Do not hoke into struct window_pane from the tty code and instead set

everything up in tty_ctx. Provide a way to initialize the tty_ctx from a
callback and use it to let popups draw directly through input_parse in
the same way as panes do, rather than forcing a full redraw on every
change.

16 files changed, 484 insertions, 372 deletions

diff --git a/usr.bin/tmux/cmd-display-panes.c b/usr.bin/tmux/cmd-display-panes.c
index 2680c9835a1..62786d7a264 100644
--- a/usr.bin/tmux/cmd-display-panes.c
+++ b/usr.bin/tmux/cmd-display-panes.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: cmd-display-panes.c,v 1.34 2020/04/13 20:51:57 nicm Exp $ */
+/* $OpenBSD: cmd-display-panes.c,v 1.35 2020/05/16 15:34:08 nicm Exp $ */
 
 /*
  * Copyright (c) 2009 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -131,9 +131,7 @@ cmd_display_panes_draw_pane(struct screen_redraw_ctx *ctx,
 		gc.bg = active_colour;
 	else
 		gc.bg = colour;
-	gc.flags |= GRID_FLAG_NOPALETTE;
-
-	tty_attributes(tty, &gc, wp);
+	tty_attributes(tty, &gc, &grid_default_cell, NULL);
 	for (ptr = buf; *ptr != '\0'; ptr++) {
 		if (*ptr < '0' || *ptr > '9')
 			continue;
@@ -160,9 +158,7 @@ draw_text:
 		gc.fg = active_colour;
 	else
 		gc.fg = colour;
-	gc.flags |= GRID_FLAG_NOPALETTE;
-
-	tty_attributes(tty, &gc, wp);
+	tty_attributes(tty, &gc, &grid_default_cell, NULL);
 	tty_puts(tty, buf);
 
 	tty_cursor(tty, 0, 0);
diff --git a/usr.bin/tmux/format-draw.c b/usr.bin/tmux/format-draw.c
index 15940c12d4f..9f8b08862b7 100644
--- a/usr.bin/tmux/format-draw.c
+++ b/usr.bin/tmux/format-draw.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: format-draw.c,v 1.17 2020/05/16 15:24:28 nicm Exp $ */
+/* $OpenBSD: format-draw.c,v 1.18 2020/05/16 15:34:08 nicm Exp $ */
 
 /*
  * Copyright (c) 2019 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -242,7 +242,7 @@ format_draw_left(struct screen_write_ctx *octx, u_int available, u_int ocx,
 
 	/* If there is no list left, pass off to the no list function. */
 	if (width_list == 0) {
-		screen_write_start(&ctx, NULL, left);
+		screen_write_start(&ctx, left);
 		screen_write_fast_copy(&ctx, after, 0, 0, width_after, 1);
 		screen_write_stop(&ctx);
 
@@ -334,7 +334,7 @@ format_draw_centre(struct screen_write_ctx *octx, u_int available, u_int ocx,
 
 	/* If there is no list left, pass off to the no list function. */
 	if (width_list == 0) {
-		screen_write_start(&ctx, NULL, centre);
+		screen_write_start(&ctx, centre);
 		screen_write_fast_copy(&ctx, after, 0, 0, width_after, 1);
 		screen_write_stop(&ctx);
 
@@ -431,7 +431,7 @@ format_draw_right(struct screen_write_ctx *octx, u_int available, u_int ocx,
 
 	/* If there is no list left, pass off to the no list function. */
 	if (width_list == 0) {
-		screen_write_start(&ctx, NULL, right);
+		screen_write_start(&ctx, right);
 		screen_write_fast_copy(&ctx, after, 0, 0, width_after, 1);
 		screen_write_stop(&ctx);
 
@@ -536,7 +536,7 @@ format_draw(struct screen_write_ctx *octx, const struct grid_cell *base,
 	 */
 	for (i = 0; i < TOTAL; i++) {
 		screen_init(&s[i], size, 1, 0);
-		screen_write_start(&ctx[i], NULL, &s[i]);
+		screen_write_start(&ctx[i], &s[i]);
 		screen_write_clearendofline(&ctx[i], current_default.bg);
 		width[i] = 0;
 	}
diff --git a/usr.bin/tmux/input.c b/usr.bin/tmux/input.c
index 5ee5eafe211..61023dbecd9 100644
--- a/usr.bin/tmux/input.c
+++ b/usr.bin/tmux/input.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: input.c,v 1.176 2020/05/16 15:01:31 nicm Exp $ */
+/* $OpenBSD: input.c,v 1.177 2020/05/16 15:34:08 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -842,9 +842,9 @@ input_reset(struct input_ctx *ictx, int clear)
 
 	if (clear && wp != NULL) {
 		if (TAILQ_EMPTY(&wp->modes))
-			screen_write_start(sctx, wp, &wp->base);
+			screen_write_start_pane(sctx, wp, &wp->base);
 		else
-			screen_write_start(sctx, NULL, &wp->base);
+			screen_write_start(sctx, &wp->base);
 		screen_write_reset(sctx);
 		screen_write_stop(sctx);
 	}
@@ -960,9 +960,9 @@ input_parse_buffer(struct window_pane *wp, u_char *buf, size_t len)
 
 	/* NULL wp if there is a mode set as don't want to update the tty. */
 	if (TAILQ_EMPTY(&wp->modes))
-		screen_write_start(sctx, wp, &wp->base);
+		screen_write_start_pane(sctx, wp, &wp->base);
 	else
-		screen_write_start(sctx, NULL, &wp->base);
+		screen_write_start(sctx, &wp->base);
 
 	log_debug("%s: %%%u %s, %zu bytes: %.*s", __func__, wp->id,
 	    ictx->state->name, len, (int)len, buf);
@@ -973,15 +973,15 @@ input_parse_buffer(struct window_pane *wp, u_char *buf, size_t len)
 
 /* Parse given input for screen. */
 void
-input_parse_screen(struct input_ctx *ictx, struct screen *s, u_char *buf,
-    size_t len)
+input_parse_screen(struct input_ctx *ictx, struct screen *s,
+    screen_write_init_ctx_cb cb, void *arg, u_char *buf, size_t len)
 {
 	struct screen_write_ctx	*sctx = &ictx->ctx;
 
 	if (len == 0)
 		return;
 
-	screen_write_start(sctx, NULL, s);
+	screen_write_start_callback(sctx, s, cb, arg);
 	input_parse(ictx, buf, len);
 	screen_write_stop(sctx);
 }
@@ -1632,7 +1632,6 @@ static void
 input_csi_dispatch_rm_private(struct input_ctx *ictx)
 {
 	struct screen_write_ctx	*sctx = &ictx->ctx;
-	struct window_pane	*wp = ictx->wp;
 	struct grid_cell	*gc = &ictx->cell.cell;
 	u_int			 i;
 
@@ -1677,16 +1676,10 @@ input_csi_dispatch_rm_private(struct input_ctx *ictx)
 			break;
 		case 47:
 		case 1047:
-			if (wp != NULL)
-				window_pane_alternate_off(wp, gc, 0);
-			else
-				screen_alternate_off(sctx->s, gc, 0);
+			screen_write_alternateoff(sctx, gc, 0);
 			break;
 		case 1049:
-			if (wp != NULL)
-				window_pane_alternate_off(wp, gc, 1);
-			else
-				screen_alternate_off(sctx->s, gc, 1);
+			screen_write_alternateoff(sctx, gc, 1);
 			break;
 		case 2004:
 			screen_write_mode_clear(sctx, MODE_BRACKETPASTE);
@@ -1782,16 +1775,10 @@ input_csi_dispatch_sm_private(struct input_ctx *ictx)
 			break;
 		case 47:
 		case 1047:
-			if (wp != NULL)
-				window_pane_alternate_on(wp, gc, 0);
-			else
-				screen_alternate_on(sctx->s, gc, 0);
+			screen_write_alternateon(sctx, gc, 0);
 			break;
 		case 1049:
-			if (wp != NULL)
-				window_pane_alternate_on(wp, gc, 1);
-			else
-				screen_alternate_on(sctx->s, gc, 1);
+			screen_write_alternateon(sctx, gc, 1);
 			break;
 		case 2004:
 			screen_write_mode_set(sctx, MODE_BRACKETPASTE);
@@ -2595,7 +2582,7 @@ input_osc_52(struct input_ctx *ictx, const char *p)
 		return;
 	}
 
-	screen_write_start(&ctx, wp, NULL);
+	screen_write_start_pane(&ctx, wp, NULL);
 	screen_write_setselection(&ctx, out, outlen);
 	screen_write_stop(&ctx);
 	notify_pane("pane-set-clipboard", wp);
diff --git a/usr.bin/tmux/menu.c b/usr.bin/tmux/menu.c
index 5acd4ad6441..a8b4ded58d5 100644
--- a/usr.bin/tmux/menu.c
+++ b/usr.bin/tmux/menu.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: menu.c,v 1.26 2020/05/16 15:06:03 nicm Exp $ */
+/* $OpenBSD: menu.c,v 1.27 2020/05/16 15:34:08 nicm Exp $ */
 
 /*
  * Copyright (c) 2019 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -130,14 +130,12 @@ menu_free(struct menu *menu)
 	free(menu);
 }
 
-static int
+static struct screen *
 menu_mode_cb(struct client *c, __unused u_int *cx, __unused u_int *cy)
 {
 	struct menu_data	*md = c->overlay_data;
 
-	if (~md->flags & MENU_NOMOUSE)
-		return (MODE_MOUSE_ALL);
-	return (0);
+	return (&md->s);
 }
 
 static void
@@ -153,13 +151,15 @@ menu_draw_cb(struct client *c, __unused struct screen_redraw_ctx *ctx0)
 
 	style_apply(&gc, c->session->curw->window->options, "mode-style", NULL);
 
-	screen_write_start(&ctx, NULL, s);
+	screen_write_start(&ctx, s);
 	screen_write_clearscreen(&ctx, 8);
 	screen_write_menu(&ctx, menu, md->choice, &gc);
 	screen_write_stop(&ctx);
 
-	for (i = 0; i < screen_size_y(&md->s); i++)
-		tty_draw_line(tty, NULL, s, 0, i, menu->width + 4, px, py + i);
+	for (i = 0; i < screen_size_y(&md->s); i++) {
+		tty_draw_line(tty, s, 0, i, menu->width + 4, px, py + i,
+		    &grid_default_cell, NULL);
+	}
 }
 
 static void
@@ -349,6 +349,8 @@ menu_display(struct menu *menu, int flags, struct cmdq_item *item, u_int px,
 	if (fs != NULL)
 		cmd_find_copy_state(&md->fs, fs);
 	screen_init(&md->s, menu->width + 4, menu->count + 2, 0);
+	if (~md->flags & MENU_NOMOUSE)
+		md->s.mode |= MODE_MOUSE_ALL;
 
 	md->px = px;
 	md->py = py;
diff --git a/usr.bin/tmux/mode-tree.c b/usr.bin/tmux/mode-tree.c
index e87c3653d42..08327b52866 100644
--- a/usr.bin/tmux/mode-tree.c
+++ b/usr.bin/tmux/mode-tree.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: mode-tree.c,v 1.42 2020/05/16 15:01:31 nicm Exp $ */
+/* $OpenBSD: mode-tree.c,v 1.43 2020/05/16 15:34:08 nicm Exp $ */
 
 /*
  * Copyright (c) 2017 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -562,7 +562,7 @@ mode_tree_draw(struct mode_tree_data *mtd)
 	w = mtd->width;
 	h = mtd->height;
 
