patch 8.0.0956: scrolling in a terminal window has flicker

Problem:    Scrolling in a terminal hwindow as flicker when the Normal
            background differs from the terminal window background.
Solution:   Set the attribute to clear with.

1 files changed, 180 insertions, 166 deletions

diff --git a/src/terminal.c b/src/terminal.c
index 304a7ba43..5878db793 100644
--- a/src/terminal.c
+++ b/src/terminal.c
@@ -1483,6 +1483,169 @@ may_toggle_cursor(term_T *term)
     }
 }
 
+/*
+ * Reverse engineer the RGB value into a cterm color index.
+ * First color is 1.  Return 0 if no match found.
+ */
+    static int
+color2index(VTermColor *color, int fg, int *boldp)
+{
+    int red = color->red;
+    int blue = color->blue;
+    int green = color->green;
+
+    /* The argument for lookup_color() is for the color_names[] table. */
+    if (red == 0)
+    {
+	if (green == 0)
+	{
+	    if (blue == 0)
+		return lookup_color(0, fg, boldp) + 1; /* black */
+	    if (blue == 224)
+		return lookup_color(1, fg, boldp) + 1; /* dark blue */
+	}
+	else if (green == 224)
+	{
+	    if (blue == 0)
+		return lookup_color(2, fg, boldp) + 1; /* dark green */
+	    if (blue == 224)
+		return lookup_color(3, fg, boldp) + 1; /* dark cyan */
+	}
+    }
+    else if (red == 224)
+    {
+	if (green == 0)
+	{
+	    if (blue == 0)
+		return lookup_color(4, fg, boldp) + 1; /* dark red */
+	    if (blue == 224)
+		return lookup_color(5, fg, boldp) + 1; /* dark magenta */
+	}
+	else if (green == 224)
+	{
+	    if (blue == 0)
+		return lookup_color(6, fg, boldp) + 1; /* dark yellow / brown */
+	    if (blue == 224)
+		return lookup_color(8, fg, boldp) + 1; /* white / light grey */
+	}
+    }
+    else if (red == 128)
+    {
+	if (green == 128 && blue == 128)
+	    return lookup_color(12, fg, boldp) + 1; /* high intensity black / dark grey */
+    }
+    else if (red == 255)
+    {
+	if (green == 64)
+	{
+	    if (blue == 64)
+		return lookup_color(20, fg, boldp) + 1;  /* light red */
+	    if (blue == 255)
+		return lookup_color(22, fg, boldp) + 1;  /* light magenta */
+	}
+	else if (green == 255)
+	{
+	    if (blue == 64)
+		return lookup_color(24, fg, boldp) + 1;  /* yellow */
+	    if (blue == 255)
+		return lookup_color(26, fg, boldp) + 1;  /* white */
+	}
+    }
+    else if (red == 64)
+    {
+	if (green == 64)
+	{
+	    if (blue == 255)
+		return lookup_color(14, fg, boldp) + 1;  /* light blue */
+	}
+	else if (green == 255)
+	{
+	    if (blue == 64)
+		return lookup_color(16, fg, boldp) + 1;  /* light green */
+	    if (blue == 255)
+		return lookup_color(18, fg, boldp) + 1;  /* light cyan */
+	}
+    }
+    if (t_colors >= 256)
+    {
+	if (red == blue && red == green)
+	{
+	    /* 24-color greyscale */
+	    static int cutoff[23] = {
+		0x05, 0x10, 0x1B, 0x26, 0x31, 0x3C, 0x47, 0x52,
+		0x5D, 0x68, 0x73, 0x7F, 0x8A, 0x95, 0xA0, 0xAB,
+		0xB6, 0xC1, 0xCC, 0xD7, 0xE2, 0xED, 0xF9};
+	    int i;
+
+	    for (i = 0; i < 23; ++i)
+		if (red < cutoff[i])
+		    return i + 233;
+	    return 256;
+	}
+
+	/* 216-color cube */
+	return 17 + ((red + 25) / 0x33) * 36
+	          + ((green + 25) / 0x33) * 6
+		  + (blue + 25) / 0x33;
+    }
+    return 0;
+}
+
+/*
+ * Convert the attributes of a vterm cell into an attribute index.
+ */
+    static int
+cell2attr(VTermScreenCellAttrs cellattrs, VTermColor cellfg, VTermColor cellbg)
+{
+    int attr = 0;
+
+    if (cellattrs.bold)
+	attr |= HL_BOLD;
+    if (cellattrs.underline)
+	attr |= HL_UNDERLINE;
+    if (cellattrs.italic)
+	attr |= HL_ITALIC;
+    if (cellattrs.strike)
+	attr |= HL_STANDOUT;
+    if (cellattrs.reverse)
+	attr |= HL_INVERSE;
+
+#ifdef FEAT_GUI
+    if (gui.in_use)
+    {
+	guicolor_T fg, bg;
+
+	fg = gui_mch_get_rgb_color(cellfg.red, cellfg.green, cellfg.blue);
+	bg = gui_mch_get_rgb_color(cellbg.red, cellbg.green, cellbg.blue);
+	return get_gui_attr_idx(attr, fg, bg);
+    }
+    else
+#endif
+#ifdef FEAT_TERMGUICOLORS
+    if (p_tgc)
+    {
+	guicolor_T fg, bg;
+
+	fg = gui_get_rgb_color_cmn(cellfg.red, cellfg.green, cellfg.blue);
+	bg = gui_get_rgb_color_cmn(cellbg.red, cellbg.green, cellbg.blue);
+
+	return get_tgc_attr_idx(attr, fg, bg);
+    }
+    else
+#endif
+    {
+	int bold = MAYBE;
+	int fg = color2index(&cellfg, TRUE, &bold);
+	int bg = color2index(&cellbg, FALSE, &bold);
+
+	/* with 8 colors set the bold attribute to get a bright foreground */
+	if (bold == TRUE)
+	    attr |= HL_BOLD;
+	return get_cterm_attr_idx(attr, fg, bg);
+    }
+    return 0;
+}
+
     static int
 handle_damage(VTermRect rect, void *user)
 {
@@ -1498,18 +1661,32 @@ handle_damage(VTermRect rect, void *user)
 handle_moverect(VTermRect dest, VTermRect src, void *user)
 {
     term_T	*term = (term_T *)user;
-    win_T	*wp;
 
