GDVP Gfx
GFX Effect Nodes — GDVP_NODE_GFX_* ✅
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The GFX family is GDVP's in-graph effects engine, designed around a "G×T decomposition" (a small set of primitive cells — gain curves, delay lines, all-pass chains, envelope detectors — that recombine into many named effects). The payload structs are fully designed and constrained to a strict 28-byte footprint for optimal performance.
✅ Current build status: Fully Implemented
Every GFX node is currently implemented and wired. Their processor and updater functions are successfully registered in the main dispatch tables.
Example patches referencing these nodes (like
organic_pad_reverb.gvpusinggfx_fdn) will now render their spatial acoustics and modulation tails as intended. See Patches and Build Status.
The GFX nodes are master-domain effects: they run on the Global EFX bus (post-mix, monophonic) rather than per-voice — adding spatial acoustics and global modulation to the summed mix.
GFX Delay — GDVP_NODE_GFX_DELAY
A tapped delay line used for echo, chorus, flanger, doubler, BBD, and comb filtering.
* Architecture: Utilizes up to 3 active taps. Audio samples live in the external effects pool, while the node holds the indexing geometry.
* Tap Controls: Each tap features integer delay length, fractional lerp weight, output level, and feedback.
* Routing & Mix: Supports standard and all-pass interpolation, mixed via wet and dry levels.
GFX Gain — GDVP_NODE_GFX_GAIN
A nonlinear gain cell utilized for saturation, wavefold, µ-law, VCA, tremolo, AM, ring-mod, and compressor make-up.
* Curve Selection: The lut_id selects the transfer curve accessed from the shared ROM (0=linear, 1=soft, 2=hard, 3=fold, 4=µ-law, 5=rectify).
* Dynamics: A drive parameter scales input into the LUT. A dynamic sidechain multiplier can be written directly by an Envelope or MOD node.
* Parameters: Includes static/output gain, compression threshold, knee width, and a 1-pole HP DC blocker state.
GFX Env detector — GDVP_NODE_GFX_ENV
An envelope follower enabling dynamics processing: compressors, limiters, expanders, duckers, gates, and auto-wah. * Detection: Supports peak, RMS, and external-key modes, tracking via a running state and peak-hold accumulator. * Response: Dictated by attack, release, and hold coefficients. Detection mapping follows a linear, log, or exponential law. * Output: Calculates gain reduction using a threshold, ratio, soft knee, and makeup gain. It explicitly writes its control output to a target node via byte offset.
GFX All-pass — GDVP_NODE_GFX_APF
A modular all-pass chain powering phasers, reverb diffusers, and dispersion networks.
* Stages: Supports 1 to 8 active TDF-II stages, each with a specific coefficient.
* State: Requires no external buffers; the one-multiplier APF state per stage fits entirely inline.
* Modulation: A mod_mask byte dictates which specific stages are modulated by an LFO (bit i modulates stage i).
GFX FDN reverb — GDVP_NODE_GFX_FDN
A Feedback Delay Network reverb powering plate, room, hall, and gated reverb models. * Matrix: Utilizes a 4-line Hadamard mixing matrix. * Delay & Damping: Prime-ratio delay lines sit in the external pool. Includes per-line 1-pole damping defining the RT60 HF slope, and broadband feedback decay per revolution. * Spatialization: Includes stereo width decorrelation, with pre-delay and stereo-enable mapped inside the flags bitfield.
GFX Modulator — GDVP_NODE_GFX_MOD
A parameter modulator implementing "G×T coupling". It routes an internal LFO, Envelope, velocity, aftertouch, or mod-wheel to any field of up to two target nodes (see Parameters).
* Source: Selectable via src (LFO, ENV, VEL, AT, WHEEL). The LFO features multiple shapes (sin, tri, sqr, saw, s&h, rand).
* Routing: Supports a primary target and an optional secondary target.
* Controls: Allows modulation depth, bias offset, rate, tempo sync, and a dedicated slew limiter (portamento) on the control signal itself. The DAG Compiler guarantees a MOD node ticks before its target.
What to use today
All GDVP_NODE_GFX_* payload structs and DSP execution loops are now actively bridged to the global DSP graph. You can safely assign them inside your .gvp patch files (see Patches) to utilize spatial acoustics, complex saturation, macro dynamics, and continuous parameter modulation.
See Effects & the Global EFX Bus for the bigger picture.