Implement port groups for VST2 parameters

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

distrho/src/DistrhoPluginVST2.cpp

@@ -1448,7 +1448,9 @@ static intptr_t vst_dispatcherCallback(AEffect* effect, int32_t opcode, int32_t
                 memset(properties, 0, sizeof(VstParameterProperties));
 
                 // full name
-                DISTRHO_NAMESPACE::strncpy(properties->label, plugin.getParameterName(index), VestigeMaxLabelLen);
+                DISTRHO_NAMESPACE::strncpy(properties->label,
+                                           plugin.getParameterName(index),
+                                           sizeof(properties->label));
 
                 // short name
                 const String& shortName(plugin.getParameterShortName(index));
@@ -1456,7 +1458,7 @@ static intptr_t vst_dispatcherCallback(AEffect* effect, int32_t opcode, int32_t
                 if (shortName.isNotEmpty())
                     DISTRHO_NAMESPACE::strncpy(properties->shortLabel,
                                                plugin.getParameterShortName(index),
-                                               VestigeMaxShortLabelLen);
+                                               sizeof(properties->shortLabel));
 
                 // parameter hints
                 const uint32_t hints = plugin.getParameterHints(index);
@@ -1482,6 +1484,34 @@ static intptr_t vst_dispatcherCallback(AEffect* effect, int32_t opcode, int32_t
                     properties->flags |= kVstParameterCanRamp;
                 }
 
+                // parameter group (category in vst)
+                const uint32_t groupId = plugin.getParameterGroupId(index);
+
+                if (groupId != kPortGroupNone)
+                {
+                    // we can't use groupId directly, so use the index array where this group is stored in
+                    for (uint32_t i=0, count=plugin.getPortGroupCount(); i < count; ++i)
+                    {
+                        const PortGroupWithId& portGroup(plugin.getPortGroupByIndex(i));
+
+                        if (portGroup.groupId == groupId)
+                        {
+                            properties->category = i + 1;
+                            DISTRHO_NAMESPACE::strncpy(properties->categoryLabel,
+                                                       portGroup.name.buffer(),
+                                                       sizeof(properties->categoryLabel));
+                            break;
+                        }
+                    }
+
+                    if (properties->category != 0)
+                    {
+                        for (uint32_t i=0, count=plugin.getParameterCount(); i < count; ++i)
+                            if (plugin.getParameterGroupId(i) == groupId)
+                                ++properties->numParametersInCategory;
+                    }
+                }
+
                 return 1;
             }
         }