+    /* Scrolling up is done much more efficiently by deleting lines instead of
+     * redrawing the text. */
     if (dest.start_col == src.start_col
 	    && dest.end_col == src.end_col
 	    && dest.start_row < src.start_row)
+    {
+	win_T	    *wp;
+	VTermColor  fg, bg;
+	VTermScreenCellAttrs attr;
+	int	    clear_attr;
+
+	/* Set the color to clear lines with. */
+	vterm_state_get_default_colors(vterm_obtain_state(term->tl_vterm),
+								     &fg, &bg);
+	vim_memset(&attr, 0, sizeof(attr));
+	clear_attr = cell2attr(attr, fg, bg);
+
 	FOR_ALL_WINDOWS(wp)
 	{
 	    if (wp->w_buffer == term->tl_buffer)
-		/* scrolling up is much more efficient when deleting lines */
 		win_del_lines(wp, dest.start_row,
-				 src.start_row - dest.start_row, FALSE, FALSE);
+				 src.start_row - dest.start_row, FALSE, FALSE,
+				 clear_attr);
 	}
+    }
     redraw_buf_later(term->tl_buffer, NOT_VALID);
     return 1;
 }
@@ -1774,169 +1951,6 @@ term_channel_closed(channel_T *ch)
 }
 
 /*
- * Reverse engineer the RGB value into a cterm color index.
- * First color is 1.  Return 0 if no match found.
- */
-    static int
-color2index(VTermColor *color, int fg, int *boldp)
-{
-    int red = color->red;
-    int blue = color->blue;
-    int green = color->green;
-
-    /* The argument for lookup_color() is for the color_names[] table. */
-    if (red == 0)
-    {
-	if (green == 0)
-	{
-	    if (blue == 0)
-		return lookup_color(0, fg, boldp) + 1; /* black */
-	    if (blue == 224)
-		return lookup_color(1, fg, boldp) + 1; /* dark blue */
-	}
-	else if (green == 224)
-	{
-	    if (blue == 0)
-		return lookup_color(2, fg, boldp) + 1; /* dark green */
-	    if (blue == 224)
-		return lookup_color(3, fg, boldp) + 1; /* dark cyan */
-	}
-    }
-    else if (red == 224)
-    {
-	if (green == 0)
-	{
-	    if (blue == 0)
-		return lookup_color(4, fg, boldp) + 1; /* dark red */
-	    if (blue == 224)
-		return lookup_color(5, fg, boldp) + 1; /* dark magenta */
-	}
-	else if (green == 224)
-	{
-	    if (blue == 0)
-		return lookup_color(6, fg, boldp) + 1; /* dark yellow / brown */
-	    if (blue == 224)
-		return lookup_color(8, fg, boldp) + 1; /* white / light grey */
-	}
-    }
-    else if (red == 128)
-    {
-	if (green == 128 && blue == 128)
-	    return lookup_color(12, fg, boldp) + 1; /* high intensity black / dark grey */
-    }
-    else if (red == 255)
-    {
-	if (green == 64)
-	{
-	    if (blue == 64)
-		return lookup_color(20, fg, boldp) + 1;  /* light red */
-	    if (blue == 255)
-		return lookup_color(22, fg, boldp) + 1;  /* light magenta */
