diff --git a/layout-custom.c b/layout-custom.c
index b2871f0d..2942720c 100644
--- a/layout-custom.c
+++ b/layout-custom.c
@@ -335,7 +335,7 @@ layout_assign(struct window_pane **wp, struct layout_cell *lc, int flags)
 	case LAYOUT_TOPBOTTOM:
 	case LAYOUT_FLOATING:
 		TAILQ_FOREACH(lcchild, &lc->cells, entry)
-			layout_assign(wp, lcchild, PANE_FLOATING);
+			layout_assign(wp, lcchild, flags);
 		return;
 	}
 }
diff --git a/screen-redraw.c b/screen-redraw.c
index dc96c517..4ea49176 100644
--- a/screen-redraw.c
+++ b/screen-redraw.c
@@ -702,7 +702,7 @@ screen_redraw_draw_pane_status(struct screen_redraw_ctx *ctx)
 			/* Left not visible. */
 			l = ctx->ox - xoff;
 			x = 0;
-			width = size - i;
+			width = size - l;
 		} else {
 			/* Right not visible. */
 			l = 0;
@@ -710,7 +710,8 @@ screen_redraw_draw_pane_status(struct screen_redraw_ctx *ctx)
 			width = size - x;
 		}
 
-		r = screen_redraw_get_visible_ranges(wp, x, yoff, width, NULL);
+		r = tty_check_overlay_range(tty, x, yoff, width);
+		r = screen_redraw_get_visible_ranges(wp, x, yoff, width, r);
 		if (ctx->statustop)
 			yoff += ctx->statuslines;
 		for (i = 0; i < r->used; i++) {
@@ -1273,15 +1274,42 @@ screen_redraw_draw_pane(struct screen_redraw_ctx *ctx, struct window_pane *wp)
 	struct screen		*s = wp->screen;
 	struct colour_palette	*palette = &wp->palette;
 	struct grid_cell	 defaults;
-	u_int			 i, j, woy, wx, wy, py, width;
+	u_int			 j, k, woy, wx, wy, py, width;
 	struct visible_ranges	*r;
 	struct visible_range	*ri;
 
+	/*
+	 * There are 3 coordinate spaces:
+	 *
+	 * window: (0 to w->sx-1, 0 to w->sy-1)
+	 * tty: (0 to tty->sx-1, 0 to tty->sy-1)
+	 * pane: (0 to wp->sx-1, 0 to wp->sy-1)
+	 *
+	 * Transformations:
+	 * window <-> tty (x-axis):
+	 *   window_x = tty_x + ctx->ox
+	 *   tty_x = window_x - ctx->ox
+	 *
+	 * window <-> tty (y-axis):
+	 *   woy = (ctx->statustop) ? ctx->statuslines : 0
+	 *   window_y = tty_y + ctx->oy - woy
+	 *   tty_y = woy + window_y - ctx->oy
+	 *
+	 * window <-> pane (x-axis):
+	 *   window_x = pane_x + wp->xoff
+	 *   pane_x = window_x - wp->xoff
+	 *
+	 * window <-> pane (y-axis):
+	 *   window_y = pane_y + wp->yoff
+	 *   pane_y = window_y - wp->yoff
+	 */
+
 	if (wp->base.mode & MODE_SYNC)
 		screen_write_stop_sync(wp);
 
 	log_debug("%s: %s @%u %%%u", __func__, c->name, w->id, wp->id);
 
+	/* Check if pane completely not visible. */
 	if (wp->xoff + (int)wp->sx <= ctx->ox ||
 	    wp->xoff >= (int)ctx->ox + (int)ctx->sx)
 		return;
@@ -1303,37 +1331,36 @@ screen_redraw_draw_pane(struct screen_redraw_ctx *ctx, struct window_pane *wp)
 		if (wp->xoff >= (int)ctx->ox &&
 		    wp->xoff + (int)wp->sx <= (int)ctx->ox + (int)ctx->sx) {
 			/* All visible. */
-			i = 0;
 			wx = (u_int)(wp->xoff - (int)ctx->ox);
 			width = wp->sx;
 		} else if (wp->xoff < (int)ctx->ox &&
 		    wp->xoff + (int)wp->sx > (int)ctx->ox + (int)ctx->sx) {
 			/* Both left and right not visible. */
-			i = ctx->ox;
 			wx = 0;
 			width = ctx->sx;
 		} else if (wp->xoff < (int)ctx->ox) {
 			/* Left not visible. */
-			i = (u_int)((int)ctx->ox - wp->xoff);
 			wx = 0;
-			width = wp->sx - i;
+			width = wp->sx - ((u_int)((int)ctx->ox - wp->xoff));
 		} else {
 			/* Right not visible. */
-			i = 0;
 			wx = (u_int)(wp->xoff - (int)ctx->ox);
 			width = ctx->sx - wx;
 		}
-		log_debug("%s: %s %%%u line %u,%u at %u,%u, width %u",
-		    __func__, c->name, wp->id, i, j, wx, wy, width);
 
