GDVP License

Engine Status

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Appendix A · Engine Status & Known Divergences

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This manual documents as-built behaviour. Where the running code diverges from its own header comments, example patches, or obvious intent, it is listed here so you are never surprised. All claims are against the live dispatch tables and kernels, not prose.

How to verify any item: the ground truth for node activity is gdvp_dsp_dispatch.c (gdvp_node_processors[] / gdvp_node_updaters[]). A NULL entry = silently skipped = no audio.

A.1 Inactive node types (NULL in dispatch) ⛔

These node types exist in the enum (and most have payload structs and/or DSP source files) but are NULL in the processor table, so the voice executor skips them and they produce no sound:

  • GDVP_NODE_MASTER_BUS — the dedicated stereo master accumulator node.
  • GDVP_NODE_ROM_READER, GDVP_NODE_FEEDBACK, GDVP_NODE_MACRO_DELAY, GDVP_NODE_FDN (legacy reverb slot).

The GFX effect family (GDVP_NODE_GFX_DELAY, _GFX_GAIN, _GFX_ENV, _GFX_APF, _GFX_FDN, _GFX_MOD) is active and fully wired in the dispatch tables. They run on the Global EFX Bus (master domain, post-mix, monophonic) and produce audio. See Effects and GFX nodes.

Impact on patches: any .gvp that includes master_bus or one of the legacy inactive nodes loads and plays its synthesis graph, but the listed node is dropped. The *_reverb, *_phaser, *_chorus, *_hall, *_fuzz, *_fold, *_compressed, *_tremolo, *_warm and similar effects-suffixed patches now render their GFX tails. See Patches §7.4.

A.2 Resolved divergences ✅

  • GDVP_NODE_EXCITER and GDVP_NODE_MIXER are now documented as active in gdvp_nodes.h and are registered in gdvp_dsp_dispatch.c. See Exciter and Mixer.
  • The GFX effect family (GDVP_NODE_GFX_*) is documented as active in gdvp_nodes.h and fully wired in the dispatch tables. See Effects and GFX nodes.

The header's "NODE TYPE STATUS SUMMARY" comment block is now aligned with the dispatch table.

A.3 LFO transport-sync not yet wired ⚠️

The LFO kernel receives the transport tick_mask but casts it to (void) (commented "Phase 2"). Therefore:

  • Key sync (mode 2): works — phase resets on note.
  • Transport sync (mode 1): selectable but does not lock the LFO to tempo yet.

The arpeggiator does consume the transport clock, so tempo sync works there. See Performance §3.8.

A.4 MIDI messages tracked but not acted on ⚠️

Received and stored in the MIDI matrix, but currently no engine action (MIDI §8.5):

  • CC 64 Sustain pedal, CC 65 Portamento on/off, CC 66 Sostenuto, CC 68 Legato footswitch.
  • CC 126 Mono Mode On, CC 127 Poly Mode On (do not reconfigure the VAM — change voice mode via the front panel / gdvp_param_bridge_update_voice_mode instead).
  • CC 91/93 (reverb/chorus depth) route as generic sound-controllers but drive the active GFX effects.

A.5 Things that DO work and might surprise you ✅

  • DELAY voice mode is a real, working strum/echo built from staggered voices — independent of the GFX delay line. See Performance §3.6.
  • Per-voice filter decorrelation / cascade uses a voice-indexed static bank, so steep slopes and section-2 state are correct and per-voice. See Filter §slope.
  • Exciter per-voice decorrelation spreads chord voices across the shared noise ring. See Exciter §decorr.

A.6 Demo-mode limitation

In standalone without a valid licence, audio is interrupted with noise after 60 seconds (Hosts §standalone). Not a bug — the licence gate.

This appendix reflects the source tree as analysed for manual revision 1. As GFX processors and the LFO transport path are wired in, the corresponding items here should be retired.

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