mfoutline.h

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/******************************************************************************
 ** Filename:    mfoutline.h
 ** Purpose:     Interface spec for fx outline structures
 ** 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.
 ******************************************************************************/
 
#ifndef MFOUTLINE_H
#define MFOUTLINE_H
 
#include "blobs.h"
#include "fpoint.h"
#include "oldlist.h"
#include "params.h"
 
namespace tesseract {
 
using MFOUTLINE = LIST;
 
enum DIRECTION : uint8_t { north, south, east, west, northeast, northwest, southeast, southwest };
 
struct MFEDGEPT {
  // Inline functions for manipulating micro-feature outline edge points.
 
  void ClearMark() {
    ExtremityMark = false;
  }
 
  void MarkPoint() {
    ExtremityMark = true;
  }
 
  FPOINT Point;
  float Slope;
  bool Hidden;
  bool ExtremityMark;
  DIRECTION Direction;
  DIRECTION PreviousDirection;
};
 
enum OUTLINETYPE { outer, hole };
 
enum NORM_METHOD { baseline, character };
 
#define AverageOf(A, B) (((A) + (B)) / 2)
 
// Constant for computing the scale factor to use to normalize characters.
const float MF_SCALE_FACTOR = 0.5f / kBlnXHeight;
 
// Inline functions for manipulating micro-feature outlines.
 
static inline bool DegenerateOutline(MFOUTLINE Outline) {
  return (Outline == NIL_LIST) || (Outline == Outline->list_rest());
}
 
static inline MFEDGEPT *PointAt(MFOUTLINE Outline) {
  return reinterpret_cast<MFEDGEPT *>(Outline->first_node());
}
 
static inline MFOUTLINE NextPointAfter(MFOUTLINE Outline) {
  return Outline->list_rest();
}
 
static inline void MakeOutlineCircular(MFOUTLINE Outline) {
  set_rest(last(Outline), Outline);
}
 
void ComputeBlobCenter(TBLOB *Blob, TPOINT *BlobCenter);
 
LIST ConvertBlob(TBLOB *Blob);
 
MFOUTLINE ConvertOutline(TESSLINE *Outline);
 
LIST ConvertOutlines(TESSLINE *Outline, LIST ConvertedOutlines, OUTLINETYPE OutlineType);
 
void FilterEdgeNoise(MFOUTLINE Outline, float NoiseSegmentLength);
 
void FindDirectionChanges(MFOUTLINE Outline, float MinSlope, float MaxSlope);
 
void FreeMFOutline(void *agr); // MFOUTLINE Outline);
 
void FreeOutlines(LIST Outlines);
 
void MarkDirectionChanges(MFOUTLINE Outline);
 
MFOUTLINE NextExtremity(MFOUTLINE EdgePoint);
 
void NormalizeOutline(MFOUTLINE Outline, float XOrigin);
 
/*----------------------------------------------------------------------------
          Private Function Prototypes
-----------------------------------------------------------------------------*/
void ChangeDirection(MFOUTLINE Start, MFOUTLINE End, DIRECTION Direction);
 
// Normalizes the Outline in-place using cn_denorm's local transformation,
// then converts from the integer feature range [0,255] to the clusterer
// feature range of [-0.5, 0.5].
void CharNormalizeOutline(MFOUTLINE Outline, const DENORM &cn_denorm);
 
void ComputeDirection(MFEDGEPT *Start, MFEDGEPT *Finish, float MinSlope, float MaxSlope);
 
MFOUTLINE NextDirectionChange(MFOUTLINE EdgePoint);
 
} // namespace tesseract
 
#endif