patch 9.0.0892: may redraw when not needed
Problem: May redraw when not needed, causing slow scrolling.
Solution: Do not redraw when w_skipcol doesn't change. When w_skipcol
changes only redraw from the top. (issue #11559)
diff --git a/src/move.c b/src/move.c
index e255bd6..3a5f806 100644
--- a/src/move.c
+++ b/src/move.c
@@ -202,6 +202,23 @@
#endif
/*
+ * Set curwin->s_skipcol to zero and redraw later if needed.
+ */
+ static void
+reset_skipcol(void)
+{
+ if (curwin->w_skipcol != 0)
+ {
+ curwin->w_skipcol = 0;
+
+ // Should use the least expensive way that displays all that changed.
+ // UPD_NOT_VALID is too expensive, UPD_REDRAW_TOP does not redraw
+ // enough when the top line gets another screen line.
+ redraw_later(UPD_SOME_VALID);
+ }
+}
+
+/*
* Update curwin->w_topline and redraw if necessary.
* Used to update the screen before printing a message.
*/
@@ -458,13 +475,9 @@
)
{
dollar_vcol = -1;
- if (curwin->w_skipcol != 0)
- {
- curwin->w_skipcol = 0;
- redraw_later(UPD_NOT_VALID);
- }
- else
- redraw_later(UPD_VALID);
+ redraw_later(UPD_VALID);
+ reset_skipcol();
+
// May need to set w_skipcol when cursor in w_topline.
if (curwin->w_cursor.lnum == curwin->w_topline)
validate_cursor();
@@ -1319,7 +1332,7 @@
else if (!curwin->w_p_sms)
curwin->w_skipcol = 0;
if (prev_skipcol != curwin->w_skipcol)
- redraw_later(UPD_NOT_VALID);
+ redraw_later(UPD_SOME_VALID);
#ifdef FEAT_SYN_HL
redraw_for_cursorcolumn(curwin);
@@ -1849,11 +1862,7 @@
if (curwin->w_cline_height == curwin->w_height)
{
// the line just fits in the window, don't scroll
- if (curwin->w_skipcol != 0)
- {
- curwin->w_skipcol = 0;
- redraw_later(UPD_NOT_VALID);
- }
+ reset_skipcol();
return;
}
@@ -2302,10 +2311,7 @@
#endif
// TODO: if the line doesn't fit may optimize w_skipcol
if (curwin->w_topline == curwin->w_cursor.lnum)
- {
- curwin->w_skipcol = 0;
- redraw_later(UPD_NOT_VALID);
- }
+ reset_skipcol();
if (curwin->w_topline != old_topline
|| curwin->w_skipcol != old_skipcol
#ifdef FEAT_DIFF
@@ -2737,7 +2743,7 @@
if (curwin->w_cline_height == curwin->w_height)
{
// The cursor line just fits in the window, don't scroll.
- curwin->w_skipcol = 0;
+ reset_skipcol();
return;
}
// TODO: If the cursor line doesn't fit in the window then only adjust