-	}
-	else if (green == 255)
-	{
-	    if (blue == 64)
-		return lookup_color(24, fg, boldp) + 1;  /* yellow */
-	    if (blue == 255)
-		return lookup_color(26, fg, boldp) + 1;  /* white */
-	}
-    }
-    else if (red == 64)
-    {
-	if (green == 64)
-	{
-	    if (blue == 255)
-		return lookup_color(14, fg, boldp) + 1;  /* light blue */
-	}
-	else if (green == 255)
-	{
-	    if (blue == 64)
-		return lookup_color(16, fg, boldp) + 1;  /* light green */
-	    if (blue == 255)
-		return lookup_color(18, fg, boldp) + 1;  /* light cyan */
-	}
-    }
-    if (t_colors >= 256)
-    {
-	if (red == blue && red == green)
-	{
-	    /* 24-color greyscale */
-	    static int cutoff[23] = {
-		0x05, 0x10, 0x1B, 0x26, 0x31, 0x3C, 0x47, 0x52,
-		0x5D, 0x68, 0x73, 0x7F, 0x8A, 0x95, 0xA0, 0xAB,
-		0xB6, 0xC1, 0xCC, 0xD7, 0xE2, 0xED, 0xF9};
-	    int i;
-
-	    for (i = 0; i < 23; ++i)
-		if (red < cutoff[i])
-		    return i + 233;
-	    return 256;
-	}
-
-	/* 216-color cube */
-	return 17 + ((red + 25) / 0x33) * 36
-	          + ((green + 25) / 0x33) * 6
-		  + (blue + 25) / 0x33;
-    }
-    return 0;
-}
-
-/*
- * Convert the attributes of a vterm cell into an attribute index.
- */
-    static int
-cell2attr(VTermScreenCellAttrs cellattrs, VTermColor cellfg, VTermColor cellbg)
-{
-    int attr = 0;
-
-    if (cellattrs.bold)
-	attr |= HL_BOLD;
-    if (cellattrs.underline)
-	attr |= HL_UNDERLINE;
-    if (cellattrs.italic)
-	attr |= HL_ITALIC;
-    if (cellattrs.strike)
-	attr |= HL_STANDOUT;
-    if (cellattrs.reverse)
-	attr |= HL_INVERSE;
-
-#ifdef FEAT_GUI
-    if (gui.in_use)
-    {
-	guicolor_T fg, bg;
-
-	fg = gui_mch_get_rgb_color(cellfg.red, cellfg.green, cellfg.blue);
-	bg = gui_mch_get_rgb_color(cellbg.red, cellbg.green, cellbg.blue);
-	return get_gui_attr_idx(attr, fg, bg);
-    }
-    else
-#endif
-#ifdef FEAT_TERMGUICOLORS
-    if (p_tgc)
-    {
-	guicolor_T fg, bg;
-
-	fg = gui_get_rgb_color_cmn(cellfg.red, cellfg.green, cellfg.blue);
-	bg = gui_get_rgb_color_cmn(cellbg.red, cellbg.green, cellbg.blue);
-
-	return get_tgc_attr_idx(attr, fg, bg);
-    }
-    else
-#endif
-    {
-	int bold = MAYBE;
-	int fg = color2index(&cellfg, TRUE, &bold);
-	int bg = color2index(&cellbg, FALSE, &bold);
-
-	/* with 8 colors set the bold attribute to get a bright foreground */
-	if (bold == TRUE)
-	    attr |= HL_BOLD;
-	return get_cterm_attr_idx(attr, fg, bg);
-    }
-    return 0;
-}
-
-/*
  * Called to update a window that contains an active terminal.
  * Returns FAIL when there is no terminal running in this window or in
  * Terminal-Normal mode.