 		/* Get visible ranges of line before we draw it. */
-		r = screen_redraw_get_visible_ranges(wp, wx, wy, width, NULL);
+		r = tty_check_overlay_range(tty, wx, wy, width);
+		r = screen_redraw_get_visible_ranges(wp, wx, wy, width, r);
 		tty_default_colours(&defaults, wp);
-		for (i = 0; i < r->used; i++) {
-			ri = &r->ranges[i];
+		for (k = 0; k < r->used; k++) {
+			ri = &r->ranges[k];
 			if (ri->nx == 0)
 				continue;
-			tty_draw_line(tty, s, ri->px - wp->xoff, j, ri->nx,
+			log_debug("%s: %s %%%u range pane (%u,%u) width %u, tty (%u,%u) width %u",
+			    __func__, c->name, wp->id,
+			    ri->px + (int)ctx->ox - wp->xoff, j, ri->nx,
+			    ri->px, py, ri->nx);
+			tty_draw_line(tty, s, ri->px + (int)ctx->ox - wp->xoff, j, ri->nx,
 			    ri->px, py, &defaults, palette);
 		}
 	}
@@ -1494,13 +1521,13 @@ screen_redraw_draw_scrollbar(struct screen_redraw_ctx *ctx,
 	}
 
 	for (j = jmin; j < jmax; j++) {
-		wy = sb_y + j;	   /* window y coordinate */
-		py = sb_tty_y + j;/* tty y coordinate */
+		wy = sb_y + j; /* window y coordinate */
+		py = sb_tty_y + j; /* tty y coordinate */
 		r = tty_check_overlay_range(tty, sb_x, wy, imax);
 		r = screen_redraw_get_visible_ranges(wp, sb_x, wy, imax, r);
 		for (i = imin; i < imax; i++) {
 			px = sb_x + ox + i; /* tty x coordinate */
-			wx = sb_x + i;	    /* window x coordinate */
+			wx = sb_x + i; /* window x coordinate */
 			if (wx < xoff - (int)sb_w - (int)sb_pad ||
 			    px >= sx || px < 0 ||
 			    wy < yoff - 1 ||
diff --git a/tty-draw.c b/tty-draw.c
index 865fff60..24d8b711 100644
--- a/tty-draw.c
+++ b/tty-draw.c
@@ -46,10 +46,6 @@ static void
 tty_draw_line_clear(struct tty *tty, u_int px, u_int py, u_int nx,
     const struct grid_cell *defaults, u_int bg, int wrapped)
 {
-	struct visible_ranges	*r;
-	struct visible_range	*rr;
-	u_int			 i;
-
 	/* Nothing to clear. */
 	if (nx == 0)
 		return;
@@ -82,20 +78,14 @@ tty_draw_line_clear(struct tty *tty, u_int px, u_int py, u_int nx,
 	}
 
         /* Couldn't use an escape sequence, use spaces. */
-	r = tty_check_overlay_range(tty, px, py, nx);
-	for (i = 0; i < r->used; i++) {
-		rr = &r->ranges[i];
-		if (rr->nx != 0) {
-			if (rr->px != 0 || !wrapped)
-				tty_cursor(tty, rr->px, py);
-			if (rr->nx == 1)
-				tty_putc(tty, ' ');
-			else if (rr->nx == 2)
-				tty_putn(tty, "  ", 2, 2);
-			else
-				tty_repeat_space(tty, rr->nx);
-		}
-	}
+	if (px != 0 || !wrapped)
+		tty_cursor(tty, px, py);
+	if (nx == 1)
+		tty_putc(tty, ' ');
+	else if (nx == 2)
+		tty_putn(tty, "  ", 2, 2);
+	else
+		tty_repeat_space(tty, nx);
 }
 
