Externals: Add rangeset.

CMakeLists.txt

@@ -803,6 +803,8 @@ endif()
 
 include_directories(Externals/picojson)
 
+add_subdirectory(Externals/rangeset)
+
 ########################################
 # Pre-build events: Define configuration variables and write SCM info header
 #

Externals/licenses.md

@@ -56,6 +56,8 @@ Dolphin includes or links code of the following third-party software projects:
    [LGPLv2.1+](http://cgit.freedesktop.org/pulseaudio/pulseaudio/tree/LICENSE)
 - [Qt5](http://qt-project.org/):
    [LGPLv3 and other licenses](http://doc.qt.io/qt-5/licensing.html)
+- [rangeset](https://github.com/AdmiralCurtiss/rangeset)
+   [zlib license](https://github.com/AdmiralCurtiss/rangeset/blob/master/LICENSE)
 - [SDL](https://www.libsdl.org/):
    [zlib license](http://hg.libsdl.org/SDL/file/tip/COPYING.txt)
 - [SFML](http://www.sfml-dev.org/):

Externals/rangeset/CMakeLists.txt

@@ -0,0 +1,4 @@
+add_library(RangeSet::RangeSet INTERFACE IMPORTED GLOBAL)
+set_target_properties(RangeSet::RangeSet PROPERTIES
+	INTERFACE_INCLUDE_DIRECTORIES ${CMAKE_CURRENT_LIST_DIR}/include
+)

Externals/rangeset/LICENSE

@@ -0,0 +1,17 @@
+Copyright (c) 2020 Admiral H. Curtiss
+
+This software is provided 'as-is', without any express or implied
+warranty. In no event will the authors be held liable for any damages
+arising from the use of this software.
+
+Permission is granted to anyone to use this software for any purpose,
+including commercial applications, and to alter it and redistribute it
+freely, subject to the following restrictions:
+
+1. The origin of this software must not be misrepresented; you must not
+   claim that you wrote the original software. If you use this software
+   in a product, an acknowledgment in the product documentation would be
+   appreciated but is not required.
+2. Altered source versions must be plainly marked as such, and must not be
+   misrepresented as being the original software.
+3. This notice may not be removed or altered from any source distribution.

