Module engine 

Main Milkdrop engine implementation.

The update() orchestrator lives here; the three heavyweight per-frame phases that used to dominate the file are split into sibling modules, each adding its own impl MilkEngine block:

• wave_phase — evaluate_custom_waves
• shape_phase — evaluate_custom_shapes
• state_sync — update_render_state_from_evaluator

That split keeps engine.rs focused on the lifecycle (new, load_preset, update, public getters) and supports preset transitions, where two engine instances drive the wave/shape paths in parallel.

Modules

morph 🔒

Smart boolean interpolation of motion params across a preset transition.

preset_slot 🔒

Per-preset state bundle.

shape_phase 🔒

Custom-shape (shapecode_N) phase of the engine update loop.

state_sync 🔒

Mirror a slot’s evaluator context into its RenderState.

transition_state 🔒

Engine-side preset transition state.

wave_phase 🔒

Custom-wave (wavecode_N) phase of the engine update loop.

Structs

EngineConfig

Engine configuration.

FrameProfile

Per-phase wall-clock breakdown for one MilkEngine::update call. Populated when EngineConfig::profile is true; exposed by MilkEngine::last_profile() for the bench tool and any future overlay.

MilkEngine

Main Milkdrop visualization engine.

Enums

ProgressSource

Source for the MD2 progress uniform.

QualityPreset

Quality preset for engine configuration.

Constants

SPECTRUM_FFT_SIZE 🔒

FFT window size used to expose value1/value2 spectrum bins to wavecode_N per-point equations when b_spectrum is set. Power of 2, large enough to give a reasonable bin density without ballooning the analyzer cost. Matches the standard MD2 FFT size.

Functions

tick_slot_evaluator 🔒

Advance one slot’s per-frame state: push the shared audio levels + time + frame into its evaluator context, then run its per-frame equations. Called once for current and (during transitions) once for fading_out each frame.