-	screen_write_start(&ctx, NULL, s);
+	screen_write_start(&ctx, s);
 	screen_write_clearscreen(&ctx, 8);
 
 	if (mtd->line_size > 10)
diff --git a/usr.bin/tmux/popup.c b/usr.bin/tmux/popup.c
index 5d0254beb75..ec75dc4774a 100644
--- a/usr.bin/tmux/popup.c
+++ b/usr.bin/tmux/popup.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: popup.c,v 1.14 2020/05/16 15:24:28 nicm Exp $ */
+/* $OpenBSD: popup.c,v 1.15 2020/05/16 15:34:08 nicm Exp $ */
 
 /*
  * Copyright (c) 2020 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -58,6 +58,44 @@ struct popup_data {
 };
 
 static void
+popup_redraw_cb(const struct tty_ctx *ttyctx)
+{
+	struct popup_data	*pd = ttyctx->arg;
+
+	pd->c->flags |= CLIENT_REDRAWOVERLAY;
+}
+
+static int
+popup_set_client_cb(struct tty_ctx *ttyctx, struct client *c)
+{
+	struct popup_data	*pd = ttyctx->arg;
+
+	if (pd->c->flags & CLIENT_REDRAWOVERLAY)
+		return (-1);
+
+	ttyctx->bigger = 0;
+	ttyctx->wox = 0;
+	ttyctx->woy = 0;
+	ttyctx->wsx = c->tty.sx;
+	ttyctx->wsy = c->tty.sy;
+
+	ttyctx->xoff = ttyctx->rxoff = pd->px + 1;
+	ttyctx->yoff = ttyctx->ryoff = pd->py + 1;
+
+	return (1);
+}
+
+static void
+popup_init_ctx_cb(struct screen_write_ctx *ctx, struct tty_ctx *ttyctx)
+{
+	struct popup_data	*pd = ctx->arg;
+
+	ttyctx->redraw_cb = popup_redraw_cb;
+	ttyctx->set_client_cb = popup_set_client_cb;
+	ttyctx->arg = pd;
+}
+
+static void
 popup_write_screen(struct client *c, struct popup_data *pd)
 {
 	struct cmdq_item	*item = pd->item;
@@ -72,7 +110,7 @@ popup_write_screen(struct client *c, struct popup_data *pd)
 	else
 		format_defaults(ft, c, NULL, NULL, NULL);
 
-	screen_write_start(&ctx, NULL, &pd->s);
+	screen_write_start(&ctx, &pd->s);
 	screen_write_clearscreen(&ctx, 8);
 
 	y = 0;
@@ -98,7 +136,7 @@ popup_write_screen(struct client *c, struct popup_data *pd)
 	screen_write_stop(&ctx);
 }
 
-static int
+static struct screen *
 popup_mode_cb(struct client *c, u_int *cx, u_int *cy)
 {
 	struct popup_data	*pd = c->overlay_data;
@@ -107,7 +145,7 @@ popup_mode_cb(struct client *c, u_int *cx, u_int *cy)
 		return (0);
 	*cx = pd->px + 1 + pd->s.cx;
 	*cy = pd->py + 1 + pd->s.cy;
-	return (pd->s.mode);
+	return (&pd->s);
 }
 
 static int
@@ -132,7 +170,7 @@ popup_draw_cb(struct client *c, __unused struct screen_redraw_ctx *ctx0)
 	u_int			 i, px = pd->px, py = pd->py;
 
 	screen_init(&s, pd->sx, pd->sy, 0);
-	screen_write_start(&ctx, NULL, &s);
+	screen_write_start(&ctx, &s);
 	screen_write_clearscreen(&ctx, 8);
 	screen_write_box(&ctx, pd->sx, pd->sy);
 	screen_write_cursormove(&ctx, 1, 1, 0);
@@ -140,8 +178,10 @@ popup_draw_cb(struct client *c, __unused struct screen_redraw_ctx *ctx0)
 	screen_write_stop(&ctx);
 
 	c->overlay_check = NULL;
-	for (i = 0; i < pd->sy; i++)
-		tty_draw_line(tty, NULL, &s, 0, i, pd->sx, px, py + i);
+	for (i = 0; i < pd->sy; i++){
+		tty_draw_line(tty, &s, 0, i, pd->sx, px, py + i,
+		    &grid_default_cell, NULL);
+	}
 	c->overlay_check = popup_check_cb;
 }
 
@@ -327,15 +367,23 @@ popup_job_update_cb(struct job *job)
 {
 	struct popup_data	*pd = job_get_data(job);
 	struct evbuffer		*evb = job_get_event(job)->input;
+	struct client		*c = pd->c;
 	struct screen		*s = &pd->s;
 	void			*data = EVBUFFER_DATA(evb);
 	size_t			 size = EVBUFFER_LENGTH(evb);
 
-	if (size != 0) {
-		input_parse_screen(pd->ictx, s, data, size);
-		evbuffer_drain(evb, size);
-		pd->c->flags |= CLIENT_REDRAWOVERLAY;
-	}
+	if (size == 0)
+		return;
+
+	c->overlay_check = NULL;
+	c->tty.flags &= ~TTY_FREEZE;
+
+	input_parse_screen(pd->ictx, s, popup_init_ctx_cb, pd, data, size);
+
+	c->tty.flags |= TTY_FREEZE;
+	c->overlay_check = popup_check_cb;
+
+	evbuffer_drain(evb, size);
 }
 
 static void
diff --git a/usr.bin/tmux/screen-redraw.c b/usr.bin/tmux/screen-redraw.c
index 9dcfa91769d..789b40189c7 100644
--- a/usr.bin/tmux/screen-redraw.c
+++ b/usr.bin/tmux/screen-redraw.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: screen-redraw.c,v 1.75 2020/05/16 15:01:31 nicm Exp $ */
+/* $OpenBSD: screen-redraw.c,v 1.76 2020/05/16 15:34:08 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -346,7 +346,7 @@ screen_redraw_make_pane_status(struct client *c, struct window *w,
 	screen_init(&wp->status_screen, width, 1, 0);
 	wp->status_screen.mode = 0;
 
-	screen_write_start(&ctx, NULL, &wp->status_screen);
+	screen_write_start(&ctx, &wp->status_screen);
 
 	gc.attr |= GRID_ATTR_CHARSET;
 	for (i = 0; i < width; i++)
@@ -423,7 +423,8 @@ screen_redraw_draw_pane_status(struct screen_redraw_ctx *ctx)
 
 		if (ctx->statustop)
 			yoff += ctx->statuslines;
-		tty_draw_line(tty, NULL, s, i, 0, width, x, yoff - ctx->oy);
+		tty_draw_line(tty, s, i, 0, width, x, yoff - ctx->oy,
+		    &grid_default_cell, NULL);
 	}
 	tty_cursor(tty, 0, 0);
 }
@@ -615,7 +616,7 @@ screen_redraw_draw_borders_cell(struct screen_redraw_ctx *ctx, u_int i, u_int j)
 		}
 	}
 
-	tty_attributes(tty, gc, NULL);
+	tty_attributes(tty, gc, &grid_default_cell, NULL);
 	if (ctx->statustop)
 		tty_cursor(tty, i, ctx->statuslines + j);
 	else
@@ -676,8 +677,10 @@ screen_redraw_draw_status(struct screen_redraw_ctx *ctx)
 		y = 0;
 	else
 		y = c->tty.sy - ctx->statuslines;
-	for (i = 0; i < ctx->statuslines; i++)
-		tty_draw_line(tty, NULL, s, 0, i, UINT_MAX, 0, y + i);
+	for (i = 0; i < ctx->statuslines; i++) {
+		tty_draw_line(tty, s, 0, i, UINT_MAX, 0, y + i,
+		    &grid_default_cell, NULL);
+	}
 }
 
 /* Draw one pane. */
@@ -688,6 +691,7 @@ screen_redraw_draw_pane(struct screen_redraw_ctx *ctx, struct window_pane *wp)
 	struct window	*w = c->session->curw->window;
 	struct tty	*tty = &c->tty;
 	struct screen	*s;
+	struct grid_cell defaults;
 	u_int		 i, j, top, x, y, width;
 
 	log_debug("%s: %s @%u %%%u", __func__, c->name, w->id, wp->id);
@@ -731,6 +735,8 @@ screen_redraw_draw_pane(struct screen_redraw_ctx *ctx, struct window_pane *wp)
 		log_debug("%s: %s %%%u line %u,%u at %u,%u, width %u",
 		    __func__, c->name, wp->id, i, j, x, y, width);
 
-		tty_draw_line(tty, wp, s, i, j, width, x, y);
+		tty_default_colours(&defaults, wp);
+		tty_draw_line(tty, s, i, j, width, x, y, &defaults,
+		    wp->palette);
 	}
 }
diff --git a/usr.bin/tmux/screen-write.c b/usr.bin/tmux/screen-write.c
index 8280f82adc2..ebe09254ba4 100644
--- a/usr.bin/tmux/screen-write.c
+++ b/usr.bin/tmux/screen-write.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: screen-write.c,v 1.177 2020/05/16 15:27:08 nicm Exp $ */
+/* $OpenBSD: screen-write.c,v 1.178 2020/05/16 15:34:08 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -27,8 +27,8 @@ static void	screen_write_collect_clear(struct screen_write_ctx *, u_int,
 		    u_int);
 static int	screen_write_collect_clear_end(struct screen_write_ctx *, u_int,
 		    u_int, u_int);
-static int	screen_write_collect_clear_start(struct screen_write_ctx *, u_int,
-		    u_int, u_int);
+static int	screen_write_collect_clear_start(struct screen_write_ctx *,
+		    u_int, u_int, u_int);
 static void	screen_write_collect_scroll(struct screen_write_ctx *);
 static void	screen_write_collect_flush(struct screen_write_ctx *, int,
 		    const char *);
@@ -101,6 +101,50 @@ screen_write_set_cursor(struct screen_write_ctx *ctx, int cx, int cy)
 		evtimer_add(&w->offset_timer, &tv);
 }
 
+/* Do a full redraw. */
+static void
+screen_write_redraw_cb(const struct tty_ctx *ttyctx)
+{
+	struct window_pane	*wp = ttyctx->arg;
+
+	wp->flags |= PANE_REDRAW;
+}
+
+/* Update context for client. */
+static int
+screen_write_set_client_cb(struct tty_ctx *ttyctx, struct client *c)
+{
+	struct window_pane	*wp = ttyctx->arg;
+
+	if (c->session->curw->window != wp->window)
+		return (0);
+	if (wp->layout_cell == NULL)
+		return (0);
+
+	if (wp->flags & (PANE_REDRAW|PANE_DROP))
+		return (-1);
+	if (c->flags & CLIENT_REDRAWPANES) {
+		/*
+		 * Redraw is already deferred to redraw another pane - redraw
+		 * this one also when that happens.
+		 */
+		log_debug("adding %%%u to deferred redraw", wp->id);
+		wp->flags |= PANE_REDRAW;
+		return (-1);
+	}
+
+	ttyctx->bigger = tty_window_offset(&c->tty, &ttyctx->wox, &ttyctx->woy,
+	    &ttyctx->wsx, &ttyctx->wsy);
+
+	ttyctx->xoff = ttyctx->rxoff = wp->xoff;
+	ttyctx->yoff = ttyctx->ryoff = wp->yoff;
+
+	if (status_at_line(c) == 0)
+		ttyctx->yoff += status_line_size(c);
+
+	return (1);
+}
+
 /* Set up context for TTY command. */
 static void
 screen_write_initctx(struct screen_write_ctx *ctx, struct tty_ctx *ttyctx,
@@ -110,17 +154,35 @@ screen_write_initctx(struct screen_write_ctx *ctx, struct tty_ctx *ttyctx,
 
 	memset(ttyctx, 0, sizeof *ttyctx);
 