Externals/rangeset/include/rangeset/rangeset.h

@@ -0,0 +1,368 @@
+#pragma once
+
+#include <cassert>
+#include <map>
+
+namespace HyoutaUtilities {
+template <typename T> class RangeSet {
+private:
+  using MapT = std::map<T, T>;
+
+public:
+  struct const_iterator {
+  public:
+    const T& from() const {
+      return It->first;
+    }
+
+    const T& to() const {
+      return It->second;
+    }
+
+    const_iterator& operator++() {
+      ++It;
+      return *this;
+    }
+
+    const_iterator operator++(int) {
+      const_iterator old = *this;
+      ++It;
+      return old;
+    }
+
+    const_iterator& operator--() {
+      --It;
+      return *this;
+    }
+
+    const_iterator operator--(int) {
+      const_iterator old = *this;
+      --It;
+      return old;
+    }
+
+    bool operator==(const const_iterator& rhs) const {
+      return this->It == rhs.It;
+    }
+
+    bool operator!=(const const_iterator& rhs) const {
+      return !operator==(rhs);
+    }
+
+  private:
+    typename MapT::const_iterator It;
+    const_iterator(typename MapT::const_iterator it) : It(it) {}
+    friend class RangeSet;
+  };
+
+  void insert(T from, T to) {
+    if (from >= to)
+      return;
+
+    // Start by finding the closest range.
+    // upper_bound() returns the closest range whose starting position
+    // is greater than 'from'.
+    auto bound = Map.upper_bound(from);
+    if (bound == Map.end()) {
+      // There is no range that starts greater than the given one.
+      // This means we have three options:
+      // - 1. No range exists yet, this is the first range.
+      if (Map.empty()) {
+        insert_range(from, to);
+        return;
+      }
+
+      // - 2. The given range does not overlap the last range.
+      --bound;
+      if (from > get_to(bound)) {
+        insert_range(from, to);
+        return;
+      }
+
+      // - 3. The given range does overlap the last range.
+      maybe_expand_to(bound, to);
+      return;
+    }
+
+    if (bound == Map.begin()) {
+      // The given range starts before any of the existing ones.
+      // We must insert this as a new range even if we potentially overlap
+      // an existing one as we can't modify a key in a std::map.
+      auto inserted = insert_range(from, to);
+      merge_from_iterator_to_value(inserted, bound, to);
+      return;
+    }
+
+    auto abound = bound--;
+
+    // 'bound' now points at the first range in the map that
+    // could possibly be affected.
+
+    // If 'bound' overlaps with given range, update bounds object.
+    if (get_to(bound) >= from) {
+      maybe_expand_to(bound, to);
+      auto inserted = bound;
+      ++bound;
+      merge_from_iterator_to_value(inserted, bound, to);
+      return;
+    }
+
+    // 'bound' *doesn't* overlap with given range, check next range.
+
+    // If this range overlaps with given range,
+    if (get_from(abound) <= to) {
+      // insert new range
+      auto inserted = insert_range(from, to >= get_to(abound) ? to : get_to(abound));
+      // and delete overlaps
+      abound = erase_range(abound);
+      merge_from_iterator_to_value(inserted, abound, to);
+      return;
+    }
+
+    // Otherwise, if we come here, then this new range overlaps nothing
+    // and must be inserted as a new range.
+    insert_range(from, to);
+  }
+
+  void erase(T from, T to) {
+    if (from >= to)
+      return;
+
+    // Like insert(), we use upper_bound to find the closest range.
+    auto bound = Map.upper_bound(from);
+    if (bound == Map.end()) {
+      // There is no range that starts greater than the given one.
+      if (Map.empty()) {
+        // nothing to do
+        return;
+      }
+      --bound;
+      // 'bound' now points at the last range.
+      if (from >= get_to(bound)) {
+        // Given range is larger than any range that exists, nothing to do.
+        return;
+      }
+
+      if (to >= get_to(bound)) {
+        if (from == get_from(bound)) {
+          // Given range fully overlaps last range, erase it.
+          erase_range(bound);
+          return;
+        } else {
+          // Given range overlaps end of last range, reduce it.
+          reduce_to(bound, from);
+          return;
+        }
+      }
+
+      if (from == get_from(bound)) {
+        // Given range overlaps begin of last range, reduce it.
+        reduce_from(bound, to);
+        return;
+      } else {
+        // Given range overlaps middle of last range, bisect it.
+        bisect_range(bound, from, to);
+        return;
+      }
+    }
+
+    if (bound == Map.begin()) {
+      // If we found the first range that means 'from' is before any stored range.
+      // This means we can just erase from start until 'to' and be done with it.
+      erase_from_iterator_to_value(bound, to);
+      return;
+    }
+
+    // check previous range
+    auto abound = bound--;
+
+    if (from == get_from(bound)) {
+      // Similarly, if the previous range starts with the given one, just erase until 'to'.
