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Groups > comp.lang.c > #383695

Re: filling area by color atack safety

From Malcolm McLean <malcolm.arthur.mclean@gmail.com>
Newsgroups comp.lang.c
Subject Re: filling area by color atack safety
Date 2024-03-17 14:56 +0000
Organization A noiseless patient Spider
Message-ID <ut70b4$3itvb$1@dont-email.me> (permalink)
References <ut3669$21eur$1@i2pn2.org> <ut4020$2s8ov$1@dont-email.me> <ut4b09$2uhpm$1@dont-email.me> <ut4cnc$2ut2t$1@dont-email.me>

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On 16/03/2024 15:09, Malcolm McLean wrote:
> On 16/03/2024 14:40, David Brown wrote:
>> On 16/03/2024 12:33, Malcolm McLean wrote:
>>
>>> And here's some code I wrote a while ago. Use that as a pattern. But 
>>> not sure how well it works. Haven't used it for a long time.
>>>
>>> https://github.com/MalcolmMcLean/binaryimagelibrary/blob/master/drawbinary.c
>>>
>>
>> Your implementation is a mess, /vastly/ more difficult to prove 
>> correct than the OP's original one, and unlikely to be very much 
>> faster (it will certainly scale in the same way in both time and 
>> memory usage).
>>
> Now is this David Brown being David Borwn, ot its it actaully ture?

> And I need to run some tests, don't I?
> 
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>

int floodfill_r(unsigned char *grey, int width, int height, int x, int y,
unsigned char target, unsigned char dest)
{
    if (x < 0 || x >= width || y < 0 || y >= height)
      return 0;
    if (grey[y*width+x] != target)
      return 0;
    grey[y*width+x] = dest;
    floodfill_r(grey, width, height, x - 1, y, target, dest);
    floodfill_r(grey, width, height, x + 1, y, target, dest);
    floodfill_r(grey, width, height, x, y - 1, target, dest);
    floodfill_r(grey, width, height, x, y + 1, target, dest);

    return 0;
}

/**
   Floodfill4 - floodfill, 4 connectivity.

   @param[in,out] grey - the image (formally it's greyscale but it could be
binary or indexed)
   @param width - image width
   @param height - image height
   @param x - seed point x
   @param y - seed point y
   @param target - the colour to flood
   @param dest - the colur to replace it by.
   @returns Number of pixels flooded.
*/
int floodfill4(unsigned char *grey, int width, int height, int x, int y,
unsigned char target, unsigned char dest)
{
   int *qx = 0;
   int *qy = 0;
   int qN = 0;
   int qpos = 0;
   int qcapacity = 0;
   int wx, wy;
   int ex, ey;
   int tx, ty;
   int ix;
   int *temp;
   int answer = 0;

   if(grey[y * width + x] != target)
     return 0;
   qx = malloc(width * sizeof(int));
   qy = malloc(width * sizeof(int));
   if(qx == 0 || qy == 0)
     goto error_exit;
   qcapacity = width;
   qx[qpos] = x;
   qy[qpos] = y;
   qN = 1;

   while(qN != 0)
   {
     tx = qx[qpos];
     ty = qy[qpos];
     qpos++;
     qN--;

     if(qpos == 256)
     {
       memmove(qx, qx + 256, qN*sizeof(int));
       memmove(qy, qy + 256, qN*sizeof(int));
       qpos = 0;
     }
     if(grey[ty*width+tx] != target)
       continue;
     wx = tx;
     wy = ty;
     while(wx >= 0 && grey[wy*width+wx] == target)
       wx--;
     wx++;
     ex = tx;
     ey = ty;
     while(ex < width && grey[ey*width+ex] == target)
       ex++;
     ex--;


     for(ix=wx;ix<=ex;ix++)
     {
       grey[ty*width+ix] = dest;
       answer++;
     }