-	ttyctx->wp = ctx->wp;
+	if (ctx->wp != NULL) {
+		tty_default_colours(&ttyctx->defaults, ctx->wp);
+		ttyctx->palette = ctx->wp->palette;
+	} else {
+		memcpy(&ttyctx->defaults, &grid_default_cell,
+		    sizeof ttyctx->defaults);
+		ttyctx->palette = NULL;
+	}
 
+	ttyctx->s = s;
 	ttyctx->sx = screen_size_x(s);
 	ttyctx->sy = screen_size_y(s);
 
 	ttyctx->ocx = s->cx;
 	ttyctx->ocy = s->cy;
-
 	ttyctx->orlower = s->rlower;
 	ttyctx->orupper = s->rupper;
 
+	if (ctx->init_ctx_cb != NULL)
+		ctx->init_ctx_cb(ctx, ttyctx);
+	else {
+		ttyctx->redraw_cb = screen_write_redraw_cb;
+		if (ctx->wp == NULL)
+			ttyctx->set_client_cb = NULL;
+		else
+			ttyctx->set_client_cb = screen_write_set_client_cb;
+		ttyctx->arg = ctx->wp;
+	}
+
 	if (ctx->wp != NULL &&
 	    !ctx->sync &&
 	    (sync || ctx->wp != ctx->wp->window->active)) {
@@ -151,18 +213,13 @@ screen_write_free_list(struct screen *s)
 	free(s->write_list);
 }
 
-/* Initialize writing with a window. */
-void
-screen_write_start(struct screen_write_ctx *ctx, struct window_pane *wp,
-    struct screen *s)
+/* Set up for writing. */
+static void
+screen_write_init(struct screen_write_ctx *ctx, struct screen *s)
 {
 	memset(ctx, 0, sizeof *ctx);
 
-	ctx->wp = wp;
-	if (wp != NULL && s == NULL)
-		ctx->s = wp->screen;
-	else
-		ctx->s = s;
+	ctx->s = s;
 
 	if (ctx->s->write_list == NULL)
 		screen_write_make_list(ctx->s);
@@ -170,17 +227,51 @@ screen_write_start(struct screen_write_ctx *ctx, struct window_pane *wp,
 
 	ctx->scrolled = 0;
 	ctx->bg = 8;
+}
+
+/* Initialize writing with a pane. */
+void
+screen_write_start_pane(struct screen_write_ctx *ctx, struct window_pane *wp,
+    struct screen *s)
+{
+	if (s == NULL)
+		s = wp->screen;
+	screen_write_init(ctx, s);
+	ctx->wp = wp;
 
 	if (log_get_level() != 0) {
-		if (wp != NULL) {
-			log_debug("%s: size %ux%u, pane %%%u (at %u,%u)",
-			    __func__, screen_size_x(ctx->s),
-			    screen_size_y(ctx->s), wp->id, wp->xoff, wp->yoff);
-		} else {
-			log_debug("%s: size %ux%u, no pane",
-			    __func__, screen_size_x(ctx->s),
-			    screen_size_y(ctx->s));
-		}
+		log_debug("%s: size %ux%u, pane %%%u (at %u,%u)",
+		    __func__, screen_size_x(ctx->s), screen_size_y(ctx->s),
+		    wp->id, wp->xoff, wp->yoff);
+	}
+}
+
+/* Initialize writing with a callback. */
+void
+screen_write_start_callback(struct screen_write_ctx *ctx, struct screen *s,
+    screen_write_init_ctx_cb cb, void *arg)
+{
+	screen_write_init(ctx, s);
+
+	ctx->init_ctx_cb = cb;
+	ctx->arg = arg;
+
+	if (log_get_level() != 0) {
+		log_debug("%s: size %ux%u, with callback", __func__,
+		    screen_size_x(ctx->s), screen_size_y(ctx->s));
+	}
+}
+
+
+/* Initialize writing. */
+void
+screen_write_start(struct screen_write_ctx *ctx, struct screen *s)
+{
+	screen_write_init(ctx, s);
+
+	if (log_get_level() != 0) {
+		log_debug("%s: size %ux%u, no pane", __func__,
+		    screen_size_x(ctx->s), screen_size_y(ctx->s));
 	}
 }
 
@@ -1799,3 +1890,35 @@ screen_write_rawstring(struct screen_write_ctx *ctx, u_char *str, u_int len)
 
 	tty_write(tty_cmd_rawstring, &ttyctx);
 }
+
+/* Turn alternate screen on. */
+void
+screen_write_alternateon(struct screen_write_ctx *ctx, struct grid_cell *gc,
+    int cursor)
+{
+	struct tty_ctx		 ttyctx;
+	struct window_pane	*wp = ctx->wp;
+
+	if (wp != NULL && !options_get_number(wp->options, "alternate-screen"))
+		return;
+	screen_alternate_on(ctx->s, gc, cursor);
+
+	screen_write_initctx(ctx, &ttyctx, 1);
+	ttyctx.redraw_cb(&ttyctx);
+}
+
+/* Turn alternate screen off. */
+void
+screen_write_alternateoff(struct screen_write_ctx *ctx, struct grid_cell *gc,
+    int cursor)
+{
+	struct tty_ctx		 ttyctx;
+	struct window_pane	*wp = ctx->wp;
+
+	if (wp != NULL && !options_get_number(wp->options, "alternate-screen"))
+		return;
+	screen_alternate_off(ctx->s, gc, cursor);
+
+	screen_write_initctx(ctx, &ttyctx, 1);
+	ttyctx.redraw_cb(&ttyctx);
+}
diff --git a/usr.bin/tmux/server-client.c b/usr.bin/tmux/server-client.c
index c298e38d64a..dc9a650355d 100644
--- a/usr.bin/tmux/server-client.c
+++ b/usr.bin/tmux/server-client.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: server-client.c,v 1.335 2020/05/16 15:06:03 nicm Exp $ */
+/* $OpenBSD: server-client.c,v 1.336 2020/05/16 15:34:08 nicm Exp $ */
 
 /*
  * Copyright (c) 2009 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -1542,9 +1542,9 @@ server_client_reset_state(struct client *c)
 	struct tty		*tty = &c->tty;
 	struct window		*w = c->session->curw->window;
 	struct window_pane	*wp = w->active, *loop;
-	struct screen		*s;
+	struct screen		*s = NULL;
 	struct options		*oo = c->session->options;
-	int			 mode, cursor, flags;
+	int			 mode = 0, cursor, flags;
 	u_int			 cx = 0, cy = 0, ox, oy, sx, sy;
 
 	if (c->flags & (CLIENT_CONTROL|CLIENT_SUSPENDED))
@@ -1556,17 +1556,14 @@ server_client_reset_state(struct client *c)
 
 	/* Get mode from overlay if any, else from screen. */
 	if (c->overlay_draw != NULL) {
-		s = NULL;
-		if (c->overlay_mode == NULL)
-			mode = 0;
-		else
-			mode = c->overlay_mode(c, &cx, &cy);
-	} else {
+		if (c->overlay_mode != NULL)
+			s = c->overlay_mode(c, &cx, &cy);
+	} else
 		s = wp->screen;
+	if (s != NULL)
 		mode = s->mode;
-		if (c->prompt_string != NULL || c->message_string != NULL)
-			mode &= ~MODE_CURSOR;
-	}
+	if (c->prompt_string != NULL || c->message_string != NULL)
+		mode &= ~MODE_CURSOR;
 	log_debug("%s: client %s mode %x", __func__, c->name, mode);
 
 	/* Reset region and margin. */
diff --git a/usr.bin/tmux/server-fn.c b/usr.bin/tmux/server-fn.c
index 6f9e23db92b..6ceb2d27939 100644
--- a/usr.bin/tmux/server-fn.c
+++ b/usr.bin/tmux/server-fn.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: server-fn.c,v 1.124 2020/04/16 07:28:36 nicm Exp $ */
+/* $OpenBSD: server-fn.c,v 1.125 2020/05/16 15:34:08 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -318,7 +318,7 @@ server_destroy_pane(struct window_pane *wp, int notify)
 		if (notify)
 			notify_pane("pane-died", wp);
 
-		screen_write_start(&ctx, wp, &wp->base);
+		screen_write_start_pane(&ctx, wp, &wp->base);
 		screen_write_scrollregion(&ctx, 0, screen_size_y(ctx.s) - 1);
 		screen_write_cursormove(&ctx, 0, screen_size_y(ctx.s) - 1, 0);
 		screen_write_linefeed(&ctx, 1, 8);
diff --git a/usr.bin/tmux/status.c b/usr.bin/tmux/status.c
index 200190919c3..ddcd9d7915f 100644
--- a/usr.bin/tmux/status.c
+++ b/usr.bin/tmux/status.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: status.c,v 1.207 2020/05/16 15:19:04 nicm Exp $ */
+/* $OpenBSD: status.c,v 1.208 2020/05/16 15:34:08 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -372,7 +372,7 @@ status_redraw(struct client *c)
 		screen_resize(&sl->screen, width, lines, 0);
 		changed = force = 1;
 	}
-	screen_write_start(&ctx, NULL, &sl->screen);
+	screen_write_start(&ctx, &sl->screen);
 
 	/* Write the status lines. */
 	o = options_get(s->options, "status-format");
@@ -509,7 +509,7 @@ status_message_redraw(struct client *c)
 	style_apply(&gc, s->options, "message-style", ft);
 	format_free(ft);
 
-	screen_write_start(&ctx, NULL, sl->active);
+	screen_write_start(&ctx, sl->active);
 	screen_write_fast_copy(&ctx, &sl->screen, 0, 0, c->tty.sx, lines - 1);
 	screen_write_cursormove(&ctx, 0, lines - 1, 0);
 	for (offset = 0; offset < c->tty.sx; offset++)
@@ -664,7 +664,7 @@ status_prompt_redraw(struct client *c)
 	if (start > c->tty.sx)
 		start = c->tty.sx;
 
-	screen_write_start(&ctx, NULL, sl->active);
+	screen_write_start(&ctx, sl->active);
 	screen_write_fast_copy(&ctx, &sl->screen, 0, 0, c->tty.sx, lines - 1);
 	screen_write_cursormove(&ctx, 0, lines - 1, 0);
 	for (offset = 0; offset < c->tty.sx; offset++)
diff --git a/usr.bin/tmux/tmux.h b/usr.bin/tmux/tmux.h
index cb643f3a8c5..578c7cd0398 100644
--- a/usr.bin/tmux/tmux.h
+++ b/usr.bin/tmux/tmux.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: tmux.h,v 1.1030 2020/05/16 15:27:08 nicm Exp $ */
+/* $OpenBSD: tmux.h,v 1.1031 2020/05/16 15:34:08 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -55,7 +55,11 @@ struct mouse_event;
 struct options;
 struct options_array_item;
 struct options_entry;
+struct screen_write_collect_item;
+struct screen_write_collect_line;
+struct screen_write_ctx;
 struct session;
+struct tty_ctx;
 struct tmuxpeer;
 struct tmuxproc;
 struct winlink;
@@ -786,13 +790,16 @@ struct screen {
 };
 
 /* Screen write context. */
-struct screen_write_collect_item;
-struct screen_write_collect_line;
+typedef void (*screen_write_init_ctx_cb)(struct screen_write_ctx *,
+    struct tty_ctx *);
 struct screen_write_ctx {
 	struct window_pane	*wp;
 	struct screen		*s;
 	int			 sync;
 
+	screen_write_init_ctx_cb init_ctx_cb;
+	void			*arg;
+
 	struct screen_write_collect_item *item;
 	u_int			 scrolled;
 	u_int			 bg;
@@ -1252,8 +1259,6 @@ struct tty {
 	struct termios	 tio;
 
 	struct grid_cell cell;
-
-	int		 last_wp;
 	struct grid_cell last_cell;
 