+      erase_from_iterator_to_value(bound, to);
+      return;
+    }
+
+    // If we come here, the given range may or may not overlap part of the current 'bound'
+    // (but never the full range), which means we may need to update the end position of it,
+    // or possibly even split it into two.
+    if (from < get_to(bound)) {
+      if (to < get_to(bound)) {
+        // need to split in two
+        bisect_range(bound, from, to);
+        return;
+      } else {
+        // just update end
+        reduce_to(bound, from);
+      }
+    }
+
+    // and then just erase until 'to'
+    erase_from_iterator_to_value(abound, to);
+    return;
+  }
+
+  const_iterator erase(const_iterator it) {
+    return const_iterator(erase_range(it.It));
+  }
+
+  void clear() {
+    Map.clear();
+  }
+
+  bool contains(T value) const {
+    auto it = Map.upper_bound(value);
+    if (it == Map.begin())
+      return false;
+    --it;
+    return get_from(it) <= value && value < get_to(it);
+  }
+
+  size_t size() const {
+    return Map.size();
+  }
+
+  bool empty() const {
+    return Map.empty();
+  }
+
+  void swap(RangeSet<T>& other) {
+    Map.swap(other.Map);
+  }
+
+  const_iterator begin() const {
+    return const_iterator(Map.begin());
+  }
+
+  const_iterator end() const {
+    return const_iterator(Map.end());
+  }
+
+  const_iterator cbegin() const {
+    return const_iterator(Map.cbegin());
+  }
+
+  const_iterator cend() const {
+    return const_iterator(Map.cend());
+  }
+
+  bool operator==(const RangeSet<T>& other) const {
+    return this->Map == other.Map;
+  }
+
+  bool operator!=(const RangeSet<T>& other) const {
+    return !(*this == other);
+  }
+
+private:
+  // Assumptions that can be made about the data:
+  // - Range are stored in the form [from, to[
+  //   That is, the starting value is inclusive, and the end value is exclusive.
+  // - 'from' is the map key, 'to' is the map value
+  // - 'from' is always smaller than 'to'
+  // - Stored ranges never touch.
+  // - Stored ranges never overlap.
+  MapT Map;
+
+  T get_from(typename MapT::iterator it) const {
+    return it->first;
+  }
+
+  T get_to(typename MapT::iterator it) const {
+    return it->second;
+  }
+
+  T get_from(typename MapT::const_iterator it) const {
+    return it->first;
+  }
+
+  T get_to(typename MapT::const_iterator it) const {
+    return it->second;
+  }
+
+  typename MapT::iterator insert_range(T from, T to) {
+    return Map.emplace(from, to).first;
+  }
+
+  typename MapT::iterator erase_range(typename MapT::iterator it) {
+    return Map.erase(it);
+  }
+
+  typename MapT::const_iterator erase_range(typename MapT::const_iterator it) {
+    return Map.erase(it);
+  }
+
+  void bisect_range(typename MapT::iterator it, T from, T to) {
+    assert(get_from(it) < from);
+    assert(get_from(it) < to);
+    assert(get_to(it) > from);
+    assert(get_to(it) > to);
+    assert(from < to);
+    T itto = get_to(it);
+    reduce_to(it, from);
+    insert_range(to, itto);
+  }
+
+  typename MapT::iterator reduce_from(typename MapT::iterator it, T from) {
+    assert(get_from(it) < from);
+    T itto = get_to(it);
+    erase_range(it);
+    return insert_range(from, itto);
+  }
+
+  void maybe_expand_to(typename MapT::iterator it, T to) {
+    if (to <= get_to(it))
+      return;
+
+    expand_to(it, to);
+  }
+
+  void expand_to(typename MapT::iterator it, T to) {
+    assert(get_to(it) < to);
+    it->second = to;
+  }
+
+  void reduce_to(typename MapT::iterator it, T to) {
+    assert(get_to(it) > to);
+    it->second = to;
+  }
+
+  void merge_from_iterator_to_value(typename MapT::iterator inserted, typename MapT::iterator bound, T to) {
+    // Erase all ranges that overlap the inserted while updating the upper end.
+    while (bound != Map.end() && get_from(bound) <= to) {
+      maybe_expand_to(inserted, get_to(bound));
+      bound = erase_range(bound);
+    }
+  }
+
+  void erase_from_iterator_to_value(typename MapT::iterator bound, T to) {
+    // Assumption: Given bound starts at or after the 'from' value of the range to erase.
+    while (true) {
+      // Given range starts before stored range.
+      if (to <= get_from(bound)) {
+        // Range ends before this range too, nothing to do.
+        return;
+      }
+
+      if (to < get_to(bound)) {
+        // Range ends in the middle of current range, reduce current.
+        reduce_from(bound, to);
+        return;
+      }
+
+      if (to == get_to(bound)) {
+        // Range ends exactly with current range, erase current.
+        erase_range(bound);
+        return;
+      }
+
+      // Range ends later than current range.
+      // First erase current, then loop to check the range(s) after this one too.
+      bound = erase_range(bound);
+      if (bound == Map.end()) {
+        // Unless that was the last range, in which case there's nothing else to do.
+        return;
+      }
+    }
+  }
+};
+} // namespace HyoutaUtilities

