lIt, *bIt))) {
result.added.emplace((*bIt)->id, *bIt);
bIt++;
} else {
if (aIt->get() != bIt->get()) {
result.changed.emplace((*bIt)->id, StyleChange<T> { *aIt, *bIt });
}
aIt++;
bIt++;
lIt++;
}
}
return result;
}
ImageDifference diffImages(const Immutable<std::vector<ImmutableImage>>& a,
const Immutable<std::vector<ImmutableImage>>& b) {
return diff(a, b, [] (const ImmutableImage& lhs, const ImmutableImage& rhs) {
return lhs->id == rhs->id;
});
}
SourceDifference diffSources(const Immutable<std::vector<ImmutableSource>>& a,
const Immutable<std::vector<ImmutableSource>>& b) {
return diff(a, b, [] (const ImmutableSource& lhs, const ImmutableSource& rhs) {
return std::tie(lhs->id, lhs->type)
== std::tie(rhs->id, rhs->type);
});
}
LayerDifference diffLayers(const Immutable<std::vector<ImmutableLayer>>& a,
const Immutable<std::vector<ImmutableLayer>>& b) {
return diff(a, b, [] (const ImmutableLayer& lhs, const ImmutableLayer& rhs) {
return (lhs->id == rhs->id) && (lhs->getTypeInfo() == rhs->getTypeInfo());
});
}
bool hasLayoutDifference(const LayerDifference& layerDiff, const std::string& layerID) {
if (layerDiff.added.count(layerID))
return true;
const auto it = layerDiff.changed.find(layerID);
if (it == layerDiff.changed.end())
return false;
return it->second.before->hasLayoutDifference(*it->second.after);
}
} // namespace mbgl