1 files changed, 76 insertions, 0 deletions
diff --git a/src/comm.h b/src/comm.h
new file mode 100644
index 0000000..75f098b
--- /dev/null
+++ b/src/comm.h
@@ -0,0 +1,76 @@
+// Copyright 2007-2024 David Robillard <d@drobilla.net>
+// SPDX-License-Identifier: ISC
+
+#ifndef JALV_COMM_H
+#define JALV_COMM_H
+
+#include "attributes.h"
+
+#include "lv2/urid/urid.h"
+#include "zix/ring.h"
+#include "zix/status.h"
+
+#include <stdint.h>
+
+JALV_BEGIN_DECLS
+
+// Communication between the audio and main threads via rings
+
+/**
+   Write a message in two parts to a ring.
+
+   This is used to conveniently write a message with a fixed-size header and
+   possibly variably-sized body in a single call.
+
+   @param target Communication ring (jalv->plugin_to_ui or jalv->ui_to_plugin).
+   @param header Pointer to start of header data.
+   @param header_size Size of header in bytes.
+   @param body Pointer to start of body data.
+   @param body_size Size of body in bytes.
+   @return 0 on success, non-zero on failure (overflow).
+*/
+ZixStatus
+jalv_write_split_message(ZixRing*    target,
+                         const void* header,
+                         uint32_t    header_size,
+                         const void* body,
+                         uint32_t    body_size);
+
+/**
+   Write a port event using the atom:eventTransfer protocol.
+
+   This is used to transfer atoms between the plugin and UI via sequence ports.
+
+   @param target Communication ring (jalv->plugin_to_ui or jalv->ui_to_plugin).
+   @param port_index Index of the port this change is for.
+   @param protocol Port protocol (0 for float control, or atom:eventTransfer).o
+   @param size Size of body in bytes.
+   @param type Atom type URID.
+   @param body Atom body.
+   @return 0 on success, non-zero on failure (overflow).
+*/
+ZixStatus
+jalv_write_event(ZixRing*    target,
+                 uint32_t    port_index,
+                 uint32_t    protocol,
+                 uint32_t    size,
+                 LV2_URID    type,
+                 const void* body);
+
+/**
+   Write a control port change using the default (0) protocol.
+
+   This is used to transfer control port value changes between the plugin and
+   UI.
+
+   @param target Communication ring (jalv->plugin_to_ui or jalv->ui_to_plugin).
+   @param port_index Index of the port this change is for.
+   @param value New control port value.
+   @return 0 on success, non-zero on failure (overflow).
+*/
+ZixStatus
+jalv_write_control(ZixRing* target, uint32_t port_index, float value);
+
+JALV_END_DECLS
+
+#endif // JALV_COMM_H