 /* Draw a line from screen to tty. */
diff --git a/tty.c b/tty.c
index ea1705d3..39f79c22 100644
--- a/tty.c
+++ b/tty.c
@@ -108,6 +108,7 @@ tty_init(struct tty *tty, struct client *c)
 	tty->cstyle = SCREEN_CURSOR_DEFAULT;
 	tty->ccolour = -1;
 	tty->fg = tty->bg = -1;
+	tty->mouse_last_pane = -1;
 
 	if (tcgetattr(c->fd, &tty->tio) != 0)
 		return (-1);
@@ -1092,12 +1093,14 @@ tty_redraw_region(struct tty *tty, const struct tty_ctx *ctx)
 	 * 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", __func__, c->name);
+	if (tty_large_region(tty, ctx) && ~ctx->flags & TTY_CTX_PANE_OBSCURED) {
+		log_debug("%s: %s large region redraw", __func__, c->name);
 		ctx->redraw_cb(ctx);
 		return;
 	}
 
+	log_debug("%s: %s small region redraw (%u-%u)", __func__, c->name,
+	    ctx->orupper, ctx->orlower);
 	for (i = ctx->orupper; i <= ctx->orlower; i++)
 		tty_draw_pane(tty, ctx, i);
 }
@@ -1123,23 +1126,23 @@ 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)
 {
-	u_int	xoff = ctx->rxoff + px;
+	int	xoff = ctx->rxoff + px;
 
 	if (!tty_is_visible(tty, ctx, px, py, nx, 1))
 		return (0);
 	*ry = ctx->yoff + py - ctx->woy;
 
-	if (xoff >= ctx->wox && xoff + nx <= ctx->wox + ctx->wsx) {
+	if (xoff >= (int)ctx->wox && xoff + nx <= ctx->wox + ctx->wsx) {
 		/* All visible. */
 		*i = 0;
 		*x = ctx->xoff + px - ctx->wox;
 		*rx = nx;
-	} else if (xoff < ctx->wox && xoff + nx > ctx->wox + ctx->wsx) {
+	} else if (xoff < (int)ctx->wox && xoff + nx > ctx->wox + ctx->wsx) {
 		/* Both left and right not visible. */
 		*i = ctx->wox;
 		*x = 0;
 		*rx = ctx->wsx;
-	} else if (xoff < ctx->wox) {
+	} else if (xoff < (int)ctx->wox) {
 		/* Left not visible. */
 		*i = ctx->wox - (ctx->xoff + px);
 		*x = 0;
@@ -1215,13 +1218,23 @@ static void
 tty_clear_pane_line(struct tty *tty, const struct tty_ctx *ctx, u_int py,
     u_int px, u_int nx, u_int bg)
 {
-	struct client	*c = tty->client;
-	u_int		 i, x, rx, ry;
+	struct client		*c = tty->client;
+	struct visible_ranges	*r;
+	struct visible_range	*ri;
+	u_int			 i, l, x, rx, ry;
 
 	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->defaults, ry, x, rx, bg);
+	if (tty_clamp_line(tty, ctx, px, py, nx, &l, &x, &rx, &ry)) {
+		r = tty_check_overlay_range(tty, x, ry, rx);
+		for (i = 0; i < r->used; i++) {
+			ri = &r->ranges[i];
+			if (ri->nx == 0)
+				continue;
+			tty_clear_line(tty, &ctx->defaults, ry, ri->px, ri->nx,
+			    bg);
+		}
+	}
 }
 
 /* Clamp area position to visible part of pane. */
@@ -1288,12 +1301,13 @@ 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, const struct grid_cell *defaults, u_int py,
+tty_clear_area(struct tty *tty, const struct tty_ctx *ctx, u_int py,
     u_int ny, u_int px, u_int nx, u_int bg)
 {
-	struct client	*c = tty->client;
-	u_int		 yy;
-	char		 tmp[64];
+	struct client		*c = tty->client;
+	const struct grid_cell	*defaults = &ctx->defaults;
+	u_int			 yy;
+	char			 tmp[64];
 
 	log_debug("%s: %s, %u,%u at %u,%u", __func__, c->name, nx, ny, px, py);
 
@@ -1301,7 +1315,10 @@ tty_clear_area(struct tty *tty, const struct grid_cell *defaults, u_int py,
 	if (nx == 0 || ny == 0)
 		return;
 
