Rename get_present_clock to get_presentation clock, use it

backend/backend.c

@@ -64,9 +64,9 @@ struct wlr_session *wlr_backend_get_session(struct wlr_backend *backend) {
 	return NULL;
 }
 
-clockid_t wlr_backend_get_present_clock(struct wlr_backend *backend) {
+clockid_t wlr_backend_get_presentation_clock(struct wlr_backend *backend) {
-	if (backend->impl->get_present_clock) {
+	if (backend->impl->get_presentation_clock) {
-		return backend->impl->get_present_clock(backend);
+		return backend->impl->get_presentation_clock(backend);
 	}
 	return CLOCK_MONOTONIC;
 }

backend/drm/backend.c

@@ -65,7 +65,7 @@ static struct wlr_renderer *backend_get_renderer(
 	}
 }
 
-static clockid_t backend_get_present_clock(struct wlr_backend *backend) {
+static clockid_t backend_get_presentation_clock(struct wlr_backend *backend) {
 	struct wlr_drm_backend *drm = get_drm_backend_from_backend(backend);
 	return drm->clock;
 }
@@ -74,7 +74,7 @@ static struct wlr_backend_impl backend_impl = {
 	.start = backend_start,
 	.destroy = backend_destroy,
 	.get_renderer = backend_get_renderer,
-	.get_present_clock = backend_get_present_clock,
+	.get_presentation_clock = backend_get_presentation_clock,
 };
 
 bool wlr_backend_is_drm(struct wlr_backend *b) {

backend/multi/backend.c

@@ -1,6 +1,8 @@
+#define _POSIX_C_SOURCE 199309L
 #include <assert.h>
 #include <stdbool.h>
 #include <stdlib.h>
+#include <time.h>
 #include <wlr/backend/interface.h>
 #include <wlr/backend/session.h>
 #include <wlr/util/log.h>
@@ -77,11 +79,26 @@ static struct wlr_session *multi_backend_get_session(
 	return backend->session;
 }
 
+static clockid_t multi_backend_get_presentation_clock(
+		struct wlr_backend *backend) {
+	struct wlr_multi_backend *multi = multi_backend_from_backend(backend);
+
+	struct subbackend_state *sub;
+	wl_list_for_each(sub, &multi->backends, link) {
+		if (sub->backend->impl->get_presentation_clock) {
+			return wlr_backend_get_presentation_clock(sub->backend);
+		}
+	}
+
+	return CLOCK_MONOTONIC;
+}
+
 struct wlr_backend_impl backend_impl = {
 	.start = multi_backend_start,
 	.destroy = multi_backend_destroy,
 	.get_renderer = multi_backend_get_renderer,
 	.get_session = multi_backend_get_session,
+	.get_presentation_clock = multi_backend_get_presentation_clock,
 };
 
 static void handle_display_destroy(struct wl_listener *listener, void *data) {

include/wlr/backend.h

@@ -65,6 +65,6 @@ struct wlr_session *wlr_backend_get_session(struct wlr_backend *backend);
 /**
  * Returns the clock used by the backend for presentation feedback.
  */
-clockid_t wlr_backend_get_present_clock(struct wlr_backend *backend);
+clockid_t wlr_backend_get_presentation_clock(struct wlr_backend *backend);
 
 #endif

include/wlr/backend/interface.h

@@ -19,7 +19,7 @@ struct wlr_backend_impl {
 	void (*destroy)(struct wlr_backend *backend);
 	struct wlr_renderer *(*get_renderer)(struct wlr_backend *backend);
 	struct wlr_session *(*get_session)(struct wlr_backend *backend);
-	clockid_t (*get_present_clock)(struct wlr_backend *backend);
+	clockid_t (*get_presentation_clock)(struct wlr_backend *backend);
 };
 
 /**

include/wlr/types/wlr_presentation_time.h

@@ -47,7 +47,10 @@ struct wlr_presentation_event {
 	uint32_t flags; // wp_presentation_feedback_kind
 };
 
-struct wlr_presentation *wlr_presentation_create(struct wl_display *display);
+struct wlr_backend;
+
+struct wlr_presentation *wlr_presentation_create(struct wl_display *display,
+	struct wlr_backend *backend);
 void wlr_presentation_destroy(struct wlr_presentation *presentation);
 void wlr_presentation_send_surface_presented(
 	struct wlr_presentation *presentation, struct wlr_surface *surface,

types/wlr_output.c

@@ -565,7 +565,7 @@ void wlr_output_send_present(struct wlr_output *output, struct timespec *when,
 		unsigned seq, uint32_t flags) {
 	struct timespec now;
 	if (when == NULL) {
-		clockid_t clock = wlr_backend_get_present_clock(output->backend);
+		clockid_t clock = wlr_backend_get_presentation_clock(output->backend);
 		errno = 0;
 		if (clock_gettime(clock, &now) != 0) {
 			wlr_log_errno(WLR_ERROR, "failed to send output present event: "

types/wlr_presentation_time.c

@@ -3,6 +3,7 @@
 #include <stdlib.h>
 #include <wlr/types/wlr_presentation_time.h>
 #include <wlr/types/wlr_surface.h>
+#include <wlr/backend.h>
 #include "presentation-time-protocol.h"
 #include "util/signal.h"
 
@@ -147,7 +148,7 @@ static void presentation_bind(struct wl_client *client, void *data,
 		presentation_handle_resource_destroy);
 	wl_list_insert(&presentation->resources, wl_resource_get_link(resource));
 
-	wp_presentation_send_clock_id(resource, presentation->clock);
+	wp_presentation_send_clock_id(resource, (uint32_t)presentation->clock);
 }
 
 static void handle_display_destroy(struct wl_listener *listener, void *data) {
@@ -156,7 +157,8 @@ static void handle_display_destroy(struct wl_listener *listener, void *data) {
 	wlr_presentation_destroy(presentation);
 }
 
-struct wlr_presentation *wlr_presentation_create(struct wl_display *display) {
+struct wlr_presentation *wlr_presentation_create(struct wl_display *display,
+		struct wlr_backend *backend) {
 	struct wlr_presentation *presentation =
 		calloc(1, sizeof(struct wlr_presentation));
 	if (presentation == NULL) {
@@ -170,8 +172,7 @@ struct wlr_presentation *wlr_presentation_create(struct wl_display *display) {
 		return NULL;
 	}
 
-	// TODO: get clock from backend
+	presentation->clock = wlr_backend_get_presentation_clock(backend);
-	presentation->clock = CLOCK_MONOTONIC;
 
 	wl_list_init(&presentation->resources);
 	wl_list_init(&presentation->feedbacks);