Externals/rangeset/include/rangeset/rangesizeset.h

@@ -0,0 +1,541 @@
+#pragma once
+
+#include <cassert>
+#include <map>
+#include <type_traits>
+
+namespace HyoutaUtilities {
+// Like RangeSet, but additionally stores a map of the ranges sorted by their size, for quickly finding the largest or
+// smallest range.
+template <typename T> class RangeSizeSet {
+private:
+  // Key type used in the by-size multimap. Should be a type big enough to hold all possible distances between
+  // possible 'from' and 'to'.
+  // I'd actually love to just do
+  // using SizeT = typename std::conditional<std::is_pointer_v<T>,
+  //     std::size_t, typename std::make_unsigned<T>::type>::type;
+  // but that's apparently not possible due to the std::make_unsigned<T>::type not existing for pointer types
+  // so we'll work around this...
+  template <typename U, bool IsPointer> struct GetSizeType { using S = typename std::make_unsigned<U>::type; };
+  template <typename U> struct GetSizeType<U, true> { using S = std::size_t; };
+
+public:
+  using SizeT = typename GetSizeType<T, std::is_pointer_v<T>>::S;
+
+private:
+  // Value type stored in the regular range map.
+  struct Value {
+    // End point of the range.
+    T To;
+
+    // Pointer to the same range in the by-size multimap.
+    typename std::multimap<SizeT, typename std::map<T, Value>::iterator, std::greater<SizeT>>::iterator SizeIt;
+
+    Value(T to) : To(to) {}
+
+    bool operator==(const Value& other) const {
+      return this->To == other.To;
+    }
+
+    bool operator!=(const Value& other) const {
+      return !operator==(other);
+    }
+  };
+
+  using MapT = std::map<T, Value>;
+  using SizeMapT = std::multimap<SizeT, typename MapT::iterator, std::greater<SizeT>>;
+
+public:
+  struct by_size_const_iterator;
+
+  struct const_iterator {
+  public:
+    const T& from() const {
+      return It->first;
+    }
+
+    const T& to() const {
+      return It->second.To;
+    }
+
+    const_iterator& operator++() {
+      ++It;
+      return *this;
+    }
+
+    const_iterator operator++(int) {
+      const_iterator old = *this;
+      ++It;
+      return old;
+    }
+
+    const_iterator& operator--() {
+      --It;
+      return *this;
+    }
+
+    const_iterator operator--(int) {
+      const_iterator old = *this;
+      --It;
+      return old;
+    }
+
+    bool operator==(const const_iterator& rhs) const {
+      return this->It == rhs.It;
+    }
+
+    bool operator!=(const const_iterator& rhs) const {
+      return !operator==(rhs);
+    }
+
+    by_size_const_iterator to_size_iterator() {
+      return by_size_const_iterator(It->second.SizeIt);
+    }
+
+  private:
+    typename MapT::const_iterator It;
+    const_iterator(typename MapT::const_iterator it) : It(it) {}
+    friend class RangeSizeSet;
+  };
+
+  struct by_size_const_iterator {
+  public:
+    const T& from() const {
+      return It->second->first;
+    }
+
+    const T& to() const {
+      return It->second->second.To;
+    }
+
+    by_size_const_iterator& operator++() {
+      ++It;
+      return *this;
+    }
+
+    by_size_const_iterator operator++(int) {
+      by_size_const_iterator old = *this;
+      ++It;
+      return old;
+    }
+
+    by_size_const_iterator& operator--() {
+      --It;
+      return *this;
+    }
+
+    by_size_const_iterator operator--(int) {
+      by_size_const_iterator old = *this;
+      --It;
+      return old;
+    }
+
+    bool operator==(const by_size_const_iterator& rhs) const {
+      return this->It == rhs.It;
+    }
+
+    bool operator!=(const by_size_const_iterator& rhs) const {
+      return !operator==(rhs);
+    }
+
+    const_iterator to_range_iterator() {
+      return const_iterator(It->second);
+    }
+
+  private:
+    typename SizeMapT::const_iterator It;
+    by_size_const_iterator(typename SizeMapT::const_iterator it) : It(it) {}
+    friend class RangeSizeSet;
+  };
+
+  // We store iterators internally, so disallow copying.
+  RangeSizeSet() = default;
+  RangeSizeSet(const RangeSizeSet<T>&) = delete;
+  RangeSizeSet(RangeSizeSet<T>&&) = default;
+  RangeSizeSet<T>& operator=(const RangeSizeSet<T>&) = delete;
