#pragma once
//###########################################################################
//
//	L4AUDEFX.h -- OpenAL EFX bridge for the authored filter/reverb chains
//	(task #50, AUDIO_FIDELITY F9/F11).
//
//	The original drove the AWE32 initial-filter-cutoff NRPN per frame
//	(brightness x distance HF rolloff) and sent CC91 reverb on the 3D
//	channels (global_reverb_scale=0.3, AUDIO.INI) while keeping the cockpit
//	Direct channels dry.  This bridge reproduces both through OpenAL Soft's
//	EFX extension: one EAXReverb aux slot + a scratch AL_FILTER_LOWPASS
//	whose parameters are copied at attach time.
//
//###########################################################################

#include "openal/al.h"

// Load the EFX entry points, create the reverb slot (gain = the authentic
// global_reverb_scale) and the scratch lowpass.  Call once, with the AL
// context current.  Returns false (and stays inert) without ALC_EXT_EFX.
bool EFX_Initialize(float global_reverb_scale);

bool EFX_Available();

// Per-frame direct-path lowpass: gainhf is the linear HF gain at the EFX
// 5 kHz reference.  Callers map the AWE cutoff (100 + scale*7900/127 Hz)
// through EFX_CutoffScaleToGainHF below.
void EFX_SetSourceLowpassGainHF(ALuint source, float gainhf);

// AWE NRPN 21 curve -> EFX gainhf: cutoff_scale in [0,1] of the 100-8000 Hz
// span; approximated as the attenuation of a 2-pole lowpass at the 5 kHz
// reference [T3 -- curve shape approximate, endpoints exact].
inline float EFX_CutoffScaleToGainHF(float cutoff_scale)
{
	if (cutoff_scale < 0.0f) cutoff_scale = 0.0f;
	if (cutoff_scale > 1.0f) cutoff_scale = 1.0f;
	float cutoff_hz = 100.0f + cutoff_scale * 7900.0f;
	float g = (cutoff_hz / 5000.0f) * (cutoff_hz / 5000.0f);
	return (g > 1.0f) ? 1.0f : ((g < 0.001f) ? 0.001f : g);
}

// Wet-exterior routing: attach the source's aux send to the reverb slot
// (Dynamic3D/Static3D).  Direct cockpit sources stay dry by default.
void EFX_AttachReverbSend(ALuint source);