     if(ty > 0)
       for(ix=wx;ix<=ex;ix++)
       {
	    if(grey[(ty-1)*width+ix] == target)
	    {
           if(qpos + qN == qcapacity)
	      {
             temp = realloc(qx, (qcapacity + width) * sizeof(int));
             if(temp == 0)
               goto error_exit;
             qx = temp;
             temp = realloc(qy, (qcapacity + width) * sizeof(int));
             if(temp == 0)
               goto error_exit;
             qy = temp;
             qcapacity += width;
	      }
           qx[qpos+qN] = ix;
           qy[qpos+qN] = ty-1;
           qN++;
	    }
       }
     if(ty < height -1)
       for(ix=wx;ix<=ex;ix++)
       {
         if(grey[(ty+1)*width+ix] == target)
	    {
           if(qpos + qN == qcapacity)
	      {
             temp = realloc(qx, (qcapacity + width) * sizeof(int));
             if(temp == 0)
               goto error_exit;
             qx = temp;
             temp = realloc(qy, (qcapacity + width) * sizeof(int));
             if(temp == 0)
               goto error_exit;
             qy = temp;
             qcapacity += width;
	      }
           qx[qpos+qN] = ix;
           qy[qpos+qN] = ty+1;
           qN++;
	    }
       }
   }

   free(qx);
   free(qy);

   return answer;
  error_exit:
   free(qx);
   free(qy);
   return -1;
}

int main(void)
{
    unsigned char *image;
    clock_t tick, tock;
    int i;

    image = malloc(100 * 100);
    tick = clock();
    for (i = 0 ; i < 10000; i++)
    {
       memset(image, 0, 100 * 100);
       floodfill_r(image, 100, 100, 50, 50, 0, 1);
    }
    tock = clock();
    printf("floodfill_r %g\n", ((double)(tock - tick))/CLOCKS_PER_SEC);

    tick = clock();
    for (i = 0 ; i < 10000; i++)
    {
       memset(image, 0, 100 * 100);
       floodfill4(image, 100, 100, 50, 50, 0, 1);
    }
    tock = clock();
    printf("floodfill4 %g\n", ((double)(tock - tick))/CLOCKS_PER_SEC);

    return 0;
}


Let's give it a whirl

malcolm@Malcolms-iMac cscratch % gcc -O3 testfloodfill.c
malcolm@Malcolms-iMac cscratch % ./a.out
floodfill_r 1.69274
floodfill4 0.336705


-- 
Check out Basic Algorithms and my other books:
https://www.lulu.com/spotlight/bgy1mm

