CC as parameters for LV2

cmake/LV2Config.cmake

@@ -40,3 +40,46 @@ else()
     set(LV2PLUGIN_INSTALL_DIR "${CMAKE_INSTALL_PREFIX}/lib/lv2" CACHE STRING
     "Install destination for LV2 bundle [default: ${CMAKE_INSTALL_PREFIX}/lib/lv2]")
 endif()
+
+include(StringUtility)
+
+function(sfizz_lv2_generate_controllers_ttl FILE)
+    file(WRITE "${FILE}" "# LV2 parameters for SFZ controllers
+@prefix atom:   <http://lv2plug.in/ns/ext/atom#> .
+@prefix lv2:    <http://lv2plug.in/ns/lv2core#> .
+@prefix patch:  <http://lv2plug.in/ns/ext/patch#> .
+@prefix rdfs:   <http://www.w3.org/2000/01/rdf-schema#> .
+@prefix sfizz:  <${LV2PLUGIN_URI}#> .
+")
+    math(EXPR _j "${SFIZZ_NUM_CCS}-1")
+    foreach(_i RANGE "${_j}")
+        string_left_pad(_i "${_i}" 3 0)
+        file(APPEND "${FILE}" "
+sfizz:cc${_i}
+  a lv2:Parameter ;
+  rdfs:label \"Controller ${_i}\" ;
+  rdfs:range atom:Float .
+")
+    endforeach()
+
+    file(APPEND "${FILE}" "
+<${LV2PLUGIN_URI}>
+  a lv2:Plugin ;
+")
+
+    file(APPEND "${FILE}" "  patch:readable sfizz:cc000")
+    foreach(_i RANGE 1 "${_j}")
+        string_left_pad(_i "${_i}" 3 0)
+        file(APPEND "${FILE}" ", sfizz:cc${_i}")
+    endforeach()
+    file(APPEND "${FILE}" " ;
+")
+
+    file(APPEND "${FILE}" "  patch:writable sfizz:cc000")
+    foreach(_i RANGE 1 "${_j}")
+        string_left_pad(_i "${_i}" 3 0)
+        file(APPEND "${FILE}" ", sfizz:cc${_i}")
+    endforeach()
+    file(APPEND "${FILE}" " .
+")
+endfunction()

cmake/StringUtility.cmake

@@ -0,0 +1,11 @@
+# SPDX-License-Identifier: BSD-2-Clause
+
+function(string_left_pad VAR INPUT LENGTH FILLCHAR)
+    set(_output "${INPUT}")
+    string(LENGTH "${_output}" _length)
+    while(_length LESS "${LENGTH}")
+        string(PREPEND _output "${FILLCHAR}")
+        string(LENGTH "${_output}" _length)
+    endwhile()
+    set("${VAR}" "${_output}" PARENT_SCOPE)
+endfunction()

plugins/lv2/CMakeLists.txt

@@ -82,6 +82,9 @@ if(SFIZZ_USE_VCPKG OR SFIZZ_STATIC_DEPENDENCIES OR CMAKE_CXX_COMPILER_ID MATCHES
     file(COPY "lgpl-3.0.txt" DESTINATION ${PROJECT_BINARY_DIR})
 endif()
 
+# Generate controllers.ttl
+sfizz_lv2_generate_controllers_ttl("${PROJECT_BINARY_DIR}/controllers.ttl")
+
 # Copy resource files into the bundle
 set(LV2_RESOURCES
     DefaultInstrument.sfz

plugins/lv2/manifest.ttl.in

@@ -5,7 +5,7 @@
 <@LV2PLUGIN_URI@>
   a lv2:Plugin ;
   lv2:binary <Contents/Binary/@PROJECT_NAME@@CMAKE_SHARED_MODULE_SUFFIX@> ;
-  rdfs:seeAlso <@PROJECT_NAME@.ttl> .
+  rdfs:seeAlso <@PROJECT_NAME@.ttl>, <controllers.ttl> .
 
 @LV2PLUGIN_IF_ENABLE_UI@<@LV2PLUGIN_URI@#ui>
 @LV2PLUGIN_IF_ENABLE_UI@    a ui:@LV2_UI_TYPE@ ;

plugins/lv2/sfizz.cpp

@@ -329,6 +329,65 @@ sfizz_lv2_receive_message(void* data, int delay, const char* path, const char* s
     (void)write_ok;
 }
 
