--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/tesseract/src/classify/featdefs.cpp	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,213 @@
+/******************************************************************************
+ ** Filename:    featdefs.cpp
+ ** Purpose:     Definitions of currently defined feature types.
+ ** 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 "featdefs.h"
+
+#include "picofeat.h" // for PicoFeatureLength
+#include "scanutils.h"
+
+#include <cstdio>
+#include <cstring>
+
+namespace tesseract {
+
+#define PICO_FEATURE_LENGTH 0.05
+
+/*-----------------------------------------------------------------------------
+        Global Data Definitions and Declarations
+-----------------------------------------------------------------------------*/
+const char *const kMicroFeatureType = "mf";
+const char *const kCNFeatureType = "cn";
+const char *const kIntFeatureType = "if";
+const char *const kGeoFeatureType = "tb";
+
+// Define all of the parameters for the MicroFeature type.
+StartParamDesc(MicroFeatureParams) DefineParam(0, 0, -0.5, 0.5) DefineParam(0, 0, -0.25, 0.75)
+    DefineParam(0, 1, 0.0, 1.0) DefineParam(1, 0, 0.0, 1.0) DefineParam(0, 1, -0.5, 0.5)
+        DefineParam(0, 1, -0.5, 0.5) EndParamDesc
+    // Now define the feature type itself (see features.h for parameters).
+    DefineFeature(MicroFeatureDesc, 5, 1, kMicroFeatureType, MicroFeatureParams)
+
+    // Define all of the parameters for the NormFeat type.
+    StartParamDesc(CharNormParams) DefineParam(0, 0, -0.25, 0.75) DefineParam(0, 1, 0.0, 1.0)
+        DefineParam(0, 0, 0.0, 1.0) DefineParam(0, 0, 0.0, 1.0) EndParamDesc
+    // Now define the feature type itself (see features.h for parameters).
+    DefineFeature(CharNormDesc, 4, 0, kCNFeatureType, CharNormParams)
+
+    // Define all of the parameters for the IntFeature type
+    StartParamDesc(IntFeatParams) DefineParam(0, 0, 0.0, 255.0) DefineParam(0, 0, 0.0, 255.0)
+        DefineParam(1, 0, 0.0, 255.0) EndParamDesc
+    // Now define the feature type itself (see features.h for parameters).
+    DefineFeature(IntFeatDesc, 2, 1, kIntFeatureType, IntFeatParams)
+
+    // Define all of the parameters for the GeoFeature type
+    StartParamDesc(GeoFeatParams) DefineParam(0, 0, 0.0, 255.0) DefineParam(0, 0, 0.0, 255.0)
+        DefineParam(0, 0, 0.0, 255.0) EndParamDesc
+    // Now define the feature type itself (see features.h for parameters).
+    DefineFeature(GeoFeatDesc, 3, 0, kGeoFeatureType, GeoFeatParams)
+
+    // Other features used for training the adaptive classifier, but not used
+    // during normal training, therefore not in the DescDefs array.
+
+    // Define all of the parameters for the PicoFeature type
+    // define knob that can be used to adjust pico-feature length.
+    float PicoFeatureLength = PICO_FEATURE_LENGTH;
+StartParamDesc(PicoFeatParams) DefineParam(0, 0, -0.25, 0.75) DefineParam(1, 0, 0.0, 1.0)
+    DefineParam(0, 0, -0.5, 0.5) EndParamDesc
+    // Now define the feature type itself (see features.h for parameters).
+    DefineFeature(PicoFeatDesc, 2, 1, "pf", PicoFeatParams)
+
+    // Define all of the parameters for the OutlineFeature type.
+    StartParamDesc(OutlineFeatParams) DefineParam(0, 0, -0.5, 0.5) DefineParam(0, 0, -0.25, 0.75)
+        DefineParam(0, 0, 0.0, 1.0) DefineParam(1, 0, 0.0, 1.0) EndParamDesc
+    // Now define the feature type itself (see features.h for parameters).
+    DefineFeature(OutlineFeatDesc, 3, 1, "of", OutlineFeatParams)
+
+    // MUST be kept in-sync with ExtractorDefs in fxdefs.cpp.
+    static const FEATURE_DESC_STRUCT *DescDefs[NUM_FEATURE_TYPES] = {
+        &MicroFeatureDesc, &CharNormDesc, &IntFeatDesc, &GeoFeatDesc};
+
+/*-----------------------------------------------------------------------------
+              Public Code
+-----------------------------------------------------------------------------*/
+void InitFeatureDefs(FEATURE_DEFS_STRUCT *featuredefs) {
+  featuredefs->NumFeatureTypes = NUM_FEATURE_TYPES;
+  for (int i = 0; i < NUM_FEATURE_TYPES; ++i) {
+    featuredefs->FeatureDesc[i] = DescDefs[i];
+  }
+}
+
+/*---------------------------------------------------------------------------*/
+/**
+ * Appends a textual representation of CharDesc to str.