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filling area by color atack safety fir <fir@grunge.pl> - 2024-03-16 05:11 +0100
  Re: filling area by color atack safety Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2024-03-16 11:33 +0000
    Re: filling area by color atack safety Ben Bacarisse <ben.usenet@bsb.me.uk> - 2024-03-16 13:55 +0000
      Re: filling area by color atack safety bart <bc@freeuk.com> - 2024-03-16 14:41 +0000
        Re: filling area by color atack safety Ben Bacarisse <ben.usenet@bsb.me.uk> - 2024-03-17 10:42 +0000
        Re: filling area by color atack safety Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-03-18 03:00 -0700
          Re: filling area by color atack safety Michael S <already5chosen@yahoo.com> - 2024-03-18 14:23 +0200
            Re: filling area by color atack safety Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-03-18 14:13 -0700
            Re: filling area by color atack safety fir <fir@grunge.pl> - 2024-03-19 16:05 +0100
              Re: filling area by color atack safety bart <bc@freeuk.com> - 2024-03-19 17:16 +0000
                Re: filling area by color atack safety bart <bc@freeuk.com> - 2024-03-19 17:33 +0000
                Re: filling area by color atack safety fir <fir@grunge.pl> - 2024-03-19 23:07 +0100
                Re: filling area by color atack safety David Brown <david.brown@hesbynett.no> - 2024-03-20 09:29 +0100
        Re: filling area by color atack safety Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-03-18 03:04 -0700
      Re: filling area by color atack safety Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2024-03-16 14:45 +0000
        Re: filling area by color atack safety scott@slp53.sl.home (Scott Lurndal) - 2024-03-16 18:21 +0000
          Re: filling area by color atack safety Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2024-03-16 20:02 +0000
            Re: filling area by color atack safety "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-03-16 13:29 -0700
              Re: filling area by color atack safety "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-03-17 13:19 -0700
                Re: filling area by color atack safety Michael S <already5chosen@yahoo.com> - 2024-03-18 14:40 +0200
            Re: filling area by color atack safety fir <fir@grunge.pl> - 2024-03-19 23:23 +0100
          Re: filling area by color atack safety Michael S <already5chosen@yahoo.com> - 2024-03-17 15:32 +0200
        Re: filling area by color atack safety Ben Bacarisse <ben.usenet@bsb.me.uk> - 2024-03-17 11:25 +0000
          Re: filling area by color atack safety Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2024-03-17 12:37 +0000
            Re: filling area by color atack safety Kaz Kylheku <433-929-6894@kylheku.com> - 2024-03-17 17:11 +0000
            Re: filling area by color atack safety Ben Bacarisse <ben.usenet@bsb.me.uk> - 2024-03-23 00:21 +0000
            Re: filling area by color atack safety scott@slp53.sl.home (Scott Lurndal) - 2024-03-23 14:43 +0000
              Re: filling area by color atack safety Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-03-23 11:48 -0700
                Re: filling area by color atack safety scott@slp53.sl.home (Scott Lurndal) - 2024-03-24 20:48 +0000
                Re: filling area by color atack safety Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-03-28 22:51 -0700
    Re: filling area by color atack safety David Brown <david.brown@hesbynett.no> - 2024-03-16 15:40 +0100
      Re: filling area by color atack safety Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2024-03-16 15:09 +0000
        Re: filling area by color atack safety Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2024-03-17 14:56 +0000
          Re: filling area by color atack safety Michael S <already5chosen@yahoo.com> - 2024-03-17 17:42 +0200
          Re: filling area by color atack safety Michael S <already5chosen@yahoo.com> - 2024-03-17 18:25 +0200
            Re: filling area by color atack safety Michael S <already5chosen@yahoo.com> - 2024-03-17 19:39 +0200
              Re: filling area by color atack safety Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-03-18 11:36 -0700
                Re: filling area by color atack safety Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2024-03-18 18:51 +0000
                Re: filling area by color atack safety Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-03-18 23:10 -0700
                Re: filling area by color atack safety Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2024-03-19 12:06 +0000
            Re: filling area by color atack safety fir <fir@grunge.pl> - 2024-03-20 00:03 +0100
              Re: filling area by color atack safety Michael S <already5chosen@yahoo.com> - 2024-03-20 01:17 +0200
                Re: filling area by color atack safety fir <fir@grunge.pl> - 2024-03-20 00:30 +0100
                Re: filling area by color atack safety Michael S <already5chosen@yahoo.com> - 2024-03-20 12:06 +0200
                Re: filling area by color atack safety fir <fir@grunge.pl> - 2024-03-20 13:44 +0100
                Re: filling area by color atack safety Michael S <already5chosen@yahoo.com> - 2024-03-20 15:44 +0200
                Re: filling area by color atack safety fir <fir@grunge.pl> - 2024-03-20 15:17 +0100
          Re: filling area by color atack safety fir <fir@grunge.pl> - 2024-03-20 02:15 +0100
