--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/tesseract/src/classify/shapeclassifier.h	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,118 @@
+///////////////////////////////////////////////////////////////////////
+// File:        shapeclassifier.h
+// Description: Base interface class for classifiers that return a
+//              shape index.
+// Author:      Ray Smith
+//
+// (C) Copyright 2011, Google Inc.
+// 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 TESSERACT_CLASSIFY_SHAPECLASSIFIER_H_
+#define TESSERACT_CLASSIFY_SHAPECLASSIFIER_H_
+
+#include "image.h"
+
+#include <tesseract/unichar.h>
+
+#include <vector>
+
+struct Pix;
+
+namespace tesseract {
+
+class ScrollView;
+class UNICHARSET;
+
+struct ShapeRating;
+class ShapeTable;
+class TrainingSample;
+class TrainingSampleSet;
+struct UnicharRating;
+
+// Interface base class for classifiers that produce ShapeRating results.
+class TESS_API ShapeClassifier {
+public:
+  virtual ~ShapeClassifier() = default;
+
+  // Classifies the given [training] sample, writing to results.
+  // If page_pix is not nullptr, the overriding function may call
+  // sample.GetSamplePix(padding, page_pix) to get an image of the sample
+  // padded (with real image data) by the given padding to extract features
+  // from the image of the character. Other members of TrainingSample:
+  // features(), micro_features(), cn_feature(), geo_feature() may be used
+  // to get the appropriate tesseract features.
+  // If debug is non-zero, then various degrees of classifier dependent debug
+  // information is provided.
+  // If keep_this (a UNICHAR_ID) is >= 0, then the results should always
+  // contain keep_this, and (if possible) anything of intermediate confidence.
+  // (Used for answering "Why didn't it get that right?" questions.) It must
+  // be a UNICHAR_ID as the callers have no clue how to choose the best shape
+  // that may contain a desired answer.
+  // The return value is the number of classes saved in results.
+  // NOTE that overriding functions MUST clear and sort the results by
+  // descending rating unless the classifier is working with a team of such
+  // classifiers.
+  // NOTE: Neither overload of ClassifySample is pure, but at least one must
+  // be overridden by a classifier in order for it to do anything.
+  virtual int UnicharClassifySample(const TrainingSample &sample, Image page_pix, int debug,
+                                    UNICHAR_ID keep_this, std::vector<UnicharRating> *results);
+
+protected:
+  virtual int ClassifySample(const TrainingSample &sample, Image page_pix, int debug,
+                             UNICHAR_ID keep_this, std::vector<ShapeRating> *results);
+
+public:
+  // Returns the shape that contains unichar_id that has the best result.
+  // If result is not nullptr, it is set with the shape_id and rating.
+  // Returns -1 if ClassifySample fails to provide any result containing
+  // unichar_id. BestShapeForUnichar does not need to be overridden if
+  // ClassifySample respects the keep_this rule.
+  virtual int BestShapeForUnichar(const TrainingSample &sample, Image page_pix,
+                                  UNICHAR_ID unichar_id, ShapeRating *result);
+
+  // Provides access to the ShapeTable that this classifier works with.
+  virtual const ShapeTable *GetShapeTable() const = 0;
+  // Provides access to the UNICHARSET that this classifier works with.
+  // Must be overridden IFF GetShapeTable() returns nullptr.
+  virtual const UNICHARSET &GetUnicharset() const;
+
+  // Visual debugger classifies the given sample, displays the results and
+  // solicits user input to display other classifications. Returns when
+  // the user has finished with debugging the sample.
+  // Probably doesn't need to be overridden if the subclass provides
+  // DisplayClassifyAs.
+  void DebugDisplay(const TrainingSample &sample, Image page_pix, UNICHAR_ID unichar_id);
+
+  // Displays classification as the given unichar_id. Creates as many windows
+  // as it feels fit, using index as a guide for placement. Adds any created
+  // windows to the windows output and returns a new index that may be used
+  // by any subsequent classifiers. Caller waits for the user to view and
+  // then destroys the windows by clearing the vector.
+  virtual int DisplayClassifyAs(const TrainingSample &sample, Image page_pix, UNICHAR_ID unichar_id,
+                                int index, std::vector<ScrollView *> &windows);
+
+  // Prints debug information on the results. context is some introductory/title
+  // message.
+  virtual void UnicharPrintResults(const char *context,
+                                   const std::vector<UnicharRating> &results) const;
+  virtual void PrintResults(const char *context, const std::vector<ShapeRating> &results) const;
+
+protected:
+  // Removes any result that has all its unichars covered by a better choice,
+  // regardless of font.
+  void FilterDuplicateUnichars(std::vector<ShapeRating> *results) const;
+};
+
+} // namespace tesseract.
+
+#endif // TESSERACT_CLASSIFY_SHAPECLASSIFIER_H_