/******************************************************************************

 ** Filename:       mfx.c

 ** Purpose:        Micro feature extraction routines

 ** 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 "mfx.h"

#include "clusttool.h" //NEEDED

#include "intfx.h"

#include "mfdefs.h"

#include "mfoutline.h"

#include "normalis.h"

#include "params.h"

namespace tesseract {

/* old numbers corresponded to 10.0 degrees and 80.0 degrees */

double_VAR(classify_min_slope, 0.414213562, "Slope below which lines are called horizontal");

double_VAR(classify_max_slope, 2.414213562, "Slope above which lines are called vertical");

/*----------------------------------------------------------------------------

          Private Function Prototypes

-----------------------------------------------------------------------------*/

MICROFEATURES ConvertToMicroFeatures(MFOUTLINE Outline, MICROFEATURES MicroFeatures);

MicroFeature ExtractMicroFeature(MFOUTLINE Start, MFOUTLINE End);

/*----------------------------------------------------------------------------

            Public Code

----------------------------------------------------------------------------*/

/**

 * This routine extracts micro-features from the specified

 * blob and returns a list of the micro-features.  All

 * micro-features are normalized according to the specified

 * line statistics.

 * @param Blob blob to extract micro-features from

 * @param cn_denorm control parameter to feature extractor

 * @return List of micro-features extracted from the blob.

 */

MICROFEATURES BlobMicroFeatures(TBLOB *Blob, const DENORM &cn_denorm) {

  MICROFEATURES MicroFeatures;

  LIST Outlines;

  LIST RemainingOutlines;

  if (Blob != nullptr) {

    Outlines = ConvertBlob(Blob);

    RemainingOutlines = Outlines;

    iterate(RemainingOutlines) {

      auto Outline = static_cast<MFOUTLINE>(RemainingOutlines->first_node());

      CharNormalizeOutline(Outline, cn_denorm);

    }

    RemainingOutlines = Outlines;

    iterate(RemainingOutlines) {

      auto Outline = static_cast<MFOUTLINE>(RemainingOutlines->first_node());

      FindDirectionChanges(Outline, classify_min_slope, classify_max_slope);

      MarkDirectionChanges(Outline);

      MicroFeatures = ConvertToMicroFeatures(Outline, MicroFeatures);

    }

    FreeOutlines(Outlines);

  }

  return MicroFeatures;

} /* BlobMicroFeatures */

/*---------------------------------------------------------------------------

            Private Code

---------------------------------------------------------------------------*/

/**

 * Convert Outline to MicroFeatures

 * @param Outline         outline to extract micro-features from

 * @param MicroFeatures   list of micro-features to add to

 * @return List of micro-features with new features added to front.

 * @note Globals: none

 */

MICROFEATURES ConvertToMicroFeatures(MFOUTLINE Outline, MICROFEATURES MicroFeatures) {

  MFOUTLINE Current;

  MFOUTLINE Last;

  MFOUTLINE First;

  if (DegenerateOutline(Outline)) {

    return (MicroFeatures);

  }

  First = NextExtremity(Outline);

  Last = First;

  do {

    Current = NextExtremity(Last);

    if (!PointAt(Current)->Hidden) {

      auto NewFeature = ExtractMicroFeature(Last, Current);

      MicroFeatures.push_front(NewFeature);

    }

    Last = Current;

  } while (Last != First);

  return MicroFeatures;

} /* ConvertToMicroFeatures */

/**

 * This routine computes the feature parameters which describe

 * the micro-feature that starts and Start and ends at End.

 * A new micro-feature is allocated, filled with the feature

 * parameters, and returned.  The routine assumes that

 * Start and End are not the same point.  If they are the

 * same point, nullptr is returned, a warning message is

 * printed, and the current outline is dumped to stdout.

 * @param Start starting point of micro-feature

 * @param End ending point of micro-feature

 * @return New micro-feature or nullptr if the feature was rejected.

 * @note Globals: none

 */

MicroFeature ExtractMicroFeature(MFOUTLINE Start, MFOUTLINE End) {

  MFEDGEPT *P1, *P2;

  P1 = PointAt(Start);

  P2 = PointAt(End);

  MicroFeature NewFeature;

  NewFeature[(int)MicroFeatureParameter::MFXPosition] = AverageOf(P1->Point.x, P2->Point.x);

  NewFeature[(int)MicroFeatureParameter::MFYPosition] = AverageOf(P1->Point.y, P2->Point.y);

  NewFeature[(int)MicroFeatureParameter::MFLength] = DistanceBetween(P1->Point, P2->Point);

  NewFeature[(int)MicroFeatureParameter::MFDirection] = NormalizedAngleFrom(&P1->Point, &P2->Point, 1.0);

  NewFeature[(int)MicroFeatureParameter::MFBulge1] = 0.0f;  // deprecated

  NewFeature[(int)MicroFeatureParameter::MFBulge2] = 0.0f; // deprecated

  return NewFeature;

} /* ExtractMicroFeature */

} // namespace tesseract