From 5c40cc43b250382f3e73f1729104dfd98c504321 Mon Sep 17 00:00:00 2001
From: nicm <nicm>
Date: Wed, 27 May 2026 20:57:53 +0000
Subject: [PATCH] Bring in the single-cell redraw parts for floating panes.

---
 screen-redraw.c |  9 ++---
 screen-write.c  | 96 ++++++++++++++++++++++++++++++++++++++++---------
 tty.c           |  9 +----
 3 files changed, 86 insertions(+), 28 deletions(-)

diff --git a/screen-redraw.c b/screen-redraw.c
index 36307f94..1b41a9a6 100644
--- a/screen-redraw.c
+++ b/screen-redraw.c
@@ -1351,12 +1351,13 @@ screen_redraw_draw_pane(struct screen_redraw_ctx *ctx, struct window_pane *wp)
 			ri = &r->ranges[k];
 			if (ri->nx == 0)
 				continue;
-			log_debug("%s: %s %%%u range pane (%u,%u) width %u, tty (%u,%u) width %u",
-			    __func__, c->name, wp->id,
+			log_debug("%s: %s %%%u range %u (%u,%u) width %u, "
+			    "tty (%u,%u) width %u",
+			    __func__, c->name, wp->id, k,
 			    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);
+			tty_draw_line(tty, s, ri->px + (int)ctx->ox - wp->xoff,
+			    j, ri->nx, ri->px, py, &defaults, palette);
 		}
 	}
 }
diff --git a/screen-write.c b/screen-write.c
index 35bdec8a..1fe44ed7 100644
--- a/screen-write.c
+++ b/screen-write.c
@@ -1127,7 +1127,7 @@ screen_write_redraw_line(struct screen_write_ctx *ctx, struct tty_ctx *ttyctx,
 {
 	struct window_pane	*wp = ctx->wp;
 	struct screen		*s = ctx->s;
-	struct grid_cell	 gc;
+	struct grid_cell	 gc, ngc;
 	u_int			 sx = screen_size_x(s), cx, i, n;
 	u_int			 xoff = wp->xoff, yoff = wp->yoff;
 	struct visible_ranges	*r;
@@ -1142,9 +1142,15 @@ screen_write_redraw_line(struct screen_write_ctx *ctx, struct tty_ctx *ttyctx,
 		cx = ri->px - xoff;
 		for (n = 0; n < ri->nx && cx < sx; n++, cx++) {
 			grid_view_get_cell(s->grid, cx, yy, &gc);
+			if (~gc.flags & GRID_FLAG_SELECTED)
+				ttyctx->cell = &gc;
+			else {
+				screen_select_cell(s, &ngc, &gc);
+				ttyctx->cell = &ngc;
+			}
+
 			ttyctx->ocx = cx;
 			ttyctx->ocy = yy;
-			ttyctx->cell = &gc;
 			tty_write(tty_cmd_cell, ttyctx);
 		}
 	}
@@ -2262,6 +2268,7 @@ void
 screen_write_cell(struct screen_write_ctx *ctx, const struct grid_cell *gc)
 {
 	struct screen		*s = ctx->s;
+	struct window_pane	*wp = ctx->wp;
 	struct grid		*gd = s->grid;
 	const struct utf8_data	*ud = &gc->data;
 	struct grid_line	*gl;
@@ -2269,8 +2276,10 @@ screen_write_cell(struct screen_write_ctx *ctx, const struct grid_cell *gc)
 	struct grid_cell	 tmp_gc, now_gc;
 	struct tty_ctx		 ttyctx;
 	u_int			 sx = screen_size_x(s), sy = screen_size_y(s);
-	u_int			 width = ud->width, xx, not_wrap;
-	int			 selected, skip = 1, redraw = 0;
+	u_int			 width = ud->width, xx, not_wrap, i, n, vis;
+	int			 selected, skip = 1, redraw = 0, yoff = 0;
+	struct visible_ranges	*r;
+	struct visible_range	*ri;
 
 	/* Ignore padding cells. */
 	if (gc->flags & GRID_FLAG_PADDING)
@@ -2368,6 +2377,12 @@ screen_write_cell(struct screen_write_ctx *ctx, const struct grid_cell *gc)
 	if (selected)
 		skip = 0;
 
+	/* Get visible ranges for the character before moving the cursor. */
+	if (wp != NULL)
+		yoff = wp->yoff;
+	r = screen_redraw_get_visible_ranges(wp, s->cx, s->cy + yoff, width,
+	    NULL);
+
 	/*
 	 * Move the cursor. If not wrapping, stick at the last character and
 	 * replace it.
@@ -2376,7 +2391,7 @@ screen_write_cell(struct screen_write_ctx *ctx, const struct grid_cell *gc)
 	if (s->cx <= sx - not_wrap - width)
 		screen_write_set_cursor(ctx, s->cx + width, -1);
 	else
-		screen_write_set_cursor(ctx,  sx - not_wrap, -1);
+		screen_write_set_cursor(ctx, sx - not_wrap, -1);
 
 	/* Create space for character in insert mode. */
 	if (s->mode & MODE_INSERT) {
@@ -2385,16 +2400,44 @@ screen_write_cell(struct screen_write_ctx *ctx, const struct grid_cell *gc)
 		tty_write(tty_cmd_insertcharacter, &ttyctx);
 	}
 
