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diff --git a/third_party/jpeg-xl/lib/jxl/base/rect.h b/third_party/jpeg-xl/lib/jxl/base/rect.h
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+++ b/third_party/jpeg-xl/lib/jxl/base/rect.h
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+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#ifndef LIB_JXL_BASE_RECT_H_
+#define LIB_JXL_BASE_RECT_H_
+
+#include <algorithm>
+#include <cstddef>
+#include <cstdint>
+#include <cstring>
+#include <sstream>
+#include <string>
+#include <utility>  // std::move
+
+#include "lib/jxl/base/compiler_specific.h"
+#include "lib/jxl/base/status.h"
+
+namespace jxl {
+
+// Rectangular region in image(s). Factoring this out of Image instead of
+// shifting the pointer by x0/y0 allows this to apply to multiple images with
+// different resolutions (e.g. color transform and quantization field).
+// Can compare using SameSize(rect1, rect2).
+template <typename T>
+class RectT {
+ public:
+  // Most windows are xsize_max * ysize_max, except those on the borders where
+  // begin + size_max > end.
+  constexpr RectT(T xbegin, T ybegin, size_t xsize_max, size_t ysize_max,
+                  T xend, T yend)
+      : x0_(xbegin),
+        y0_(ybegin),
+        xsize_(ClampedSize(xbegin, xsize_max, xend)),
+        ysize_(ClampedSize(ybegin, ysize_max, yend)) {}
+
+  // Construct with origin and known size (typically from another Rect).
+  constexpr RectT(T xbegin, T ybegin, size_t xsize, size_t ysize)
+      : x0_(xbegin), y0_(ybegin), xsize_(xsize), ysize_(ysize) {}
+
+  // Construct a rect that covers a whole image/plane/ImageBundle etc.
+  template <typename ImageT>
+  explicit RectT(const ImageT& image)
+      : RectT(0, 0, image.xsize(), image.ysize()) {}
+
+  RectT() : RectT(0, 0, 0, 0) {}
+
+  RectT(const RectT&) = default;
+  RectT& operator=(const RectT&) = default;
+
+  // Construct a subrect that resides in an image/plane/ImageBundle etc.
+  template <typename ImageT>
+  RectT Crop(const ImageT& image) const {
+    return Intersection(RectT(image));
+  }
+
+  // Construct a subrect that resides in the [0, ysize) x [0, xsize) region of
+  // the current rect.
+  RectT Crop(size_t area_xsize, size_t area_ysize) const {
+    return Intersection(RectT(0, 0, area_xsize, area_ysize));
+  }
+
+  // Returns a rect that only contains `num` lines with offset `y` from `y0()`.
+  RectT Lines(size_t y, size_t num) const {
+    JXL_DASSERT(y + num <= ysize_);
+    return RectT(x0_, y0_ + y, xsize_, num);
+  }
+
+  RectT Line(size_t y) const { return Lines(y, 1); }
+
+  JXL_MUST_USE_RESULT RectT Intersection(const RectT& other) const {
+    return RectT(std::max(x0_, other.x0_), std::max(y0_, other.y0_), xsize_,
+                 ysize_, std::min(x1(), other.x1()),
+                 std::min(y1(), other.y1()));
+  }
+
+  JXL_MUST_USE_RESULT RectT Translate(int64_t x_offset,
+                                      int64_t y_offset) const {
+    return RectT(x0_ + x_offset, y0_ + y_offset, xsize_, ysize_);
+  }
+
+  template <template <class> class P, typename V>
+  V* Row(P<V>* image, size_t y) const {
+    JXL_DASSERT(y + y0_ >= 0);
+    return image->Row(y + y0_) + x0_;
+  }
+
+  template <template <class> class P, typename V>
+  const V* Row(const P<V>* image, size_t y) const {
+    JXL_DASSERT(y + y0_ >= 0);
+    return image->Row(y + y0_) + x0_;
+  }
+
+  template <template <class> class MP, typename V>
+  V* PlaneRow(MP<V>* image, const size_t c, size_t y) const {
+    JXL_DASSERT(y + y0_ >= 0);
+    return image->PlaneRow(c, y + y0_) + x0_;
+  }
+
+  template <template <class> class P, typename V>
+  const V* ConstRow(const P<V>& image, size_t y) const {
+    JXL_DASSERT(y + y0_ >= 0);
+    return image.ConstRow(y + y0_) + x0_;
+  }
+
+  template <template <class> class MP, typename V>
+  const V* ConstPlaneRow(const MP<V>& image, size_t c, size_t y) const {
+    JXL_DASSERT(y + y0_ >= 0);
+    return image.ConstPlaneRow(c, y + y0_) + x0_;
+  }
+
+  bool IsInside(const RectT& other) const {
+    return x0_ >= other.x0() && x1() <= other.x1() && y0_ >= other.y0() &&
+           y1() <= other.y1();
+  }
+
+  // Returns true if this Rect fully resides in the given image. ImageT could be
+  // Plane<T> or Image3<T>; however if ImageT is Rect, results are nonsensical.