 #define TTY_NOCURSOR 0x1
@@ -1285,8 +1290,14 @@ struct tty {
 };
 
 /* TTY command context. */
+typedef void (*tty_ctx_redraw_cb)(const struct tty_ctx *);
+typedef int (*tty_ctx_set_client_cb)(struct tty_ctx *, struct client *);
 struct tty_ctx {
-	struct window_pane	*wp;
+	struct screen		*s;
+
+	tty_ctx_redraw_cb	 redraw_cb;
+	tty_ctx_set_client_cb	 set_client_cb;
+	void			*arg;
 
 	const struct grid_cell	*cell;
 	int			 wrapped;
@@ -1308,12 +1319,18 @@ struct tty_ctx {
 	/* Target region (usually pane) offset and size. */
 	u_int		 xoff;
 	u_int		 yoff;
+	u_int		 rxoff;
+	u_int		 ryoff;
 	u_int		 sx;
 	u_int		 sy;
 
 	/* The background colour used for clearing (erasing). */
 	u_int		 bg;
 
+	/* The default colours and palette. */
+	struct grid_cell defaults;
+	int		*palette;
+
 	/* Containing region (usually window) offset and size. */
 	int		 bigger;
 	u_int		 wox;
@@ -1492,7 +1509,7 @@ RB_HEAD(client_files, client_file);
 typedef int (*prompt_input_cb)(struct client *, void *, const char *, int);
 typedef void (*prompt_free_cb)(void *);
 typedef int (*overlay_check_cb)(struct client *, u_int, u_int);
-typedef int (*overlay_mode_cb)(struct client *, u_int *, u_int *);
+typedef struct screen *(*overlay_mode_cb)(struct client *, u_int *, u_int *);
 typedef void (*overlay_draw_cb)(struct client *, struct screen_redraw_ctx *);
 typedef int (*overlay_key_cb)(struct client *, struct key_event *);
 typedef void (*overlay_free_cb)(struct client *);
@@ -1969,7 +1986,7 @@ void	tty_update_window_offset(struct window *);
 void	tty_update_client_offset(struct client *);
 void	tty_raw(struct tty *, const char *);
 void	tty_attributes(struct tty *, const struct grid_cell *,
-	    struct window_pane *);
+	    const struct grid_cell *, int *);
 void	tty_reset(struct tty *);
 void	tty_region_off(struct tty *);
 void	tty_margin_off(struct tty *);
@@ -1992,8 +2009,8 @@ void	tty_send_requests(struct tty *);
 void	tty_stop_tty(struct tty *);
 void	tty_set_title(struct tty *, const char *);
 void	tty_update_mode(struct tty *, int, struct screen *);
-void	tty_draw_line(struct tty *, struct window_pane *, struct screen *,
-	    u_int, u_int, u_int, u_int, u_int);
+void	tty_draw_line(struct tty *, struct screen *, u_int, u_int, u_int,
+	    u_int, u_int, const struct grid_cell *, int *);
 void	tty_sync_start(struct tty *);
 void	tty_sync_end(struct tty *);
 int	tty_open(struct tty *, char **);
@@ -2024,6 +2041,7 @@ void	tty_cmd_reverseindex(struct tty *, const struct tty_ctx *);
 void	tty_cmd_setselection(struct tty *, const struct tty_ctx *);
 void	tty_cmd_rawstring(struct tty *, const struct tty_ctx *);
 void	tty_cmd_syncstart(struct tty *, const struct tty_ctx *);
+void	tty_default_colours(struct grid_cell *, struct window_pane *);
 
 /* tty-term.c */
 extern struct tty_terms tty_terms;
@@ -2342,8 +2360,8 @@ void	 input_reset(struct input_ctx *, int);
 struct evbuffer *input_pending(struct input_ctx *);
 void	 input_parse_pane(struct window_pane *);
 void	 input_parse_buffer(struct window_pane *, u_char *, size_t);
-void	 input_parse_screen(struct input_ctx *, struct screen *, u_char *,
-	     size_t);
+void	 input_parse_screen(struct input_ctx *, struct screen *,
+	     screen_write_init_ctx_cb, void *, u_char *, size_t);
 
 /* input-key.c */
 int	 input_key_pane(struct window_pane *, key_code, struct mouse_event *);
@@ -2426,8 +2444,11 @@ char	*grid_view_string_cells(struct grid *, u_int, u_int, u_int);
 /* screen-write.c */
 void	 screen_write_make_list(struct screen *);
 void	 screen_write_free_list(struct screen *);
-void	 screen_write_start(struct screen_write_ctx *, struct window_pane *,
-	     struct screen *);
+void	 screen_write_start_pane(struct screen_write_ctx *,
+	     struct window_pane *, struct screen *);
+void	 screen_write_start(struct screen_write_ctx *, struct screen *);
+void	 screen_write_start_callback(struct screen_write_ctx *, struct screen *,
+	     screen_write_init_ctx_cb, void *);
 void	 screen_write_stop(struct screen_write_ctx *);
 void	 screen_write_reset(struct screen_write_ctx *);
 size_t printflike(1, 2) screen_write_strlen(const char *, ...);
@@ -2481,6 +2502,10 @@ void	 screen_write_collect_add(struct screen_write_ctx *,
 void	 screen_write_cell(struct screen_write_ctx *, const struct grid_cell *);
 void	 screen_write_setselection(struct screen_write_ctx *, u_char *, u_int);
 void	 screen_write_rawstring(struct screen_write_ctx *, u_char *, u_int);
+void	 screen_write_alternateon(struct screen_write_ctx *,
+	     struct grid_cell *, int);
+void	 screen_write_alternateoff(struct screen_write_ctx *,
+	     struct grid_cell *, int);
 
 /* screen-redraw.c */
 void	 screen_redraw_screen(struct client *);
@@ -2569,10 +2594,6 @@ struct window_pane *window_pane_find_by_id_str(const char *);
 struct window_pane *window_pane_find_by_id(u_int);
 int		 window_pane_destroy_ready(struct window_pane *);
 void		 window_pane_resize(struct window_pane *, u_int, u_int);
-void		 window_pane_alternate_on(struct window_pane *,
-		     struct grid_cell *, int);
-void		 window_pane_alternate_off(struct window_pane *,
-		     struct grid_cell *, int);
 void		 window_pane_set_palette(struct window_pane *, u_int, int);
 void		 window_pane_unset_palette(struct window_pane *, u_int);
 void		 window_pane_reset_palette(struct window_pane *);
diff --git a/usr.bin/tmux/tty.c b/usr.bin/tmux/tty.c
index 0986f307a21..a235ca4c963 100644
--- a/usr.bin/tmux/tty.c
+++ b/usr.bin/tmux/tty.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: tty.c,v 1.372 2020/05/16 15:27:08 nicm Exp $ */
+/* $OpenBSD: tty.c,v 1.373 2020/05/16 15:34:08 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -34,7 +34,7 @@
 
 static int	tty_log_fd = -1;
 
-static int	tty_client_ready(struct client *, struct window_pane *);
+static int	tty_client_ready(struct client *);
 
 static void	tty_set_italics(struct tty *);
 static int	tty_try_colour(struct tty *, int, const char *);
@@ -45,12 +45,9 @@ static void	tty_cursor_pane_unless_wrap(struct tty *,
 		    const struct tty_ctx *, u_int, u_int);
 static void	tty_invalidate(struct tty *);
 static void	tty_colours(struct tty *, const struct grid_cell *);
-static void	tty_check_fg(struct tty *, struct window_pane *,
-		    struct grid_cell *);
-static void	tty_check_bg(struct tty *, struct window_pane *,
-		    struct grid_cell *);
-static void	tty_check_us(struct tty *, struct window_pane *,
-		    struct grid_cell *);
+static void	tty_check_fg(struct tty *, int *, struct grid_cell *);
+static void	tty_check_bg(struct tty *, int *, struct grid_cell *);
+static void	tty_check_us(struct tty *, int *, struct grid_cell *);
 static void	tty_colours_fg(struct tty *, const struct grid_cell *);
 static void	tty_colours_bg(struct tty *, const struct grid_cell *);
 static void	tty_colours_us(struct tty *, const struct grid_cell *);
@@ -61,17 +58,17 @@ static void	tty_region(struct tty *, u_int, u_int);
 static void	tty_margin_pane(struct tty *, const struct tty_ctx *);
 static void	tty_margin(struct tty *, u_int, u_int);
 static int	tty_large_region(struct tty *, const struct tty_ctx *);
-static int	tty_fake_bce(const struct tty *, struct window_pane *, u_int);
+static int	tty_fake_bce(const struct tty *, const struct grid_cell *,
+		    u_int);
 static void	tty_redraw_region(struct tty *, const struct tty_ctx *);
 static void	tty_emulate_repeat(struct tty *, enum tty_code_code,
 		    enum tty_code_code, u_int);
 static void	tty_repeat_space(struct tty *, u_int);
 static void	tty_draw_pane(struct tty *, const struct tty_ctx *, u_int);
 static void	tty_cell(struct tty *, const struct grid_cell *,
-		    struct window_pane *);
-static void	tty_default_colours(struct grid_cell *, struct window_pane *);
-static void	tty_default_attributes(struct tty *, struct window_pane *,
-		    u_int);
+		    const struct grid_cell *, int *);
+static void	tty_default_attributes(struct tty *, const struct grid_cell *,
+		    int *, u_int);
 
 #define tty_use_margin(tty) \
 	(tty->term->flags & TERM_DECSLRM)
@@ -888,6 +885,27 @@ tty_update_client_offset(struct client *c)
 	c->flags |= (CLIENT_REDRAWWINDOW|CLIENT_REDRAWSTATUS);
 }
 
+/* Get a palette entry. */
+static int
+tty_get_palette(int *palette, int c)
+{
+	int	new;
+
+	if (palette == NULL)
+		return (-1);
+
+	new = -1;
+	if (c < 8)
+		new = palette[c];
+	else if (c >= 90 && c <= 97)
+		new = palette[8 + c - 90];
+	else if (c & COLOUR_FLAG_256)
+		new = palette[c & ~COLOUR_FLAG_256];
+	if (new == 0)
+		return (-1);
+	return (new);
+}
+
 /*
  * Is the region large enough to be worth redrawing once later rather than
  * probably several times now? Currently yes if it is more than 50% of the
@@ -904,18 +922,11 @@ tty_large_region(__unused struct tty *tty, const struct tty_ctx *ctx)
  * emulated.
  */
 static int
-tty_fake_bce(const struct tty *tty, struct window_pane *wp, u_int bg)
+tty_fake_bce(const struct tty *tty, const struct grid_cell *gc, u_int bg)
 {
-	struct grid_cell	gc;
-
 	if (tty_term_flag(tty->term, TTYC_BCE))
 		return (0);
-
-	memcpy(&gc, &grid_default_cell, sizeof gc);
-	if (wp != NULL)
-		tty_default_colours(&gc, wp);
-
-	if (!COLOUR_DEFAULT(bg) || !COLOUR_DEFAULT(gc.bg))
+	if (!COLOUR_DEFAULT(bg) || !COLOUR_DEFAULT(gc->bg))
 		return (1);
 	return (0);
 }
@@ -929,16 +940,15 @@ static void
 tty_redraw_region(struct tty *tty, const struct tty_ctx *ctx)
 {
 	struct client		*c = tty->client;
-	struct window_pane	*wp = ctx->wp;
 	u_int			 i;
 
 	/*
-	 * If region is large, schedule a window redraw. In most cases this is
-	 * likely to be followed by some more scrolling.
+	 * If region is large, schedule a redraw. In most cases this is likely
+	 * to be followed by some more scrolling.
 	 */
 	if (tty_large_region(tty, ctx)) {
-		log_debug("%s: %s, large redraw of %%%u", __func__, c->name, wp->id);
-		wp->flags |= PANE_REDRAW;
+		log_debug("%s: %s large redraw", __func__, c->name);
+		ctx->redraw_cb(ctx);
 		return;
 	}
 
