Tidy up Context and ProcessContext interfaces (ProcessContext only lives on as a useful type).

git-svn-id: http://svn.drobilla.net/lad/trunk/ingen@2487 a436a847-0d15-0410-975c-d299462d15a1

5 files changed, 43 insertions, 33 deletions

diff --git a/src/engine/Context.hpp b/src/engine/Context.hpp
index a30706da..2a3bd7ca 100644
--- a/src/engine/Context.hpp
+++ b/src/engine/Context.hpp
@@ -25,6 +25,19 @@ namespace Ingen {
 
 class Engine;
 
+
+/** Graph execution context.
+ *
+ * This is used to pass whatever information a GraphObject might need to
+ * process; such as the current time, a sink for generated events, etc.
+ *
+ * Note the logical distinction between nframes (jack relative) and start/end
+ * (timeline relative).  If transport speed != 1.0, then end-start != nframes
+ * (though currently this is never the case, it may be if ingen incorporates
+ * tempo and varispeed).
+ *
+ * \ingroup engine
+ */
 class Context
 {
 public:
@@ -34,12 +47,12 @@ public:
 	};
 
 	Context(Engine& engine, ID id)
-		: _id(id)
-		, _engine(engine)
+		: _engine(engine)
+		, _id(id)
 		, _event_sink(engine, event_queue_size)
 		, _start(0)
-		, _nframes(0)
 		, _end(0)
+		, _nframes(0)
 		, _offset(0)
 		, _realtime(true)
 	{}
@@ -48,12 +61,24 @@ public:
 
 	ID id() const { return _id; }
 
-	void locate(FrameTime s, SampleCount o=0) { _start = s; _offset=o; }
+	void locate(FrameTime s, SampleCount nframes, SampleCount offset) {
+		_start = s;
+		_end = s + nframes;
+		_nframes = nframes;
+		_offset = offset;
+	}
+
+	void locate(const Context& other) {
+		_start = other._start;
+		_end = other._end;
+		_nframes = other._nframes;
+		_offset = other._offset;
+	}
 
 	inline Engine&     engine()   const { return _engine; }
 	inline FrameTime   start()    const { return _start; }
-	inline SampleCount nframes()  const { return _nframes; }
 	inline FrameTime   end()      const { return _end; }
+	inline SampleCount nframes()  const { return _nframes; }
 	inline SampleCount offset()   const { return _offset; }
 	inline bool        realtime() const { return _realtime; }
 
@@ -61,13 +86,13 @@ public:
 	inline EventSink&        event_sink()       { return _event_sink; }
 
 protected:
-	ID      _id;      ///< Fast ID for this context
 	Engine& _engine;  ///< Engine we're running in
+	ID      _id;      ///< Fast ID for this context
 
 	EventSink   _event_sink; ///< Sink for events generated in a realtime context
 	FrameTime   _start;      ///< Start frame of this cycle, timeline relative
-	SampleCount _nframes;    ///< Length of this cycle in frames
 	FrameTime   _end;        ///< End frame of this cycle, timeline relative
+	SampleCount _nframes;    ///< Length of this cycle in frames
 	SampleCount _offset;     ///< Start offset relative to start of driver buffers
 	bool        _realtime;   ///< True iff context is hard realtime
 };
diff --git a/src/engine/JackDriver.cpp b/src/engine/JackDriver.cpp
index 78b14121..a604aeae 100644
--- a/src/engine/JackDriver.cpp
+++ b/src/engine/JackDriver.cpp
@@ -413,15 +413,14 @@ JackDriver::_process_cb(jack_nframes_t nframes)
 
 	// Note that Jack can not call this function for a cycle, if overloaded
 	const jack_nframes_t start_of_current_cycle = jack_last_frame_time(_client);
-	const jack_nframes_t end_of_current_cycle   = start_of_current_cycle + nframes;
 
 	_transport_state = jack_transport_query(_client, &_position);
 