+  RangeSizeSet<T>& operator=(RangeSizeSet<T>&&) = default;
+
+  void insert(T from, T to) {
+    if (from >= to)
+      return;
+
+    // Start by finding the closest range.
+    // upper_bound() returns the closest range whose starting position
+    // is greater than 'from'.
+    auto bound = Map.upper_bound(from);
+    if (bound == Map.end()) {
+      // There is no range that starts greater than the given one.
+      // This means we have three options:
+      // - 1. No range exists yet, this is the first range.
+      if (Map.empty()) {
+        insert_range(from, to);
+        return;
+      }
+
+      // - 2. The given range does not overlap the last range.
+      --bound;
+      if (from > get_to(bound)) {
+        insert_range(from, to);
+        return;
+      }
+
+      // - 3. The given range does overlap the last range.
+      maybe_expand_to(bound, to);
+      return;
+    }
+
+    if (bound == Map.begin()) {
+      // The given range starts before any of the existing ones.
+      // We must insert this as a new range even if we potentially overlap
+      // an existing one as we can't modify a key in a std::map.
+      auto inserted = insert_range(from, to);
+      merge_from_iterator_to_value(inserted, bound, to);
+      return;
+    }
+
+    auto abound = bound--;
+
+    // 'bound' now points at the first range in the map that
+    // could possibly be affected.
+
+    // If 'bound' overlaps with given range, update bounds object.
+    if (get_to(bound) >= from) {
+      maybe_expand_to(bound, to);
+      auto inserted = bound;
+      ++bound;
+      merge_from_iterator_to_value(inserted, bound, to);
+      return;
+    }
+
+    // 'bound' *doesn't* overlap with given range, check next range.
+
+    // If this range overlaps with given range,
+    if (get_from(abound) <= to) {
+      // insert new range
+      auto inserted = insert_range(from, to >= get_to(abound) ? to : get_to(abound));
+      // and delete overlaps
+      abound = erase_range(abound);
+      merge_from_iterator_to_value(inserted, abound, to);
+      return;
+    }
+
+    // Otherwise, if we come here, then this new range overlaps nothing
+    // and must be inserted as a new range.
+    insert_range(from, to);
+  }
+
+  void erase(T from, T to) {
+    if (from >= to)
+      return;
+
+    // Like insert(), we use upper_bound to find the closest range.
+    auto bound = Map.upper_bound(from);
+    if (bound == Map.end()) {
+      // There is no range that starts greater than the given one.
+      if (Map.empty()) {
+        // nothing to do
+        return;
+      }
+      --bound;
+      // 'bound' now points at the last range.
+      if (from >= get_to(bound)) {
+        // Given range is larger than any range that exists, nothing to do.
+        return;
+      }
+
+      if (to >= get_to(bound)) {
+        if (from == get_from(bound)) {
+          // Given range fully overlaps last range, erase it.
+          erase_range(bound);
+          return;
+        } else {
+          // Given range overlaps end of last range, reduce it.
+          reduce_to(bound, from);
+          return;
+        }
+      }
+
+      if (from == get_from(bound)) {
+        // Given range overlaps begin of last range, reduce it.
+        reduce_from(bound, to);
+        return;
+      } else {
+        // Given range overlaps middle of last range, bisect it.
+        bisect_range(bound, from, to);
+        return;
+      }
+    }
+
+    if (bound == Map.begin()) {
+      // If we found the first range that means 'from' is before any stored range.
+      // This means we can just erase from start until 'to' and be done with it.
+      erase_from_iterator_to_value(bound, to);
+      return;
+    }
+
+    // check previous range
+    auto abound = bound--;
+
+    if (from == get_from(bound)) {
+      // Similarly, if the previous range starts with the given one, just erase until 'to'.
+      erase_from_iterator_to_value(bound, to);
+      return;
+    }
+
+    // If we come here, the given range may or may not overlap part of the current 'bound'
+    // (but never the full range), which means we may need to update the end position of it,
