coutln.cpp

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/**********************************************************************
 * File:        coutln.c  (Formerly coutline.c)
 * Description: Code for the C_OUTLINE class.
 * Author:                  Ray Smith
 * Created:                 Mon Oct 07 16:01:57 BST 1991
 *
 * (C) Copyright 1991, Hewlett-Packard Ltd.
 ** 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 "mfcpch.h"
#include          <string.h>
#ifdef __UNIX__
#include          <assert.h>
#endif
#include          "coutln.h"

ELISTIZE_S (C_OUTLINE)
ICOORD C_OUTLINE::step_coords[4] = {
  ICOORD (-1, 0), ICOORD (0, -1), ICOORD (1, 0), ICOORD (0, 1)
};

/**********************************************************************
 * C_OUTLINE::C_OUTLINE
 *
 * Constructor to build a C_OUTLINE from a CRACKEDGE LOOP.
 **********************************************************************/

C_OUTLINE::C_OUTLINE (
//constructor
CRACKEDGE * startpt,             //outline to convert
ICOORD bot_left,                 //bounding box
ICOORD top_right, inT16 length   //length of loop
):box (bot_left, top_right), start (startpt->pos) {
  inT16 stepindex;               //index to step
  CRACKEDGE *edgept;             //current point

  stepcount = length;            //no of steps
  if (length == 0) {
    steps = NULL;
    return;
  }
                                 //get memory
  steps = (uinT8 *) alloc_mem (step_mem());
  memset(steps, 0, step_mem());
  edgept = startpt;

  for (stepindex = 0; stepindex < length; stepindex++) {
                                 //set compact step
    set_step (stepindex, edgept->stepdir);
    edgept = edgept->next;
  }
}


/**********************************************************************
 * C_OUTLINE::C_OUTLINE
 *
 * Constructor to build a C_OUTLINE from a C_OUTLINE_FRAG.
 **********************************************************************/
C_OUTLINE::C_OUTLINE (
//constructor
                                 //steps to copy
ICOORD startpt, DIR128 * new_steps,
inT16 length                     //length of loop
):start (startpt) {
  inT8 dirdiff;                  //direction difference
  DIR128 prevdir;                //previous direction
  DIR128 dir;                    //current direction
  DIR128 lastdir;                //dir of last step
  TBOX new_box;                   //easy bounding
  inT16 stepindex;               //index to step
  inT16 srcindex;                //source steps
  ICOORD pos;                    //current position

  pos = startpt;
  stepcount = length;            //no of steps
                                 //get memory
  steps = (uinT8 *) alloc_mem (step_mem());
  memset(steps, 0, step_mem());

  lastdir = new_steps[length - 1];
  prevdir = lastdir;
  for (stepindex = 0, srcindex = 0; srcindex < length;
  stepindex++, srcindex++) {
    new_box = TBOX (pos, pos);
    box += new_box;
                                 //copy steps
    dir = new_steps[srcindex];
    set_step(stepindex, dir);
    dirdiff = dir - prevdir;
    pos += step (stepindex);
    if ((dirdiff == 64 || dirdiff == -64) && stepindex > 0) {
      stepindex -= 2;            //cancel there-and-back
      prevdir = stepindex >= 0 ? step_dir (stepindex) : lastdir;
    }
    else
      prevdir = dir;
  }
  ASSERT_HOST (pos.x () == startpt.x () && pos.y () == startpt.y ());
  do {
    dirdiff = step_dir (stepindex - 1) - step_dir (0);
    if (dirdiff == 64 || dirdiff == -64) {
      start += step (0);
      stepindex -= 2;            //cancel there-and-back
      for (int i = 0; i < stepindex; ++i)
        set_step(i, step_dir(i + 1));
    }
  }
  while (stepindex > 1 && (dirdiff == 64 || dirdiff == -64));
  stepcount = stepindex;
  ASSERT_HOST (stepcount >= 4);
}

/**********************************************************************
 * C_OUTLINE::C_OUTLINE
 *
 * Constructor to build a C_OUTLINE from a rotation of a C_OUTLINE.
 **********************************************************************/

C_OUTLINE::C_OUTLINE(                     //constructor
                     C_OUTLINE *srcline,  //outline to
                     FCOORD rotation      //rotate
                    ) {
  TBOX new_box;                   //easy bounding
  inT16 stepindex;               //index to step
  inT16 dirdiff;                 //direction change
  ICOORD pos;                    //current position
  ICOORD prevpos;                //previous dest point