@@ -977,8 +987,7 @@ static int
 tty_clamp_line(struct tty *tty, const struct tty_ctx *ctx, u_int px, u_int py,
     u_int nx, u_int *i, u_int *x, u_int *rx, u_int *ry)
 {
-	struct window_pane	*wp = ctx->wp;
-	u_int			 xoff = wp->xoff + px;
+	u_int	xoff = ctx->rxoff + px;
 
 	if (!tty_is_visible(tty, ctx, px, py, nx, 1))
 		return (0);
@@ -1013,8 +1022,8 @@ tty_clamp_line(struct tty *tty, const struct tty_ctx *ctx, u_int px, u_int py,
 
 /* Clear a line. */
 static void
-tty_clear_line(struct tty *tty, struct window_pane *wp, u_int py, u_int px,
-    u_int nx, u_int bg)
+tty_clear_line(struct tty *tty, const struct grid_cell *defaults, u_int py,
+    u_int px, u_int nx, u_int bg)
 {
 	struct client	*c = tty->client;
 
@@ -1025,7 +1034,7 @@ tty_clear_line(struct tty *tty, struct window_pane *wp, u_int py, u_int px,
 		return;
 
 	/* If genuine BCE is available, can try escape sequences. */
-	if (!tty_fake_bce(tty, wp, bg)) {
+	if (!tty_fake_bce(tty, defaults, bg)) {
 		/* Off the end of the line, use EL if available. */
 		if (px + nx >= tty->sx && tty_term_has(tty->term, TTYC_EL)) {
 			tty_cursor(tty, px, py);
@@ -1064,7 +1073,7 @@ tty_clear_pane_line(struct tty *tty, const struct tty_ctx *ctx, u_int py,
 	log_debug("%s: %s, %u at %u,%u", __func__, c->name, nx, px, py);
 
 	if (tty_clamp_line(tty, ctx, px, py, nx, &i, &x, &rx, &ry))
-		tty_clear_line(tty, ctx->wp, ry, x, rx, bg);
+		tty_clear_line(tty, &ctx->defaults, ry, x, rx, bg);
 }
 
 /* Clamp area position to visible part of pane. */
@@ -1073,8 +1082,7 @@ tty_clamp_area(struct tty *tty, const struct tty_ctx *ctx, u_int px, u_int py,
     u_int nx, u_int ny, u_int *i, u_int *j, u_int *x, u_int *y, u_int *rx,
     u_int *ry)
 {
-	struct window_pane	*wp = ctx->wp;
-	u_int			 xoff = wp->xoff + px, yoff = wp->yoff + py;
+	u_int	xoff = ctx->rxoff + px, yoff = ctx->ryoff + py;
 
 	if (!tty_is_visible(tty, ctx, px, py, nx, ny))
 		return (0);
@@ -1132,8 +1140,8 @@ tty_clamp_area(struct tty *tty, const struct tty_ctx *ctx, u_int px, u_int py,
 
 /* Clear an area, adjusting to visible part of pane. */
 static void
-tty_clear_area(struct tty *tty, struct window_pane *wp, u_int py, u_int ny,
-    u_int px, u_int nx, u_int bg)
+tty_clear_area(struct tty *tty, const struct grid_cell *defaults, u_int py,
+    u_int ny, u_int px, u_int nx, u_int bg)
 {
 	struct client	*c = tty->client;
 	u_int		 yy;
@@ -1146,7 +1154,7 @@ tty_clear_area(struct tty *tty, struct window_pane *wp, u_int py, u_int ny,
 		return;
 
 	/* If genuine BCE is available, can try escape sequences. */
-	if (!tty_fake_bce(tty, wp, bg)) {
+	if (!tty_fake_bce(tty, defaults, bg)) {
 		/* Use ED if clearing off the bottom of the terminal. */
 		if (px == 0 &&
 		    px + nx >= tty->sx &&
@@ -1199,7 +1207,7 @@ tty_clear_area(struct tty *tty, struct window_pane *wp, u_int py, u_int ny,
 
 	/* Couldn't use an escape sequence, loop over the lines. */
 	for (yy = py; yy < py + ny; yy++)
-		tty_clear_line(tty, wp, yy, px, nx, bg);
+		tty_clear_line(tty, defaults, yy, px, nx, bg);
 }
 
 /* Clear an area in a pane. */
@@ -1210,24 +1218,26 @@ tty_clear_pane_area(struct tty *tty, const struct tty_ctx *ctx, u_int py,
 	u_int	i, j, x, y, rx, ry;
 
 	if (tty_clamp_area(tty, ctx, px, py, nx, ny, &i, &j, &x, &y, &rx, &ry))
-		tty_clear_area(tty, ctx->wp, y, ry, x, rx, bg);
+		tty_clear_area(tty, &ctx->defaults, y, ry, x, rx, bg);
 }
 
 static void
 tty_draw_pane(struct tty *tty, const struct tty_ctx *ctx, u_int py)
 {
-	struct window_pane	*wp = ctx->wp;
-	struct screen		*s = wp->screen;
-	u_int			 nx = ctx->sx, i, x, rx, ry;
+	struct screen	*s = ctx->s;
+	u_int		 nx = ctx->sx, i, x, rx, ry;
 
 	log_debug("%s: %s %u %d", __func__, tty->client->name, py, ctx->bigger);
 
 	if (!ctx->bigger) {
-		tty_draw_line(tty, wp, s, 0, py, nx, ctx->xoff, ctx->yoff + py);
+		tty_draw_line(tty, s, 0, py, nx, ctx->xoff, ctx->yoff + py,
+		    &ctx->defaults, ctx->palette);
 		return;
 	}
-	if (tty_clamp_line(tty, ctx, 0, py, nx, &i, &x, &rx, &ry))
-		tty_draw_line(tty, wp, s, i, py, rx, x, ry);
+	if (tty_clamp_line(tty, ctx, 0, py, nx, &i, &x, &rx, &ry)) {
+		tty_draw_line(tty, s, i, py, rx, x, ry, &ctx->defaults,
+		    ctx->palette);
+	}
 }
 
 static const struct grid_cell *
@@ -1265,8 +1275,8 @@ tty_check_overlay(struct tty *tty, u_int px, u_int py)
 }
 
 void
-tty_draw_line(struct tty *tty, struct window_pane *wp, struct screen *s,
-    u_int px, u_int py, u_int nx, u_int atx, u_int aty)
+tty_draw_line(struct tty *tty, struct screen *s, u_int px, u_int py, u_int nx,
+    u_int atx, u_int aty, const struct grid_cell *defaults, int *palette)
 {
 	struct grid		*gd = s->grid;
 	struct grid_cell	 gc, last;
@@ -1314,8 +1324,7 @@ tty_draw_line(struct tty *tty, struct window_pane *wp, struct screen *s,
 		gl = NULL;
 	else
 		gl = grid_get_line(gd, gd->hsize + py - 1);
-	if (wp == NULL ||
-	    gl == NULL ||
+	if (gl == NULL ||
 	    (~gl->flags & GRID_LINE_WRAPPED) ||
 	    atx != 0 ||
 	    tty->cx < tty->sx ||
@@ -1324,8 +1333,8 @@ tty_draw_line(struct tty *tty, struct window_pane *wp, struct screen *s,
 		    atx == 0 &&
 		    px + sx != nx &&
 		    tty_term_has(tty->term, TTYC_EL1) &&
-		    !tty_fake_bce(tty, wp, 8)) {
-			tty_default_attributes(tty, wp, 8);
+		    !tty_fake_bce(tty, defaults, 8)) {
+			tty_default_attributes(tty, defaults, palette, 8);
 			tty_cursor(tty, nx - 1, aty);
 			tty_putcode(tty, TTYC_EL1);
 			cleared = 1;
@@ -1352,11 +1361,11 @@ tty_draw_line(struct tty *tty, struct window_pane *wp, struct screen *s,
 		    gcp->us != last.us ||
 		    ux + width + gcp->data.width > nx ||
 		    (sizeof buf) - len < gcp->data.size)) {
-			tty_attributes(tty, &last, wp);
+			tty_attributes(tty, &last, defaults, palette);
 			if (last.flags & GRID_FLAG_CLEARED) {
 				log_debug("%s: %zu cleared", __func__, len);
-				tty_clear_line(tty, wp, aty, atx + ux, width,
-				    last.bg);
+				tty_clear_line(tty, defaults, aty, atx + ux,
+				    width, last.bg);
 			} else {
 				if (!wrapped || atx != 0 || ux != 0)
 					tty_cursor(tty, atx + ux, aty);
@@ -1376,7 +1385,7 @@ tty_draw_line(struct tty *tty, struct window_pane *wp, struct screen *s,
 		if (!tty_check_overlay(tty, atx + ux, aty))
 			ux += gcp->data.width;
 		else if (ux + gcp->data.width > nx) {
-			tty_attributes(tty, &last, wp);
+			tty_attributes(tty, &last, defaults, palette);
 			tty_cursor(tty, atx + ux, aty);
 			for (j = 0; j < gcp->data.width; j++) {
 				if (ux + j > nx)
@@ -1385,7 +1394,7 @@ tty_draw_line(struct tty *tty, struct window_pane *wp, struct screen *s,
 				ux++;
 			}
 		} else if (gcp->attr & GRID_ATTR_CHARSET) {
-			tty_attributes(tty, &last, wp);
+			tty_attributes(tty, &last, defaults, palette);
 			tty_cursor(tty, atx + ux, aty);
 			for (j = 0; j < gcp->data.size; j++)
 				tty_putc(tty, gcp->data.data[j]);
@@ -1397,10 +1406,11 @@ tty_draw_line(struct tty *tty, struct window_pane *wp, struct screen *s,
 		}
 	}
 	if (len != 0 && ((~last.flags & GRID_FLAG_CLEARED) || last.bg != 8)) {
-		tty_attributes(tty, &last, wp);
+		tty_attributes(tty, &last, defaults, palette);
 		if (last.flags & GRID_FLAG_CLEARED) {
 			log_debug("%s: %zu cleared (end)", __func__, len);
-			tty_clear_line(tty, wp, aty, atx + ux, width, last.bg);
+			tty_clear_line(tty, defaults, aty, atx + ux, width,
+			    last.bg);
 		} else {
 			if (!wrapped || atx != 0 || ux != 0)
 				tty_cursor(tty, atx + ux, aty);
@@ -1412,8 +1422,8 @@ tty_draw_line(struct tty *tty, struct window_pane *wp, struct screen *s,
 	if (!cleared && ux < nx) {
 		log_debug("%s: %u to end of line (%zu cleared)", __func__,
 		    nx - ux, len);
-		tty_default_attributes(tty, wp, 8);
-		tty_clear_line(tty, wp, aty, atx + ux, nx - ux, 8);
+		tty_default_attributes(tty, defaults, palette, 8);
+		tty_clear_line(tty, defaults, aty, atx + ux, nx - ux, 8);
 	}
 
 	tty->flags = (tty->flags & ~TTY_NOCURSOR) | flags;
@@ -1451,7 +1461,7 @@ tty_sync_end(struct tty *tty)
 }
 
 static int
-tty_client_ready(struct client *c, struct window_pane *wp)
+tty_client_ready(struct client *c)
 {
 	if (c->session == NULL || c->tty.term == NULL)
 		return (0);
@@ -1459,10 +1469,6 @@ tty_client_ready(struct client *c, struct window_pane *wp)
 		return (0);
 	if (c->tty.flags & TTY_FREEZE)
 		return (0);
-	if (c->session->curw->window != wp->window)
-		return (0);
-	if (wp->layout_cell == NULL)
-		return (0);
 	return (1);
 }
 
