Make positions hidden by overlays range-based rather than character-based,

from Anindya Mukherjee.

1 files changed, 81 insertions, 50 deletions

diff --git a/tty.c b/tty.c
index 0f295f6c..9a8265ef 100644
--- a/tty.c
+++ b/tty.c
@@ -71,6 +71,8 @@ static void	tty_draw_pane(struct tty *, const struct tty_ctx *, u_int);
 static void	tty_default_attributes(struct tty *, const struct grid_cell *,
 		    struct colour_palette *, u_int);
 static int	tty_check_overlay(struct tty *, u_int, u_int);
+static void	tty_check_overlay_range(struct tty *, u_int, u_int, u_int,
+		    struct overlay_ranges *);
 
 #define tty_use_margin(tty) \
 	(tty->term->flags & TERM_DECSLRM)
@@ -1046,8 +1048,9 @@ static void
 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;
-	u_int		 i;
+	struct client		*c = tty->client;
+	struct overlay_ranges	 r;
+	u_int			 i;
 
 	log_debug("%s: %s, %u at %u,%u", __func__, c->name, nx, px, py);
 
@@ -1083,18 +1086,13 @@ tty_clear_line(struct tty *tty, const struct grid_cell *defaults, u_int py,
 	 * Couldn't use an escape sequence, use spaces. Clear only the visible
 	 * bit if there is an overlay.
 	 */
-	for (i = 0; i < nx; i++) {
-		if (!tty_check_overlay(tty, px + i, py))
-			break;
-	}
-	tty_cursor(tty, px, py);
-	tty_repeat_space(tty, i);
-	for (; i < nx; i++) {
-		if (tty_check_overlay(tty, px + i, py))
-			break;
+	tty_check_overlay_range(tty, px, py, nx, &r);
+	for (i = 0; i < OVERLAY_MAX_RANGES; i++) {
+		if (r.nx[i] == 0)
+			continue;
+		tty_cursor(tty, r.px[i], py);
+		tty_repeat_space(tty, r.nx[i]);
 	}
-	tty_cursor(tty, px + i, py);
-	tty_repeat_space(tty, nx - i);
 }
 
 /* Clear a line, adjusting to visible part of pane. */
@@ -1306,14 +1304,44 @@ tty_check_codeset(struct tty *tty, const struct grid_cell *gc)
 	return (&new);
 }
 
+/*
+ * Check if a single character is obstructed by the overlay and return a
+ * boolean.
+ */
 static int
 tty_check_overlay(struct tty *tty, u_int px, u_int py)
 {
+	struct overlay_ranges	r;
+
+	/*
+	 * A unit width range will always return nx[2] == 0 from a check, even
+	 * with multiple overlays, so it's sufficient to check just the first
+	 * two entries.
+	 */
+	tty_check_overlay_range(tty, px, py, 1, &r);
+	if (r.nx[0] + r.nx[1] == 0)
+		return (0);
+	return (1);
+}
+
+/* Return parts of the input range which are visible. */
+static void
+tty_check_overlay_range(struct tty *tty, u_int px, u_int py, u_int nx,
+    struct overlay_ranges *r)
+{
 	struct client	*c = tty->client;
 
-	if (c->overlay_check == NULL)
-		return (1);
-	return (c->overlay_check(c, c->overlay_data, px, py));
+	if (c->overlay_check == NULL) {
+		r->px[0] = px;
+		r->nx[0] = nx;
+		r->px[1] = 0;
+		r->nx[1] = 0;
+		r->px[2] = 0;
+		r->nx[2] = 0;
+		return;
+	}
+
+	c->overlay_check(c, c->overlay_data, px, py, nx, r);
 }
 
 void
@@ -1326,11 +1354,12 @@ tty_draw_line(struct tty *tty, struct screen *s, u_int px, u_int py, u_int nx,
 	const struct grid_cell	*gcp;
 	struct grid_line	*gl;
 	struct client		*c = tty->client;
-	u_int			 i, j, ux, sx, width, hidden;
+	struct overlay_ranges	 r;
+	u_int			 i, j, ux, sx, width, hidden, eux, nxx;
+	u_int			 cellsize;
 	int			 flags, cleared = 0, wrapped = 0;
 	char			 buf[512];
 	size_t			 len;
-	u_int			 cellsize;
 
 	log_debug("%s: px=%u py=%u nx=%u atx=%u aty=%u", __func__,
 	    px, py, nx, atx, aty);
@@ -1430,29 +1459,31 @@ tty_draw_line(struct tty *tty, struct screen *s, u_int px, u_int py, u_int nx,
 		else
 			memcpy(&last, gcp, sizeof last);
 
