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diff --git a/src/control.h b/src/control.h
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+// Copyright 2007-2022 David Robillard <d@drobilla.net>
+// SPDX-License-Identifier: ISC
+
+#ifndef JALV_CONTROL_H
+#define JALV_CONTROL_H
+
+#include "attributes.h"
+#include "nodes.h"
+
+#include "lilv/lilv.h"
+#include "lv2/atom/forge.h"
+#include "lv2/urid/urid.h"
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+
+JALV_BEGIN_DECLS
+
+// Plugin control utilities
+
+/// Type of plugin control
+typedef enum {
+  PORT,    ///< Control port
+  PROPERTY ///< Property (set via atom message)
+} ControlType;
+
+// "Interesting" value in a control's value range
+typedef struct {
+  float value;
+  char* label;
+} ScalePoint;
+
+/// Plugin control
+typedef struct {
+  ControlType     type;           ///< Type of control
+  LilvNode*       node;           ///< Port or property
+  LilvNode*       symbol;         ///< Symbol
+  LilvNode*       label;          ///< Human readable label
+  LV2_Atom_Forge* forge;          ///< Forge (for URIDs)
+  LV2_URID        property;       ///< Iff type == PROPERTY
+  uint32_t        index;          ///< Iff type == PORT
+  LilvNode*       group;          ///< Port/control group, or NULL
+  void*           widget;         ///< Control Widget
+  size_t          n_points;       ///< Number of scale points
+  ScalePoint*     points;         ///< Scale points
+  LV2_URID        value_type;     ///< Type of control value
+  LilvNode*       min;            ///< Minimum value
+  LilvNode*       max;            ///< Maximum value
+  LilvNode*       def;            ///< Default value
+  bool            is_toggle;      ///< Boolean (0 and 1 only)
+  bool            is_integer;     ///< Integer values only
+  bool            is_enumeration; ///< Point values only
+  bool            is_logarithmic; ///< Logarithmic scale
+  bool            is_writable;    ///< Writable (input)
+  bool            is_readable;    ///< Readable (output)
+} ControlID;
+
+/// Set of plugin controls
+typedef struct {
+  size_t      n_controls;
+  ControlID** controls;
+} Controls;
+
+/// Control change event, sent through ring buffers for UI updates
+typedef struct {
+  uint32_t index;
+  uint32_t protocol;
+  uint32_t size;
+  // Followed immediately by size bytes of data
+} ControlChange;
+
+/// Order scale points by value
+int
+scale_point_cmp(const ScalePoint* a, const ScalePoint* b);
+
+/// Create a new ID for a control port
+ControlID*
+new_port_control(LilvWorld*        world,
+                 const LilvPlugin* plugin,
+                 const LilvPort*   port,
+                 uint32_t          port_index,
+                 float             sample_rate,
+                 const JalvNodes*  nodes,
+                 LV2_Atom_Forge*   forge);
+
+/// Create a new ID for a property-based parameter
+ControlID*
+new_property_control(LilvWorld*       world,
+                     const LilvNode*  property,
+                     const JalvNodes* nodes,
+                     LV2_URID_Map*    map,
+                     LV2_Atom_Forge*  forge);
+
+void
+add_control(Controls* controls, ControlID* control);
+
+ControlID*
+get_property_control(const Controls* controls, LV2_URID property);
+
+JALV_END_DECLS
+
+#endif // JALV_CONTROL_H