-	/* If genuine BCE is available, can try escape sequences. */
+	/*
+	 * If there is an overlay or BCE is not available, cannot clear as a
+	 * region.
+	 */
 	if (c->overlay_check == NULL && !tty_fake_bce(tty, defaults, bg)) {
 		/* Use ED if clearing off the bottom of the terminal. */
 		if (px == 0 &&
@@ -1366,9 +1383,10 @@ 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->defaults, y, ry, x, rx, bg);
+		tty_clear_area(tty, ctx, y, ry, x, rx, bg);
 }
 
+/* Redraw a line of a screen at py. */
 static void
 tty_draw_pane(struct tty *tty, const struct tty_ctx *ctx, u_int py)
 {
@@ -1404,6 +1422,7 @@ tty_draw_pane(struct tty *tty, const struct tty_ctx *ctx, u_int py)
 	}
 }
 
+/* Check if character needs to be mapped for codeset. */
 const struct grid_cell *
 tty_check_codeset(struct tty *tty, const struct grid_cell *gc)
 {
@@ -1612,7 +1631,7 @@ tty_cmd_insertcharacter(struct tty *tty, const struct tty_ctx *ctx)
 {
 	struct client	*c = tty->client;
 
-	if ((ctx->flags & TTY_CTX_WINDOW_BIGGER) ||
+	if ((ctx->flags & (TTY_CTX_WINDOW_BIGGER|TTY_CTX_PANE_OBSCURED)) ||
 	    !tty_full_width(tty, ctx) ||
 	    tty_fake_bce(tty, &ctx->defaults, ctx->bg) ||
 	    (!tty_term_has(tty->term, TTYC_ICH) &&
@@ -1635,7 +1654,7 @@ tty_cmd_deletecharacter(struct tty *tty, const struct tty_ctx *ctx)
 {
 	struct client	*c = tty->client;
 
-	if ((ctx->flags & TTY_CTX_WINDOW_BIGGER) ||
+	if (ctx->flags & (TTY_CTX_WINDOW_BIGGER|TTY_CTX_PANE_OBSCURED) ||
 	    !tty_full_width(tty, ctx) ||
 	    tty_fake_bce(tty, &ctx->defaults, ctx->bg) ||
 	    (!tty_term_has(tty->term, TTYC_DCH) &&
@@ -1667,7 +1686,7 @@ tty_cmd_insertline(struct tty *tty, const struct tty_ctx *ctx)
 {
 	struct client	*c = tty->client;
 
-	if ((ctx->flags & TTY_CTX_WINDOW_BIGGER) ||
+	if ((ctx->flags & (TTY_CTX_WINDOW_BIGGER|TTY_CTX_PANE_OBSCURED)) ||
 	    !tty_full_width(tty, ctx) ||
 	    tty_fake_bce(tty, &ctx->defaults, ctx->bg) ||
 	    !tty_term_has(tty->term, TTYC_CSR) ||
@@ -1695,7 +1714,7 @@ tty_cmd_deleteline(struct tty *tty, const struct tty_ctx *ctx)
 {
 	struct client	*c = tty->client;
 
-	if ((ctx->flags & TTY_CTX_WINDOW_BIGGER) ||
+	if (ctx->flags & (TTY_CTX_WINDOW_BIGGER|TTY_CTX_PANE_OBSCURED) ||
 	    !tty_full_width(tty, ctx) ||
 	    tty_fake_bce(tty, &ctx->defaults, ctx->bg) ||
 	    !tty_term_has(tty->term, TTYC_CSR) ||
@@ -1755,7 +1774,7 @@ tty_cmd_reverseindex(struct tty *tty, const struct tty_ctx *ctx)
 	if (ctx->ocy != ctx->orupper)
 		return;
 
-	if ((ctx->flags & TTY_CTX_WINDOW_BIGGER) ||
+	if (ctx->flags & (TTY_CTX_WINDOW_BIGGER|TTY_CTX_PANE_OBSCURED) ||
 	    (!tty_full_width(tty, ctx) && !tty_use_margin(tty)) ||
 	    tty_fake_bce(tty, &ctx->defaults, 8) ||
 	    !tty_term_has(tty->term, TTYC_CSR) ||
@@ -1827,10 +1846,10 @@ tty_cmd_linefeed(struct tty *tty, const struct tty_ctx *ctx)
 void
 tty_cmd_scrollup(struct tty *tty, const struct tty_ctx *ctx)
 {
-	struct client	*c = tty->client;
-	u_int		 i;
+	struct client		*c = tty->client;
+	u_int			 i;
 
