%ffp
Category: "FM Tutorial"
Title: "Blur  II"
Author: "Ilyich the Toad"

ctl[0]:"Blur Width",range=(2,scaleFactor*X/2),val=3,pagesize=3,linesize=1
ctl[1]:"Blur Height",range=(2,scaleFactor*Y/2),val=3,pagesize=3,linesize=1

ForEveryTile:
{

int kernelheight; int kernelwidth;
int xlook; int ylook;
int sum; int amount; int progress;

One more variable added - "progress" - to easily count total progress during multistep processeing.

setCtlRange(0,2,scaleFactor*X/2);
setCtlRange(1,2,scaleFactor*Y/2);

kernelheight=max(ctl(1)/scaleFactor, 1);
kernelwidth=max(ctl(0)/scaleFactor, 1);

progress=0;

Here we start first pass of the filter:

for (y=0; y < Y; y++) {
 if(updateProgress(progress,2*Y)) break;  progress++;

We update progress bar as usual, at every row calculation, but now we use 2*Y as a maximum value since we process the entire image two times.

for (x=0; x   for (z= 0; z < Z; z++) {
  sum=0; amount=0;
  for (xlook=0; xlook<kernelwidth; xlook++)
  {
  sum+= src((x+xlook-kernelwidth/2),y,z);
  amount++;
  }; //accumulate pixels in a raw
  tset(x,y,z,sum/amount);

We calculate blur along "xlook" only and store the result into "t" array using "tset" function.

  }
 }
}

Finishing first pass. Now the "semiblurred" image is stored in "t" array and we start a second pass:

for (y=0; y < Y; y++) {
 if(updateProgress(progress, 2*Y)) break;
 progress++;
 for (x=0; x < X; x++) {
  for (z= 0; z < Z; z++) {
  sum=0; amount=0;
  for (ylook=0; ylook<kernelheight; ylook++)
  {
  sum+= tget(x,(y+ylook-kernelheight/2),z);

Retrieving values from "t" array using "tget" command.

  amount++;
  }; //accumulate pixels in a column
  pset(x,y,z,sum/amount); //divide the sum onto kernel size
  }
 }
}

updateProgress(0, 100);
true;
}

Filter ended.