        Re: filling area by color atack safety David Brown <david.brown@hesbynett.no> - 2024-03-17 17:45 +0100
          Re: filling area by color atack safety Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2024-03-17 18:28 +0000
            Re: filling area by color atack safety David Brown <david.brown@hesbynett.no> - 2024-03-18 07:58 +0100
              Re: filling area by color atack safety Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2024-03-18 09:26 +0000
                Re: filling area by color atack safety David Brown <david.brown@hesbynett.no> - 2024-03-18 17:28 +0100
                Re: filling area by color atack safety Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2024-03-18 17:25 +0000
                Re: filling area by color atack safety scott@slp53.sl.home (Scott Lurndal) - 2024-03-18 17:42 +0000
                Re: filling area by color atack safety bart <bc@freeuk.com> - 2024-03-18 18:50 +0000
                Re: filling area by color atack safety David Brown <david.brown@hesbynett.no> - 2024-03-19 11:41 +0100
                Re: filling area by color atack safety Richard Harnden <richard.nospam@gmail.invalid> - 2024-03-19 12:19 +0000
                Re: filling area by color atack safety Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-03-18 11:10 -0700
                Keith-world (Was: filling area by color atack safety) gazelle@shell.xmission.com (Kenny McCormack) - 2024-03-18 22:42 +0000
                Re: filling area by color atack safety David Brown <david.brown@hesbynett.no> - 2024-03-19 12:31 +0100
                Re: filling area by color atack safety "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-03-18 16:18 -0700
                Re: filling area by color atack safety David Brown <david.brown@hesbynett.no> - 2024-03-19 11:32 +0100
      Re: filling area by color atack safety scott@slp53.sl.home (Scott Lurndal) - 2024-03-16 18:25 +0000
        Re: filling area by color atack safety Ben Bacarisse <ben.usenet@bsb.me.uk> - 2024-03-17 10:31 +0000
          Re: filling area by color atack safety Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2024-03-17 12:28 +0000
            Re: filling area by color atack safety bart <bc@freeuk.com> - 2024-03-17 12:49 +0000
          Re: filling area by color atack safety David Brown <david.brown@hesbynett.no> - 2024-03-17 17:59 +0100
      Re: filling area by color atack safety fir <fir@grunge.pl> - 2024-03-19 23:52 +0100
        Re: filling area by color atack safety fir <fir@grunge.pl> - 2024-03-20 01:36 +0100
    Re: filling area by color atack safety Michael S <already5chosen@yahoo.com> - 2024-03-17 14:46 +0200
      Re: filling area by color atack safety bart <bc@freeuk.com> - 2024-03-17 12:54 +0000
        Re: filling area by color atack safety Michael S <already5chosen@yahoo.com> - 2024-03-17 15:15 +0200
          Re: filling area by color atack safety bart <bc@freeuk.com> - 2024-03-17 13:23 +0000
            Re: filling area by color atack safety Michael S <already5chosen@yahoo.com> - 2024-03-17 15:37 +0200
              Re: filling area by color atack safety David Brown <david.brown@hesbynett.no> - 2024-03-17 18:05 +0100
            Re: filling area by color atack safety Ben Bacarisse <ben.usenet@bsb.me.uk> - 2024-03-17 14:10 +0000
              Re: filling area by color atack safety Spiros Bousbouras <spibou@gmail.com> - 2024-03-17 16:58 +0000
                Re: filling area by color atack safety Ben Bacarisse <ben.usenet@bsb.me.uk> - 2024-03-17 22:14 +0000
                Re: filling area by color atack safety bart <bc@freeuk.com> - 2024-03-17 22:21 +0000
      Re: filling area by color atack safety Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-03-18 02:30 -0700
        Re: filling area by color atack safety Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2024-03-18 11:08 +0000
          Re: filling area by color atack safety Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-03-18 22:54 -0700
            Re: filling area by color atack safety Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2024-03-19 11:41 +0000
              Re: filling area by color atack safety Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-03-19 21:19 -0700
      Re: filling area by color atack safety fir <fir@grunge.pl> - 2024-03-20 01:13 +0100
        Re: filling area by color atack safety Michael S <already5chosen@yahoo.com> - 2024-03-20 10:41 +0200
          Re: filling area by color atack safety fir <fir@grunge.pl> - 2024-03-20 15:20 +0100
    Re: filling area by color atack safety Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2024-03-17 14:27 +0000
      Re: filling area by color atack safety bart <bc@freeuk.com> - 2024-03-17 15:13 +0000
      Re: filling area by color atack safety Peter 'Shaggy' Haywood <phaywood@alphalink.com.au> - 2024-03-19 10:57 +1100
        Re: filling area by color atack safety fir <fir@grunge.pl> - 2024-03-20 01:26 +0100
  Re: filling area by color atack safety bart <bc@freeuk.com> - 2024-03-16 19:13 +0000
    Re: filling area by color atack safety bart <bc@freeuk.com> - 2024-03-16 20:23 +0000
      Re: filling area by color atack safety Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2024-03-16 20:29 +0000
    Re: filling area by color atack safety fir <fir@grunge.pl> - 2024-03-20 01:48 +0100
