From 71841aaf4f9759069a8e82f30d0a2278f279b5b2 Mon Sep 17 00:00:00 2001
From: Kagamiin~ <kagamiin@riseup.net>
Date: Sun, 17 Dec 2023 09:05:46 -0300
Subject: [PATCH] Updated mapVelocity; also changed back to MIDI standard

---
 src/engine/platform/esfm.cpp | 6 +++---
 src/engine/platform/esfm.h   | 2 +-
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/engine/platform/esfm.cpp b/src/engine/platform/esfm.cpp
index 4b23522fd..13604abf4 100644
--- a/src/engine/platform/esfm.cpp
+++ b/src/engine/platform/esfm.cpp
@@ -1019,10 +1019,10 @@ void DivPlatformESFM::notifyInsDeletion(void* ins) {
   }
 }
 
-int DivPlatformESFM::mapVelocity(int ch, unsigned char vel) {
+int DivPlatformESFM::mapVelocity(int ch, float vel) {
   const int volMax=MAX(1,dispatch(DivCommand(DIV_CMD_GET_VOLMAX,MAX(ch,0))));
-  double attenDb=20*log10(vel/127); // 20dB/decade for a linear mapping
-  double attenUnits=attenDb*(8.0/6.0);
+  double attenDb=40*log10(vel); // 40dB/decade for a quadratic mapping, per MIDI standard
+  double attenUnits=attenDb/0.75; // 0.75dB/unit
   return MAX(0,volMax+attenUnits);
 }
 
diff --git a/src/engine/platform/esfm.h b/src/engine/platform/esfm.h
index 8ec29fb8c..fbb971003 100644
--- a/src/engine/platform/esfm.h
+++ b/src/engine/platform/esfm.h
@@ -136,7 +136,7 @@ class DivPlatformESFM: public DivDispatch {
     void toggleRegisterDump(bool enable);
     void notifyInsChange(int ins);
     void notifyInsDeletion(void* ins);
-    int mapVelocity(int ch, unsigned char vel);
+    int mapVelocity(int ch, float vel);
     void poke(unsigned int addr, unsigned short val);
     void poke(std::vector<DivRegWrite>& wlist);
     void setFlags(const DivConfig& flags);