@@ -1470,36 +1476,19 @@ void
 tty_write(void (*cmdfn)(struct tty *, const struct tty_ctx *),
     struct tty_ctx *ctx)
 {
-	struct window_pane	*wp = ctx->wp;
-	struct client		*c;
+	struct client	*c;
+	int		 state;
 
-	if (wp == NULL)
+	if (ctx->set_client_cb == NULL)
 		return;
-	if (wp->flags & (PANE_REDRAW|PANE_DROP))
-		return;
-
 	TAILQ_FOREACH(c, &clients, entry) {
-		if (!tty_client_ready(c, wp))
+		if (!tty_client_ready(c))
 			continue;
-		if (c->flags & CLIENT_REDRAWPANES) {
-			/*
-			 * Redraw is already deferred to redraw another pane -
-			 * redraw this one also when that happens.
-			 */
-			log_debug("adding %%%u to deferred redraw", wp->id);
-			wp->flags |= PANE_REDRAW;
+		state = ctx->set_client_cb(ctx, c);
+		if (state == -1)
 			break;
-		}
-
-		ctx->bigger = tty_window_offset(&c->tty, &ctx->wox, &ctx->woy,
-		    &ctx->wsx, &ctx->wsy);
-
-		ctx->xoff = wp->xoff;
-		ctx->yoff = wp->yoff;
-
-		if (status_at_line(c) == 0)
-			ctx->yoff += status_line_size(c);
-
+		if (state == 0)
+			continue;
 		cmdfn(&c->tty, ctx);
 	}
 }
@@ -1507,18 +1496,16 @@ tty_write(void (*cmdfn)(struct tty *, const struct tty_ctx *),
 void
 tty_cmd_insertcharacter(struct tty *tty, const struct tty_ctx *ctx)
 {
-	struct window_pane	*wp = ctx->wp;
-
 	if (ctx->bigger ||
 	    !tty_full_width(tty, ctx) ||
-	    tty_fake_bce(tty, wp, ctx->bg) ||
+	    tty_fake_bce(tty, &ctx->defaults, ctx->bg) ||
 	    (!tty_term_has(tty->term, TTYC_ICH) &&
 	    !tty_term_has(tty->term, TTYC_ICH1))) {
 		tty_draw_pane(tty, ctx, ctx->ocy);
 		return;
 	}
 
-	tty_default_attributes(tty, wp, ctx->bg);
+	tty_default_attributes(tty, &ctx->defaults, ctx->palette, ctx->bg);
 
 	tty_cursor_pane(tty, ctx, ctx->ocx, ctx->ocy);
 
@@ -1528,18 +1515,16 @@ tty_cmd_insertcharacter(struct tty *tty, const struct tty_ctx *ctx)
 void
 tty_cmd_deletecharacter(struct tty *tty, const struct tty_ctx *ctx)
 {
-	struct window_pane	*wp = ctx->wp;
-
 	if (ctx->bigger ||
 	    !tty_full_width(tty, ctx) ||
-	    tty_fake_bce(tty, wp, ctx->bg) ||
+	    tty_fake_bce(tty, &ctx->defaults, ctx->bg) ||
 	    (!tty_term_has(tty->term, TTYC_DCH) &&
 	    !tty_term_has(tty->term, TTYC_DCH1))) {
 		tty_draw_pane(tty, ctx, ctx->ocy);
 		return;
 	}
 
-	tty_default_attributes(tty, wp, ctx->bg);
+	tty_default_attributes(tty, &ctx->defaults, ctx->palette, ctx->bg);
 
 	tty_cursor_pane(tty, ctx, ctx->ocx, ctx->ocy);
 
@@ -1554,12 +1539,12 @@ tty_cmd_clearcharacter(struct tty *tty, const struct tty_ctx *ctx)
 		return;
 	}
 
-	tty_default_attributes(tty, ctx->wp, ctx->bg);
+	tty_default_attributes(tty, &ctx->defaults, ctx->palette, ctx->bg);
 
 	tty_cursor_pane(tty, ctx, ctx->ocx, ctx->ocy);
 
 	if (tty_term_has(tty->term, TTYC_ECH) &&
-	    !tty_fake_bce(tty, ctx->wp, 8))
+	    !tty_fake_bce(tty, &ctx->defaults, 8))
 		tty_putcode1(tty, TTYC_ECH, ctx->num);
 	else
 		tty_repeat_space(tty, ctx->num);
@@ -1570,16 +1555,16 @@ tty_cmd_insertline(struct tty *tty, const struct tty_ctx *ctx)
 {
 	if (ctx->bigger ||
 	    !tty_full_width(tty, ctx) ||
-	    tty_fake_bce(tty, ctx->wp, ctx->bg) ||
+	    tty_fake_bce(tty, &ctx->defaults, ctx->bg) ||
 	    !tty_term_has(tty->term, TTYC_CSR) ||
 	    !tty_term_has(tty->term, TTYC_IL1) ||
-	    ctx->wp->sx == 1 ||
-	    ctx->wp->sy == 1) {
+	    ctx->sx == 1 ||
+	    ctx->sy == 1) {
 		tty_redraw_region(tty, ctx);
 		return;
 	}
 
-	tty_default_attributes(tty, ctx->wp, ctx->bg);
+	tty_default_attributes(tty, &ctx->defaults, ctx->palette, ctx->bg);
 
 	tty_region_pane(tty, ctx, ctx->orupper, ctx->orlower);
 	tty_margin_off(tty);
@@ -1594,16 +1579,16 @@ tty_cmd_deleteline(struct tty *tty, const struct tty_ctx *ctx)
 {
 	if (ctx->bigger ||
 	    !tty_full_width(tty, ctx) ||
-	    tty_fake_bce(tty, ctx->wp, ctx->bg) ||
+	    tty_fake_bce(tty, &ctx->defaults, ctx->bg) ||
 	    !tty_term_has(tty->term, TTYC_CSR) ||
 	    !tty_term_has(tty->term, TTYC_DL1) ||
-	    ctx->wp->sx == 1 ||
-	    ctx->wp->sy == 1) {
+	    ctx->sx == 1 ||
+	    ctx->sy == 1) {
 		tty_redraw_region(tty, ctx);
 		return;
 	}
 
-	tty_default_attributes(tty, ctx->wp, ctx->bg);
+	tty_default_attributes(tty, &ctx->defaults, ctx->palette, ctx->bg);
 
 	tty_region_pane(tty, ctx, ctx->orupper, ctx->orlower);
 	tty_margin_off(tty);
@@ -1616,9 +1601,7 @@ tty_cmd_deleteline(struct tty *tty, const struct tty_ctx *ctx)
 void
 tty_cmd_clearline(struct tty *tty, const struct tty_ctx *ctx)
 {
-	struct window_pane	*wp = ctx->wp;
-
-	tty_default_attributes(tty, wp, ctx->bg);
+	tty_default_attributes(tty, &ctx->defaults, ctx->palette, ctx->bg);
 
 	tty_clear_pane_line(tty, ctx, ctx->ocy, 0, ctx->sx, ctx->bg);
 }
@@ -1626,10 +1609,9 @@ tty_cmd_clearline(struct tty *tty, const struct tty_ctx *ctx)
 void
 tty_cmd_clearendofline(struct tty *tty, const struct tty_ctx *ctx)
 {
-	struct window_pane	*wp = ctx->wp;
-	u_int			 nx = ctx->sx - ctx->ocx;
+	u_int	nx = ctx->sx - ctx->ocx;
 
-	tty_default_attributes(tty, wp, ctx->bg);
+	tty_default_attributes(tty, &ctx->defaults, ctx->palette, ctx->bg);
 
 	tty_clear_pane_line(tty, ctx, ctx->ocy, ctx->ocx, nx, ctx->bg);
 }
@@ -1637,9 +1619,7 @@ tty_cmd_clearendofline(struct tty *tty, const struct tty_ctx *ctx)
 void
 tty_cmd_clearstartofline(struct tty *tty, const struct tty_ctx *ctx)
 {
-	struct window_pane	*wp = ctx->wp;
-
-	tty_default_attributes(tty, wp, ctx->bg);
+	tty_default_attributes(tty, &ctx->defaults, ctx->palette, ctx->bg);
 
 	tty_clear_pane_line(tty, ctx, ctx->ocy, 0, ctx->ocx + 1, ctx->bg);
 }
@@ -1647,24 +1627,22 @@ tty_cmd_clearstartofline(struct tty *tty, const struct tty_ctx *ctx)
 void
 tty_cmd_reverseindex(struct tty *tty, const struct tty_ctx *ctx)
 {
-	struct window_pane	*wp = ctx->wp;
-
 	if (ctx->ocy != ctx->orupper)
 		return;
 
 	if (ctx->bigger ||
 	    (!tty_full_width(tty, ctx) && !tty_use_margin(tty)) ||
-	    tty_fake_bce(tty, wp, 8) ||
+	    tty_fake_bce(tty, &ctx->defaults, 8) ||
 	    !tty_term_has(tty->term, TTYC_CSR) ||
 	    (!tty_term_has(tty->term, TTYC_RI) &&
 	    !tty_term_has(tty->term, TTYC_RIN)) ||
-	    ctx->wp->sx == 1 ||
-	    ctx->wp->sy == 1) {
+	    ctx->sx == 1 ||
+	    ctx->sy == 1) {
 		tty_redraw_region(tty, ctx);
 		return;
 	}
 
-	tty_default_attributes(tty, wp, ctx->bg);
+	tty_default_attributes(tty, &ctx->defaults, ctx->palette, ctx->bg);
 
 	tty_region_pane(tty, ctx, ctx->orupper, ctx->orlower);
 	tty_margin_pane(tty, ctx);
@@ -1679,22 +1657,20 @@ tty_cmd_reverseindex(struct tty *tty, const struct tty_ctx *ctx)
 void
 tty_cmd_linefeed(struct tty *tty, const struct tty_ctx *ctx)
 {
-	struct window_pane	*wp = ctx->wp;
-
 	if (ctx->ocy != ctx->orlower)
 		return;
 
 	if (ctx->bigger ||
 	    (!tty_full_width(tty, ctx) && !tty_use_margin(tty)) ||
-	    tty_fake_bce(tty, wp, 8) ||
+	    tty_fake_bce(tty, &ctx->defaults, 8) ||
 	    !tty_term_has(tty->term, TTYC_CSR) ||
-	    wp->sx == 1 ||
-	    wp->sy == 1) {
+	    ctx->sx == 1 ||
+	    ctx->sy == 1) {
 		tty_redraw_region(tty, ctx);
 		return;
 	}
 
-	tty_default_attributes(tty, wp, ctx->bg);
+	tty_default_attributes(tty, &ctx->defaults, ctx->palette, ctx->bg);
 
 	tty_region_pane(tty, ctx, ctx->orupper, ctx->orlower);
 	tty_margin_pane(tty, ctx);
@@ -1720,20 +1696,19 @@ tty_cmd_linefeed(struct tty *tty, const struct tty_ctx *ctx)
 void
 tty_cmd_scrollup(struct tty *tty, const struct tty_ctx *ctx)
 {
-	struct window_pane	*wp = ctx->wp;
-	u_int			 i;
+	u_int	i;
 
 	if (ctx->bigger ||
 	    (!tty_full_width(tty, ctx) && !tty_use_margin(tty)) ||
-	    tty_fake_bce(tty, wp, 8) ||
+	    tty_fake_bce(tty, &ctx->defaults, 8) ||
 	    !tty_term_has(tty->term, TTYC_CSR) ||
-	    wp->sx == 1 ||
-	    wp->sy == 1) {
+	    ctx->sx == 1 ||
+	    ctx->sy == 1) {
 		tty_redraw_region(tty, ctx);
 		return;
 	}
 