+  template <class ImageT>
+  bool IsInside(const ImageT& image) const {
+    return IsInside(RectT(image));
+  }
+
+  T x0() const { return x0_; }
+  T y0() const { return y0_; }
+  size_t xsize() const { return xsize_; }
+  size_t ysize() const { return ysize_; }
+  T x1() const { return x0_ + xsize_; }
+  T y1() const { return y0_ + ysize_; }
+
+  RectT<T> ShiftLeft(size_t shiftx, size_t shifty) const {
+    return RectT<T>(x0_ * (1 << shiftx), y0_ * (1 << shifty), xsize_ << shiftx,
+                    ysize_ << shifty);
+  }
+  RectT<T> ShiftLeft(size_t shift) const { return ShiftLeft(shift, shift); }
+
+  // Requires x0(), y0() to be multiples of 1<<shiftx, 1<<shifty.
+  RectT<T> CeilShiftRight(size_t shiftx, size_t shifty) const {
+    JXL_ASSERT(x0_ % (1 << shiftx) == 0);
+    JXL_ASSERT(y0_ % (1 << shifty) == 0);
+    return RectT<T>(x0_ / (1 << shiftx), y0_ / (1 << shifty),
+                    DivCeil(xsize_, T{1} << shiftx),
+                    DivCeil(ysize_, T{1} << shifty));
+  }
+  RectT<T> CeilShiftRight(std::pair<size_t, size_t> shift) const {
+    return CeilShiftRight(shift.first, shift.second);
+  }
+  RectT<T> CeilShiftRight(size_t shift) const {
+    return CeilShiftRight(shift, shift);
+  }
+
+  RectT<T> Extend(T border, RectT<T> parent) const {
+    T new_x0 = x0() > parent.x0() + border ? x0() - border : parent.x0();
+    T new_y0 = y0() > parent.y0() + border ? y0() - border : parent.y0();
+    T new_x1 = x1() + border > parent.x1() ? parent.x1() : x1() + border;
+    T new_y1 = y1() + border > parent.y1() ? parent.y1() : y1() + border;
+    return RectT<T>(new_x0, new_y0, new_x1 - new_x0, new_y1 - new_y0);
+  }
+
+  template <typename U>
+  RectT<U> As() const {
+    return RectT<U>(static_cast<U>(x0_), static_cast<U>(y0_),
+                    static_cast<U>(xsize_), static_cast<U>(ysize_));
+  }
+
+ private:
+  // Returns size_max, or whatever is left in [begin, end).
+  static constexpr size_t ClampedSize(T begin, size_t size_max, T end) {
+    return (static_cast<T>(begin + size_max) <= end)
+               ? size_max
+               : (end > begin ? end - begin : 0);
+  }
+
+  T x0_;
+  T y0_;
+
+  size_t xsize_;
+  size_t ysize_;
+};
+
+template <typename T>
+std::string Description(RectT<T> r) {
+  std::ostringstream os;
+  os << "[" << r.x0() << ".." << r.x1() << ")x"
+     << "[" << r.y0() << ".." << r.y1() << ")";
+  return os.str();
+}
+
+using Rect = RectT<size_t>;
+
+}  // namespace jxl
+
+#endif  // LIB_JXL_BASE_RECT_H_