+ * The format used is to write out the number of feature
+ * sets which will be written followed by a representation of
+ * each feature set.
+ *
+ * Each set starts with the short name for that feature followed
+ * by a description of the feature set.  Feature sets which are
+ * not present are not written.
+ *
+ * @param FeatureDefs    definitions of feature types/extractors
+ * @param str            string to append CharDesc to
+ * @param CharDesc       character description to write to File
+ */
+void WriteCharDescription(const FEATURE_DEFS_STRUCT &FeatureDefs, CHAR_DESC_STRUCT *CharDesc, std::string &str) {
+  int NumSetsToWrite = 0;
+
+  for (size_t Type = 0; Type < CharDesc->NumFeatureSets; Type++) {
+    if (CharDesc->FeatureSets[Type]) {
+      NumSetsToWrite++;
+    }
+  }
+
+  str += " " + std::to_string(NumSetsToWrite);
+  str += "\n";
+  for (size_t Type = 0; Type < CharDesc->NumFeatureSets; Type++) {
+    if (CharDesc->FeatureSets[Type]) {
+      str += FeatureDefs.FeatureDesc[Type]->ShortName;
+      str += " ";
+      WriteFeatureSet(CharDesc->FeatureSets[Type], str);
+    }
+  }
+} /* WriteCharDescription */
+
+// Return whether all of the fields of the given feature set
+// are well defined (not inf or nan).
+bool ValidCharDescription(const FEATURE_DEFS_STRUCT &FeatureDefs, CHAR_DESC_STRUCT *CharDesc) {
+  bool anything_written = false;
+  bool well_formed = true;
+  for (size_t Type = 0; Type < CharDesc->NumFeatureSets; Type++) {
+    if (CharDesc->FeatureSets[Type]) {
+      for (int i = 0; i < CharDesc->FeatureSets[Type]->NumFeatures; i++) {
+        FEATURE feat = CharDesc->FeatureSets[Type]->Features[i];
+        for (int p = 0; p < feat->Type->NumParams; p++) {
+          if (std::isnan(feat->Params[p]) || std::isinf(feat->Params[p])) {
+            well_formed = false;
+          } else {
+            anything_written = true;
+          }
+        }
+      }
+    } else {
+      return false;
+    }
+  }
+  return anything_written && well_formed;
+} /* ValidCharDescription */
+
+/*---------------------------------------------------------------------------*/
+/**
+ * Read a character description from File, and return
+ * a data structure containing this information.  The data
+ * is formatted as follows:
+ * @verbatim
+     NumberOfSets
+             ShortNameForSet1 Set1
+             ShortNameForSet2 Set2
+             ...
+   @endverbatim
+ *
+ * Globals:
+ * - none
+ *
+ * @param FeatureDefs    definitions of feature types/extractors
+ * @param File open text file to read character description from
+ * @return Character description read from File.
+ */
+CHAR_DESC_STRUCT *ReadCharDescription(const FEATURE_DEFS_STRUCT &FeatureDefs, FILE *File) {
+  int NumSetsToRead;
+  char ShortName[FEAT_NAME_SIZE];
+  int Type;
+
+  ASSERT_HOST(tfscanf(File, "%d", &NumSetsToRead) == 1);
+  ASSERT_HOST(NumSetsToRead >= 0);
+  ASSERT_HOST(NumSetsToRead <= FeatureDefs.NumFeatureTypes);
+
+  auto CharDesc = new CHAR_DESC_STRUCT(FeatureDefs);
+  for (; NumSetsToRead > 0; NumSetsToRead--) {
+    tfscanf(File, "%s", ShortName);
+    Type = ShortNameToFeatureType(FeatureDefs, ShortName);
+    CharDesc->FeatureSets[Type] = ReadFeatureSet(File, FeatureDefs.FeatureDesc[Type]);
+  }
+  return CharDesc;
+}
+
+/*---------------------------------------------------------------------------*/
+/**
+ * Search through all features currently defined and return
+ * the feature type for the feature with the specified short
+ * name.  Trap an error if the specified name is not found.
+ *
+ * Globals:
+ * - none
+ *
+ * @param FeatureDefs    definitions of feature types/extractors
+ * @param ShortName short name of a feature type
+ * @return Feature type which corresponds to ShortName.
+ */
+uint32_t ShortNameToFeatureType(const FEATURE_DEFS_STRUCT &FeatureDefs, const char *ShortName) {
+  for (int i = 0; i < FeatureDefs.NumFeatureTypes; i++) {
+    if (!strcmp((FeatureDefs.FeatureDesc[i]->ShortName), ShortName)) {
+      return static_cast<uint32_t>(i);
+    }
+  }
+  ASSERT_HOST(!"Illegal short name for a feature");
+  return 0;
+}
+
+} // namespace tesseract