Add macro command 0x31 for its only user, Turrican III title, where in some macro scripts it is used to trigger key up on channel/voice 0 and 1. There are rips of the soundtrack that have been modified so the macro scripts execute macro 4 Wait instead as not to break in TFMX players where macro 0x31 is missing.

Author: mschwendt

src/Chris/Macro.cpp

@@ -749,4 +749,13 @@ void TFMXDecoder::macroFunc_BranchIfSame(VoiceVars& voice) {
     }
 }
 
+// Macro command $31. Available in e.g. Gem'Z and Turrican III players,
+// but only used by T3 title.
+void TFMXDecoder::macroFunc_KeyUp(VoiceVars& voice) {
+    cmd.aa = 0xf5;  // key up command
+    noteCmd();      // with cmd.cd = channel number
+    voice.macro.step++;
+    macroEvalAgain = true;
+}
+
 }  // namespace

src/Chris/TFMXDecoder.cpp

@@ -395,6 +395,7 @@ bool TFMXDecoder::init(void *data, udword length, int songNumber) {
     MacroDefs[0x29] = &macroDef_29;
 
     MacroDefs[0x30] = &macroDef_BranchIfSame;
+    MacroDefs[0x31] = &macroDef_KeyUp;
 
     // TFMX v1.x up to and including v2.2 cannot be distinguished from
     // the later TFMX and/or variants. Unless the very rarely used old
@@ -863,7 +864,7 @@ void TFMXDecoder::noteCmd() {
             v.macro.branchIfSame = false;
         }
         v.macro.offset = mo;
-        v.macro.state = 1;
+        v.macro.state = 1;  // delayed macro init
     }
     else {  // cmd.aa >= $c0   portamento note
         v.portamento.count = cmd.bb;

src/Chris/TFMXDecoder.h

@@ -553,6 +553,13 @@ class TFMXDecoder : public Decoder {
                                        &TFMXDecoder::macroFunc_BranchIfSame
     };
 
+    // NB! This macro command is not named anywhere. It's used only by
+    // Turrican III title.
+    void macroFunc_KeyUp(VoiceVars&);
+    MacroDef macroDef_KeyUp = { "Key up      ../.x/.. channel",
+                                &TFMXDecoder::macroFunc_KeyUp
+    };
+
 
     bool trackCmdUsed[TRACK_CMD_MAX+1];
     bool patternCmdUsed[16];