update [LV2] Plugin Inline Display API: drop cairo dependency

4 files changed, 31 insertions, 9 deletions

diff --git a/libs/ardour/ardour/lv2_extensions.h b/libs/ardour/ardour/lv2_extensions.h
index 5fd69cfe99..139e1a6594 100644
--- a/libs/ardour/ardour/lv2_extensions.h
+++ b/libs/ardour/ardour/lv2_extensions.h
@@ -36,13 +36,23 @@
 /** Opaque handle for LV2_Inline_Display::queue_draw() */
 typedef void* LV2_Inline_Display_Handle;
 
-/** Alias for cairo_image_surface_t */
-typedef void* LV2_Inline_Display_Image_Surface;
+/** raw image pixmap format is ARGB32,
+ * the data pointer is owned by the plugin and must be valid
+ * from the first call to render until cleanup.
+ */
+typedef struct {
+	unsigned char *data;
+	int width;
+	int height;
+	int stride;
+} LV2_Inline_Display_Image_Surface;
 
+/** a LV2 Feature provided by the Host to the plugin */
 typedef struct {
 	/** Opaque host data */
 	LV2_Inline_Display_Handle handle;
-	/** Request from run() that the host should call render() */
+	/** Request from run() that the host should call render() at a later time
+	 * to update the inline display */
 	void (*queue_draw)(LV2_Inline_Display_Handle handle);
 } LV2_Inline_Display;
 
@@ -53,12 +63,15 @@ typedef struct {
 	/**
 	 * The render method. This is called by the host in a non-realtime context,
 	 * usually the main GUI thread.
+	 * The data pointer is owned by the plugin and must be valid
+	 * from the first call to render until cleanup.
 	 *
 	 * @param instance The LV2 instance
 	 * @param w the max available width
-	 * @return pointer to a cairo image surface or NULL
+	 * @param h the max available height
+	 * @return pointer to a LV2_Inline_Display_Image_Surface or NULL
 	 */
-	LV2_Inline_Display_Image_Surface (*render)(LV2_Handle instance, uint32_t w, uint32_t h);
+	LV2_Inline_Display_Image_Surface* (*render)(LV2_Handle instance, uint32_t w, uint32_t h);
 } LV2_Inline_Display_Interface;
 
 /**
diff --git a/libs/ardour/ardour/lv2_plugin.h b/libs/ardour/ardour/lv2_plugin.h
index 020cddf34b..936fd9019f 100644
--- a/libs/ardour/ardour/lv2_plugin.h
+++ b/libs/ardour/ardour/lv2_plugin.h
@@ -301,7 +301,7 @@ class LIBARDOUR_API LV2Plugin : public ARDOUR::Plugin, public ARDOUR::Workee
 
 #ifdef LV2_EXTENDED
 	bool has_inline_display ();
-	void* render_inline_display (uint32_t, uint32_t);
+	Plugin::Display_Image_Surface* render_inline_display (uint32_t, uint32_t);
 #endif
 
 	void latency_compute_run ();
diff --git a/libs/ardour/ardour/plugin.h b/libs/ardour/ardour/plugin.h
index 17ac4e04d9..084f5a876d 100644
--- a/libs/ardour/ardour/plugin.h
+++ b/libs/ardour/ardour/plugin.h
@@ -111,8 +111,15 @@ class LIBARDOUR_API Plugin : public PBD::StatefulDestructible, public Latent
 	void realtime_locate ();
 	void monitoring_changed ();
 
+	typedef struct {
+		unsigned char *data;
+		int width;
+		int height;
+		int stride;
+	} Display_Image_Surface;
+
 	virtual bool has_inline_display () { return false; }
-	virtual void* render_inline_display (uint32_t, uint32_t) { return NULL; }
+	virtual Display_Image_Surface* render_inline_display (uint32_t, uint32_t) { return NULL; }
 	PBD::Signal0<void> QueueDraw;
 
 	struct PresetRecord {
diff --git a/libs/ardour/lv2_plugin.cc b/libs/ardour/lv2_plugin.cc
index 8283062f3f..1f0e20f779 100644
--- a/libs/ardour/lv2_plugin.cc
+++ b/libs/ardour/lv2_plugin.cc
@@ -866,10 +866,12 @@ LV2Plugin::has_inline_display () {
 	return _display_interface ? true : false;
 }
 
-void*
+Plugin::Display_Image_Surface*
 LV2Plugin::render_inline_display (uint32_t w, uint32_t h) {
 	if (_display_interface) {
-		return _display_interface->render ((void*)_impl->instance->lv2_handle, w, h);
+		/* Plugin::Display_Image_Surface is identical to
+		 * LV2_Inline_Display_Image_Surface */
+		return (Plugin::Display_Image_Surface*) _display_interface->render ((void*)_impl->instance->lv2_handle, w, h);
 	}
 	return NULL;
 }