-	tty_default_attributes(tty, wp, ctx->bg);
+	tty_default_attributes(tty, &ctx->defaults, ctx->palette, ctx->bg);
 
 	tty_region_pane(tty, ctx, ctx->orupper, ctx->orlower);
 	tty_margin_pane(tty, ctx);
@@ -1757,22 +1732,21 @@ tty_cmd_scrollup(struct tty *tty, const struct tty_ctx *ctx)
 void
 tty_cmd_scrolldown(struct tty *tty, const struct tty_ctx *ctx)
 {
-	struct window_pane	*wp = ctx->wp;
-	u_int			 i;
+	u_int	i;
 
 	if (ctx->bigger ||
 	    (!tty_full_width(tty, ctx) && !tty_use_margin(tty)) ||
-	    tty_fake_bce(tty, wp, 8) ||
+	    tty_fake_bce(tty, &ctx->defaults, 8) ||
 	    !tty_term_has(tty->term, TTYC_CSR) ||
 	    (!tty_term_has(tty->term, TTYC_RI) &&
 	    !tty_term_has(tty->term, TTYC_RIN)) ||
-	    wp->sx == 1 ||
-	    wp->sy == 1) {
+	    ctx->sx == 1 ||
+	    ctx->sy == 1) {
 		tty_redraw_region(tty, ctx);
 		return;
 	}
 
-	tty_default_attributes(tty, wp, ctx->bg);
+	tty_default_attributes(tty, &ctx->defaults, ctx->palette, ctx->bg);
 
 	tty_region_pane(tty, ctx, ctx->orupper, ctx->orlower);
 	tty_margin_pane(tty, ctx);
@@ -1789,10 +1763,9 @@ tty_cmd_scrolldown(struct tty *tty, const struct tty_ctx *ctx)
 void
 tty_cmd_clearendofscreen(struct tty *tty, const struct tty_ctx *ctx)
 {
-	struct window_pane	*wp = ctx->wp;
-	u_int			 px, py, nx, ny;
+	u_int	px, py, nx, ny;
 
-	tty_default_attributes(tty, wp, ctx->bg);
+	tty_default_attributes(tty, &ctx->defaults, ctx->palette, ctx->bg);
 
 	tty_region_pane(tty, ctx, 0, ctx->sy - 1);
 	tty_margin_off(tty);
@@ -1814,10 +1787,9 @@ tty_cmd_clearendofscreen(struct tty *tty, const struct tty_ctx *ctx)
 void
 tty_cmd_clearstartofscreen(struct tty *tty, const struct tty_ctx *ctx)
 {
-	struct window_pane	*wp = ctx->wp;
-	u_int			 px, py, nx, ny;
+	u_int	px, py, nx, ny;
 
-	tty_default_attributes(tty, wp, ctx->bg);
+	tty_default_attributes(tty, &ctx->defaults, ctx->palette, ctx->bg);
 
 	tty_region_pane(tty, ctx, 0, ctx->sy - 1);
 	tty_margin_off(tty);
@@ -1839,10 +1811,9 @@ tty_cmd_clearstartofscreen(struct tty *tty, const struct tty_ctx *ctx)
 void
 tty_cmd_clearscreen(struct tty *tty, const struct tty_ctx *ctx)
 {
-	struct window_pane	*wp = ctx->wp;
-	u_int			 px, py, nx, ny;
+	u_int	px, py, nx, ny;
 
-	tty_default_attributes(tty, wp, ctx->bg);
+	tty_default_attributes(tty, &ctx->defaults, ctx->palette, ctx->bg);
 
 	tty_region_pane(tty, ctx, 0, ctx->sy - 1);
 	tty_margin_off(tty);
@@ -1858,15 +1829,14 @@ tty_cmd_clearscreen(struct tty *tty, const struct tty_ctx *ctx)
 void
 tty_cmd_alignmenttest(struct tty *tty, const struct tty_ctx *ctx)
 {
-	struct window_pane	*wp = ctx->wp;
-	u_int			 i, j;
+	u_int	i, j;
 
 	if (ctx->bigger) {
-		wp->flags |= PANE_REDRAW;
+		ctx->redraw_cb(ctx);
 		return;
 	}
 
-	tty_attributes(tty, &grid_default_cell, wp);
+	tty_attributes(tty, &grid_default_cell, &ctx->defaults, ctx->palette);
 
 	tty_region_pane(tty, ctx, 0, ctx->sy - 1);
 	tty_margin_off(tty);
@@ -1892,14 +1862,12 @@ tty_cmd_cell(struct tty *tty, const struct tty_ctx *ctx)
 	tty_margin_off(tty);
 	tty_cursor_pane_unless_wrap(tty, ctx, ctx->ocx, ctx->ocy);
 
-	tty_cell(tty, ctx->cell, ctx->wp);
+	tty_cell(tty, ctx->cell, &ctx->defaults, ctx->palette);
 }
 
 void
 tty_cmd_cells(struct tty *tty, const struct tty_ctx *ctx)
 {
-	struct window_pane	*wp = ctx->wp;
-
 	if (!tty_is_visible(tty, ctx, ctx->ocx, ctx->ocy, ctx->num, 1))
 		return;
 
@@ -1915,14 +1883,14 @@ tty_cmd_cells(struct tty *tty, const struct tty_ctx *ctx)
 		    tty->cy == tty->rlower)
 			tty_draw_pane(tty, ctx, ctx->ocy);
 		else
-			wp->flags |= PANE_REDRAW;
+			ctx->redraw_cb(ctx);
 		return;
 	}
 
 	tty_margin_off(tty);
 	tty_cursor_pane_unless_wrap(tty, ctx, ctx->ocx, ctx->ocy);
 
-	tty_attributes(tty, ctx->cell, ctx->wp);
+	tty_attributes(tty, ctx->cell, &ctx->defaults, ctx->palette);
 	tty_putn(tty, ctx->ptr, ctx->num, ctx->num);
 }
 
@@ -1958,7 +1926,8 @@ tty_cmd_syncstart(struct tty *tty, __unused const struct tty_ctx *ctx)
 }
 
 static void
-tty_cell(struct tty *tty, const struct grid_cell *gc, struct window_pane *wp)
+tty_cell(struct tty *tty, const struct grid_cell *gc,
+    const struct grid_cell *defaults, int *palette)
 {
 	const struct grid_cell	*gcp;
 
@@ -1973,7 +1942,7 @@ tty_cell(struct tty *tty, const struct grid_cell *gc, struct window_pane *wp)
 		return;
 
 	/* Set the attributes. */
-	tty_attributes(tty, gc, wp);
+	tty_attributes(tty, gc, defaults, palette);
 
 	/* Get the cell and if ASCII write with putc to do ACS translation. */
 	gcp = tty_check_codeset(tty, gc);
@@ -1999,21 +1968,16 @@ tty_reset(struct tty *tty)
 		tty_putcode(tty, TTYC_SGR0);
 		memcpy(gc, &grid_default_cell, sizeof *gc);
 	}
-
 	memcpy(&tty->last_cell, &grid_default_cell, sizeof tty->last_cell);
-	tty->last_wp = -1;
 }
 
 static void
 tty_invalidate(struct tty *tty)
 {
 	memcpy(&tty->cell, &grid_default_cell, sizeof tty->cell);
-
 	memcpy(&tty->last_cell, &grid_default_cell, sizeof tty->last_cell);
-	tty->last_wp = -1;
 
 	tty->cx = tty->cy = UINT_MAX;
-
 	tty->rupper = tty->rleft = UINT_MAX;
 	tty->rlower = tty->rright = UINT_MAX;
 
@@ -2089,7 +2053,7 @@ static void
 tty_margin_pane(struct tty *tty, const struct tty_ctx *ctx)
 {
 	tty_margin(tty, ctx->xoff - ctx->wox,
-	    ctx->xoff + ctx->wp->sx - 1 - ctx->wox);
+	    ctx->xoff + ctx->sx - 1 - ctx->wox);
 }
 
 /* Set margin at absolute position. */
@@ -2282,27 +2246,24 @@ out:
 
 void
 tty_attributes(struct tty *tty, const struct grid_cell *gc,
-    struct window_pane *wp)
+    const struct grid_cell *defaults, int *palette)
 {
 	struct grid_cell	*tc = &tty->cell, gc2;
 	int			 changed;
 
-	/* Ignore cell if it is the same as the last one. */
-	if (wp != NULL &&
-	    (int)wp->id == tty->last_wp &&
-	    ~(wp->flags & PANE_STYLECHANGED) &&
-	    gc->attr == tty->last_cell.attr &&
-	    gc->fg == tty->last_cell.fg &&
-	    gc->bg == tty->last_cell.bg &&
-	    gc->us == tty->last_cell.us)
-		return;
-	tty->last_wp = (wp != NULL ? (int)wp->id : -1);
-	memcpy(&tty->last_cell, gc, sizeof tty->last_cell);
-
 	/* Copy cell and update default colours. */
 	memcpy(&gc2, gc, sizeof gc2);
-	if (wp != NULL)
-		tty_default_colours(&gc2, wp);
+	if (gc2.fg == 8)
+		gc2.fg = defaults->fg;
+	if (gc2.bg == 8)
+		gc2.bg = defaults->bg;
+
+	/* Ignore cell if it is the same as the last one. */
+	if (gc2.attr == tty->last_cell.attr &&
+	    gc2.fg == tty->last_cell.fg &&
+	    gc2.bg == tty->last_cell.bg &&
+	    gc2.us == tty->last_cell.us)
+		return;
 
 	/*
 	 * If no setab, try to use the reverse attribute as a best-effort for a
@@ -2320,9 +2281,9 @@ tty_attributes(struct tty *tty, const struct grid_cell *gc,
 	}
 
 	/* Fix up the colours if necessary. */
-	tty_check_fg(tty, wp, &gc2);
-	tty_check_bg(tty, wp, &gc2);
-	tty_check_us(tty, wp, &gc2);
+	tty_check_fg(tty, palette, &gc2);
+	tty_check_bg(tty, palette, &gc2);
+	tty_check_us(tty, palette, &gc2);
 
 	/*
 	 * If any bits are being cleared or the underline colour is now default,
@@ -2377,6 +2338,8 @@ tty_attributes(struct tty *tty, const struct grid_cell *gc,
 		tty_putcode(tty, TTYC_SMOL);
 	if ((changed & GRID_ATTR_CHARSET) && tty_acs_needed(tty))
 		tty_putcode(tty, TTYC_SMACS);
+
+	memcpy(&tty->last_cell, &gc2, sizeof tty->last_cell);
 }
 
 static void
@@ -2441,7 +2404,7 @@ tty_colours(struct tty *tty, const struct grid_cell *gc)
 }
 
 static void
-tty_check_fg(struct tty *tty, struct window_pane *wp, struct grid_cell *gc)
+tty_check_fg(struct tty *tty, int *palette, struct grid_cell *gc)
 {
 	u_char	r, g, b;
 	u_int	colours;
@@ -2456,7 +2419,7 @@ tty_check_fg(struct tty *tty, struct window_pane *wp, struct grid_cell *gc)
 		c = gc->fg;
 		if (c < 8 && gc->attr & GRID_ATTR_BRIGHT)
 			c += 90;
-		if ((c = window_pane_get_palette(wp, c)) != -1)
+		if ((c = tty_get_palette(palette, c)) != -1)
 			gc->fg = c;
 	}
 
