// .----------------------------------------------------------------------.
// |  Jaap's distributed render system for povray animations      v 0.01  |
// |                                                                      |
// |  (for a Windows network)                                             |
// |                                                                      |
// |  2006 J.W. Stolk                       http://www.jwstolk.xs4all.nl  |
// '----------------------------------------------------------------------'

// .----------------------------------------------------------------------.
// |  Why?                                                                |
// '----------------------------------------------------------------------'
//
// It's very easy to speed up rendering of animation by using more computers,
// simply render a subset of frames on each computer. it can be done by
// choosing apropreate start_frame and end_frame settings for each computer.
// The biggest disadvantage of this methode is that the render time per frame
// (as wel as the processing power of the used computers) can vary a lot.
// This results is that some comuters have finished ther part (and do nothing)
// while other computers still have a few days to go...
// 
// This render system contains a "master" (this file) that distributes the
// to-be-rendered frames to the "clients" one by one, untill all frmes are
// rendered. this way all computers will be used untill the whole animation
// is compleated.
//
// appart from a small dos batch file that repeatetly runs povray, its all SDL,
// so you should be able to change it to your needs.  :-)

// .----------------------------------------------------------------------.
// |  How it works:                                                       |
// '----------------------------------------------------------------------'
//
// Please note: I'm have just thrown this together and I don't have the time
//              to clean things up right now. a lot of directories and file
//              names are hard-coded, so you will have to change them if needed.
//
// mater <-> client communication:
// very simple: it is done with files in a shared folder on a windows network.
// all clients need to have read and write permission in this folder.
//
//
// It all starts with the master_loop.bat batch file. This batch file
// contains a simple loop that repeatedly "renders" the master.pov file.
// you should run this _ONLY_ on the master computer.
//
// master.pov keeps track of the render farm status using a simple textfile.
// the textfile mainly indicates which frame each client is rendering.
// master.pov assigns frames to the clients by generating a batch file with
// the name of the client, containing a render command for that frame.
//
// Each client runs its own copy of the client_loop.bat batch file. This
// batch file moves the render command to the client, runs it and copies the
// rendered image back to the shared folder.
//
// master.pov detects that a client is ready by testing for the returned image
// file. if the image is returned, it assigns a new frame to that client.
//

// .----------------------------------------------------------------------.
// |  usage:                                                              |
// '----------------------------------------------------------------------'

// Make up a name for each computer and put it in this list:

#declare clients = 3;
#declare client_name = array[clients] {
  "pc_red",
  "pc_green",
  "pc_blue"  // (note the missing comma after the last entry)
}

// put the following batch file on each client. (call it client_loop.bat)

/* --- client_loop.bat --- (cut here) ----

@echo off

:loop

REM -- move the render command to this client:
copy "z:\render_farm\run_pov_pc_red.bat" "c:\render_farm\" /y
del  "z:\render_farm\run_pov_pc_red.bat"

REM -- run the render command:
call run_pov_pc_red.bat

REM -- 1 sec delay: (needs the sleep.exe program!)
sleep 1

REM -- delete the finished render command:
REM    (prevents running it again)
del  "c:\render_farm\run_pov_pc_red.bat"

REM -- move the resulting image to the shared directory:
REM    (this indicates that the client is ready)
copy "c:\render_farm\*.png" "z:\render_farm\"
del  "c:\render_farm\*.png"

goto loop
   
*/ //--- (upto here) ----

// change "pc_red" to the name of that client.
// change "z:\render_farm\" to the name of the folder shared by all clients.
// change "c:\render_farm\" to the name of the local folder on the client.
// you will also need the sleep.exe DOS utility !!

// set the render settings for the animation:

// "test.pov" -> test001.png .. test199.png
#declare animation_name = "test";  // the pov-file you want to render, without ".pov" !!

#declare animation_first_frame   = 1;
#declare animation_last_frame    = 199;

// options without "+SF" or "+EF" !!!!!:
//(i don't know why I needed the "+L". it's already in the povray.ini file)
#declare animation_render_options= "+w720 +h400 +a0.3 -j +KF8.0 +KFF199 +FN +L\"C:\\render_farm\\POV-Ray for Windows v3.6\\INCLUDE\""; 

#declare client_povray_location  = "C:\\render_farm\\POV-Ray for Windows v3.6\\bin\\megapov.exe";
#declare status_file_name        = "render_farm_status.txt";

#debug " -=- -=- -=- -=- -=- -=- -=- -=- -=- -=- -=- -=- -=- -=-\n"

// the master computer runs (renders) master.pov repeatedly using
// the following batch file on each computer. (call it master_loop.bat)

/* --- master_loop.bat --- (cut here) ----

@echo off

:loop

REM -- try to assign frames to clients:
C:\render_farm\POV-Ray for Windows v3.6\bin\megapov.exe master.pov +w10 +h10 -a -j -D -F

REM -- rename new assignments from .tmp to .bat:
REM    (to prevent race conditions)
call rename_list.bat

REM -- 1 sec delay: (needs the sleep.exe program!)
sleep 1

goto loop
   
*/ //--- (upto here) ----

// That's it !! you are now ready to start your render farm :-)
//
// start the client_loop.bat on each client first.
// finally start the master_loop.bat on the master computer.