-	/* Write to the screen. */
-	if (!skip && !(s->mode & MODE_SYNC)) {
-		if (selected) {
-			screen_select_cell(s, &tmp_gc, gc);
-			ttyctx.cell = &tmp_gc;
-		} else
-			ttyctx.cell = gc;
-		if (redraw)
-			ttyctx.flags |= TTY_CTX_CELL_DRAW_LINE;
+	/* If not writing, done now. */
+	if (skip || s->mode & MODE_SYNC)
+		return;
+
+	/* Do a full line redraw if needed. */
+	if (redraw) {
+		screen_write_redraw_line(ctx, &ttyctx, s->cy);
+		return;
+	}
+
+	/* Work out the cell attributes. */
+	if (selected)
+		screen_select_cell(s, &tmp_gc, gc);
+	else
+		memcpy(&tmp_gc, gc, sizeof tmp_gc);
+	ttyctx.cell = &tmp_gc;
+
+	/* If the cell is fully visible, it can be written entirely. */
+	for (i = 0, vis = 0; i < r->used; i++)
+		vis += r->ranges[i].nx;
+	if (vis >= width) {
 		tty_write(tty_cmd_cell, &ttyctx);
+		return;
+	}
+
+	/*
+	 * Otherwise this is a wide character or tab partly obscured. Write
+	 * spaces in the visible regions.
+	 */
+	utf8_set(&tmp_gc.data, ' ');
+	for (i = 0; i < r->used; i++) {
+		ri = &r->ranges[i];
+		if (ri->nx == 0)
+			continue;
+		for (n = 0; n < ri->nx; n++) {
+			ttyctx.ocx = ri->px + n;
+			tty_write(tty_cmd_cell, &ttyctx);
+		}
 	}
 }
 
@@ -2403,12 +2446,15 @@ static int
 screen_write_combine(struct screen_write_ctx *ctx, const struct grid_cell *gc)
 {
 	struct screen		*s = ctx->s;
+	struct window_pane	*wp = ctx->wp;
 	struct grid		*gd = s->grid;
 	const struct utf8_data	*ud = &gc->data;
-	u_int			 n, cx = s->cx, cy = s->cy;
+	struct options		*oo = global_options;
+	u_int			 i, n, cx = s->cx, cy = s->cy, vis, yoff = 0;
 	struct grid_cell	 last;
 	struct tty_ctx		 ttyctx;
 	int			 force_wide = 0, zero_width = 0;
+	struct visible_ranges	*r;
 
 	/* Ignore U+3164 HANGUL_FILLER entirely. */
 	if (utf8_is_hangul_filler(ud))
@@ -2423,7 +2469,7 @@ screen_write_combine(struct screen_write_ctx *ctx, const struct grid_cell *gc)
 		zero_width = 1;
 	else if (utf8_is_vs(ud)) {
 		zero_width = 1;
-		if (options_get_number(global_options, "variation-selector-always-wide"))
+		if (options_get_number(oo, "variation-selector-always-wide"))
 			force_wide = 1;
 	} else if (ud->width == 0)
 		zero_width = 1;
@@ -2496,6 +2542,24 @@ screen_write_combine(struct screen_write_ctx *ctx, const struct grid_cell *gc)
 	if (force_wide)
 		grid_view_set_padding(gd, cx - 1, cy);
 
+	/*
+	 * Check if all of this character is visible. No character will be
+	 * obscured in the middle, only on left or right, but there could be an
+	 * empty range in the visible ranges so we add them all up.
+	 */
+	if (wp != NULL)
+		yoff = wp->yoff;
+	r = screen_redraw_get_visible_ranges(wp, cx - n, cy + yoff, n, NULL);
+	for (i = 0, vis = 0; i < r->used; i++)
+		vis += r->ranges[i].nx;
+	if (vis < n) {
+		/*
+		 * Part of this character is obscured. Return 1 and let
+		 * screen_write_cell write a space.
+		 */
+		return (1);
+	}
+
 	/*
 	 * Redraw the combined cell. If forcing the cell to width 2, reset the
 	 * cached cursor position in the tty, since we don't really know
diff --git a/tty.c b/tty.c
index f4382abb..95fe90e4 100644
--- a/tty.c
+++ b/tty.c
@@ -1952,14 +1952,7 @@ tty_cmd_cell(struct tty *tty, const struct tty_ctx *ctx)
 	    (gcp->data.width == 1 && !tty_check_overlay(tty, px, py)))
 		return;
 
-	if (ctx->flags & TTY_CTX_CELL_DRAW_LINE) {
-		tty_draw_line(tty, s, 0, s->cy, screen_size_x(s),
-		    ctx->xoff - ctx->wox, py, &ctx->defaults, ctx->palette);
-		return;
-	}
-
-	/* Handle partially obstructed wide characters. */
-	if (gcp->data.width > 1) {
+	if (gcp->data.width > 1) { /* could be partially obscured */
 		r = tty_check_overlay_range(tty, px, py, gcp->data.width);
 		for (i = 0; i < r->used; i++)
 			vis += r->ranges[i].nx;