From e598811e76a4ee6666b680545097fb06b0ba59aa Mon Sep 17 00:00:00 2001 From: Björn Linse Date: Sat, 20 Oct 2018 23:43:47 +0200 Subject: ui: disable clearing almost everywhere Avoid clearing the screen in most situations. NOT_VALID should be equivalent to CLEAR unless some external force messed up the terminal, for these situations and :mode will still clear the screen. Also eliminate some obsolete code in screen.c, that dealt with that in vim drawing window 1 can mess up window 2, but this never happens in nvim. But what about slow terminals? There is two common meanings in which a terminal is said to be "slow": Most commonly (and in the sense of vim:s nottyfast) it means low bandwidth for sending bytes from nvim to the terminal. If the screen is very similar before and after the update_screen(CLEAR) this change should reduce bandwidth. If the screen is quite different, but there is no new regions of contiguous whitespace, clearing doesn't reduce bandwidth significantly. If the new screen contains a lot of whitespace, it will depend of if vsplits are used or not: as long as there is no vsplits, ce is used to cheaply clear the rest of the line, so full-screen clear is not needed to reduce bandwith. However a left vsplit currently needs to be padded with whitespace all the way to the separator. It is possible ec (clear N chars) can be used to reduce bandwidth here if this is a problem. (All of this assumes that one doesn't set Normal guibg=... on a non-BCE terminal, if you do you are doomed regardless of this change). Slow can also mean that drawing pixels on the screen is slow. E-ink screens is a recent example. Avoiding clearing and redrawing the unchanged part of the screen will always improve performance in these cases. --- test/functional/ui/highlight_spec.lua | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'test/functional/ui/highlight_spec.lua') diff --git a/test/functional/ui/highlight_spec.lua b/test/functional/ui/highlight_spec.lua index 50df3c3606..55fc343e4c 100644 --- a/test/functional/ui/highlight_spec.lua +++ b/test/functional/ui/highlight_spec.lua @@ -122,7 +122,7 @@ describe('highlight defaults', function() {0:~ }| {0:~ }| {2:[No Name] }| - | + :vsp | ]]) -- navigate to verify that the attributes are properly moved feed('j') @@ -140,7 +140,7 @@ describe('highlight defaults', function() {0:~ }| {0:~ }| {1:[No Name] }| - | + :vsp | ]]) -- note that when moving to a window with small width nvim will increase -- the width of the new active window at the expense of a inactive window @@ -160,7 +160,7 @@ describe('highlight defaults', function() {0:~ }| {0:~ }| {2:[No Name] }| - | + :vsp | ]]) feed('l') screen:expect([[ @@ -177,7 +177,7 @@ describe('highlight defaults', function() {0:~ }| {0:~ }| {2:[No Name] }| - | + :vsp | ]]) feed('hh') screen:expect([[ @@ -194,7 +194,7 @@ describe('highlight defaults', function() {0:~ }| {0:~ }| {2:[No Name] }| - | + :vsp | ]]) end) -- cgit