Introduce kParameterIsHidden flag, implement it for LV2

Signed-off-by: falkTX <falktx@falktx.com>

distrho/DistrhoPlugin.hpp

@@ -139,6 +139,13 @@ static const uint32_t kParameterIsOutput = 0x10;
 */
 static const uint32_t kParameterIsTrigger = 0x20 | kParameterIsBoolean;
 
+/**
+   Parameter should be hidden from the host and user-visible GUIs.@n
+   It is still saved and handled as any regular parameter, just not visible to the user
+   (for example in a host generated GUI)
+ */
+static const uint32_t kParameterIsHidden = 0x40;
+
 /** @} */
 
 /* ------------------------------------------------------------------------------------------------------------

distrho/src/DistrhoPluginLV2export.cpp

@@ -939,6 +939,8 @@ void lv2_generate_ttl(const char* const basename)
                         pluginString += "        lv2:portProperty lv2:integer ;\n";
                     if (hints & kParameterIsLogarithmic)
                         pluginString += "        lv2:portProperty <" LV2_PORT_PROPS__logarithmic "> ;\n";
+                    if (hints & kParameterIsHidden)
+                        pluginString += "        lv2:portProperty <" LV2_PORT_PROPS__notOnGUI "> ;\n";
                     if ((hints & kParameterIsAutomatable) == 0 && plugin.isParameterInput(i))
                     {
                         pluginString += "        lv2:portProperty <" LV2_PORT_PROPS__expensive "> ,\n";