  ICOORD destpos;                //destination point
  inT16 destindex;               //index to step
  DIR128 dir;                    //coded direction
  uinT8 new_step;

  stepcount = srcline->stepcount * 2;
                                 //get memory
  steps = (uinT8 *) alloc_mem (step_mem());
  memset(steps, 0, step_mem());

  for (int iteration = 0; iteration < 2; ++iteration) {
    DIR128 round1 = iteration == 0 ? 32 : 0;
    DIR128 round2 = iteration != 0 ? 32 : 0;
    pos = srcline->start;
    prevpos = pos;
    prevpos.rotate (rotation);
    start = prevpos;
    box = TBOX (start, start);
    destindex = 0;
    for (stepindex = 0; stepindex < srcline->stepcount; stepindex++) {
      pos += srcline->step (stepindex);
      destpos = pos;
      destpos.rotate (rotation);
      if (destpos.x () != prevpos.x () || destpos.y () != prevpos.y ()) {
        dir = DIR128 (FCOORD (destpos - prevpos));
        dir += 64;                 //turn to step style
        new_step = dir.get_dir ();
        if (new_step & 31) {
          set_step(destindex++, dir + round1);
          if (destindex < 2
            || ((dirdiff =
            step_dir (destindex - 1) - step_dir (destindex - 2)) !=
            -64 && dirdiff != 64))
            set_step(destindex++, dir + round2);
          else {
            set_step(destindex - 1, dir + round2);
            set_step(destindex++, dir + round1);
          }
        }
        else {
          set_step(destindex++, dir);
          if (destindex >= 2
            &&
            ((dirdiff =
            step_dir (destindex - 1) - step_dir (destindex - 2)) ==
            -64 || dirdiff == 64))
            destindex -= 2;        // Forget u turn
        }
        prevpos = destpos;
        new_box = TBOX (destpos, destpos);
        box += new_box;
      }
    }
    ASSERT_HOST (destpos.x () == start.x () && destpos.y () == start.y ());
    dirdiff = step_dir (destindex - 1) - step_dir (0);
    while ((dirdiff == 64 || dirdiff == -64) && destindex > 1) {
      start += step (0);
      destindex -= 2;
      for (int i = 0; i < destindex; ++i)
        set_step(i, step_dir(i + 1));
      dirdiff = step_dir (destindex - 1) - step_dir (0);
    }
    if (destindex >= 4)
      break;
  }
  stepcount = destindex;
  destpos = start;
  for (stepindex = 0; stepindex < stepcount; stepindex++) {
    destpos += step (stepindex);
  }
  ASSERT_HOST (destpos.x () == start.x () && destpos.y () == start.y ());
}


/**********************************************************************
 * C_OUTLINE::area
 *
 * Compute the area of the outline.
 **********************************************************************/

inT32 C_OUTLINE::area() {  //winding number
  int stepindex;                 //current step
  inT32 total_steps;             //steps to do
  inT32 total;                   //total area
  ICOORD pos;                    //position of point
  ICOORD next_step;              //step to next pix
  C_OUTLINE_IT it = child ();

  pos = start_pos ();
  total_steps = pathlength ();
  total = 0;
  for (stepindex = 0; stepindex < total_steps; stepindex++) {
                                 //all intersected
    next_step = step (stepindex);
    if (next_step.x () < 0)
      total += pos.y ();
    else if (next_step.x () > 0)
      total -= pos.y ();
    pos += next_step;
  }
  for (it.mark_cycle_pt (); !it.cycled_list (); it.forward ())
    total += it.data ()->area ();//add areas of children

  return total;
}


/**********************************************************************
 * C_OUTLINE::outer_area
 *
 * Compute the area of the outline.
 **********************************************************************/

inT32 C_OUTLINE::outer_area() {  //winding number
  int stepindex;                 //current step
  inT32 total_steps;             //steps to do
  inT32 total;                   //total area
  ICOORD pos;                    //position of point
  ICOORD next_step;              //step to next pix

  pos = start_pos ();
  total_steps = pathlength ();
  if (total_steps == 0)
    return box.area();
  total = 0;
  for (stepindex = 0; stepindex < total_steps; stepindex++) {
                                 //all intersected
    next_step = step (stepindex);
    if (next_step.x () < 0)
      total += pos.y ();
    else if (next_step.x () > 0)
      total -= pos.y ();
    pos += next_step;
  }

  return total;
}


/**********************************************************************
 * C_OUTLINE::count_transitions
 *
 * Compute the number of x and y maxes and mins in the outline.
 **********************************************************************/

inT32 C_OUTLINE::count_transitions(                 //winding number
                                   inT32 threshold  //on size
                                  ) {
  BOOL8 first_was_max_x;         //what was first
  BOOL8 first_was_max_y;
  BOOL8 looking_for_max_x;       //what is next
  BOOL8 looking_for_min_x;
  BOOL8 looking_for_max_y;       //what is next
  BOOL8 looking_for_min_y;
  int stepindex;                 //current step
  inT32 total_steps;             //steps to do
                                 //current limits
  inT32 max_x, min_x, max_y, min_y;
  inT32 initial_x, initial_y;    //initial limits
  inT32 total;                   //total changes
  ICOORD pos;                    //position of point
  ICOORD next_step;              //step to next pix

  pos = start_pos ();
  total_steps = pathlength ();
  total = 0;
  max_x = min_x = pos.x ();
  max_y = min_y = pos.y ();
  looking_for_max_x = TRUE;