From 2895a2bfee782ebb5d9c7a6879ffaff2f181fa0f Mon Sep 17 00:00:00 2001
From: Jean Pierre Cimalando <jp-dev@inbox.ru>
Date: Thu, 11 Jun 2020 22:37:08 +0200
Subject: [PATCH] Implement stretch tuning in LV2

---
 lv2/sfizz.c      | 19 +++++++++++++++++++
 lv2/sfizz.ttl.in | 11 +++++++++++
 2 files changed, 30 insertions(+)

diff --git a/lv2/sfizz.c b/lv2/sfizz.c
index 69784a85..52815295 100644
--- a/lv2/sfizz.c
+++ b/lv2/sfizz.c
@@ -108,6 +108,7 @@ typedef struct
     const float *freewheel_port;
     const float *scala_root_key_port;
     const float *tuning_frequency_port;
+    const float *stretch_tuning_port;
 
     // Atom forge
     LV2_Atom_Forge forge;              ///< Forge for writing atoms in run thread
@@ -150,6 +151,7 @@ typedef struct
     int num_voices;
     unsigned int preload_size;
     sfizz_oversampling_factor_t oversampling;
+    float stretch_tuning;
     volatile bool check_modification;
     int max_block_size;
     int sample_counter;
@@ -170,6 +172,7 @@ enum
     SFIZZ_FREEWHEELING = 8,
     SFIZZ_SCALA_ROOT_KEY = 9,
     SFIZZ_TUNING_FREQUENCY = 10,
+    SFIZZ_STRETCH_TUNING = 11,
 };
 
 static void
@@ -242,6 +245,9 @@ connect_port(LV2_Handle instance,
     case SFIZZ_TUNING_FREQUENCY:
         self->tuning_frequency_port = (const float *)data;
         break;
+    case SFIZZ_STRETCH_TUNING:
+        self->stretch_tuning_port = (const float *)data;
+        break;
     default:
         break;
     }
@@ -302,6 +308,7 @@ instantiate(const LV2_Descriptor *descriptor,
     self->num_voices = DEFAULT_VOICES;
     self->oversampling = DEFAULT_OVERSAMPLING;
     self->preload_size = DEFAULT_PRELOAD;
+    self->stretch_tuning = 0.0f;
     self->check_modification = true;
     self->sample_counter = 0;
 
@@ -654,6 +661,17 @@ sfizz_lv2_check_freewheeling(sfizz_plugin_t* self)
     }
 }
 
+static void
+sfizz_lv2_check_stretch_tuning(sfizz_plugin_t* self)
+{
+    float stretch_tuning = (float)*self->stretch_tuning_port;
+    if (stretch_tuning != self->stretch_tuning)
+    {
+        sfizz_load_stretch_tuning_by_ratio(self->synth, stretch_tuning);
+        self->stretch_tuning = stretch_tuning;
+    }
+}
+
 static void
 run(LV2_Handle instance, uint32_t sample_count)
 {
@@ -719,6 +737,7 @@ run(LV2_Handle instance, uint32_t sample_count)
     sfizz_set_volume(self->synth, *(self->volume_port));
     sfizz_set_scala_root_key(self->synth, *(self->scala_root_key_port));
     sfizz_set_tuning_frequency(self->synth, *(self->tuning_frequency_port));
+    sfizz_lv2_check_stretch_tuning(self);
     sfizz_lv2_check_preload_size(self);
     sfizz_lv2_check_oversampling(self);
     sfizz_lv2_check_num_voices(self);
diff --git a/lv2/sfizz.ttl.in b/lv2/sfizz.ttl.in
index 4e52bcfe..189849ba 100644
--- a/lv2/sfizz.ttl.in
+++ b/lv2/sfizz.ttl.in
@@ -280,4 +280,15 @@ midnam:update a lv2:Feature .
     lv2:minimum 300.0 ;
     lv2:maximum 500.0 ;
     units:unit units:hz
+  ] , [
+    a lv2:InputPort, lv2:ControlPort ;
+    lv2:index 11 ;
+    lv2:symbol "stretched_tuning" ;
+    lv2:name "Stretched tuning",
+      "Accordage étiré"@fr ;
+    pg:group <@LV2PLUGIN_URI@#tuning> ;
+    lv2:default 0.0 ;
+    lv2:minimum 0.0 ;
+    lv2:maximum 1.0 ;
+    units:unit units:coef
   ] .