Cache scene for client and invalidate when changes.

layout.c

@@ -453,6 +453,7 @@ layout_fix_panes(struct window *w, struct window_pane *skip)
 
 		window_pane_resize(wp, sx, sy);
 	}
+	screen_redraw_invalidate_scene(w);
 }
 
 /* Count the number of available cells in a layout. */
@@ -777,6 +778,7 @@ layout_resize_floating_pane_to(struct window_pane *wp, enum layout_type type,
 		lc->sy = size;
 	else
 		lc->sx = size;
+	screen_redraw_invalidate_scene(wp->window);
 }
 
 /* Resize a floating pane relative to its current size. */
@@ -811,6 +813,7 @@ layout_resize_floating_pane(struct window_pane *wp, enum layout_type type,
 		if (opposite)
 			lc->xoff -= change;
 	}
+	screen_redraw_invalidate_scene(wp->window);
 }
 
 /* Resize a layout cell. */

options.c

@@ -1219,6 +1219,15 @@ options_push_changes(const char *name)
 	if (strcmp(name, "status") == 0 ||
 	    strcmp(name, "status-interval") == 0)
 		status_timer_start_all();
+	if (strcmp(name, "status") == 0 ||
+	    strcmp(name, "status-position") == 0 ||
+	    strcmp(name, "pane-border-indicators") == 0 ||
+	    strcmp(name, "pane-border-lines") == 0 ||
+	    strcmp(name, "pane-border-status") == 0 ||
+	    strcmp(name, "pane-scrollbars") == 0 ||
+	    strcmp(name, "pane-scrollbars-position") == 0 ||
+	    strcmp(name, "pane-scrollbars-style") == 0)
+		screen_redraw_invalidate_all_scenes();
 	if (strcmp(name, "monitor-silence") == 0)
 		alerts_reset_all();
 	if (strcmp(name, "window-style") == 0 ||

screen-redraw.c

@@ -149,6 +149,8 @@ struct redraw_scene {
 	struct client		*c;
 	struct window		*w;
 
+	uint64_t		 generation;
+
 	u_int			 sx;
 	u_int			 sy;
 	u_int			 ox;
@@ -818,6 +820,7 @@ screen_redraw_make_scene(struct client *c)
 	scene = xcalloc(1, sizeof *scene);
 	scene->c = c;
 	scene->w = bctx.w;
+	scene->generation = bctx.w->redraw_scene_generation;
 	scene->sx = bctx.sx;
 	scene->sy = bctx.sy;
 	scene->ox = bctx.ox;
@@ -851,13 +854,16 @@ screen_redraw_make_scene(struct client *c)
 }
 
 /* Free a scene. */
-static void
+void
 screen_redraw_free_scene(struct redraw_scene *scene)
 {
 	struct redraw_spans	*spans;
 	struct redraw_span	*span, *span1;
 	u_int			 y, type;
 
+	if (scene == NULL)
+		return;
+
 	for (y = 0; y < scene->sy; y++) {
 		for (type = 0; type < REDRAW_SPAN_TYPES; type++) {
 			spans = &scene->lines[y].spans[type];
@@ -871,6 +877,46 @@ screen_redraw_free_scene(struct redraw_scene *scene)
 	free(scene);
 }
 
+/* Mark a window's cached redraw scenes as out of date. */
+void
+screen_redraw_invalidate_scene(struct window *w)
+{
+	w->redraw_scene_generation++;
+}
+
+/* Mark all cached redraw scenes as out of date. */
+void
+screen_redraw_invalidate_all_scenes(void)
+{
+	struct window	*w;
+
+	RB_FOREACH(w, windows, &windows)
+		screen_redraw_invalidate_scene(w);
+}
+
+/* Get the cached redraw scene, rebuilding it if needed. */
+static struct redraw_scene *
+screen_redraw_get_scene(struct client *c)
+{
+	struct redraw_scene	*scene = c->redraw_scene;
+	struct window		*w = c->session->curw->window;
+	u_int			 ox, oy, sx, sy;
+
+	tty_window_offset(&c->tty, &ox, &oy, &sx, &sy);
+	if (scene == NULL ||
+	    scene->w != w ||
+	    scene->generation != w->redraw_scene_generation ||
+	    scene->ox != ox ||
+	    scene->oy != oy ||
+	    scene->sx != sx ||
+	    scene->sy != sy) {
+		screen_redraw_free_scene(scene);
+		scene = screen_redraw_make_scene(c);
+		c->redraw_scene = scene;
+	}
+	return (scene);
+}
+
 /* Is this span adjacent to this pane? */
 static int
 screen_redraw_span_has_pane(struct redraw_span *span, struct window_pane *wp)
@@ -1379,7 +1425,9 @@ screen_redraw_draw(struct client *c, struct window_pane *wp, int flags)
 		}
 	}
 