// .----------------------------------------------------------------------.
// |  notes: (PLEASE READ):                                               |
// '----------------------------------------------------------------------'
//
// -you can open the render_farm_status.txt at any time using notepad
//  (notepad will open the file as read-only). so you can see what the next
//  (non-rendered) frame is and which frame each client is rendering.
// -the only limmitation is the number of computers that you can give read/write
//  acces to a shared folder. (limmited to 10 in XP ??? (to sell more windows server?))
// -it's setup for PNG output images.
// -it's setup for megapov, you only need to change the client_povray_location
//  to make it work with the official pov-ray
// -you probably need to disable I/O restrictions (only for the shared folder?)
// -each client has it's own copy of the povray code that you want to render.
//  (local copy is faster anyway)
// -before starting:
//    -old render_farm_status.txt file should be deleted !!!
//    -the output directories in the clients should not contain _any_ PNG's
//    -the clients should not contain old render commands
//    -the shared directory should not contain PNG's with the same filename.
//    -the shared directory should not contain old render commands
// -you should probably not run the client on the master computers. it would
//  result in two instances of povray running on the same computer.
// -you can use a slow computer as master, since it doesn't do any rendering.
// -it's best to start the loop.bat files from a dos-box. that way the dos-box
//  is not closed if there is an error, so you can read the error :-)
// -the loops can only be stoped manually ( <ctrl>+c ) or close the dos-box.
//  they don't stop automatically if the animation is rendered.
// -povray must be installed in the same path on each client
// -I installed povray+megapov in c:\render_farm\  (can be anywhere)
// -I needed to use a very short pov-ray name to keep the name of the rendered
//  images (including the frame number!) within 8 chracters. it's probably a
//  windows megapov limmitation, I haven't noticed it in the Linux version.
// -possible (big?) rewrite: don't define a table with clients names here,
//  let each client indicate it's own name in some way. That would make it
//  possible to add and remove clients while rendering.

// .----------------------------------------------------------------------.
// |----------------------------------------------------------------------|
// '----------------------------------------------------------------------'

// .----------------------------------------------------------------------.
// |  read the status file:                                               |
// '----------------------------------------------------------------------'
#declare status_first_frame = 0;
#declare client_working = array[clients];
#declare client_frame   = array[clients];
#declare not_used       = "not_used";

#if(file_exists(status_file_name)=1)
  // file exists: read it:
  #fopen status_file status_file_name read
  #read (status_file, not_used, status_first_frame)
  #declare client=0;
  #while (client < clients)
    #read (status_file, not_used, val1, val2)
    #declare client_working[client] = val1;
    #declare client_frame[client]   = val2;
    #declare client=client+1;
  #end
  #fclose status_file
#else
  // file does not exist: start with clear status:
  #declare status_first_frame = animation_first_frame; 
  #declare client=0;
  #while (client < clients)
    #declare client_working[client] = 0;
    #declare client_frame[client]   = 0;
    #declare client=client+1;
  #end
#end

// .----------------------------------------------------------------------.
// |  check if any of the clients are ready:                              |
// '----------------------------------------------------------------------'

// if a client has returned its output image, it's ready :-)

// calculate number of digits in output images:
#declare animation_output_digits = 1;
#declare animation_output_max    = 9;
#while(animation_last_frame > animation_output_max)
  #declare animation_output_digits = animation_output_digits + 1;
  #declare animation_output_max    = animation_output_max*10 + 9;
#end

#declare client=0;
#while (client < clients)
  #if(client_working[client] = 1)
    #declare PNG_file_name = concat("z:\\render_farm\\",animation_name, str(client_frame[client],-animation_output_digits,0),".png");
    #if(file_exists(PNG_file_name)=1)
      #debug concat("client ",client_name[client]," has compleated frame ",str(client_frame[client],0,0),".\n")
      #declare client_working[client] = 0;
      #declare client_frame[client]   = 0;
    #else
      #debug concat(PNG_file_name," not ready\n")
    #end
  #end
  #declare client=client+1;
#end

// .----------------------------------------------------------------------.
// |  generate new command batch files for clients that are ready:        |
// '----------------------------------------------------------------------'
// The file is generated with a .tmp extension, and later renamed,
// to prevent that a client reads an incompleat command.

#fopen bat_rename "rename_list.bat" write
#declare client=0;
#while (client < clients)
  #if(status_first_frame > animation_last_frame)
    #debug "all frames are done !! (currently rendering the last frame(s) )\n"
    #declare client=9999; // (break out of loop)
  #else
    #if(client_working[client] = 0)
      #debug concat("assigned frame ",str(status_first_frame,0,0)," to client ",client_name[client],"\n")
      // generate new command batch file:
//    #declare tmp_file_name = concat("z:\\render_farm\\run_pov_",client_name[client],".tmp");
//    #declare bat_file_name = concat("z:\\render_farm\\run_pov_",client_name[client],".bat");
      #declare tmp_file_name = concat("run_pov_",client_name[client],".tmp");
      #declare bat_file_name = concat("run_pov_",client_name[client],".bat");
      #fopen bat_file tmp_file_name write
      #write(bat_file, "\"",client_povray_location,"\" ",animation_name,".pov ",animation_render_options)
      #write(bat_file, " +SF",str(status_first_frame,0,0)," +EF",str(status_first_frame,0,0),"\n")
      #fclose bat_file
      // add it to the rename_list batch file:
      #write(bat_rename, "rename \"",tmp_file_name,"\" \"",bat_file_name,"\"\n")
      // update the client status:
      #declare client_working[client] = 1;
      #declare client_frame[client]   = status_first_frame;
      #declare status_first_frame = status_first_frame + 1;
    #end
  #end
  #declare client=client+1;
#end
#fclose bat_rename

#debug " -=- -=- -=- -=- -=- -=- -=- -=- -=- -=- -=- -=- -=- -=-\n"

// .----------------------------------------------------------------------.
// |  write the status file:                                              |
// '----------------------------------------------------------------------'
#fopen status_file status_file_name write

#write(status_file, "\"next_frame:\",",status_first_frame,",\n")
#declare client=0;
#while (client < clients)
  #write(status_file,"\"",client_name[client],"\",",client_working[client],",",client_frame[client]",\n")
  #declare client=client+1;
#end
#fclose status_file

//end