+static void
+sfizz_lv2_setup_cc_parameters(sfizz_plugin_t* self)
+{
+    // store the associations between CC number and parameter URID
+    // construct it trivially in the form of a tabulated perfect hash function
+
+    LV2_URID* cc_to_urid = new LV2_URID[sfz::config::numCCs];
+    int* urid_to_cc;
+    int urid_to_cc_size;
+
+    LV2_URID min_cc_urid {};
+    LV2_URID max_cc_urid {};
+    for (int cc = 0; cc < sfz::config::numCCs; ++cc) {
+        char name[256];
+        sprintf(name, SFIZZ_URI "#cc%03d", cc);
+        LV2_URID urid = self->map->map(self->map->handle, name);
+        if (cc == 0) {
+            min_cc_urid = urid;
+            max_cc_urid = urid;
+        }
+        else {
+            min_cc_urid = (urid < min_cc_urid) ? urid : min_cc_urid;
+            max_cc_urid = (urid > max_cc_urid) ? urid : max_cc_urid;
+        }
+        cc_to_urid[cc] = urid;
+    }
+
+    urid_to_cc_size = max_cc_urid - min_cc_urid + 1;
+    urid_to_cc = new int[urid_to_cc_size];
+
+    for (int i = 0; i < urid_to_cc_size; ++i)
+        urid_to_cc[i] = -1;
+
+    for (int cc = 0; cc < sfz::config::numCCs; ++cc) {
+        LV2_URID urid = cc_to_urid[cc];
+        urid_to_cc[urid - min_cc_urid] = cc;
+    }
+
+    self->cc_to_urid = cc_to_urid;
+    self->urid_to_cc = urid_to_cc;
+    self->min_cc_urid = min_cc_urid;
+    self->max_cc_urid = max_cc_urid;
+}
+
+static int
+sfizz_lv2_get_cc_from_parameter_urid(const sfizz_plugin_t* self, LV2_URID urid)
+{
+    int cc = -1;
+    if (urid >= self->min_cc_urid && urid <= self->max_cc_urid)
+        cc = self->urid_to_cc[urid - self->min_cc_urid];
+    return cc;
+}
+
+static LV2_URID
+sfizz_lv2_get_parameter_urid_from_cc(const sfizz_plugin_t* self, int cc)
+{
+    return self->cc_to_urid[cc];
+}
+
 static LV2_Handle
 instantiate(const LV2_Descriptor *descriptor,
             double rate,
@@ -476,6 +535,8 @@ instantiate(const LV2_Descriptor *descriptor,
         return NULL;
     }
 
+    sfizz_lv2_setup_cc_parameters(self);
+
     self->synth = sfizz_create_synth();
     self->client = sfizz_create_client(self);
     self->synth_mutex = spin_mutex_create();
@@ -501,6 +562,8 @@ cleanup(LV2_Handle instance)
     spin_mutex_destroy(self->synth_mutex);
     sfizz_delete_client(self->client);
     sfizz_free(self->synth);
+    delete[] self->cc_to_urid;
+    delete[] self->urid_to_cc;
     delete self;
 }
 
@@ -575,7 +638,14 @@ sfizz_lv2_handle_atom_object(sfizz_plugin_t *self, const LV2_Atom_Object *obj)
         char body[MAX_PATH_SIZE];
     } sfizz_path_atom_buffer_t;
 
-    if (key == self->sfizz_sfz_file_uri)
+    int cc = sfizz_lv2_get_cc_from_parameter_urid(self, key);
+    if (cc != -1) {
+        if (atom->type == self->atom_float_uri && atom->size == sizeof(float)) {
+            float value = *(const float *)LV2_ATOM_BODY_CONST(atom);
+            // TODO: CC parameter arrived
+        }
+    }
+    else if (key == self->sfizz_sfz_file_uri)
     {
         LV2_Atom_Forge *forge = &self->forge_secondary;
         sfizz_path_atom_buffer_t buffer;
@@ -796,6 +866,7 @@ run(LV2_Handle instance, uint32_t sample_count)
         if (ev->body.type == self->atom_object_uri || ev->body.type == self->atom_blank_uri)
         {
             const LV2_Atom_Object *obj = (const LV2_Atom_Object *)&ev->body;
+
             if (obj->body.otype == self->patch_set_uri)
             {
                 sfizz_lv2_handle_atom_object(self, obj);

plugins/lv2/sfizz.ttl.in

@@ -371,4 +371,6 @@ midnam:update a lv2:Feature .
     lv2:default 0 ;
     lv2:minimum 0 ;
     lv2:maximum 65535 ;
-  ] .
+  ] ;
+
+  rdfs:seeAlso <controllers.ttl> .

plugins/lv2/sfizz_lv2_plugin.h

@@ -92,6 +92,12 @@ struct sfizz_plugin_t
     LV2_URID time_beats_per_minute_uri {};
     LV2_URID time_speed_uri {};
 
+    // CC parameters
+    LV2_URID* cc_to_urid {};
+    int* urid_to_cc {};
+    LV2_URID min_cc_urid {};
+    LV2_URID max_cc_urid {};
+
     // Sfizz related data
     sfizz_synth_t *synth {};
     sfizz_client_t *client {};