Short:        Mouse/autonomous Workbench plasma
Author:       ShK
Uploader:     shk sci fi
Type:         gfx/misc
Version:      1.21
Replaces:     gfx/misc/PlasmaWB.lha
Requires:     AmigaOS 3.1+, Picasso96; 68k: 68020+ and FPU; PPC: WarpOS
Architecture: m68k-amigaos >= 3.1.0; ppc-warpup

PlasmaWB is an interactive and autonomous plasma trail effect for AmigaOS
Workbench.

The program opens a resizable window on the Workbench public screen and
renders a colourful glowing plasma trail. In normal mode the trail follows
the mouse pointer. Version 1.21 adds five evolving autonomous motion modes
that use the existing plasma trail, blur and presentation pipeline.

Version 1.21 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 renders more frames of
the same motion, while a slower 68k renders fewer. The final window update
uses a Picasso96 off-screen bitmap, allowing a graphics board blitter to
perform the scaling blit when the bitmap fits in board memory.

Autonomous motion:

  Press A to cycle through:

    Lissajous
    Rose
    Spiro
    Orbit
    Harmono
    Off

  Pressing and holding A changes the mode only once. Release A and press it
  again to advance to the next mode. When an autonomous mode is active,
  real mouse coordinates are ignored.

  The autonomous paths use Q32 phase accumulators and the existing sine
  lookup table. No per-frame sin(), cos(), exp(), pow() or sqrt() calls are
  added to the render loop.

  The autonomous speed can be adjusted while a mode is active:

    Wheel up              increase speed
    Wheel down            decrease speed
    Hold middle button
      and move mouse up   increase speed
      and move mouse down decrease speed

  The speed range is 25-400 percent. The initial speed is 100 percent.

  While autonomous motion is active, the window title shows the mode name,
  FPS and speed, for example:

    PlasmaWB 1.21 | Auto: Rose | FPS: 50 | Speed: 100%

  FPS is sampled about once per second by reusing the existing frame timer.
  Long stalls are discarded, preventing temporary 0 FPS readings.

  When autonomous motion is disabled, the title is:

    PlasmaWB 1.21 | Auto: Off

Controls:

  Mouse move       Draw the plasma trail when Auto is Off
  A                Select the next autonomous mode
  Mouse wheel      Adjust autonomous speed
  Hold MMB + move  Adjust autonomous speed vertically
  Hold LMB         Use a tighter trail spread
  R                Clear and reseed at the current control position
  Q/Esc            Quit

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 before doing any real work.

Source code:

  The C source code and dual-target Makefile are included. Full build and
  inspection instructions are in README.txt inside the archive.

Notes:

  PlasmaWB is intended for AmigaOS 3.x systems with Picasso96. The trail
  looks best in 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.

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 WarpOS/PPC binaries.
        The animation is time-normalized, the trail rasterizer is faster,
        and the WarpOS binary manages its own PPC stack.
  1.21  Added an autonomous mode and an A-key mode cycle: Lissajous, Rose,
        Spiro, Orbit, Harmono and Off. Added wheel and middle-button drag
        speed control, mode names and speed in the title, A-key repeat
        suppression, Intuition V47 extended-wheel input with a legacy
        RAWKEY fallback, and corrected the non-Lissajous motion scaling.