mfoutline.cpp

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/******************************************************************************
 ** Filename:    mfoutline.c
 ** Purpose:     Interface to outline struct used for extracting features
 ** 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 Files and Type Defines
----------------------------------------------------------------------------*/
#include "clusttool.h"           //If remove you get cought in a loop somewhere
#include "mfoutline.h"
#include "blobs.h"
#include "mfx.h"
#include "params.h"
#include "classify.h"

#include <cmath>
#include <cstdio>

/*----------------------------------------------------------------------------
              Public Code
----------------------------------------------------------------------------*/

/*---------------------------------------------------------------------------*/
LIST ConvertBlob(TBLOB *blob) {
  LIST outlines = NIL_LIST;
  return (blob == nullptr)
      ? NIL_LIST
      : ConvertOutlines(blob->outlines, outlines, outer);
}


/*---------------------------------------------------------------------------*/
MFOUTLINE ConvertOutline(TESSLINE *outline) {
  MFEDGEPT *NewPoint;
  MFOUTLINE MFOutline = NIL_LIST;
  EDGEPT *EdgePoint;
  EDGEPT *StartPoint;
  EDGEPT *NextPoint;

  if (outline == nullptr || outline->loop == nullptr)
    return MFOutline;

  StartPoint = outline->loop;
  EdgePoint = StartPoint;
  do {
    NextPoint = EdgePoint->next;

    /* filter out duplicate points */
    if (EdgePoint->pos.x != NextPoint->pos.x ||
        EdgePoint->pos.y != NextPoint->pos.y) {
      NewPoint = NewEdgePoint();
      ClearMark(NewPoint);
      NewPoint->Hidden = EdgePoint->IsHidden();
      NewPoint->Point.x = EdgePoint->pos.x;
      NewPoint->Point.y = EdgePoint->pos.y;
      MFOutline = push(MFOutline, NewPoint);
    }
    EdgePoint = NextPoint;
  } while (EdgePoint != StartPoint);

  if (MFOutline != nullptr)
    MakeOutlineCircular(MFOutline);
  return MFOutline;
}


/*---------------------------------------------------------------------------*/
LIST ConvertOutlines(TESSLINE *outline,
                     LIST mf_outlines,
                     OUTLINETYPE outline_type) {
  MFOUTLINE mf_outline;

  while (outline != nullptr) {
    mf_outline = ConvertOutline(outline);
    if (mf_outline != nullptr)
      mf_outlines = push(mf_outlines, mf_outline);
    outline = outline->next;
  }
  return mf_outlines;
}

/*---------------------------------------------------------------------------*/
void FindDirectionChanges(MFOUTLINE Outline,
                          float MinSlope,
                          float MaxSlope) {
  MFEDGEPT *Current;
  MFEDGEPT *Last;
  MFOUTLINE EdgePoint;

  if (DegenerateOutline (Outline))
    return;

  Last = PointAt (Outline);
  Outline = NextPointAfter (Outline);
  EdgePoint = Outline;
  do {
    Current = PointAt (EdgePoint);
    ComputeDirection(Last, Current, MinSlope, MaxSlope);

    Last = Current;
    EdgePoint = NextPointAfter (EdgePoint);
  }
  while (EdgePoint != Outline);

}                                /* FindDirectionChanges */


/*---------------------------------------------------------------------------*/
void FreeMFOutline(void *arg) {  //MFOUTLINE                             Outline)
  MFOUTLINE Start;
  auto Outline = static_cast<MFOUTLINE>(arg);

  /* break the circular outline so we can use std. techniques to deallocate */
  Start = list_rest (Outline);
  set_rest(Outline, NIL_LIST);
  while (Start != nullptr) {
    free(first_node(Start));
    Start = pop (Start);
  }

}                                /* FreeMFOutline */


/*---------------------------------------------------------------------------*/
void FreeOutlines(LIST Outlines) {
  destroy_nodes(Outlines, FreeMFOutline);
}                                /* FreeOutlines */


/*---------------------------------------------------------------------------*/
void MarkDirectionChanges(MFOUTLINE Outline) {
  MFOUTLINE Current;
  MFOUTLINE Last;
  MFOUTLINE First;

  if (DegenerateOutline (Outline))
    return;

  First = NextDirectionChange (Outline);
  Last = First;
  do {
    Current = NextDirectionChange (Last);
    MarkPoint (PointAt (Current));
    Last = Current;
  }
  while (Last != First);

}                                /* MarkDirectionChanges */


/*---------------------------------------------------------------------------*/
MFEDGEPT *NewEdgePoint() {
  return reinterpret_cast<MFEDGEPT *>(malloc(sizeof(MFEDGEPT)));
}

/*---------------------------------------------------------------------------*/
MFOUTLINE NextExtremity(MFOUTLINE EdgePoint) {
  EdgePoint = NextPointAfter(EdgePoint);
  while (!PointAt(EdgePoint)->ExtremityMark)
    EdgePoint = NextPointAfter(EdgePoint);

  return (EdgePoint);

