--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/tesseract/src/ccstruct/stepblob.h	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,136 @@
+/**********************************************************************
+ * File:        stepblob.h  (Formerly cblob.h)
+ * Description: Code for C_BLOB class.
+ * Author:      Ray Smith
+ * Created:     Tue Oct 08 10:41:13 BST 1991
+ *
+ * (C) Copyright 1991, Hewlett-Packard Ltd.
+ ** Licensed under the Apache License, Version 2.0 (the "License");
+ ** you may not use this file except in compliance with the License.
+ ** You may obtain a copy of the License at
+ ** http://www.apache.org/licenses/LICENSE-2.0
+ ** Unless required by applicable law or agreed to in writing, software
+ ** distributed under the License is distributed on an "AS IS" BASIS,
+ ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ ** See the License for the specific language governing permissions and
+ ** limitations under the License.
+ *
+ **********************************************************************/
+
+#ifndef STEPBLOB_H
+#define STEPBLOB_H
+
+#include "coutln.h"     // for C_OUTLINE_LIST, C_OUTLINE
+#include "elst.h"       // for ELIST_ITERATOR, ELISTIZEH, ELIST_LINK
+#include "points.h"     // for FCOORD, ICOORD (ptr only)
+#include "rect.h"       // for TBOX
+#include "scrollview.h" // for ScrollView, ScrollView::Color
+
+#include <cstdint> // for int32_t, int16_t
+
+struct Pix;
+
+namespace tesseract {
+
+class C_BLOB;
+class DENORM;
+
+ELISTIZEH(C_BLOB)
+
+class TESS_API C_BLOB : public ELIST_LINK {
+public:
+  C_BLOB() = default;
+  explicit C_BLOB(C_OUTLINE_LIST *outline_list);
+  // Simpler constructor to build a blob from a single outline that has
+  // already been fully initialized.
+  explicit C_BLOB(C_OUTLINE *outline);
+
+  // Builds a set of one or more blobs from a list of outlines.
+  // Input: one outline on outline_list contains all the others, but the
+  // nesting and order are undefined.
+  // If good_blob is true, the blob is added to good_blobs_it, unless
+  // an illegal (generation-skipping) parent-child relationship is found.
+  // If so, the parent blob goes to bad_blobs_it, and the immediate children
+  // are promoted to the top level, recursively being sent to good_blobs_it.
+  // If good_blob is false, all created blobs will go to the bad_blobs_it.
+  // Output: outline_list is empty. One or more blobs are added to
+  // good_blobs_it and/or bad_blobs_it.
+  static void ConstructBlobsFromOutlines(bool good_blob, C_OUTLINE_LIST *outline_list,
+                                         C_BLOB_IT *good_blobs_it, C_BLOB_IT *bad_blobs_it);
+
+  // Sets the COUT_INVERSE flag appropriately on the outlines and their
+  // children recursively, reversing the outlines if needed so that
+  // everything has an anticlockwise top-level.
+  void CheckInverseFlagAndDirection();
+
+  // Build and return a fake blob containing a single fake outline with no
+  // steps.
+  static C_BLOB *FakeBlob(const TBOX &box);
+
+  C_OUTLINE_LIST *out_list() { // get outline list
+    return &outlines;
+  }
+
+  TBOX bounding_box() const; // compute bounding box
+  int32_t area();            // compute area
+  int32_t perimeter();       // Total perimeter of outlines and 1st level children.
+  int32_t outer_area();      // compute area
+  int32_t count_transitions( // count maxima
+      int32_t threshold);    // size threshold
+
+  void move(const ICOORD vec);         // reposition blob by vector
+  void rotate(const FCOORD &rotation); // Rotate by given vector.
+
+  // Adds sub-pixel resolution EdgeOffsets for the outlines using greyscale
+  // if the supplied pix is 8-bit or the binary edges if nullptr.
+  void ComputeEdgeOffsets(int threshold, Image pix);
+
+  // Estimates and returns the baseline position based on the shape of the
+  // outlines.
+  int16_t EstimateBaselinePosition();
+
+  // Returns a Pix rendering of the blob. pixDestroy after use.
+  Image render();
+  // Returns a Pix rendering of the outline of the blob. (no fill).
+  // pixDestroy after use.
+  Image render_outline();
+
+#ifndef GRAPHICS_DISABLED
+  void plot(                           // draw one
+      ScrollView *window,              // window to draw in
+      ScrollView::Color blob_colour,   // for outer bits
+      ScrollView::Color child_colour); // for holes
+  // Draws the blob in the given colour, and child_colour, normalized
+  // using the given denorm, making use of sub-pixel accurate information
+  // if available.
+  void plot_normed(const DENORM &denorm, ScrollView::Color blob_colour,
+                   ScrollView::Color child_colour, ScrollView *window);
+#endif // !GRAPHICS_DISABLED
+
+  C_BLOB &operator=(const C_BLOB &source) {
+    if (!outlines.empty()) {
+      outlines.clear();
+    }
+    outlines.deep_copy(&source.outlines, &C_OUTLINE::deep_copy);
+    return *this;
+  }
+
+  static C_BLOB *deep_copy(const C_BLOB *src) {
+    auto *blob = new C_BLOB;
+    *blob = *src;
+    return blob;
+  }
+
+  static int SortByXMiddle(const void *v1, const void *v2) {
+    const C_BLOB *blob1 = *static_cast<const C_BLOB *const *>(v1);
+    const C_BLOB *blob2 = *static_cast<const C_BLOB *const *>(v2);
+    return blob1->bounding_box().x_middle() - blob2->bounding_box().x_middle();
+  }
+
+private:
+  C_OUTLINE_LIST outlines; // master elements
+};
+
+} // namespace tesseract
+
+#endif