#!/usr/local/bin/perl
#
#RiSpheres will be emitted as ellipsoid type blobbys
#RiCurves will be emitted as segment type blobbys
#
#also the geometry should not be instanced.
#
#usage: cat in.rib | perl houdini_part2blob.filter > out.rib
#
#jiversen@d2.com

$|=1;

$sectPattern = 'Object bl_';  #it will start to process blobbies once it finds this...
$printhead = "FILTER: [BLOB]";
 
print STDERR "$printhead starting blobby filter...\n";
print STDERR "$printhead $0: converts houdini particles in rib to blobbies\n";
print STDERR "$printhead looks for objects with the prefix of 'bl_'\n";

$ingeo = 0;
$startblob = 0;
$lineno = 0;
$skip = 0;
$firstFrame = ($skip)? 1: 0;
$wantSkip = 0;
undef @blTrans;
undef @blTrans2;
undef @blgeo;
undef @repl;

while (<>) {
  $lineno++;
  if (/Display (".+\.z")/) {
    push (@repl, $1);
  }
  if (/^version/) {
    #add imager
    print STDOUT $_;
    #print STDOUT qq|Imager "background" "color" [.5 .5 .6]\n|;
    next;
  }
  elsif ($wantSkip && $firstFrame && /FrameBegin/) {
    $skip = 1;
    next;
  }
  elsif ($firstFrame && /FrameEnd/) {
    $skip = 0;
    $firstFrame = 0;
    next;
  }
  elsif ($skip) {
    print STDERR "$printhead skipping\n";
    next;
  }
  elsif ($firstFrame && /^(.+ "jitter" [0]) (.+)$/) {
    #don't want the midpoint jitter
    $_= "$1\n";
  }
  
  #$startblob = 1;
  if (/($sectPattern.+)/) {
    print STDERR "$printhead writing blobbies for $1\n";
    $startblob = 1;
  }
  elsif (!$startblob) {
    #just emit blindly
    print;
  }    
  elsif (/EndObject/) {
    $startblob = 0;
    #do blob build
    if ($sphereBlob) {
      $n = @blgeo;
      &emitSphereBlobMain;
      $sphereBlob = 0;
      print STDOUT "\tTransformEnd\n";
      print STDOUT "AttributeEnd\n";
    }
    print STDOUT $_;
  }
  elsif (/TransformBegin/) {
    $ingeo = 1;
    $_ = <>;
    $lineno++;
    
    if (/MotionBegin/) {
      print STDERR "$printhead preserving motionblur on blobbies\n"    if( !$haveMotion ); #print message only once!
      $haveMotion = 1;
      $_ = <>;
      $lineno++;
    }
    
    if (/ConcatTransform/) {
      $firstline = $_;
      chomp( $firstline );
      $_ = <>;  # read in second line of concattransform
      $lineno++;
      push (@blTrans, "$firstline$_");                
      $_ = <>;
      $lineno++;
    }
    else {
      #gotta put something
      push (@blTrans, '');
      print STDERR "$printhead Expected translate but got: $_  - line $lineno";
    }
    
    if ($haveMotion && /ConcatTransform/) {
      $firstline = $_;
      chomp( $firstline );
      $_ = <>;  # read in second line of concattransform
      $lineno++;
      push (@blTrans2, "$firstline$_");                
      $_ = <>;
      $lineno++;
    }
    if ($haveMotion && /MotionEnd/) {
      $_ = <>;
      $lineno++;
    } 
    if (/Sphere/) {
      push (@blgeo, $_);
      $sphereBlob = 1;
    }
    else {
      die ("$lineno: No sphere found: $_\n");
    }
  }
  elsif (/TransformEnd/) {
    $ingeo = 0;
    
  }
  elsif (/Curves/) {
    /"(\w+)"\s+\[([^\]]+)\]/;
    $curvetype = $1;
    @verts = split (' ', $2);
    $nverts = @verts;
    if ($curvetype =~ /linear/ && $verts[0] == 2) {
      $/ = "]";
      $_ = <>;
      $lineno++;
      $/ = "\n";
      s/\]//;
      #$_  "P" [ ...
      s/\s+"P\w*"\s+\[\s+//;
      @points = split();
      $_ = <>; # should be \n from previous block
      $lineno++;
      $_ = <>;
      $lineno++;
      if (/"constantwidth" \[(.+)\]/) {
        $width = $1;
        &emitCurveBlobMain;
      }
      else {
        die ("RiCurve wasn't constantwidth:$_");
      }
    }
    else {
      die "only support RiCurves that are linear and have 2 vertices";
    }
  }
  elsif ($sphereBlob && /AttributeEnd/) {
    #do nothing
    next;
  }
  else {
    #not sure so emit
    print STDOUT $_;
  }
  
}


print STDERR "$printhead exiting blobby filter...\n";



# ------------------------------------------------

sub emitSphereBlobMain {  
  if ($haveMotion) {
    print STDOUT "MotionBegin [0 1]\n";
  }

  &emitSphereBlob (@blTrans);

  if ($haveMotion) {
    &emitSphereBlob (@blTrans2);
    print STDOUT "MotionEnd\n";
  }
  $haveMotion = 0;
}

# ------------------------------------------------

sub emitSphereBlob {
  local (@trans) = @_;
  local ($i, $blobPos, $coord, $scale, $nentries);
  local ($headMatrix);
  $nentries = @blgeo;

  print STDOUT "Blobby $nentries [\n";
  $blobPos = 0;
  for ($i = 0; $i < $nentries; $i++) {    
    print STDOUT "\t1001 $blobPos\n";
    $blobPos += 16;
  }
  print STDOUT "0 $nentries ";
  for ($i = 0; $i < $nentries; $i++) {    
    print STDOUT "$i ";
  }
  print STDOUT "\n] [\n";
  for ($i = 0; $i < $nentries; $i++) {    
    $coord = $trans[$i];
    $coord =~ /\[(.*?)\]/;   # everything between the square brackets (of "ConcatTransform[ .... ]" )
    $coord = $1;
    $scale = $blgeo [$i];
    $scale =~ s/Sphere (\S+)(.+)\n$/$1/;

    print STDOUT "$coord \n";
  }
  print STDOUT "]\n \t[\t\n";
  print STDOUT "\n\t]\n";
}

# ------------------------------------------------

sub emitCurveBlobMain {
  local ($iter, $x, $y, $z, $iseven, $idmatrix);
  local (@lseg);
  
  $idmatrix = "1 0 0 0  0 1 0 0  0 0 1 0  0 0 0 1";

  print STDOUT "Blobby $nverts [\n";
  $blobPos = 0;
  for ($i = 0; $i < $nverts; $i++) {
    print STDOUT "\t1002 $blobPos\n";
    $blobPos += 23;
  }
  print STDOUT "0 $nverts ";
  for ($i = 0; $i < $nverts; $i++) {
    print STDOUT "$i ";
  }
  print STDOUT "\n] [\n";
  $iter = 0;
  while ($x = shift (@points)) {
    $isodd = ($iter % 2);
    #print "iter $iter $isodd\n";
    $iter++;
    $y = shift (@points);
    $z = shift (@points);

    $lseg [$isodd] = "$x $y $z";
    if ($isodd) {
      print STDOUT "@lseg $width $idmatrix\n";
    }
  }
  print STDOUT "\n] []\n";
  print STDOUT "\tTransformEnd\n";

}