-	if ((ctx->flags & TTY_CTX_WINDOW_BIGGER) ||
+	if (ctx->flags & (TTY_CTX_WINDOW_BIGGER|TTY_CTX_PANE_OBSCURED) ||
 	    (!tty_full_width(tty, ctx) && !tty_use_margin(tty)) ||
 	    tty_fake_bce(tty, &ctx->defaults, 8) ||
 	    !tty_term_has(tty->term, TTYC_CSR) ||
@@ -1869,7 +1888,7 @@ tty_cmd_scrolldown(struct tty *tty, const struct tty_ctx *ctx)
 	u_int		 i;
 	struct client	*c = tty->client;
 
-	if ((ctx->flags & TTY_CTX_WINDOW_BIGGER) ||
+	if (ctx->flags & (TTY_CTX_WINDOW_BIGGER|TTY_CTX_PANE_OBSCURED) ||
 	    (!tty_full_width(tty, ctx) && !tty_use_margin(tty)) ||
 	    tty_fake_bce(tty, &ctx->defaults, 8) ||
 	    !tty_term_has(tty->term, TTYC_CSR) ||
@@ -1969,9 +1988,11 @@ tty_cmd_clearscreen(struct tty *tty, const struct tty_ctx *ctx)
 void
 tty_cmd_alignmenttest(struct tty *tty, const struct tty_ctx *ctx)
 {
-	u_int	i, j;
+	struct client	*c = tty->client;
+	u_int		 i, j;
 
-	if (ctx->flags & TTY_CTX_WINDOW_BIGGER) {
+	if (ctx->flags & (TTY_CTX_WINDOW_BIGGER|TTY_CTX_PANE_OBSCURED) ||
+	    c->overlay_check != NULL) {
 		ctx->redraw_cb(ctx);
 		return;
 	}
@@ -2040,7 +2061,7 @@ void
 tty_cmd_cells(struct tty *tty, const struct tty_ctx *ctx)
 {
 	struct visible_ranges	*r;
-	struct visible_range	*rr;
+	struct visible_range	*ri;
 	u_int			 i, px, py, cx;
 	const char		*cp = ctx->data.data;
 	size_t			 n = ctx->data.size;
@@ -2075,11 +2096,11 @@ tty_cmd_cells(struct tty *tty, const struct tty_ctx *ctx)
 
 	r = tty_check_overlay_range(tty, px, py, n);
 	for (i = 0; i < r->used; i++) {
-		rr = &r->ranges[i];
-		if (rr->nx != 0) {
-			cx = rr->px - ctx->xoff + ctx->wox;
+		ri = &r->ranges[i];
+		if (ri->nx != 0) {
+			cx = ri->px - ctx->xoff + ctx->wox;
 			tty_cursor_pane_unless_wrap(tty, ctx, cx, ctx->ocy);
-			tty_putn(tty, cp + rr->px - px, rr->nx, rr->nx);
+			tty_putn(tty, cp + ri->px - px, ri->nx, ri->nx);
 		}
 	}
 }
@@ -2211,6 +2232,10 @@ tty_cell(struct tty *tty, const struct grid_cell *gc,
 	if (gc->flags & GRID_FLAG_PADDING)
 		return;
 
+	/* Check if character is covered by overlay or floating pane. */
+	if (!tty_check_overlay(tty, tty->cx, tty->cy))
+		return;
+
 	/* Check the output codeset and apply attributes. */
 	gcp = tty_check_codeset(tty, gc);
 	tty_attributes(tty, gcp, defaults, palette, hl);
@@ -2324,8 +2349,21 @@ tty_margin_off(struct tty *tty)
 static void
 tty_margin_pane(struct tty *tty, const struct tty_ctx *ctx)
 {
-	tty_margin(tty, ctx->xoff - ctx->wox,
-	    ctx->xoff + ctx->sx - 1 - ctx->wox);
+	int	l, r;
+
+	l = ctx->xoff - ctx->wox;
+	r = ctx->xoff + ctx->sx - 1 - ctx->wox;
+
+	if (l < 0)
+		l = 0;
+	if (l > (int)ctx->wsx)
+		l = ctx->wsx;
+	if (r < 0)
+		r = 0;
+	if (r > (int)ctx->wsx)
+		r = ctx->wsx;
+
+	tty_margin(tty, l, r);
 }
 
 /* Set margin at absolute position. */