DESCRIPTION:

  PatchWPA8  replaces WritePixelArray8() and WritePixelLine8() functions
  of   graphics.library   with   a  highly  optimised  chunky-to-plannar
  routines.   In  most  cases on 8bit screen it gives acceleration up to
  3.5 times.


REQUIREMENTS:

  OS3.0+ (temporary bitmap is allocated via AllocBitMap)
  CPU 68020 or better
  NOTE: Don't use it with gfx boards!


BENCHMARKS:
                          Original  Patched

  Converting 640x480x8 screen 10 times:

  PAL:Hires Laced          22.23s     7.16s (1)   (3.1x faster)
  DBLPAL:Hires NoFlicker   43.68s    12.10s       (3.6x faster)

  Real applications:

  VT - JPEG 640x480x24     42.03s    38.12s
  VT - JPEG 640x480x8      13.03s     9.23s
  Flick opt ROM             2.8fps    4.2fps (2)
  CyberShow and CyberTVPlayer are faster about 2-2.5 times (visually)


  All times are measured by SpySystem3 on 68030@25Mhz.
  Testing program with a source is included in this archive.

  (1) Yes!  It's true :(  Write  access  to Chip memory is almost 3 times
      slower in doublescan modes (8bit) than in 15kHz PAL or NTSC so WPA8
      and WPL8 are slower, too.

  (2) It's  done  just for a test so DON'T use ROM option anymore because
      Flick has own very fast (state of the art) c2p routines.

  NOTE:   Many  programs  (f.e.   FastJPEG,  FastView)  use own fast c2p
  routines  with  direct access to screen (system unfriendly but faster)
  so this patch will not speed up anything.


USAGE:

  PatchWPA8 can be started ONLY from CLI. It works like a switch.
  No arguments are supported.


AUTHOR:

  PatchWPA8 was developed in Devpac assembler on A4030/882/10MB/850MB/CDROM.
  C2P  routines  are based on  several sources in Aminet and highly changed
  by me for system usage. All comments or bug reports send to:

           Pawel Hernik
           Nowowiejska 24/3
           25-532 Kielce
           POLAND
           tel. (041)27012

  E-mail:  spi-ph@srv1.tu.kielce.pl


DISTRIBUTION:

  PatchWPA8  is  FREEWARE.  You may use and copy this program freely but
  all  files  must  be  copied  in an unmodified state preferably in LhA
  or  LZX  archive.  Use it on your own risk.  If you use PatchWPA8 send
  me a postcard or message via e-mail.


BUGS:

  - I   can't   write  directly  into  RastPort's  BitMap  (it  is  system
    unfriendly!)  so  data is  blitted via BltBitMapRastPort.  In original
    function (by Commodore) c2p routine took ~80% of all time but now it's
    only  ~30%  and slow blitter is real bottle neck :( If anyone has idea
    how  to  do  it  system friendly but without using blitter let me know
    about it. Direct write to BitMaps gives acceleration over 8 times (!).

  - Patched  routine  doesn't  damage  source chunky in A2 (Is it really a
    bug? :) )

  - Patch ignores TmpRastPort in A1 and own bitmap is used (because I need
    8bit  interleaved  bitmap  aligned  to 32bit).  It makes problems when
    some tasks use WPA8 and/or WPL8 simultaneously.  I used very primitive
    semaphore  mechanism to avoid conflicts - it isn't system friendly but
    WORKS!

  - Chunky data must have less than 2048 pixels/line (look above) 

  - Only  8bit  c2p  is  optimised but it works well for 7bit and less but
    acceleration isn't as  big as in 8bit. It's still faster than original
    routines.


HISTORY:

  1.0 - first release