[OMPT-svn-commit] OpenMPT r21577 - trunk/OpenMPT/soundlib

[<sv...@op...>]

Author: sagamusix
Date: Mon Sep  9 20:12:14 2024
New Revision: 21577
URL: https://source.openmpt.org/browse/openmpt/?op=revision&rev=21577

Log:
[Fix] PTM: PolyTracker uses square root panning like FT2, and has a bug where the leftmost and rightmost positions play the sample without any attenuation on the left and right channels. Fixes bass balance in "BugFixed (The Song)" by Vic (https://www.un4seen.com/forum/?topic=15448.msg143684#msg143684).

Modified:
   trunk/OpenMPT/soundlib/Load_ptm.cpp
   trunk/OpenMPT/soundlib/Sndmix.cpp

Modified: trunk/OpenMPT/soundlib/Load_ptm.cpp
==============================================================================
--- trunk/OpenMPT/soundlib/Load_ptm.cpp	Mon Sep  9 12:37:58 2024	(r21576)
+++ trunk/OpenMPT/soundlib/Load_ptm.cpp	Mon Sep  9 20:12:14 2024	(r21577)
@@ -175,6 +175,7 @@
 	m_modFormat.madeWithTracker = MPT_UFORMAT("PolyTracker {}.{}")(fileHeader.versionHi.get(), mpt::ufmt::hex0<2>(fileHeader.versionLo.get()));
 	m_modFormat.charset = mpt::Charset::CP437;
 
+	SetMixLevels(MixLevels::CompatibleFT2);
 	m_SongFlags = SONG_ITCOMPATGXX | SONG_ITOLDEFFECTS;
 	m_nSamples = std::min(static_cast<SAMPLEINDEX>(fileHeader.numSamples), static_cast<SAMPLEINDEX>(MAX_SAMPLES - 1));
 	ReadOrderFromArray(Order(), fileHeader.orders, fileHeader.numOrders, 0xFF, 0xFE);
@@ -265,8 +266,7 @@
 				{
 				case CMD_PANNING8:
 					// Don't be surprised about the strange formula, this is directly translated from original disassembly...
-					m.command = CMD_S3MCMDEX;
-					m.param = 0x80 | ((std::max<uint8>(m.param >> 3, 1u) - 1u) & 0x0F);
+					m.SetEffectCommand(CMD_S3MCMDEX, static_cast<ModCommand::PARAM>(0x80 | ((std::max<uint8>(m.param >> 3, 1u) - 1u) & 0x0F)));
 					break;
 				case CMD_GLOBALVOLUME:
 					m.param = std::min(m.param, uint8(0x40)) * 2u;
@@ -277,8 +277,7 @@
 			}
 			if(b & 0x80)
 			{
-				m.volcmd = VOLCMD_VOLUME;
-				m.vol = file.ReadUint8();
+				m.SetVolumeCommand(VOLCMD_VOLUME, file.ReadUint8());
 			}
 		}
 	}

Modified: trunk/OpenMPT/soundlib/Sndmix.cpp
==============================================================================
--- trunk/OpenMPT/soundlib/Sndmix.cpp	Mon Sep  9 12:37:58 2024	(r21576)
+++ trunk/OpenMPT/soundlib/Sndmix.cpp	Mon Sep  9 20:12:14 2024	(r21577)
@@ -2484,15 +2484,10 @@
 			{
 				int32 pan = (m_MixerSettings.gnChannels >= 2) ? Clamp(chn.nRealPan, 0, 256) : 128;
 
-				int32 realvol;
-				if(m_PlayConfig.getUseGlobalPreAmp())
-				{
-					realvol = (chn.nRealVolume * kChnMasterVol) / 128;
-				} else
-				{
-					// Extra attenuation required here if we're bypassing pre-amp.
-					realvol = (chn.nRealVolume * kChnMasterVol) / 256;
-				}
+				int32 realvol = (chn.nRealVolume * kChnMasterVol) / 128;
+				// Extra attenuation required here if we're bypassing pre-amp.
+				if(!m_PlayConfig.getUseGlobalPreAmp())
+					realvol /= 2;
 
 				const PanningMode panningMode = m_PlayConfig.getPanningMode();
 				if(panningMode == PanningMode::SoftPanning || (panningMode == PanningMode::Undetermined && (m_MixerSettings.MixerFlags & SNDMIX_SOFTPANNING)))
@@ -2513,10 +2508,19 @@
 					// you can never truly achieve 100% right panning in FT2, only 100% left.
 					// Test case: FT2PanLaw.xm
 					LimitMax(pan, 255);
-					const int panL = pan > 0 ? XMPanningTable[256 - pan] : 65536;
-					const int panR = XMPanningTable[pan];
-					chn.newLeftVol = (realvol * panL) / 65536;
-					chn.newRightVol = (realvol * panR) / 65536;
+
+					// PolyTracker also uses square root panning, but there's a bug where the leftmost and rightmost pan positions play the sample centered, without any attenuation.
+					if(GetType() == MOD_TYPE_PTM && (pan == 0 || pan == 255))
+					{
+						chn.newLeftVol = realvol;
+						chn.newRightVol = realvol;
+					} else
+					{
+						const int panL = pan > 0 ? XMPanningTable[256 - pan] : 65536;
+						const int panR = XMPanningTable[pan];
+						chn.newLeftVol = (realvol * panL) / 65536;
+						chn.newRightVol = (realvol * panR) / 65536;
+					}
 				} else
 				{
 					chn.newLeftVol = (realvol * (256 - pan)) / 256;