opal-zig v2.0.2-1

Changed

• Binds opal 2.0.2. NEW (register 105h bit 0) is a live mode bit: bank 1, waveforms
  4-7, CHA and CHB, and four-operator pairing apply only while it is set. Disabling
  4-op no longer clears pair_index. That field is the physical partner, or ch_none
  for channels that cannot pair. chan_type says whether 4-op is active. init now
  sets every operator's eg_out to 0x1FF, so a snapshot taken before the first sample
  is silent. A masked timer overflow now sets FT1 or FT2. IRQ (bit 7) is set only when
  that timer is unmasked.

Added

• version_major, version_minor, version_patch, and the packed version
  (major * 10000 + minor * 100 + patch), matching the OPAL_VERSION_* macros in
  opal.h.
• Tests for the 2.0.2 core fixes: pair-index wiring, NEW as a live mode bit, silence
  after enabling OPL3 without writing C0, stored waveforms 4-7 while NEW is clear,
  and a masked timer overflow that must still raise FT1.

Fixed

• The pair_index field comment said it was ch_none when 4-op was off. Init
  pre-wires the physical partners, so a visualizer that treated a nonzero pair_index
  as "4-op is on" would misread every capable channel after init.

opal-zig v2.0.1-1

Changed

• Binds opal 2.0.1, which fixes a 32-bit signed overflow in the output resampler.
  The overflow was reachable whenever a track swings more than half of full scale
  between two consecutive chip samples, and it aborted the process outright under
  any toolchain that traps on signed overflow, which includes Zig's ReleaseSafe.

Added

• A regression test that drives the resampler across a full-scale step, the case
  that used to overflow, and pins the interpolated result.

opal-zig v2.0.0-1

Changed

• Binds opal 2.0.0. Rendered output is bit-identical to 1.0.2, only the API shape
  changed.
• An Opal instance is now a plain value: upstream replaced every internal pointer
  with an index, so copying, assigning, or relocating an instance is legal and a copy
  is a complete save state. The no-copy rule is gone.
• Opal.init returns the instance by value. create and destroy remain as heap
  helpers for the roughly 70 KiB struct.
• Methods follow the upstream renames: port is now writeReg, portBuffered is
  writeRegBuffered, read is readStatus. The raw externs are opalInit,
  opalWriteReg, and so on.
• Constants follow the upstream renames: num_channels is now channel_count and
  num_operators is operator_count.
• Struct mirrors follow the new pointer-free layout: op_slot, chan_index,
  mod_source, pair_index, and out_source are index fields, boolean fields are
  bool, and Opal.zero_mod is gone.

Added

• EnvelopeStage and ChannelType, non-exhaustive enum(c_int) types for the
  envelope_stage and chan_type fields.
• Index sentinels op_none, mod_own_fb, and ch_none.
• A save-state test: a copied chip renders the same audio as the original.

Removed

• The Bool alias for opal_bool, which upstream removed in favor of C11 bool.
• The optional cross-pointer fields (master, chan, mod, channel_pair,
  out_ptr), replaced by the index fields above.

opal-zig v1.0.2-1

Added

• First release, binding opal 1.0.2.
• The opal module compiles the upstream C11 core from the pinned release tarball with
  the Zig build system. No code generation step, no dependency beyond libc.
• Opal, Channel, Operator, and WriteBuf mirrored as extern struct with
  snake_case field names. The test suite verifies every struct size and field offset
  against the C compiler, so layout drift fails loudly.
• Methods wrapping the eight C functions (init, setSampleRate, port,
  portBuffered, flushWriteBuf, pan, sample, read), plus create and
  destroy to heap-pin an instance under the C core's no-copy rule, and render to
  fill interleaved stereo buffers.
• modulatorSlot and carrierSlot helpers matching the channel-to-slot table
  documented in the upstream header.
• A demo (zig build run) that renders a short FM arpeggio to opal-demo.wav.