+    // or possibly even split it into two.
+    if (from < get_to(bound)) {
+      if (to < get_to(bound)) {
+        // need to split in two
+        bisect_range(bound, from, to);
+        return;
+      } else {
+        // just update end
+        reduce_to(bound, from);
+      }
+    }
+
+    // and then just erase until 'to'
+    erase_from_iterator_to_value(abound, to);
+    return;
+  }
+
+  const_iterator erase(const_iterator it) {
+    return const_iterator(erase_range(it.It));
+  }
+
+  by_size_const_iterator erase(by_size_const_iterator it) {
+    return by_size_const_iterator(erase_range_by_size(it.It));
+  }
+
+  void clear() {
+    Map.clear();
+    Sizes.clear();
+  }
+
+  bool contains(T value) const {
+    auto it = Map.upper_bound(value);
+    if (it == Map.begin())
+      return false;
+    --it;
+    return get_from(it) <= value && value < get_to(it);
+  }
+
+  size_t size() const {
+    return Map.size();
+  }
+
+  bool empty() const {
+    return Map.empty();
+  }
+
+  size_t by_size_count(const SizeT& key) const {
+    return Sizes.count(key);
+  }
+
+  by_size_const_iterator by_size_find(const SizeT& key) const {
+    return Sizes.find(key);
+  }
+
+  std::pair<by_size_const_iterator, by_size_const_iterator> by_size_equal_range(const SizeT& key) const {
+    auto p = Sizes.equal_range(key);
+    return std::pair<by_size_const_iterator, by_size_const_iterator>(by_size_const_iterator(p.first),
+                                                                     by_size_const_iterator(p.second));
+  }
+
+  by_size_const_iterator by_size_lower_bound(const SizeT& key) const {
+    return Sizes.lower_bound(key);
+  }
+
+  by_size_const_iterator by_size_upper_bound(const SizeT& key) const {
+    return Sizes.upper_bound(key);
+  }
+
+  void swap(RangeSizeSet<T>& other) {
+    Map.swap(other.Map);
+    Sizes.swap(other.Sizes);
+  }
+
+  const_iterator begin() const {
+    return const_iterator(Map.begin());
+  }
+
+  const_iterator end() const {
+    return const_iterator(Map.end());
+  }
+
+  const_iterator cbegin() const {
+    return const_iterator(Map.cbegin());
+  }
+
+  const_iterator cend() const {
+    return const_iterator(Map.cend());
+  }
+
+  by_size_const_iterator by_size_begin() const {
+    return by_size_const_iterator(Sizes.begin());
+  }
+
+  by_size_const_iterator by_size_end() const {
+    return by_size_const_iterator(Sizes.end());
+  }
+
+  by_size_const_iterator by_size_cbegin() const {
+    return by_size_const_iterator(Sizes.cbegin());
+  }
+
+  by_size_const_iterator by_size_cend() const {
+    return by_size_const_iterator(Sizes.cend());
+  }
+
+  bool operator==(const RangeSizeSet<T>& other) const {
+    return this->Map == other.Map;
+  }
+
+  bool operator!=(const RangeSizeSet<T>& other) const {
+    return !(*this == other);
+  }
+
+private:
+  static SizeT calc_size(T from, T to) {
+    if constexpr (std::is_pointer_v<T>) {
+      // For pointers we don't want pointer arithmetic here, else void* breaks.
+      static_assert(sizeof(T) <= sizeof(SizeT));
+      return reinterpret_cast<SizeT>(to) - reinterpret_cast<SizeT>(from);
+    } else {
+      return static_cast<SizeT>(to - from);
+    }
+  }
+
+  // Assumptions that can be made about the data:
+  // - Range are stored in the form [from, to[
+  //   That is, the starting value is inclusive, and the end value is exclusive.
+  // - 'from' is the map key, 'to' is the map value
+  // - 'from' is always smaller than 'to'
+  // - Stored ranges never touch.
+  // - Stored ranges never overlap.
+  MapT Map;
+
+  // The by-size multimap.
+  // Key is the size of the range.
+  // Value is a pointer to the range in the regular range map.
+  // We use std::greater so that Sizes.begin() gives us the largest range.
+  SizeMapT Sizes;
+
+  T get_from(typename MapT::iterator it) const {
+    return it->first;
+  }
+
+  T get_to(typename MapT::iterator it) const {
+    return it->second.To;
+  }
+
+  T get_from(typename MapT::const_iterator it) const {
+    return it->first;
+  }
+
+  T get_to(typename MapT::const_iterator it) const {