+		tty_check_overlay_range(tty, atx + ux, aty, gcp->data.width,
+		    &r);
 		hidden = 0;
-		for (j = 0; j < gcp->data.width; j++) {
-			if (!tty_check_overlay(tty, atx + ux + j, aty))
-				hidden++;
-		}
+		for (j = 0; j < OVERLAY_MAX_RANGES; j++)
+			hidden += r.nx[j];
+		hidden = gcp->data.width - hidden;
 		if (hidden != 0 && hidden == gcp->data.width) {
 			if (~gcp->flags & GRID_FLAG_PADDING)
 				ux += gcp->data.width;
 		} else if (hidden != 0 || ux + gcp->data.width > nx) {
 			if (~gcp->flags & GRID_FLAG_PADDING) {
 				tty_attributes(tty, &last, defaults, palette);
-				tty_cursor(tty, atx + ux, aty);
-				for (j = 0; j < gcp->data.width; j++) {
-					if (ux > nx)
-						break;
-					if (tty_check_overlay(tty, atx + ux,
-					    aty))
-						tty_putc(tty, ' ');
-					else {
-						tty_cursor(tty, atx + ux + 1,
-						    aty);
+				for (j = 0; j < OVERLAY_MAX_RANGES; j++) {
+					if (r.nx[j] == 0)
+						continue;
+					/* Effective width drawn so far. */
+					eux = r.px[j] - atx;
+					if (eux < nx) {
+						tty_cursor(tty, r.px[j], aty);
+						nxx = nx - eux;
+						if (r.nx[j] > nxx)
+							r.nx[j] = nxx;
+						tty_repeat_space(tty, r.nx[j]);
+						ux = eux + r.nx[j];
 					}
-					ux++;
 				}
 			}
 		} else if (gcp->attr & GRID_ATTR_CHARSET) {
@@ -1926,7 +1957,8 @@ tty_cmd_cell(struct tty *tty, const struct tty_ctx *ctx)
 {
 	const struct grid_cell	*gcp = ctx->cell;
 	struct screen		*s = ctx->s;
-	u_int			 i, px, py;
+	struct overlay_ranges	 r;
+	u_int			 px, py, i, vis = 0;
 
 	px = ctx->xoff + ctx->ocx - ctx->wox;
 	py = ctx->yoff + ctx->ocy - ctx->woy;
@@ -1936,13 +1968,14 @@ tty_cmd_cell(struct tty *tty, const struct tty_ctx *ctx)
 
 	/* Handle partially obstructed wide characters. */
 	if (gcp->data.width > 1) {
-		for (i = 0; i < gcp->data.width; i++) {
-			if (!tty_check_overlay(tty, px + i, py)) {
-				tty_draw_line(tty, s, s->cx, s->cy,
+		tty_check_overlay_range(tty, px, py, gcp->data.width, &r);
+		for (i = 0; i < OVERLAY_MAX_RANGES; i++)
+			vis += r.nx[i];
+		if (vis < gcp->data.width) {
+			tty_draw_line(tty, s, s->cx, s->cy,
 				    gcp->data.width, px, py, &ctx->defaults,
 				    ctx->palette);
 				return;
-			}
 		}
 	}
 
@@ -1960,7 +1993,8 @@ tty_cmd_cell(struct tty *tty, const struct tty_ctx *ctx)
 void
 tty_cmd_cells(struct tty *tty, const struct tty_ctx *ctx)
 {
-	u_int	i, hide = 0;
+	struct overlay_ranges	r;
+	u_int			i, px;
 
 	if (!tty_is_visible(tty, ctx, ctx->ocx, ctx->ocy, ctx->num, 1))
 		return;
@@ -1985,18 +2019,15 @@ tty_cmd_cells(struct tty *tty, const struct tty_ctx *ctx)
 	tty_cursor_pane_unless_wrap(tty, ctx, ctx->ocx, ctx->ocy);
 
 	tty_attributes(tty, ctx->cell, &ctx->defaults, ctx->palette);
-	for (i = 0; i < ctx->num; i++) {
-		if (!tty_check_overlay(tty, tty->cx + i, tty->cy))
-			break;
-	}
-	tty_putn(tty, ctx->ptr, i, i);
-	for (; i < ctx->num; i++) {
-		if (tty_check_overlay(tty, tty->cx + hide, tty->cy))
-			break;
-		hide++;
+	px = tty->cx;
+	tty_check_overlay_range(tty, px, tty->cy, ctx->num, &r);
+	for (i = 0; i < OVERLAY_MAX_RANGES; i++) {
+		if (r.nx[i] == 0)
+			continue;
+		tty_cursor(tty, r.px[i], tty->cy);
+		tty_putn(tty, (char *)ctx->ptr + r.px[i] - px, r.nx[i],
+		    r.nx[i]);
 	}
-	tty_cursor(tty, tty->cx + hide, tty->cy);
-	tty_putn(tty, (char *)ctx->ptr + i, ctx->num - i, ctx->num - i);
 }
 
 void