From 1f5d6935049fc0dd5a4dc257b84b36d2048f2d83 Mon Sep 17 00:00:00 2001
From: Hanspeter Portner <dev@open-music-kontrollers.ch>
Date: Sun, 15 Aug 2021 16:48:30 +0200
Subject: [PATCH] dsp: add support for channel pressure and MPE+ LSB.

---
 VERSION   |  2 +-
 jit_dsp.c | 66 ++++++++++++++++++++++++++++++++++++++++++++++++++++---
 2 files changed, 64 insertions(+), 4 deletions(-)

diff --git a/VERSION b/VERSION
index b6689b5..044b095 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.1.421
+0.1.423
diff --git a/jit_dsp.c b/jit_dsp.c
index f3ce6dd..f0cf23a 100644
--- a/jit_dsp.c
+++ b/jit_dsp.c
@@ -142,6 +142,7 @@ struct _plughandle_t {
 	uint16_t gain [0x10];
 	uint16_t pressure [0x10];
 	uint16_t timbre [0x10];
+	uint8_t mpe_plus_lsb [0x10];
 	float bend [0x10];
 	float range [0x10];
 	bool sustain [0x10];
@@ -846,15 +847,49 @@ _voice_send_event(plughandle_t *handle, dsp_t *dsp, jit_ev_type_t etype,
 	}
 }
 
+static inline void
+_mpe_plus_lsb(plughandle_t *handle, uint8_t chn, uint16_t *tar)
+{
+	const uint8_t lsb = handle->mpe_plus_lsb[chn];
+
+	if(lsb)
+	{
+		*tar &= ~0x7f;
+		*tar |= lsb;
+	}
+
+	handle->mpe_plus_lsb[chn] = 0x0; // always clear register after usage
+}
+
 static void
-_handle_midi(plughandle_t *handle, dsp_t *dsp,
-	int64_t frames __attribute__((unused)), const uint8_t *msg, uint32_t len)
+_handle_midi_2(plughandle_t *handle, dsp_t *dsp,
+	int64_t frames __attribute__((unused)), const uint8_t *msg)
 {
-	if(len < 3)
+	const uint8_t cmd = msg[0] & 0xf0;
+	const uint8_t chn = msg[0] & 0x0f;
+
+	if(!dsp)
 	{
 		return;
 	}
 
+	switch(cmd)
+	{
+		case LV2_MIDI_MSG_CHANNEL_PRESSURE:
+		{
+			handle->pressure[chn] = msg[1] << 7;
+
+			_mpe_plus_lsb(handle, chn, &handle->pressure[chn]);
+
+			_update_pressure(handle, dsp, chn);
+		} break;
+	}
+}
+
+static void
+_handle_midi_3(plughandle_t *handle, dsp_t *dsp,
+	int64_t frames __attribute__((unused)), const uint8_t *msg)
+{
 	const uint8_t cmd = msg[0] & 0xf0;
 	const uint8_t chn = msg[0] & 0x0f;
 
@@ -1019,6 +1054,8 @@ _handle_midi(plughandle_t *handle, dsp_t *dsp,
 					handle->pressure[chn] &= ~0x3f80;
 					handle->pressure[chn] |= val << 7;
 
+					_mpe_plus_lsb(handle, chn, &handle->pressure[chn]);
+
 					_update_pressure(handle, dsp, chn);
 				} break;
 				case LV2_MIDI_CTL_SC5_BRIGHTNESS | 0x20:
@@ -1033,13 +1070,36 @@ _handle_midi(plughandle_t *handle, dsp_t *dsp,
 					handle->timbre[chn] &= ~0x3f80;
 					handle->timbre[chn] |= val << 7;
 
+					_mpe_plus_lsb(handle, chn, &handle->timbre[chn]);
+
 					_update_timbre(handle, dsp, chn);
 				} break;
+				case 0x57: // MPE+ LSB according to Haken Audio
+				{
+					handle->mpe_plus_lsb[chn] = val;
+				} break;
 			}
 		} break;
 	}
 }
 
+static void
+_handle_midi(plughandle_t *handle, dsp_t *dsp,
+	int64_t frames, const uint8_t *msg, uint32_t len)
+{
+	switch(len)
+	{
+		case 2:
+		{
+			_handle_midi_2(handle, dsp, frames, msg);
+		} break;
+		case 3:
+		{
+			_handle_midi_3(handle, dsp, frames, msg);
+		} break;
+	}
+}
+
 static void
 run(LV2_Handle instance, uint32_t nsamples)
 {
-- 
2.38.5