From b642eac4503cc89cde01103f7bacca57cc9c1a2b Mon Sep 17 00:00:00 2001
From: Nicholas Marriott <nicholas.marriott@gmail.com>
Date: Thu, 5 Dec 2019 09:11:24 +0000
Subject: [PATCH] Redraw and scroll images and part of invalidating them.

---
 input.c         |  2 +-
 screen-redraw.c |  5 ++--
 screen-write.c  | 70 ++++++++++++++++++++++++++++++++++++++++++++-----
 tmux.h          |  4 ++-
 tty.c           | 32 ++++++++++++++++++++++
 5 files changed, 102 insertions(+), 11 deletions(-)

diff --git a/input.c b/input.c
index 0cf614ff..2f6c6006 100644
--- a/input.c
+++ b/input.c
@@ -2172,7 +2172,7 @@ input_dcs_dispatch(struct input_ctx *ictx)
 		si = sixel_parse(buf, len, w->xpixel, w->ypixel);
 		if (si != NULL) {
 			sixel_log(si);
-			screen_write_sixelimage(sctx, si);
+			screen_write_sixelimage(sctx, si, ictx->cell.cell.bg);
 		}
 	}
 
diff --git a/screen-redraw.c b/screen-redraw.c
index e7f4f077..03b784b1 100644
--- a/screen-redraw.c
+++ b/screen-redraw.c
@@ -578,7 +578,7 @@ screen_redraw_draw_pane(struct screen_redraw_ctx *ctx, struct window_pane *wp)
 	struct client	*c = ctx->c;
 	struct window	*w = c->session->curw->window;
 	struct tty	*tty = &c->tty;
-	struct screen	*s;
+	struct screen	*s = wp->screen;
 	u_int		 i, j, top, x, y, width;
 
 	log_debug("%s: %s @%u %%%u", __func__, c->name, w->id, wp->id);
@@ -590,7 +590,6 @@ screen_redraw_draw_pane(struct screen_redraw_ctx *ctx, struct window_pane *wp)
 	else
 		top = 0;
 
-	s = wp->screen;
 	for (j = 0; j < wp->sy; j++) {
 		if (wp->yoff + j < ctx->oy || wp->yoff + j >= ctx->oy + ctx->sy)
 			continue;
@@ -624,4 +623,6 @@ screen_redraw_draw_pane(struct screen_redraw_ctx *ctx, struct window_pane *wp)
 
 		tty_draw_line(tty, wp, s, i, j, width, x, y);
 	}
+
+	tty_draw_images(tty, wp, s);
 }
diff --git a/screen-write.c b/screen-write.c
index 2d376e66..d9a06473 100644
--- a/screen-write.c
+++ b/screen-write.c
@@ -1044,6 +1044,8 @@ screen_write_linefeed(struct screen_write_ctx *ctx, int wrapped, u_int bg)
 	struct screen		*s = ctx->s;
 	struct grid		*gd = s->grid;
 	struct grid_line	*gl;
+	int			 redraw;
+	u_int			 rupper = s->rupper, rlower = s->rlower;
 
 	gl = grid_get_line(gd, gd->hsize + s->cy);
 	if (wrapped)
@@ -1052,15 +1054,21 @@ screen_write_linefeed(struct screen_write_ctx *ctx, int wrapped, u_int bg)
 		gl->flags &= ~GRID_LINE_WRAPPED;
 
 	log_debug("%s: at %u,%u (region %u-%u)", __func__, s->cx, s->cy,
-	    s->rupper, s->rlower);
+	    rupper, rlower);
 
 	if (bg != ctx->bg) {
 		screen_write_collect_flush(ctx, 1);
 		ctx->bg = bg;
 	}
 
-	if (s->cy == s->rlower) {
-		grid_view_scroll_region_up(gd, s->rupper, s->rlower, bg);
+	if (s->cy == rlower) {
+		if (rlower == screen_size_y(s) - 1)
+			redraw = image_scroll_up(s, 1);
+		else
+			redraw = image_check_line(s, rupper, rlower - rupper);
+		if (redraw && ctx->wp != NULL)
+			ctx->wp->flags |= PANE_REDRAW;
+		grid_view_scroll_region_up(gd, rupper, rlower, bg);
 		screen_write_collect_scroll(ctx);
 		ctx->scrolled++;
 	} else if (s->cy < screen_size_y(s) - 1)
@@ -1085,6 +1093,9 @@ screen_write_scrollup(struct screen_write_ctx *ctx, u_int lines, u_int bg)
 		ctx->bg = bg;
 	}
 
+	if (image_scroll_up(s, lines) && ctx->wp != NULL)
+		ctx->wp->flags |= PANE_REDRAW;
+
 	for (i = 0; i < lines; i++) {
 		grid_view_scroll_region_up(gd, s->rupper, s->rlower, bg);
 		screen_write_collect_scroll(ctx);
@@ -1109,6 +1120,9 @@ screen_write_scrolldown(struct screen_write_ctx *ctx, u_int lines, u_int bg)
 	else if (lines > s->rlower - s->rupper + 1)
 		lines = s->rlower - s->rupper + 1;
 
+	if (image_free_all(s) && ctx->wp != NULL)
+		ctx->wp->flags |= PANE_REDRAW;
+
 	for (i = 0; i < lines; i++)
 		grid_view_scroll_region_down(gd, s->rupper, s->rlower, bg);
 
