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"

#define NORMAL_X_HEIGHT (0.5)
#define NORMAL_BASELINE (0.0)

using MFOUTLINE = LIST;

typedef enum {
  north,
  south,
  east,
  west,
  northeast,
  northwest,
  southeast,
  southwest
} DIRECTION;

typedef struct {
  FPOINT Point;
  float Slope;
  unsigned Padding : 20;
  bool Hidden : true;
  bool ExtremityMark : true;
  DIRECTION Direction : 4;
  DIRECTION PreviousDirection : 4;
} MFEDGEPT;

typedef enum { outer, hole } OUTLINETYPE;

typedef enum { baseline, character } NORM_METHOD;

#define AverageOf(A, B) (((A) + (B)) / 2)

/* macro for computing the scale factor to use to normalize characters */
#define MF_SCALE_FACTOR (NORMAL_X_HEIGHT / kBlnXHeight)

/* macros for manipulating micro-feature outlines */
#define DegenerateOutline(O) (((O) == NIL_LIST) || ((O) == list_rest(O)))
#define PointAt(O) ((MFEDGEPT*)first_node(O))
#define NextPointAfter(E) (list_rest(E))
#define MakeOutlineCircular(O) (set_rest(last(O), (O)))

/* macros for manipulating micro-feature outline edge points */
#define ClearMark(P) ((P)->ExtremityMark = false)
#define MarkPoint(P) ((P)->ExtremityMark = true)

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);

MFEDGEPT* NewEdgePoint();

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);

#endif