scene: rename output_present event to output_sample

Using "present" is confusing here: the event is emitted when the
buffer is being sampled to be displayed on an output, not when it's
being presented on-screen.

Rename to match the presentation-time terminology.

include/wlr/types/wlr_scene.h

@@ -122,7 +122,7 @@ struct wlr_scene_surface {
 	struct wl_listener outputs_update;
 	struct wl_listener output_enter;
 	struct wl_listener output_leave;
-	struct wl_listener output_present;
+	struct wl_listener output_sample;
 	struct wl_listener frame_done;
 	struct wl_listener surface_destroy;
 	struct wl_listener surface_commit;
@@ -151,7 +151,7 @@ struct wlr_scene_buffer {
 		struct wl_signal outputs_update; // struct wlr_scene_outputs_update_event
 		struct wl_signal output_enter; // struct wlr_scene_output
 		struct wl_signal output_leave; // struct wlr_scene_output
-		struct wl_signal output_present; // struct wlr_scene_output
+		struct wl_signal output_sample; // struct wlr_scene_output
 		struct wl_signal frame_done; // struct timespec
 	} events;
 

types/scene/surface.c

@@ -36,10 +36,10 @@ static void handle_scene_buffer_output_leave(
 	wlr_surface_send_leave(surface->surface, output->output);
 }
 
-static void handle_scene_buffer_output_present(
+static void handle_scene_buffer_output_sample(
 		struct wl_listener *listener, void *data) {
 	struct wlr_scene_surface *surface =
-		wl_container_of(listener, surface, output_present);
+		wl_container_of(listener, surface, output_sample);
 	struct wlr_scene_output *scene_output = data;
 
 	if (surface->buffer->primary_output == scene_output) {
@@ -157,7 +157,7 @@ static void surface_addon_destroy(struct wlr_addon *addon) {
 	wl_list_remove(&surface->outputs_update.link);
 	wl_list_remove(&surface->output_enter.link);
 	wl_list_remove(&surface->output_leave.link);
-	wl_list_remove(&surface->output_present.link);
+	wl_list_remove(&surface->output_sample.link);
 	wl_list_remove(&surface->frame_done.link);
 	wl_list_remove(&surface->surface_destroy.link);
 	wl_list_remove(&surface->surface_commit.link);
@@ -208,8 +208,8 @@ struct wlr_scene_surface *wlr_scene_surface_create(struct wlr_scene_tree *parent
 	surface->output_leave.notify = handle_scene_buffer_output_leave;
 	wl_signal_add(&scene_buffer->events.output_leave, &surface->output_leave);
 
-	surface->output_present.notify = handle_scene_buffer_output_present;
-	wl_signal_add(&scene_buffer->events.output_present, &surface->output_present);
+	surface->output_sample.notify = handle_scene_buffer_output_sample;
+	wl_signal_add(&scene_buffer->events.output_sample, &surface->output_sample);
 
 	surface->frame_done.notify = handle_scene_buffer_frame_done;
 	wl_signal_add(&scene_buffer->events.frame_done, &surface->frame_done);

types/scene/wlr_scene.c

@@ -614,7 +614,7 @@ struct wlr_scene_buffer *wlr_scene_buffer_create(struct wlr_scene_tree *parent,
 	wl_signal_init(&scene_buffer->events.outputs_update);
 	wl_signal_init(&scene_buffer->events.output_enter);
 	wl_signal_init(&scene_buffer->events.output_leave);
-	wl_signal_init(&scene_buffer->events.output_present);
+	wl_signal_init(&scene_buffer->events.output_sample);
 	wl_signal_init(&scene_buffer->events.frame_done);
 	pixman_region32_init(&scene_buffer->opaque_region);
 	scene_buffer->opacity = 1;
@@ -1171,7 +1171,7 @@ static void scene_entry_render(struct render_list_entry *entry, const struct ren
 				WLR_RENDER_BLEND_MODE_PREMULTIPLIED : WLR_RENDER_BLEND_MODE_NONE,
 		});
 
-		wl_signal_emit_mutable(&scene_buffer->events.output_present, data->output);
+		wl_signal_emit_mutable(&scene_buffer->events.output_sample, data->output);
 		break;
 	}
 
@@ -1572,7 +1572,7 @@ static bool scene_entry_try_direct_scanout(struct render_list_entry *entry,
 	wlr_output_state_copy(state, &pending);
 	wlr_output_state_finish(&pending);
 
-	wl_signal_emit_mutable(&buffer->events.output_present, scene_output);
+	wl_signal_emit_mutable(&buffer->events.output_sample, scene_output);
 	return true;
 }