From 1a4321d7d0730a4f2845713179dd757795a54273 Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Tue, 5 May 2020 22:14:11 -0400
Subject: [PATCH] Attempts better to balance attenuations.

---
 Components/OPL2/Implementation/EnvelopeGenerator.hpp | 4 ++--
 Components/OPL2/OPLL.cpp                             | 9 +++++----
 2 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/Components/OPL2/Implementation/EnvelopeGenerator.hpp b/Components/OPL2/Implementation/EnvelopeGenerator.hpp
index af721781b..ae34aa62c 100644
--- a/Components/OPL2/Implementation/EnvelopeGenerator.hpp
+++ b/Components/OPL2/Implementation/EnvelopeGenerator.hpp
@@ -79,10 +79,10 @@ template <int envelope_precision, int period_precision> class EnvelopeGenerator
 		}
 
 		/*!
-			@returns The current attenuation from this envelope generator.
+			@returns The current attenuation from this envelope generator. This is independent of the envelope precision.
 		*/
 		int attenuation() const {
-			return attenuation_ + tremolo_;
+			return (attenuation_ + tremolo_) << 3;
 		}
 
 		/*!
diff --git a/Components/OPL2/OPLL.cpp b/Components/OPL2/OPLL.cpp
index 937b410cf..b18ddde0e 100644
--- a/Components/OPL2/OPLL.cpp
+++ b/Components/OPL2/OPLL.cpp
@@ -298,10 +298,11 @@ void OPLL::update_all_channels() {
 
 
 int OPLL::melodic_output(int channel) {
-	// TODO: key-rate scaling.
-	// TODO: proper scales of all attenuations below.
+	// TODO: verify attenuation scales.
 	auto modulation = WaveformGenerator<period_precision>::wave(channels_[channel].modulator_waveform, phase_generators_[channel + 9].phase());
-	modulation += envelope_generators_[channel + 9].attenuation() + channels_[channel].modulator_attenuation;
+	modulation += envelope_generators_[channel + 9].attenuation() + (channels_[channel].modulator_attenuation << 5) + key_level_scalers_[channel + 9].attenuation();
 
-	return WaveformGenerator<period_precision>::wave(channels_[channel].carrier_waveform, phase_generators_[channel].scaled_phase(), modulation).level() + channels_[channel].attenuation;
+	auto carrier = WaveformGenerator<period_precision>::wave(channels_[channel].carrier_waveform, phase_generators_[channel].scaled_phase(), modulation);
+	carrier += envelope_generators_[channel].attenuation() + (channels_[channel].attenuation << 7) + key_level_scalers_[channel].attenuation();
+	return carrier.level();
 }