--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/tesseract/src/classify/ocrfeatures.cpp	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,139 @@
+/******************************************************************************
+ ** Filename:    ocrfeatures.cpp
+ ** Purpose:     Generic definition of a feature.
+ ** Author:      Dan Johnson
+ **
+ ** (c) Copyright Hewlett-Packard Company, 1988.
+ ** 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.
+ ******************************************************************************/
+
+#include "ocrfeatures.h"
+
+#include "scanutils.h"
+
+#include <cassert>
+#include <cmath>
+#include <sstream> // for std::stringstream
+
+namespace tesseract {
+
+/*----------------------------------------------------------------------------
+              Public Code
+----------------------------------------------------------------------------*/
+/**
+ * Add a feature to a feature set.  If the feature set is
+ * already full, false is returned to indicate that the
+ * feature could not be added to the set; otherwise, true is
+ * returned.
+ * @param FeatureSet set of features to add Feature to
+ * @param Feature feature to be added to FeatureSet
+ * @return  true if feature added to set, false if set is already full.
+ */
+bool AddFeature(FEATURE_SET FeatureSet, FEATURE Feature) {
+  if (FeatureSet->NumFeatures >= FeatureSet->MaxNumFeatures) {
+    delete Feature;
+    return false;
+  }
+
+  FeatureSet->Features[FeatureSet->NumFeatures++] = Feature;
+  return true;
+} /* AddFeature */
+
+/**
+ * Create a new feature of the specified type and read in
+ * the value of its parameters from File.  The extra penalty
+ * for the feature is also computed by calling the appropriate
+ * function for the specified feature type.  The correct text
+ * representation for a feature is a list of N floats where
+ * N is the number of parameters in the feature.
+ * @param File open text file to read feature from
+ * @param FeatureDesc specifies type of feature to read from File
+ * @return New #FEATURE read from File.
+ */
+static FEATURE ReadFeature(FILE *File, const FEATURE_DESC_STRUCT *FeatureDesc) {
+  auto Feature = new FEATURE_STRUCT(FeatureDesc);
+  for (int i = 0; i < Feature->Type->NumParams; i++) {
+    ASSERT_HOST(tfscanf(File, "%f", &(Feature->Params[i])) == 1);
+#ifndef _WIN32
+    assert(!std::isnan(Feature->Params[i]));
+#endif
+  }
+  return Feature;
+}
+
+/**
+ * Create a new feature set of the specified type and read in
+ * the features from File.  The correct text representation
+ * for a feature set is an integer which specifies the number (N)
+ * of features in a set followed by a list of N feature
+ * descriptions.
+ * @param File open text file to read new feature set from
+ * @param FeatureDesc specifies type of feature to read from File
+ * @return New feature set read from File.
+ */
+FEATURE_SET ReadFeatureSet(FILE *File, const FEATURE_DESC_STRUCT *FeatureDesc) {
+  int NumFeatures;
+  ASSERT_HOST(tfscanf(File, "%d", &NumFeatures) == 1);
+  ASSERT_HOST(NumFeatures >= 0);
+
+  auto FeatureSet = new FEATURE_SET_STRUCT(NumFeatures);
+  for (int i = 0; i < NumFeatures; i++) {
+    AddFeature(FeatureSet, ReadFeature(File, FeatureDesc));
+  }
+
+  return FeatureSet;
+}
+
+/**
+ * Appends a textual representation of Feature to str.
+ * This representation is simply a list of the N parameters
+ * of the feature, terminated with a newline.  It is assumed
+ * that the ExtraPenalty field can be reconstructed from the
+ * parameters of the feature.  It is also assumed that the
+ * feature type information is specified or assumed elsewhere.
+ * @param Feature feature to write out to str
+ * @param str string to write Feature to
+ */
+static void WriteFeature(FEATURE Feature, std::string &str) {
+  for (int i = 0; i < Feature->Type->NumParams; i++) {
+#ifndef WIN32
+    assert(!std::isnan(Feature->Params[i]));
+#endif
+    std::stringstream stream;
+    // Use "C" locale (needed for double value).
+    stream.imbue(std::locale::classic());
+    // Use 8 digits for double value.
+    stream.precision(8);
+    stream << Feature->Params[i];
+    str += " " + stream.str();
+  }
+  str += "\n";
+} /* WriteFeature */
+
+/**
+ * Write a textual representation of FeatureSet to File.
+ * This representation is an integer specifying the number of
+ * features in the set, followed by a newline, followed by
+ * text representations for each feature in the set.
+ * @param FeatureSet feature set to write to File
+ * @param str string to write Feature to
+ */
+void WriteFeatureSet(FEATURE_SET FeatureSet, std::string &str) {
+  if (FeatureSet) {
+    str += "" + std::to_string(FeatureSet->NumFeatures);
+    str += "\n";
+    for (int i = 0; i < FeatureSet->NumFeatures; i++) {
+      WriteFeature(FeatureSet->Features[i], str);
+    }
+  }
+} /* WriteFeatureSet */
+
+} // namespace tesseract