Short:        Mouse-driven Workbench plasma
Author:       ShK
Uploader:     shk sci fi
Type:         gfx/misc
Version:      1.10
Requires:     AmigaOS 3.1+, Picasso96; 68k: 68020+ and FPU; PPC: WarpOS
Architecture: m68k-amigaos >= 3.1.0; ppc-warpup

PlasmaWB is a mouse-driven plasma trail effect for AmigaOS Workbench.

The program opens a resizable window on the Workbench public screen and
renders a colourful glowing plasma trail that follows the mouse pointer.
It uses CPU rendering for the effect and Picasso96 for RTG output.

Version 1.10 ships two binaries built from the same C source:

  PlasmaWB        68k (68020+ with FPU)
  PlasmaWB.ppc    PowerPC (CyberStorm/Blizzard PPC with WarpOS)

The animation is time-normalized: the trail moves and fades at the speed
of the original effect on every machine. A fast PPC simply renders more
frames of the same motion, a slow 68k fewer. The final window update uses
a Picasso96 off-screen bitmap which lets the graphics board blitter do
the scaling blit when the bitmap fits in board memory.

Controls:

  R       Clear the window and reseed the trail
  Q/Esc   Quit
  LMB     Use a tighter trail spread while held down

Installation:

  Copy the PlasmaWB drawer anywhere. Start the 68k binary from its icon
  or Shell. PlasmaWB.ppc intentionally has no icon; start it from Shell.

  PlasmaWB: if started from Workbench, a stack of 102400 bytes is
  recommended. The program also contains a stack cookie for systems that
  honour it.

  PlasmaWB.ppc: no stack setting is needed. The program switches to an
  internal 128 KB PPC stack by itself before doing any real work.

Source code:

  The C source code and the dual-target Makefile are included. The same
  PlasmaWB.c builds both binaries.

  Targets:

    make            build both binaries (same as "make all")
    make 68k        68k binary            -> PlasmaWB
    make ppc        WarpOS/PPC binary     -> PlasmaWB-604e.wos
    make strip      symbol-free 68k binary -> PlasmaWB.stripped
    make clean      remove all build products

  Variables (defaults in parentheses):

    PREFIX      68k cross toolchain, Bebbo's gcc   (/opt/amiga13)
    PPCPREFIX   PPC cross toolchain, mos2wos gcc   (/gg)
    P96SDK      Picasso96 developer package        (/opt/amiga-sdks/...)
    FPU=0       build the 68k binary without FPU instructions
    BUILD_DATE  embedded build date                (today)

  Example:

    make clean
    make P96SDK=/opt/amiga-sdks/Picasso96Develop

  The PPC target produces PlasmaWB-604e.wos, which is converted into the
  final executable on the Amiga:

    Elf2Exe2 PlasmaWB-604e.wos PlasmaWB.ppc

Notes:

  PlasmaWB is intended for AmigaOS 3.x systems with Picasso96. The trail
  looks best on a 24-bit or 32-bit screen mode; 16-bit modes show some
  banding in the soft gradients. A screenshot is included in the archive
  as Screenshots/PlasmaWB.jpg.

History:

  1.00  First public release.
  1.02  Added a Picasso96 off-screen bitmap presentation path. When the
        bitmap is placed in board memory, the final window update can use
        the graphics board blitter. The CPU-rendered plasma effect itself
        is unchanged.
  1.10  The same source now builds both the 68k and the WarpOS/PPC
        binaries with the included dual-target Makefile. The animation is
        time-normalized, so the effect runs at the original speed on
        every machine. The trail rasterizer was rewritten and is
        considerably faster. The WarpOS binary manages its own PPC stack
        and needs no stack setting.