Allow python to register custom event filters

qrenderdoc/Code/Interface/QRDInterface.h

@@ -194,9 +194,49 @@ protected:
 
 DECLARE_REFLECTION_STRUCT(IMainWindow);
 
-DOCUMENT("The event browser window.");
+DOCUMENT(R"(The event browser window.
+
+.. function:: EventFilterCallback(context, filter, params, eventId, chunk, draw, name)
+
+  Not a member function - the signature for any ``EventFilterCallback`` callbacks.
+
+  Called for each event in a capture when performing filtering in the Event Browser. The associated
+  ``FilterParseCallback`` will be called first to parse the parameters, and is available for caching
+  or syntax checking. The same filter name and params string will be passed to this function.
+
+  :param CaptureContext context: The current capture context.
+  :param str filter: The name of the filter function.
+  :param str params: The parameters to the filter function.
+  :param int eventId: The event's :data:`eventId <renderdoc.APIEvent.eventId>`.
+  :param renderdoc.SDChunk chunk: The structured data chunk for this event.
+  :param renderdoc.DrawcallDescription draw: The drawcall that contains this event. If the event is
+    the draw itself then the event ID will be equal.
+  :param str name: The name of the event as shown in the event browser, for string-based filtering.
+  :return: Whether or not this event matches the filter
+  :rtype: bool
+
+.. function:: FilterParseCallback(context, filter, params)
+
+  Not a member function - the signature for any ``FilterParseCallback`` callbacks.
+
+  Called once when the filter changes, to allow parsing any any data caching, as well as reporting
+  of errors in the filter usage.
+
+  :param CaptureContext context: The current capture context.
+  :param str filter: The name of the filter function.
+  :param str params: The parameters to the filter function.
+  :return: An empty string if the parse succeeded, otherwise any error messages to be displayed to
+    the user, such as syntax or other errors.
+  :rtype: str
+)");
 struct IEventBrowser
 {
+  typedef std::function<bool(ICaptureContext *, const rdcstr &, const rdcstr &, uint32_t,
+                             const SDChunk *, const DrawcallDescription *, const rdcstr &)>
+      EventFilterCallback;
+
+  typedef std::function<rdcstr(ICaptureContext *, const rdcstr &, const rdcstr &)> FilterParseCallback;
+
   DOCUMENT(R"(Retrieves the PySide2 QWidget for this :class:`EventBrowser` if PySide2 is available, or otherwise
 returns a unique opaque pointer that can be passed back to any RenderDoc functions expecting a
 QWidget.
@@ -234,6 +274,37 @@ If no capture is loaded or the EID doesn't correspond to a known event, ``None``
 )");
   virtual const DrawcallDescription *GetDrawcallForEID(uint32_t eventId) = 0;
 
+  DOCUMENT(R"(Registers a new event browser filter function.
+
+Filter functions are available as $name() so long as they don't shadow an existing function. The
+filter callback will be called for each event to filter.
+
+The parser callback will be called once when a filter is first specified or the parameters change.
+Note that a filter can be used multiple times in a filter expression! For this reason the parser
+may be called multiple times and the filter callback takes the parameters string. If any expensive
+work is done then the parameters can be used as a cache key to cache any data once per filter
+expression.
+
+:param str name: The name of the filter function.
+:param EventFilterCallback filter: The callback to call for each candidate event to perform
+  filtering.
+:param FilterParseCallback parser: The callback to call when the parsing the parameters and checking
+  for any errors.
+:return: Whether or not the registration was successful.
+:rtype: bool
+)");
+  virtual bool RegisterEventFilterFunction(const rdcstr &name, EventFilterCallback filter,
+                                           FilterParseCallback parser) = 0;
+
+  DOCUMENT(R"(Unregisters an event browser filter function that was previously registered.
+
+:param str name: The name of the filter function.
+
+:return: Whether or not the unregistration was successful.
+:rtype: bool
+)");
+  virtual bool UnregisterEventFilterFunction(const rdcstr &name) = 0;
+
 protected:
   IEventBrowser() = default;
   ~IEventBrowser() = default;

qrenderdoc/Code/pyrenderdoc/function_conversion.h

@@ -251,11 +251,14 @@ struct varfunc
 
     PyObject *result = PyObject_Call(func, args, 0);
 
-    if(result == NULL)
-      HandleCallbackFailure(global_handle, exHandle);
-
     Py_DECREF(args);
 
+    if(result == NULL)
+    {
+      HandleCallbackFailure(global_handle, exHandle);
+      return rettype();
+    }
+
     return get_return<rettype>(funcname, result, global_handle, exHandle);
   }
 

qrenderdoc/Code/pyrenderdoc/pyconversion.h

@@ -103,7 +103,7 @@ struct TypeConversion<Opaque *, false>
     if(cached_type_info)
       return cached_type_info;
 
-    rdcstr baseTypeName = TypeName<Opaque>();
+    rdcstr baseTypeName = TypeName<typename std::remove_const<Opaque>::type>();
     baseTypeName += " *";
     cached_type_info = SWIG_TypeQuery(baseTypeName.c_str());
 
@@ -124,7 +124,7 @@ struct TypeConversion<Opaque *, false>
     return res;
   }
 
-  static PyObject *ConvertToPy(const Opaque *&in)
+  static PyObject *ConvertToPy(const Opaque *in)
   {
     swig_type_info *type_info = GetTypeInfo();
     if(type_info == NULL)
@@ -132,8 +132,6 @@ struct TypeConversion<Opaque *, false>
 
     return SWIG_InternalNewPointerObj((void *)in, type_info, 0);
   }
-
-  static PyObject *ConvertToPy(Opaque *in) { return ConvertToPy((const Opaque *&)in); }
 };
 
 // specialisations for basic types