From 6ebc93c9950e0fa90e2ab62d1b9ca09ca5db90d6 Mon Sep 17 00:00:00 2001 From: Thomas Harte Date: Fri, 24 Apr 2020 23:50:06 -0400 Subject: [PATCH] Switches to maximum-rate multiplexing. Hopefully to eliminate the mixer as a consideration for now. --- Components/OPL2/OPL2.cpp | 12 +++++++----- Machines/MasterSystem/MasterSystem.cpp | 2 +- 2 files changed, 8 insertions(+), 6 deletions(-) diff --git a/Components/OPL2/OPL2.cpp b/Components/OPL2/OPL2.cpp index 67f1b539d..26c156a09 100644 --- a/Components/OPL2/OPL2.cpp +++ b/Components/OPL2/OPL2.cpp @@ -64,12 +64,12 @@ void OPLL::get_samples(std::size_t number_of_samples, std::int16_t *target) { // unlike the OPL2 the OPLL time-divides the output for 'mixing'. const int update_period = 72 / audio_divider_; - const int channel_output_period = 8 / audio_divider_; + const int channel_output_period = 1;//2 / audio_divider_; while(number_of_samples--) { if(!audio_offset_) update_all_chanels(); - *target = int16_t(channels_[audio_offset_ / channel_output_period].level); + *target = int16_t(channels_[(audio_offset_ / channel_output_period) % 9].level); ++target; audio_offset_ = (audio_offset_ + 1) % update_period; } @@ -192,7 +192,9 @@ void OPLL::update_all_chanels() { // Update the LFO. oscillator_.update(); - // Channels that are updated for melodic output regardless. + // Channels that are updated for melodic output regardless; + // in rhythm mode the final three channels — 6, 7, and 8 — + // are lost as their operators are used for drum noises. for(int c = 0; c < 6; ++ c) { channels_[c].level = (channels_[c].update(oscillator_) * total_volume_) >> 11; } @@ -200,8 +202,8 @@ void OPLL::update_all_chanels() { if(depth_rhythm_control_ & 0x20) { // Rhythm mode. Somehow? } else { - // All melody, all the time. - for(int c = 6; c < 9; ++ c) { + // Not in rhythm mode; channels 7, 8 and 9 are melodic. + for(int c = 7; c < 9; ++ c) { channels_[c].level = (channels_[c].update(oscillator_) * total_volume_) >> 11; } } diff --git a/Machines/MasterSystem/MasterSystem.cpp b/Machines/MasterSystem/MasterSystem.cpp index 259daf6b7..a70ff06d8 100644 --- a/Machines/MasterSystem/MasterSystem.cpp +++ b/Machines/MasterSystem/MasterSystem.cpp @@ -32,7 +32,7 @@ #include namespace { -constexpr int audio_divider = 2; +constexpr int audio_divider = 1; } namespace Sega {