+    return it->second.To;
+  }
+
+  typename MapT::iterator insert_range(T from, T to) {
+    auto m = Map.emplace(from, to).first;
+    m->second.SizeIt = Sizes.emplace(calc_size(from, to), m);
+    return m;
+  }
+
+  typename MapT::iterator erase_range(typename MapT::iterator it) {
+    Sizes.erase(it->second.SizeIt);
+    return Map.erase(it);
+  }
+
+  typename MapT::const_iterator erase_range(typename MapT::const_iterator it) {
+    Sizes.erase(it->second.SizeIt);
+    return Map.erase(it);
+  }
+
+  typename SizeMapT::const_iterator erase_range_by_size(typename SizeMapT::const_iterator it) {
+    Map.erase(it->second);
+    return Sizes.erase(it);
+  }
+
+  void bisect_range(typename MapT::iterator it, T from, T to) {
+    assert(get_from(it) < from);
+    assert(get_from(it) < to);
+    assert(get_to(it) > from);
+    assert(get_to(it) > to);
+    assert(from < to);
+    T itto = get_to(it);
+    reduce_to(it, from);
+    insert_range(to, itto);
+  }
+
+  typename MapT::iterator reduce_from(typename MapT::iterator it, T from) {
+    assert(get_from(it) < from);
+    T itto = get_to(it);
+    erase_range(it);
+    return insert_range(from, itto);
+  }
+
+  void maybe_expand_to(typename MapT::iterator it, T to) {
+    if (to <= get_to(it))
+      return;
+
+    expand_to(it, to);
+  }
+
+  void expand_to(typename MapT::iterator it, T to) {
+    assert(get_to(it) < to);
+    it->second.To = to;
+    Sizes.erase(it->second.SizeIt);
+    it->second.SizeIt = Sizes.emplace(calc_size(get_from(it), to), it);
+  }
+
+  void reduce_to(typename MapT::iterator it, T to) {
+    assert(get_to(it) > to);
+    it->second.To = to;
+    Sizes.erase(it->second.SizeIt);
+    it->second.SizeIt = Sizes.emplace(calc_size(get_from(it), to), it);
+  }
+
+  void merge_from_iterator_to_value(typename MapT::iterator inserted, typename MapT::iterator bound, T to) {
+    // Erase all ranges that overlap the inserted while updating the upper end.
+    while (bound != Map.end() && get_from(bound) <= to) {
+      maybe_expand_to(inserted, get_to(bound));
+      bound = erase_range(bound);
+    }
+  }
+
+  void erase_from_iterator_to_value(typename MapT::iterator bound, T to) {
+    // Assumption: Given bound starts at or after the 'from' value of the range to erase.
+    while (true) {
+      // Given range starts before stored range.
+      if (to <= get_from(bound)) {
+        // Range ends before this range too, nothing to do.
+        return;
+      }
+
+      if (to < get_to(bound)) {
+        // Range ends in the middle of current range, reduce current.
+        reduce_from(bound, to);
+        return;
+      }
+
+      if (to == get_to(bound)) {
+        // Range ends exactly with current range, erase current.
+        erase_range(bound);
+        return;
+      }
+
+      // Range ends later than current range.
+      // First erase current, then loop to check the range(s) after this one too.
+      bound = erase_range(bound);
+      if (bound == Map.end()) {
+        // Unless that was the last range, in which case there's nothing else to do.
+        return;
+      }
+    }
+  }
+};
+} // namespace HyoutaUtilities

Source/Core/Core/CMakeLists.txt

@@ -554,6 +554,7 @@ PUBLIC
   inputcommon
   ${MBEDTLS_LIBRARIES}
   pugixml
+  RangeSet::RangeSet
   sfml-network
   sfml-system
   videonull

Source/VSProps/Base.props

@@ -45,6 +45,7 @@
       <AdditionalIncludeDirectories>$(ExternalsDir)OpenAL\include;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <AdditionalIncludeDirectories>$(ExternalsDir)picojson;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <AdditionalIncludeDirectories>$(ExternalsDir)pugixml;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <AdditionalIncludeDirectories>$(ExternalsDir)rangeset\include;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <AdditionalIncludeDirectories>$(ExternalsDir)SFML\include;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <AdditionalIncludeDirectories>$(ExternalsDir)soundtouch;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <AdditionalIncludeDirectories>$(ExternalsDir)Vulkan\include;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>