}                                /* NextExtremity */


/*---------------------------------------------------------------------------*/
void NormalizeOutline(MFOUTLINE Outline,
                      float XOrigin) {
  if (Outline == NIL_LIST)
    return;

  MFOUTLINE EdgePoint = Outline;
  do {
    MFEDGEPT *Current = PointAt(EdgePoint);
    Current->Point.y = MF_SCALE_FACTOR *
        (Current->Point.y - kBlnBaselineOffset);
    Current->Point.x = MF_SCALE_FACTOR * (Current->Point.x - XOrigin);
    EdgePoint = NextPointAfter(EdgePoint);
  } while (EdgePoint != Outline);
}                                /* NormalizeOutline */


/*---------------------------------------------------------------------------*/
namespace tesseract {
void Classify::NormalizeOutlines(LIST Outlines,
                                 float *XScale,
                                 float *YScale) {
  MFOUTLINE Outline;

  switch (classify_norm_method) {
    case character:
      ASSERT_HOST(!"How did NormalizeOutlines get called in character mode?");
      break;

    case baseline:
      iterate(Outlines) {
        Outline = static_cast<MFOUTLINE>first_node(Outlines);
        NormalizeOutline(Outline, 0.0);
      }
      *XScale = *YScale = MF_SCALE_FACTOR;
      break;
  }
}                                /* NormalizeOutlines */
}  // namespace tesseract

/*----------------------------------------------------------------------------
              Private Code
----------------------------------------------------------------------------*/
void ChangeDirection(MFOUTLINE Start, MFOUTLINE End, DIRECTION Direction) {
  MFOUTLINE Current;

  for (Current = Start; Current != End; Current = NextPointAfter (Current))
    PointAt (Current)->Direction = Direction;

  PointAt (End)->PreviousDirection = Direction;

}                                /* ChangeDirection */

void CharNormalizeOutline(MFOUTLINE Outline, const DENORM& cn_denorm) {
  MFOUTLINE First, Current;
  MFEDGEPT *CurrentPoint;

  if (Outline == NIL_LIST)
    return;

  First = Outline;
  Current = First;
  do {
    CurrentPoint = PointAt(Current);
    FCOORD pos(CurrentPoint->Point.x, CurrentPoint->Point.y);
    cn_denorm.LocalNormTransform(pos, &pos);
    CurrentPoint->Point.x = (pos.x() - UINT8_MAX / 2) * MF_SCALE_FACTOR;
    CurrentPoint->Point.y = (pos.y() - UINT8_MAX / 2) * MF_SCALE_FACTOR;

    Current = NextPointAfter(Current);
  }
  while (Current != First);

}                                /* CharNormalizeOutline */

void ComputeDirection(MFEDGEPT *Start,
                      MFEDGEPT *Finish,
                      float MinSlope,
                      float MaxSlope) {
  FVECTOR Delta;

  Delta.x = Finish->Point.x - Start->Point.x;
  Delta.y = Finish->Point.y - Start->Point.y;
  if (Delta.x == 0) {
    if (Delta.y < 0) {
      Start->Slope = -FLT_MAX;
      Start->Direction = south;
    } else {
      Start->Slope = FLT_MAX;
      Start->Direction = north;
    }
  } else {
    Start->Slope = Delta.y / Delta.x;
    if (Delta.x > 0) {
      if (Delta.y > 0) {
        if (Start->Slope > MinSlope) {
          if (Start->Slope < MaxSlope) {
            Start->Direction = northeast;
          } else {
            Start->Direction = north;
          }
        } else {
          Start->Direction = east;
        }
      }
      else if (Start->Slope < -MinSlope) {
        if (Start->Slope > -MaxSlope) {
          Start->Direction = southeast;
        } else {
          Start->Direction = south;
        }
      } else {
        Start->Direction = east;
      }
    } else if (Delta.y > 0) {
      if (Start->Slope < -MinSlope) {
        if (Start->Slope > -MaxSlope) {
          Start->Direction = northwest;
        } else {
          Start->Direction = north;
        }
      } else {
        Start->Direction = west;
      }
    } else if (Start->Slope > MinSlope) {
      if (Start->Slope < MaxSlope) {
        Start->Direction = southwest;
      } else {
        Start->Direction = south;
      }
    } else {
      Start->Direction = west;
    }
  }
  Finish->PreviousDirection = Start->Direction;
}

MFOUTLINE NextDirectionChange(MFOUTLINE EdgePoint) {
  DIRECTION InitialDirection;

  InitialDirection = PointAt (EdgePoint)->Direction;

  MFOUTLINE next_pt = nullptr;
  do {
    EdgePoint = NextPointAfter(EdgePoint);
    next_pt = NextPointAfter(EdgePoint);
  } while (PointAt(EdgePoint)->Direction == InitialDirection &&
           !PointAt(EdgePoint)->Hidden &&
           next_pt != nullptr && !PointAt(next_pt)->Hidden);

  return (EdgePoint);
}