From 7eab6ba67f8a51577bf56caac85ff4b9fd6133a7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Oscar=20Ace=C3=B1a?= <oscaracena@gmail.com>
Date: Wed, 1 Jan 2025 02:46:02 +0100
Subject: [PATCH] Fix a problem with events not sent from Jack to RTP

---
 .gitignore       |  3 +++
 Makefile         | 15 +++++++++++++++
 jackrtpmidid.cpp | 22 ++++++++++++++++++++++
 3 files changed, 40 insertions(+)
 create mode 100644 .gitignore

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..dbec3f4
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,3 @@
+*.o
+.vscode
+jackrtpmidid
diff --git a/Makefile b/Makefile
index 07e5bc2..2264eae 100644
--- a/Makefile
+++ b/Makefile
@@ -20,9 +20,24 @@ vpath %.cpp libs/RTP-MIDI libs/BEBSDK
 
 all: $(TARGET)
 
+debug: CXXFLAGS += -g -DSHOW_RTP_INFO
+debug: all
+
 $(TARGET): $(OBJECTS)
 	$(CXX) $(CXXFLAGS) $^ $(LDLIBS) -o $@
 
 .PHONY: clean
 clean:
 	$(RM) -frv *.o $(TARGET)
+
+
+## Other helper rules
+
+run:
+	./$(TARGET)
+
+run-with-gdb:
+	gdb \
+		-ex 'set print pretty on' \
+		-ex run \
+		$(TARGET)
diff --git a/jackrtpmidid.cpp b/jackrtpmidid.cpp
index dbee800..bfd8460 100644
--- a/jackrtpmidid.cpp
+++ b/jackrtpmidid.cpp
@@ -90,7 +90,29 @@ void* RTThreadFunc (CThread* Control)
     while (Control->ShouldStop==false)
     {
         if (RTPMIDIHandler1)
+        {
+            // NOTE: writePtr could be modified by Jack thread, but readPtr is not
+            int readPtr = JACK2RTP.ReadPtr;
+            int writePtr = JACK2RTP.WritePtr;
+
+            if (writePtr > readPtr)
+            {
+                if (RTPMIDIHandler1->SendRTPMIDIBlock(writePtr - readPtr,
+                    JACK2RTP.FIFO + JACK2RTP.ReadPtr))
+                    JACK2RTP.ReadPtr = writePtr;
+            }
+
+            else if (readPtr > writePtr)
+            {
+                if (RTPMIDIHandler1->SendRTPMIDIBlock(
+                    MIDI_CHAR_FIFO_SIZE - readPtr, JACK2RTP.FIFO + JACK2RTP.ReadPtr))
+                    if (RTPMIDIHandler1->SendRTPMIDIBlock(writePtr, JACK2RTP.FIFO))
+                        JACK2RTP.ReadPtr = writePtr;
+            }
+
             RTPMIDIHandler1->RunSession();
+        }
+
         if (RTPMIDIHandler2)
             RTPMIDIHandler2->RunSession();
         SystemSleepMillis(1);