From 8ef6997e2d90808dec033373c96dda68843af12e Mon Sep 17 00:00:00 2001 From: Bram Moolenaar Date: Sun, 3 Apr 2022 13:23:22 +0100 Subject: patch 8.2.4673: redrawing a split window is slow when using CTRL-F and CTRL-B Problem: Redrawing a vertically split window is slow when using CTRL-F and CTRL-B. Solution: When deciding on USE_REDRAW bail out if scrolling more than three lines. (issue #8002) --- src/screen.c | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) (limited to 'src/screen.c') diff --git a/src/screen.c b/src/screen.c index 3713f49fd..7caf2995f 100644 --- a/src/screen.c +++ b/src/screen.c @@ -3707,7 +3707,15 @@ screen_ins_lines( */ result_empty = (row + line_count >= end); if (wp != NULL && wp->w_width != Columns && *T_CSV == NUL) + { + // Avoid that lines are first cleared here and then redrawn, which + // results in many characters updated twice. This happens with CTRL-F + // in a vertically split window. With line-by-line scrolling + // USE_REDRAW should be faster. + if (line_count > 3) + return FAIL; type = USE_REDRAW; + } else if (can_clear(T_CD) && result_empty) type = USE_T_CD; else if (*T_CAL != NUL && (line_count > 1 || *T_AL == NUL)) @@ -3879,7 +3887,7 @@ screen_del_lines( int end, int force, // even when line_count > p_ttyscroll int clear_attr, // used for clearing lines - win_T *wp UNUSED) // NULL or window to use width from + win_T *wp) // NULL or window to use width from { int j; int i; @@ -3934,7 +3942,15 @@ screen_del_lines( * 6. redraw the characters from ScreenLines[]. */ if (wp != NULL && wp->w_width != Columns && *T_CSV == NUL) + { + // Avoid that lines are first cleared here and then redrawn, which + // results in many characters updated twice. This happens with CTRL-F + // in a vertically split window. With line-by-line scrolling + // USE_REDRAW should be faster. + if (line_count > 3) + return FAIL; type = USE_REDRAW; + } else if (can_clear(T_CD) && result_empty) type = USE_T_CD; else if (row == 0 && ( -- cgit v1.2.1