-	scene = screen_redraw_make_scene(c); //XXX
+	scene = screen_redraw_get_scene(c);
+	if (scene == NULL)
+		return;
 	if (scene == NULL)
 		return;
 	screen_redraw_set_draw_context(&dctx, scene);
@@ -1411,10 +1459,8 @@ screen_redraw_draw(struct client *c, struct window_pane *wp, int flags)
 		}
 		if (!redraw && !REDRAW_IS_ALL(flags)) {
 			flags &= ~REDRAW_PANE_STATUS;
-			if (flags == 0) {
-				screen_redraw_free_scene(scene);
+			if (flags == 0)
 				return;
-			}
 		}
 	}
 
@@ -1457,7 +1503,6 @@ screen_redraw_draw(struct client *c, struct window_pane *wp, int flags)
 	tty_reset(tty);
 	tty_sync_end(tty);
 
-	screen_redraw_free_scene(scene); //XXX
 }
 
 /* Get cell type for offset from span. */

server-client.c

@@ -530,6 +530,7 @@ server_client_free(__unused int fd, __unused short events, void *arg)
 
 	log_debug("free client %p (%d references)", c, c->references);
 
+	screen_redraw_free_scene(c->redraw_scene);
 	cmdq_free(c->queue);
 
 	if (c->references == 0) {

tmux.h

@@ -63,6 +63,7 @@ struct mouse_event;
 struct options;
 struct options_array_item;
 struct options_entry;
+struct redraw_scene;
 struct redraw_span;
 struct screen_write_citem;
 struct screen_write_cline;
@@ -1380,6 +1381,8 @@ struct window {
 	u_int			 new_xpixel;
 	u_int			 new_ypixel;
 
+	uint64_t		 redraw_scene_generation;
+
 	u_int			 last_new_pane_x;
 	u_int			 last_new_pane_y;
 
@@ -2073,6 +2076,8 @@ struct client {
 	size_t			 discarded;
 	size_t			 redraw;
 
+	struct redraw_scene	*redraw_scene;
+
 	struct event		 repeat_timer;
 
 	struct event		 click_timer;
@@ -3367,6 +3372,9 @@ void	 screen_write_alternateoff(struct screen_write_ctx *,
 void	 screen_redraw_screen(struct client *);
 void	 screen_redraw_pane(struct client *, struct window_pane *);
 void	 screen_redraw_pane_scrollbar(struct client *, struct window_pane *);
+void	 screen_redraw_free_scene(struct redraw_scene *);
+void	 screen_redraw_invalidate_scene(struct window *);
+void	 screen_redraw_invalidate_all_scenes(void);
 int	 screen_redraw_get_span_cell_type(struct redraw_span **, u_int);
 
 /* screen.c */

window.c

@@ -758,6 +758,7 @@ window_zoom(struct window_pane *wp)
 	w->flags |= WINDOW_ZOOMED;
 	notify_window("window-layout-changed", w);
 
+	screen_redraw_invalidate_scene(w);
 	return (0);
 }
 
@@ -784,6 +785,7 @@ window_unzoom(struct window *w, int notify)
 	if (notify)
 		notify_window("window-layout-changed", w);
 
+	screen_redraw_invalidate_scene(w);
 	return (0);
 }
 
@@ -840,6 +842,7 @@ window_add_pane(struct window *w, struct window_pane *other, u_int hlimit,
 	else {
 		TAILQ_INSERT_HEAD(&w->z_index, wp, zentry);
 	}
+	screen_redraw_invalidate_scene(w);
 	return (wp);
 }
 
@@ -866,6 +869,7 @@ window_lost_pane(struct window *w, struct window_pane *wp)
 			window_update_focus(w);
 		}
 	}
+	screen_redraw_invalidate_scene(w);
 }
 
 void
@@ -874,6 +878,7 @@ window_remove_pane(struct window *w, struct window_pane *wp)
 	window_lost_pane(w, wp);
 	TAILQ_REMOVE(&w->panes, wp, entry);
 	TAILQ_REMOVE(&w->z_index, wp, zentry);
+	screen_redraw_invalidate_scene(w);
 	window_pane_destroy(wp);
 }