@@ -1326,6 +1340,9 @@ screen_write_collect_end(struct screen_write_ctx *ctx)
 		}
 	}
 
+	if (image_check_area(s, s->cx, s->cy, ci->used, 1) && ctx->wp != NULL)
+		ctx->wp->flags |= PANE_REDRAW;
+
 	grid_view_set_cells(s->grid, s->cx, s->cy, &ci->gc, ci->data, ci->used);
 	screen_write_set_cursor(ctx, s->cx + ci->used, -1);
 
@@ -1674,16 +1691,55 @@ screen_write_rawstring(struct screen_write_ctx *ctx, u_char *str, u_int len)
 
 /* Write a SIXEL image. */
 void
-screen_write_sixelimage(struct screen_write_ctx *ctx, struct sixel_image *si)
+screen_write_sixelimage(struct screen_write_ctx *ctx, struct sixel_image *si,
+    u_int bg)
 {
-	struct screen	*s = ctx->s;
-	struct tty_ctx	 ttyctx;
+	struct screen		*s = ctx->s;
+	struct grid		*gd = s->grid;
+	struct tty_ctx		 ttyctx;
+	u_int			 x, y, sx, sy, cx = s->cx, cy = s->cy, i, lines;
+	struct sixel_image	*new;
+
+	sixel_size_in_cells(si, &x, &y);
+	if (x > screen_size_x(s) || y > screen_size_y(s)) {
+		if (x > screen_size_x(s) - cx)
+			sx = screen_size_x(s) - cx;
+		else
+			sx = x;
+		if (y > screen_size_y(s) - 1)
+			sy = screen_size_y(s) - 1;
+		else
+			sy = y;
+		new = sixel_scale(si, 0, 0, 0, y - sy, sx, sy, 1);
+		sixel_free(si);
+		si = new;
+		sixel_size_in_cells(si, &x, &y);
+	}
+
+	sy = screen_size_y(s) - cy;
+	if (sy < y) {
+		lines = y - sy + 1;
+		if (image_scroll_up(s, lines) && ctx->wp != NULL)
+			ctx->wp->flags |= PANE_REDRAW;
+		for (i = 0; i < lines; i++) {
+			grid_view_scroll_region_up(gd, 0, screen_size_y(s) - 1,
+			    bg);
+			screen_write_collect_scroll(ctx);
+		}
+		ctx->scrolled += lines;
+		if (lines > cy)
+			screen_write_cursormove(ctx, -1, 0, 0);
+		else
+			screen_write_cursormove(ctx, -1, cy - lines, 0);
+	}
+	screen_write_collect_flush(ctx, 0);
 
 	image_store(s, si);
 
 	screen_write_initctx(ctx, &ttyctx);
 	ttyctx.ptr = si;
 
-	screen_write_collect_flush(ctx, 0);
 	tty_write(tty_cmd_sixelimage, &ttyctx);
+
+	screen_write_cursormove(ctx, 0, cy + y, 0);
 }
diff --git a/tmux.h b/tmux.h
index 48b36354..79c08491 100644
--- a/tmux.h
+++ b/tmux.h
@@ -1963,6 +1963,7 @@ 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_images(struct tty *, struct window_pane *, struct screen *);
 int	tty_open(struct tty *, char **);
 void	tty_close(struct tty *);
 void	tty_free(struct tty *);
@@ -2377,7 +2378,8 @@ 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_sixelimage(struct screen_write_ctx *, struct sixel_image *);
+void	 screen_write_sixelimage(struct screen_write_ctx *,
+	     struct sixel_image *, u_int);
 
 /* screen-redraw.c */
 void	 screen_redraw_screen(struct client *);
diff --git a/tty.c b/tty.c
index e5e7e78a..e69d9c38 100644
--- a/tty.c
+++ b/tty.c
@@ -1378,6 +1378,38 @@ tty_draw_line(struct tty *tty, struct window_pane *wp, struct screen *s,
 	tty_update_mode(tty, tty->mode, s);
 }
 
+void
+tty_draw_images(struct tty *tty, struct window_pane *wp, struct screen *s)
+{
+	struct client	*c = tty->client;
+	struct image	*im;
+	struct tty_ctx	 ttyctx;
+
+	TAILQ_FOREACH(im, &s->images, entry) {
+		memset(&ttyctx, 0, sizeof ttyctx);
+
+		ttyctx.wp = wp;
+
+		ttyctx.ocx = im->px;
+		ttyctx.ocy = im->py;
+
+		ttyctx.orlower = s->rlower;
+		ttyctx.orupper = s->rupper;
+
+		ttyctx.bigger = tty_window_offset(&c->tty, &ttyctx.ox,
+		    &ttyctx.oy, &ttyctx.sx, &ttyctx.sy);
+
+		ttyctx.xoff = wp->xoff;
+		ttyctx.yoff = wp->yoff;
+
+		if (status_at_line(c) == 0)
+			ttyctx.yoff += status_line_size(c);
+
+		ttyctx.ptr = im->data;
+		tty_cmd_sixelimage(tty, &ttyctx);
+	}
+}
+
 static int
 tty_client_ready(struct client *c, struct window_pane *wp)
 {