-	_process_context.set_time_slice(nframes, 0, start_of_current_cycle, end_of_current_cycle);
+	_process_context.locate(start_of_current_cycle, nframes, 0);
 
 	for (Engine::ProcessSlaves::iterator i = _engine.process_slaves().begin();
 			i != _engine.process_slaves().end(); ++i) {
-		(*i)->context().set_time_slice(nframes, 0, start_of_current_cycle, end_of_current_cycle);
+		(*i)->context().locate(start_of_current_cycle, nframes, 0);
 	}
 
 	// Read input
@@ -442,15 +441,12 @@ JackDriver::_process_cb(jack_nframes_t nframes)
 	if (_root_patch) {
 		_root_patch->process(_process_context);
 #if 0
-		const FrameTime cycle_start = _process_context.start();
 		static const SampleCount control_block_size = nframes / 2;
 		for (jack_nframes_t i = 0; i < nframes; i += control_block_size) {
 			const SampleCount block_size = (i + control_block_size < nframes)
 					? control_block_size
 					: nframes - i;
-			_process_context.set_time_slice(block_size, i,
-					cycle_start + i,
-					cycle_start + i + block_size);
+			_process_context.locate(start_of_current_cycle + i, block_size, i);
 			_root_patch->process(_process_context);
 		}
 #endif
diff --git a/src/engine/ProcessContext.hpp b/src/engine/ProcessContext.hpp
index fa8e3910..663fea78 100644
--- a/src/engine/ProcessContext.hpp
+++ b/src/engine/ProcessContext.hpp
@@ -25,30 +25,19 @@
 namespace Ingen {
 
 
-/** Context of a process() call.
+/** Context of a process() call (the audio context).
  *
- * This is used to pass whatever information a GraphObject might need to
- * process in the audio thread, e.g. the available thread pool, sink for
- * events (generated in the audio thread, not user initiated events), etc.
- *
- * Note the distinction between nframes and start/end.  If transport speed
- * != 1.0, end-start != nframes (though currently that is never the case, it
- * may be in the future with sequencerey things).
+ * This class currently adds no functionality to Context, but the
+ * separate type is useful for writing functions that must only
+ * be run in the audio context (the function taking a ProcessContext
+ * parameter makes this clear, and makes breaking the rules obvious).
  *
  * \ingroup engine
  */
 class ProcessContext : public Context
 {
 public:
-	ProcessContext(Engine& engine)
-		: Context(engine, AUDIO)
-	{}
-
-	void set_time_slice(SampleCount nframes, SampleCount offset, FrameTime start, FrameTime end) {
-		locate(start, offset);
-		_nframes = nframes;
-		_end = end;
-	}
+	ProcessContext(Engine& engine) : Context(engine, AUDIO) {}
 };
 
 
diff --git a/src/engine/ProcessSlave.hpp b/src/engine/ProcessSlave.hpp
index f6efcb8e..cd7d5e8d 100644
--- a/src/engine/ProcessSlave.hpp
+++ b/src/engine/ProcessSlave.hpp
@@ -59,7 +59,7 @@ public:
 		_index = start_index;
 		_state = STATE_RUNNING;
 		_compiled_patch = compiled_patch;
-		_process_context.set_time_slice(context.nframes(), context.offset(), context.start(), context.end());
+		_process_context.locate(context);
 
 		Raul::Slave::whip();
 	}
diff --git a/src/engine/ingen.lv2/ingen_lv2.cpp b/src/engine/ingen.lv2/ingen_lv2.cpp
index fb145c53..424df46c 100644
--- a/src/engine/ingen.lv2/ingen_lv2.cpp
+++ b/src/engine/ingen.lv2/ingen_lv2.cpp
@@ -48,7 +48,7 @@ struct IngenLV2Driver : public Ingen::Driver {
 	bool is_activated() const { return true; }
 
 	void run(uint32_t nframes) {
-		_context.set_time_slice(nframes, _frame_time, _frame_time + nframes);
+		_context.locate(_frame_time, nframes, 0);
 		if (_root_patch)
 			_root_patch->process(_context);
 		_frame_time += nframes;