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/eval/input_spec.lua | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'test/functional/eval/input_spec.lua') diff --git a/test/functional/eval/input_spec.lua b/test/functional/eval/input_spec.lua index 82e75d7a8e..8c65297ac6 100644 --- a/test/functional/eval/input_spec.lua +++ b/test/functional/eval/input_spec.lua @@ -149,7 +149,7 @@ describe('input()', function() {EOB:~ }| {T:Foo>}Bar^ | ]]) - command('redraw!') + command('mode') screen:expect{grid=[[ | {EOB:~ }| @@ -165,7 +165,7 @@ describe('input()', function() {EOB:~ }| {T:Foo>}Ba^ | ]]) - command('redraw!') + command('mode') screen:expect{grid=[[ | {EOB:~ }| @@ -347,7 +347,7 @@ describe('inputdialog()', function() {EOB:~ }| {T:Foo>}Bar^ | ]]) - command('redraw!') + command('mode') screen:expect{grid=[[ | {EOB:~ }| @@ -363,7 +363,7 @@ describe('inputdialog()', function() {EOB:~ }| {T:Foo>}Ba^ | ]]) - command('redraw!') + command('mode') screen:expect{grid=[[ | {EOB:~ }| -- cgit