Merge pull request #1272 from emersion/presentation-time

Implement presentation-time

6 files changed, 104 insertions, 4 deletions

diff --git a/include/wlr/backend.h b/include/wlr/backend.h
index dfb8d2a8..54f2b5e8 100644
--- a/include/wlr/backend.h
+++ b/include/wlr/backend.h
@@ -62,5 +62,9 @@ struct wlr_renderer *wlr_backend_get_renderer(struct wlr_backend *backend);
  * Might return NULL for backends that don't use a session.
  */
 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_presentation_clock(struct wlr_backend *backend);
 
 #endif
diff --git a/include/wlr/backend/interface.h b/include/wlr/backend/interface.h
index 2c300709..4a6a5cbb 100644
--- a/include/wlr/backend/interface.h
+++ b/include/wlr/backend/interface.h
@@ -10,6 +10,7 @@
 #define WLR_BACKEND_INTERFACE_H
 
 #include <stdbool.h>
+#include <time.h>
 #include <wlr/backend.h>
 #include <wlr/render/egl.h>
 
@@ -18,6 +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_presentation_clock)(struct wlr_backend *backend);
 };
 
 /**
diff --git a/include/wlr/interfaces/wlr_output.h b/include/wlr/interfaces/wlr_output.h
index bfb3bc9d..52581768 100644
--- a/include/wlr/interfaces/wlr_output.h
+++ b/include/wlr/interfaces/wlr_output.h
@@ -45,5 +45,7 @@ void wlr_output_update_enabled(struct wlr_output *output, bool enabled);
 void wlr_output_update_needs_swap(struct wlr_output *output);
 void wlr_output_damage_whole(struct wlr_output *output);
 void wlr_output_send_frame(struct wlr_output *output);
+void wlr_output_send_present(struct wlr_output *output,
+	struct wlr_output_event_present *event);
 
 #endif
diff --git a/include/wlr/types/meson.build b/include/wlr/types/meson.build
index 6a8955c3..7a02c3da 100644
--- a/include/wlr/types/meson.build
+++ b/include/wlr/types/meson.build
@@ -5,10 +5,10 @@ install_headers(
 	'wlr_cursor.h',
 	'wlr_data_device.h',
 	'wlr_export_dmabuf_v1.h',
-	'wlr_gamma_control.h',
 	'wlr_gamma_control_v1.h',
-	'wlr_idle.h',
+	'wlr_gamma_control.h',
 	'wlr_idle_inhibit_v1.h',
+	'wlr_idle.h',
 	'wlr_input_device.h',
 	'wlr_input_inhibitor.h',
 	'wlr_keyboard.h',
@@ -16,10 +16,11 @@ install_headers(
 	'wlr_linux_dmabuf_v1.h',
 	'wlr_list.h',
 	'wlr_matrix.h',
-	'wlr_output.h',
 	'wlr_output_damage.h',
 	'wlr_output_layout.h',
+	'wlr_output.h',
 	'wlr_pointer.h',
+	'wlr_presentation_time.h',
 	'wlr_primary_selection.h',
 	'wlr_region.h',
 	'wlr_screencopy_v1.h',
@@ -36,7 +37,7 @@ install_headers(
 	'wlr_xcursor_manager.h',
 	'wlr_xdg_decoration_v1.h',
 	'wlr_xdg_output_v1.h',
-	'wlr_xdg_shell.h',
 	'wlr_xdg_shell_v6.h',
+	'wlr_xdg_shell.h',
 	subdir: 'wlr/types',
 )
diff --git a/include/wlr/types/wlr_output.h b/include/wlr/types/wlr_output.h
index 96394ba4..9ccfbbb5 100644
--- a/include/wlr/types/wlr_output.h
+++ b/include/wlr/types/wlr_output.h
@@ -88,9 +88,15 @@ struct wlr_output {
 	float transform_matrix[9];
 
 	struct {
+		// Request to render a frame
 		struct wl_signal frame;
+		// Emitted when buffers need to be swapped (because software cursors or
+		// fullscreen damage or because of backend-specific logic)
 		struct wl_signal needs_swap;
+		// Emitted right before buffer swap
 		struct wl_signal swap_buffers; // wlr_output_event_swap_buffers
+		// Emitted right after the buffer has been presented to the user
+		struct wl_signal present; // wlr_output_event_present
 		struct wl_signal enable;
 		struct wl_signal mode;
 		struct wl_signal scale;
@@ -123,6 +129,32 @@ struct wlr_output_event_swap_buffers {
 	pixman_region32_t *damage;
 };
 
+enum wlr_output_present_flag {
+	// The presentation was synchronized to the "vertical retrace" by the
+	// display hardware such that tearing does not happen.
+	WLR_OUTPUT_PRESENT_VSYNC = 0x1,
+	// The display hardware provided measurements that the hardware driver
+	// converted into a presentation timestamp.
+	WLR_OUTPUT_PRESENT_HW_CLOCK = 0x2,
+	// The display hardware signalled that it started using the new image
+	// content.
+	WLR_OUTPUT_PRESENT_HW_COMPLETION = 0x4,
+	// The presentation of this update was done zero-copy.
+	WLR_OUTPUT_PRESENT_ZERO_COPY = 0x8,
+};
+
+struct wlr_output_event_present {
+	struct wlr_output *output;
+	// Time when the content update turned into light the first time.
+	struct timespec *when;
+	// Vertical retrace counter. Zero if unavailable.
+	unsigned seq;
+	// Prediction of how many nanoseconds after `when` the very next output
+	// refresh may occur. Zero if unknown.
+	int refresh; // nsec
+	uint32_t flags; // enum wlr_output_present_flag
+};
+
 struct wlr_surface;
 
 /**
diff --git a/include/wlr/types/wlr_presentation_time.h b/include/wlr/types/wlr_presentation_time.h
new file mode 100644
index 00000000..9f9f0e87
--- /dev/null
+++ b/include/wlr/types/wlr_presentation_time.h
@@ -0,0 +1,59 @@
+/*
+ * This an unstable interface of wlroots. No guarantees are made regarding the
+ * future consistency of this API.
+ */
+#ifndef WLR_USE_UNSTABLE
+#error "Add -DWLR_USE_UNSTABLE to enable unstable wlroots features"
+#endif
+
+#ifndef WLR_TYPES_WLR_PRESENTATION_TIME_H
+#define WLR_TYPES_WLR_PRESENTATION_TIME_H
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <time.h>
+#include <wayland-server.h>
+
+struct wlr_presentation {
+	struct wl_global *global;
+	struct wl_list resources; // wl_resource_get_link
+	struct wl_list feedbacks; // wlr_presentation_feedback::link
+	clockid_t clock;
+
+	struct {
+		struct wl_signal destroy;
+	} events;
+
+	struct wl_listener display_destroy;
+};
+
+struct wlr_presentation_feedback {
+	struct wl_resource *resource;
+	struct wlr_presentation *presentation;
+	struct wlr_surface *surface;
+	bool committed;
+	struct wl_list link; // wlr_presentation::feedbacks
+
+	struct wl_listener surface_commit;
+	struct wl_listener surface_destroy;
+};
+
+struct wlr_presentation_event {
+	struct wlr_output *output;
+	uint64_t tv_sec;
+	uint32_t tv_nsec;
+	uint32_t refresh;
+	uint64_t seq;
+	uint32_t flags; // wp_presentation_feedback_kind
+};
+
+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,
+	struct wlr_presentation_event *event);
+
+#endif