output: add damage tracking via buffer age

5 files changed, 32 insertions, 9 deletions

diff --git a/include/backend/drm/renderer.h b/include/backend/drm/renderer.h
index 45127cd0..a3f19fc3 100644
--- a/include/backend/drm/renderer.h
+++ b/include/backend/drm/renderer.h
@@ -45,7 +45,7 @@ bool wlr_drm_plane_surfaces_init(struct wlr_drm_plane *plane, struct wlr_drm_bac
 		int32_t width, uint32_t height, uint32_t format);
 
 void wlr_drm_surface_finish(struct wlr_drm_surface *surf);
-void wlr_drm_surface_make_current(struct wlr_drm_surface *surf);
+bool wlr_drm_surface_make_current(struct wlr_drm_surface *surf, int *buffer_age);
 struct gbm_bo *wlr_drm_surface_swap_buffers(struct wlr_drm_surface *surf);
 struct gbm_bo *wlr_drm_surface_get_front(struct wlr_drm_surface *surf);
 void wlr_drm_surface_post(struct wlr_drm_surface *surf);
diff --git a/include/rootston/output.h b/include/rootston/output.h
index e8241de7..c0022d1a 100644
--- a/include/rootston/output.h
+++ b/include/rootston/output.h
@@ -5,6 +5,8 @@
 #include <pixman.h>
 #include <wayland-server.h>
 
+#define ROOTS_OUTPUT_PREVIOUS_DAMAGE_LEN 2
+
 struct roots_desktop;
 
 struct roots_output {
@@ -15,9 +17,12 @@ struct roots_output {
 	struct roots_view *fullscreen_view;
 
 	struct timespec last_frame;
-	pixman_region32_t damage, previous_damage;
+	pixman_region32_t damage;
 	bool frame_pending;
 
+	pixman_region32_t previous_damage[ROOTS_OUTPUT_PREVIOUS_DAMAGE_LEN];
+	size_t previous_damage_idx;
+
 	struct wl_listener frame;
 	struct wl_listener mode;
 	struct wl_listener needs_swap;
diff --git a/include/wlr/interfaces/wlr_output.h b/include/wlr/interfaces/wlr_output.h
index 56404ec7..f2b65066 100644
--- a/include/wlr/interfaces/wlr_output.h
+++ b/include/wlr/interfaces/wlr_output.h
@@ -18,8 +18,8 @@ struct wlr_output_impl {
 		int32_t hotspot_x, int32_t hotspot_y, bool update_pixels);
 	bool (*move_cursor)(struct wlr_output *output, int x, int y);
 	void (*destroy)(struct wlr_output *output);
-	void (*make_current)(struct wlr_output *output);
-	void (*swap_buffers)(struct wlr_output *output);
+	bool (*make_current)(struct wlr_output *output, int *buffer_age);
+	bool (*swap_buffers)(struct wlr_output *output);
 	void (*set_gamma)(struct wlr_output *output,
 		uint32_t size, uint16_t *r, uint16_t *g, uint16_t *b);
 	uint32_t (*get_gamma_size)(struct wlr_output *output);
diff --git a/include/wlr/render/egl.h b/include/wlr/render/egl.h
index bdb8d286..c292a6f8 100644
--- a/include/wlr/render/egl.h
+++ b/include/wlr/render/egl.h
@@ -11,8 +11,12 @@ struct wlr_egl {
 	EGLConfig config;
 	EGLContext context;
 
-	const char *egl_exts;
-	const char *gl_exts;
+	const char *egl_exts_str;
+	const char *gl_exts_str;
+
+	struct {
+		bool buffer_age;
+	} egl_exts;
 
 	struct wl_display *wl_display;
 };
@@ -65,4 +69,10 @@ bool wlr_egl_destroy_image(struct wlr_egl *egl, EGLImageKHR image);
  */
 const char *egl_error(void);
 
+bool wlr_egl_make_current(struct wlr_egl *egl, EGLSurface surface,
+	int *buffer_age);
+
+// TODO: remove
+int wlr_egl_get_buffer_age(struct wlr_egl *egl, EGLSurface surface);
+
 #endif
diff --git a/include/wlr/types/wlr_output.h b/include/wlr/types/wlr_output.h
index 33d27501..3267a608 100644
--- a/include/wlr/types/wlr_output.h
+++ b/include/wlr/types/wlr_output.h
@@ -33,6 +33,8 @@ struct wlr_output_cursor {
 	struct wl_listener surface_destroy;
 };
 
+#define WLR_OUTPUT_PREVIOUS_DAMAGE_COUNT 2
+
 struct wlr_output_impl;
 
 struct wlr_output {
@@ -55,7 +57,7 @@ struct wlr_output {
 	enum wl_output_transform transform;
 
 	bool needs_swap;
-	pixman_region32_t damage, previous_damage;
+	pixman_region32_t damage;
 	float transform_matrix[16];
 
 	// Note: some backends may have zero modes
@@ -104,13 +106,19 @@ void wlr_output_set_scale(struct wlr_output *output, float scale);
 void wlr_output_destroy(struct wlr_output *output);
 void wlr_output_effective_resolution(struct wlr_output *output,
 	int *width, int *height);
-void wlr_output_make_current(struct wlr_output *output);
+/**
+ * Makes the output GL context current.
+ *
+ * `buffer_age` is set to the drawing buffer age in number of frames or -1 if
+ * unknown.
+ */
+bool wlr_output_make_current(struct wlr_output *output, int *buffer_age);
 /**
  * Swaps the output buffers. If the time of the frame isn't known, set `when` to
  * NULL. If the compositor doesn't support damage tracking, set `damage` to
  * NULL.
  */
-void wlr_output_swap_buffers(struct wlr_output *output, struct timespec *when,
+bool wlr_output_swap_buffers(struct wlr_output *output, struct timespec *when,
 	pixman_region32_t *damage);
 void wlr_output_set_gamma(struct wlr_output *output,
 	uint32_t size, uint16_t *r, uint16_t *g, uint16_t *b);