@@ -2497,7 +2460,7 @@ tty_check_fg(struct tty *tty, struct window_pane *wp, struct grid_cell *gc)
 }
 
 static void
-tty_check_bg(struct tty *tty, struct window_pane *wp, struct grid_cell *gc)
+tty_check_bg(struct tty *tty, int *palette, struct grid_cell *gc)
 {
 	u_char	r, g, b;
 	u_int	colours;
@@ -2505,7 +2468,7 @@ tty_check_bg(struct tty *tty, struct window_pane *wp, struct grid_cell *gc)
 
 	/* Perform substitution if this pane has a palette. */
 	if (~gc->flags & GRID_FLAG_NOPALETTE) {
-		if ((c = window_pane_get_palette(wp, gc->bg)) != -1)
+		if ((c = tty_get_palette(palette, gc->bg)) != -1)
 			gc->bg = c;
 	}
 
@@ -2548,14 +2511,13 @@ tty_check_bg(struct tty *tty, struct window_pane *wp, struct grid_cell *gc)
 }
 
 static void
-tty_check_us(__unused struct tty *tty, struct window_pane *wp,
-    struct grid_cell *gc)
+tty_check_us(__unused struct tty *tty, int *palette, struct grid_cell *gc)
 {
 	int	c;
 
 	/* Perform substitution if this pane has a palette. */
 	if (~gc->flags & GRID_FLAG_NOPALETTE) {
-		if ((c = window_pane_get_palette(wp, gc->us)) != -1)
+		if ((c = tty_get_palette(palette, gc->us)) != -1)
 			gc->us = c;
 	}
 
@@ -2686,11 +2648,12 @@ tty_window_default_style(struct grid_cell *gc, struct window_pane *wp)
 	gc->bg = wp->bg;
 }
 
-static void
+void
 tty_default_colours(struct grid_cell *gc, struct window_pane *wp)
 {
 	struct options	*oo = wp->options;
-	int		 c;
+
+	memcpy(gc, &grid_default_cell, sizeof *gc);
 
 	if (wp->flags & PANE_STYLECHANGED) {
 		wp->flags &= ~PANE_STYLECHANGED;
@@ -2707,12 +2670,6 @@ tty_default_colours(struct grid_cell *gc, struct window_pane *wp)
 			gc->fg = wp->cached_active_gc.fg;
 		else
 			gc->fg = wp->cached_gc.fg;
-
-		if (gc->fg != 8) {
-			c = window_pane_get_palette(wp, gc->fg);
-			if (c != -1)
-				gc->fg = c;
-		}
 	}
 
 	if (gc->bg == 8) {
@@ -2720,21 +2677,16 @@ tty_default_colours(struct grid_cell *gc, struct window_pane *wp)
 			gc->bg = wp->cached_active_gc.bg;
 		else
 			gc->bg = wp->cached_gc.bg;
-
-		if (gc->bg != 8) {
-			c = window_pane_get_palette(wp, gc->bg);
-			if (c != -1)
-				gc->bg = c;
-		}
 	}
 }
 
 static void
-tty_default_attributes(struct tty *tty, struct window_pane *wp, u_int bg)
+tty_default_attributes(struct tty *tty, const struct grid_cell *defaults,
+    int *palette, u_int bg)
 {
-	static struct grid_cell gc;
+	struct grid_cell	gc;
 
 	memcpy(&gc, &grid_default_cell, sizeof gc);
 	gc.bg = bg;
-	tty_attributes(tty, &gc, wp);
+	tty_attributes(tty, &gc, defaults, palette);
 }
diff --git a/usr.bin/tmux/window-clock.c b/usr.bin/tmux/window-clock.c
index a296db9bfbd..140b7d41be4 100644
--- a/usr.bin/tmux/window-clock.c
+++ b/usr.bin/tmux/window-clock.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: window-clock.c,v 1.28 2019/03/12 20:02:47 nicm Exp $ */
+/* $OpenBSD: window-clock.c,v 1.29 2020/05/16 15:34:08 nicm Exp $ */
 
 /*
  * Copyright (c) 2009 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -219,7 +219,7 @@ window_clock_draw_screen(struct window_mode_entry *wme)
 	colour = options_get_number(wp->window->options, "clock-mode-colour");
 	style = options_get_number(wp->window->options, "clock-mode-style");
 
-	screen_write_start(&ctx, NULL, s);
+	screen_write_start(&ctx, s);
 
 	t = time(NULL);
 	tm = localtime(&t);
diff --git a/usr.bin/tmux/window-copy.c b/usr.bin/tmux/window-copy.c
index 3699900a2f9..66ed6ecfb39 100644
--- a/usr.bin/tmux/window-copy.c
+++ b/usr.bin/tmux/window-copy.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: window-copy.c,v 1.282 2020/05/16 15:11:52 nicm Exp $ */
+/* $OpenBSD: window-copy.c,v 1.283 2020/05/16 15:34:08 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -406,7 +406,7 @@ window_copy_init(struct window_mode_entry *wme,
 	data->screen.cx = data->cx;
 	data->screen.cy = data->cy;
 
-	screen_write_start(&ctx, NULL, &data->screen);
+	screen_write_start(&ctx, &data->screen);
 	for (i = 0; i < screen_size_y(&data->screen); i++)
 		window_copy_write_line(wme, &ctx, i);
 	screen_write_cursormove(&ctx, data->cx, data->cy, 0);
@@ -473,7 +473,7 @@ window_copy_vadd(struct window_pane *wp, const char *fmt, va_list ap)
 	memcpy(&gc, &grid_default_cell, sizeof gc);
 
 	old_hsize = screen_hsize(data->backing);
-	screen_write_start(&back_ctx, NULL, backing);
+	screen_write_start(&back_ctx, backing);
 	if (data->backing_written) {
 		/*
 		 * On the second or later line, do a CRLF before writing
@@ -489,7 +489,7 @@ window_copy_vadd(struct window_pane *wp, const char *fmt, va_list ap)
 
 	data->oy += screen_hsize(data->backing) - old_hsize;
 
-	screen_write_start(&ctx, wp, &data->screen);
+	screen_write_start_pane(&ctx, wp, &data->screen);
 
 	/*
 	 * If the history has changed, draw the top line.
@@ -713,7 +713,7 @@ window_copy_size_changed(struct window_mode_entry *wme)
 	window_copy_clear_selection(wme);
 	window_copy_clear_marks(wme);
 
-	screen_write_start(&ctx, NULL, s);
+	screen_write_start(&ctx, s);
 	window_copy_write_lines(wme, &ctx, 0, screen_size_y(s));
 	screen_write_stop(&ctx);
 
@@ -2822,7 +2822,7 @@ window_copy_search(struct window_mode_entry *wme, int direction, int regex)
 	fy = screen_hsize(data->backing) - data->oy + data->cy;
 
 	screen_init(&ss, screen_write_strlen("%s", str), 1, 0);
-	screen_write_start(&ctx, NULL, &ss);
+	screen_write_start(&ctx, &ss);
 	screen_write_nputs(&ctx, -1, &grid_default_cell, "%s", str);
 	screen_write_stop(&ctx);
 
@@ -2867,7 +2867,7 @@ window_copy_search_marks(struct window_mode_entry *wme, struct screen *ssp,
 	if (ssp == NULL) {
 		width = screen_write_strlen("%s", data->searchstr);
 		screen_init(&ss, width, 1, 0);
-		screen_write_start(&ctx, NULL, &ss);
+		screen_write_start(&ctx, &ss);
 		screen_write_nputs(&ctx, -1, &grid_default_cell, "%s",
 		    data->searchstr);
 		screen_write_stop(&ctx);
@@ -3207,7 +3207,7 @@ window_copy_redraw_lines(struct window_mode_entry *wme, u_int py, u_int ny)
 	struct screen_write_ctx	 	 ctx;
 	u_int				 i;
 
-	screen_write_start(&ctx, wp, NULL);
+	screen_write_start_pane(&ctx, wp, NULL);
 	for (i = py; i < py + ny; i++)
 		window_copy_write_line(wme, &ctx, i);
 	screen_write_cursormove(&ctx, data->cx, data->cy, 0);
@@ -3326,7 +3326,7 @@ window_copy_update_cursor(struct window_mode_entry *wme, u_int cx, u_int cy)
 	if (data->cx == screen_size_x(s))
 		window_copy_redraw_lines(wme, data->cy, 1);
 	else {
-		screen_write_start(&ctx, wp, NULL);
+		screen_write_start_pane(&ctx, wp, NULL);
 		screen_write_cursormove(&ctx, data->cx, data->cy, 0);
 		screen_write_stop(&ctx);
 	}
@@ -3579,7 +3579,7 @@ window_copy_copy_buffer(struct window_mode_entry *wme, const char *prefix,
 	struct screen_write_ctx	 ctx;
 
 	if (options_get_number(global_options, "set-clipboard") != 0) {
-		screen_write_start(&ctx, wp, NULL);
+		screen_write_start_pane(&ctx, wp, NULL);
 		screen_write_setselection(&ctx, buf, len);
 		screen_write_stop(&ctx);
 		notify_pane("pane-set-clipboard", wp);
@@ -3636,7 +3636,7 @@ window_copy_append_selection(struct window_mode_entry *wme)
 		return;
 
 	if (options_get_number(global_options, "set-clipboard") != 0) {
-		screen_write_start(&ctx, wp, NULL);
+		screen_write_start_pane(&ctx, wp, NULL);
 		screen_write_setselection(&ctx, buf, len);
 		screen_write_stop(&ctx);
 		notify_pane("pane-set-clipboard", wp);
@@ -4399,7 +4399,7 @@ window_copy_scroll_up(struct window_mode_entry *wme, u_int ny)
 		window_copy_search_marks(wme, NULL, data->searchregex);
 	window_copy_update_selection(wme, 0, 0);
 
-	screen_write_start(&ctx, wp, NULL);
+	screen_write_start_pane(&ctx, wp, NULL);
 	screen_write_cursormove(&ctx, 0, 0, 0);
 	screen_write_deleteline(&ctx, ny, 8);
 	window_copy_write_lines(wme, &ctx, screen_size_y(s) - ny, ny);
@@ -4435,7 +4435,7 @@ window_copy_scroll_down(struct window_mode_entry *wme, u_int ny)
 		window_copy_search_marks(wme, NULL, data->searchregex);
 	window_copy_update_selection(wme, 0, 0);
 
-	screen_write_start(&ctx, wp, NULL);
+	screen_write_start_pane(&ctx, wp, NULL);
 	screen_write_cursormove(&ctx, 0, 0, 0);
 	screen_write_insertline(&ctx, ny, 8);
 	window_copy_write_lines(wme, &ctx, 0, ny);
diff --git a/usr.bin/tmux/window.c b/usr.bin/tmux/window.c
index 43fa4d93072..4a5b79e3d59 100644
--- a/usr.bin/tmux/window.c
+++ b/usr.bin/tmux/window.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: window.c,v 1.259 2020/05/16 15:01:31 nicm Exp $ */
+/* $OpenBSD: window.c,v 1.260 2020/05/16 15:34:08 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -996,26 +996,6 @@ window_pane_resize(struct window_pane *wp, u_int sx, u_int sy)
 }
 
 void
-window_pane_alternate_on(struct window_pane *wp, struct grid_cell *gc,
-    int cursor)
-{
-	if (!options_get_number(wp->options, "alternate-screen"))
-		return;
-	screen_alternate_on(&wp->base, gc, cursor);
-	wp->flags |= PANE_REDRAW;
-}
-
-void
-window_pane_alternate_off(struct window_pane *wp, struct grid_cell *gc,
-    int cursor)
-{
-	if (!options_get_number(wp->options, "alternate-screen"))
-		return;
-	screen_alternate_off(&wp->base, gc, cursor);
-	wp->flags |= PANE_REDRAW;
-}
-
-void
 window_pane_set_palette(struct window_pane *wp, u_int n, int colour)
 {
 	if (n > 0xff)