      Re: filling area by color atack safety Peter 'Shaggy' Haywood <phaywood@alphalink.com.au> - 2024-03-22 13:04 +1100
        Re: filling area by color atack safety Michael S <already5chosen@yahoo.com> - 2024-03-22 17:55 +0300
          Re: filling area by color atack safety Michael S <already5chosen@yahoo.com> - 2024-03-22 18:31 +0300
        Re: filling area by color atack safety fir <fir@grunge.pl> - 2024-03-23 11:06 +0100
  Re: filling area by color atack safety Peter 'Shaggy' Haywood <phaywood@alphalink.com.au> - 2024-03-17 18:03 +1100
  Re: filling area by color atack safety Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-03-18 13:09 -0700
    Re: filling area by color atack safety Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-03-18 22:42 -0700
      Re: filling area by color atack safety Michael S <already5chosen@yahoo.com> - 2024-03-19 13:18 +0200
        Re: filling area by color atack safety Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2024-03-19 11:57 +0000
          Re: filling area by color atack safety Michael S <already5chosen@yahoo.com> - 2024-03-19 15:49 +0200
            Re: filling area by color atack safety Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-03-19 21:43 -0700
              Re: filling area by color atack safety Michael S <already5chosen@yahoo.com> - 2024-03-20 10:56 +0200
                Re: filling area by color atack safety Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-03-20 06:51 -0700
          Re: filling area by color atack safety Michael S <already5chosen@yahoo.com> - 2024-03-19 19:18 +0200
            Re: filling area by color atack safety fir <fir@grunge.pl> - 2024-03-20 09:27 +0100
              Re: filling area by color atack safety fir <fir@grunge.pl> - 2024-03-20 09:39 +0100
              Re: filling area by color atack safety fir <fir@grunge.pl> - 2024-03-20 09:51 +0100
            Re: filling area by color atack safety Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-03-20 07:27 -0700
              Re: filling area by color atack safety Michael S <already5chosen@yahoo.com> - 2024-03-24 20:27 +0300
                Re: filling area by color atack safety Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-03-24 13:26 -0700
                Re: filling area by color atack safety "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-03-24 14:26 -0700
                Re: filling area by color atack safety Michael S <already5chosen@yahoo.com> - 2024-03-25 01:28 +0300
                Re: filling area by color atack safety Michael S <already5chosen@yahoo.com> - 2024-03-26 17:52 +0200
                Re: filling area by color atack safety Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-03-30 00:54 -0700
                Re: filling area by color atack safety Michael S <already5chosen@yahoo.com> - 2024-03-30 21:26 +0300
                Re: filling area by color atack safety Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-03-28 23:04 -0700
                Re: filling area by color atack safety Michael S <already5chosen@yahoo.com> - 2024-03-29 15:21 +0200
                Re: filling area by color atack safety Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-03-29 23:58 -0700
                Re: filling area by color atack safety Michael S <already5chosen@yahoo.com> - 2024-03-30 21:15 +0300
                Re: filling area by color atack safety Michael S <already5chosen@yahoo.com> - 2024-03-31 10:54 +0200
                Re: filling area by color atack safety Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-03-30 11:59 -0700
            Re: filling area by color atack safety Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-03-20 10:26 -0700
              Re: filling area by color atack safety Michael S <already5chosen@yahoo.com> - 2024-03-21 15:36 +0200
                Re: filling area by color atack safety Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-03-21 09:47 -0700
        Re: filling area by color atack safety Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-03-19 21:40 -0700
          Re: filling area by color atack safety "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-03-19 21:43 -0700
            Re: filling area by color atack safety "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-03-19 21:48 -0700
          Re: filling area by color atack safety Michael S <already5chosen@yahoo.com> - 2024-03-20 11:54 +0200
            Re: filling area by color atack safety Ben Bacarisse <ben.usenet@bsb.me.uk> - 2024-03-20 10:23 +0000
              Re: filling area by color atack safety Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2024-03-20 12:06 +0000
              Re: filling area by color atack safety Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-03-20 07:52 -0700
            Re: filling area by color atack safety Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-03-20 10:01 -0700
              Re: filling area by color atack safety Michael S <already5chosen@yahoo.com> - 2024-03-24 19:33 +0300
                Re: filling area by color atack safety Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-03-24 10:24 -0700
                Re: filling area by color atack safety Michael S <already5chosen@yahoo.com> - 2024-03-25 01:04 +0300
                Re: filling area by color atack safety - worst memory size Michael S <already5chosen@yahoo.com> - 2024-04-05 17:30 +0300

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