From 276118107b52c1b6899ad92f74341cca295e404d Mon Sep 17 00:00:00 2001
From: Simon Howard <fraggle@soulsphere.org>
Date: Sat, 24 Jun 2023 00:46:52 -0400
Subject: [PATCH] genmidi: Add `tune=` for setting fine tune field.

The fine tuning field was previously being hard-coded to the value of
128 with no option to change it. DMXGUS in particular makes use of this
field to tune individual instruments, so let's add proper support for
it.
---
 lumps/genmidi/genmidi.py    | 5 +++--
 lumps/genmidi/instrument.py | 3 ++-
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/lumps/genmidi/genmidi.py b/lumps/genmidi/genmidi.py
index 93d6204f..92ccc851 100644
--- a/lumps/genmidi/genmidi.py
+++ b/lumps/genmidi/genmidi.py
@@ -78,7 +78,7 @@ def encode_instrument(instrument):
     else:
         fixed_note = 0
 
-    header = struct.pack("<hBB", flags, 128, fixed_note)
+    header = struct.pack("<hBB", flags, 128 + instrument.tune, fixed_note)
 
     return header + instr1_data + instr2_data
 
@@ -149,7 +149,8 @@ def decode_instrument(data, name):
         fixed_note = None
 
     return Instrument(
-        voice1, voice2, off1=offset1, off2=offset2, note=fixed_note
+        voice1, voice2, off1=offset1, off2=offset2, note=fixed_note,
+        tune=finetune - 128
     )
 
 
diff --git a/lumps/genmidi/instrument.py b/lumps/genmidi/instrument.py
index 226e1aee..15d5ecf8 100644
--- a/lumps/genmidi/instrument.py
+++ b/lumps/genmidi/instrument.py
@@ -56,7 +56,7 @@ def load_instrument(filename):
 
 
 class Instrument:
-    def __init__(self, file1, file2=None, off1=0, off2=0, note=None):
+    def __init__(self, file1, file2=None, off1=0, off2=0, note=None, tune=0):
         self.voice1 = load_instrument(file1)
 
         if file2 is not None:
@@ -67,6 +67,7 @@ class Instrument:
         self.fixed_note = note
         self.offset1 = off1
         self.offset2 = off2
+        self.tune = tune
 
 
 NullInstrument = Instrument("dummy.sbi")