From 90a7aaff286b5bde4e93b9cb8e4675f3e9be5893 Mon Sep 17 00:00:00 2001
From: SkyratBot <59378654+SkyratBot@users.noreply.github.com>
Date: Sun, 12 Dec 2021 00:33:59 +0100
Subject: [PATCH] [MIRROR] Reduces the move delay buffer to 1 tick, fixes
 "Flash stepping" (Is that what the kids are calling it?) [MDB IGNORE]
 (#10013)

* Reduces the move delay buffer to 1 tick (#63332)

We've got this delay buffer behavior
Idea is basically, if we're just holding down the key, just keep adding to the old delay
This way, fractional move delays make sense

Was added in this commit 491bdac

When it was added, movement was triggered by verbs sent by the client
So we needed a big grace window to account for networking delay

Don't need that anymore cause we use keyLoop, so let's just cut it all the way down

Why?
Because right now if you somehow manage to input a move afer move_delay is up
but before the window runs out, you will be elidgable for a new move before you visually reach the tile

Got a dm from mothblocks about this last night, something about flash stepping? IDK I don't play here
Seems silly though, let's sweep this up

Oh and mothblocks owes me a pizza, please add this to the commit history so it can be certified as a part of the blockchain

* Reduces the move delay buffer to 1 tick, fixes "Flash stepping" (Is that what the kids are calling it?)

Co-authored-by: LemonInTheDark <58055496+LemonInTheDark@users.noreply.github.com>
---
 code/modules/mob/mob_movement.dm | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/code/modules/mob/mob_movement.dm b/code/modules/mob/mob_movement.dm
index 00885308073..7d75a7323e6 100644
--- a/code/modules/mob/mob_movement.dm
+++ b/code/modules/mob/mob_movement.dm
@@ -27,9 +27,6 @@
 		else
 			mob.control_object.forceMove(get_step(mob.control_object,direct))
 
-#define MOVEMENT_DELAY_BUFFER 0.75
-#define MOVEMENT_DELAY_BUFFER_DELTA 1.25
-
 /**
  * Move a client in a direction
  *
@@ -69,9 +66,9 @@
 /client/Move(new_loc, direct)
 	if(world.time < move_delay) //do not move anything ahead of this check please
 		return FALSE
-	else
-		next_move_dir_add = 0
-		next_move_dir_sub = 0
+	next_move_dir_add = 0
+	next_move_dir_sub = 0
+
 	var/old_move_delay = move_delay
 	move_delay = world.time + world.tick_lag //this is here because Move() can now be called mutiple times per tick
 	if(!mob || !mob.loc)
@@ -130,7 +127,11 @@
 	//We are now going to move
 	var/add_delay = mob.cached_multiplicative_slowdown
 	mob.set_glide_size(DELAY_TO_GLIDE_SIZE(add_delay * ( (NSCOMPONENT(direct) && EWCOMPONENT(direct)) ? SQRT_2 : 1 ) )) // set it now in case of pulled objects
-	if(old_move_delay + (add_delay*MOVEMENT_DELAY_BUFFER_DELTA) + MOVEMENT_DELAY_BUFFER > world.time)
+	//If the move was recent, count using old_move_delay
+	//We want fractional behavior and all
+	if(old_move_delay + world.tick_lag > world.time)
+		//Yes this makes smooth movement stutter if add_delay is too fractional
+		//Yes this is better then the alternative
 		move_delay = old_move_delay
 	else
 		move_delay = world.time
@@ -152,6 +153,7 @@
 
 	if((direct & (direct - 1)) && mob.loc == new_loc) //moved diagonally successfully
 		add_delay *= SQRT_2
+
 	mob.set_glide_size(DELAY_TO_GLIDE_SIZE(add_delay))
 	move_delay += add_delay
 	if(.) // If mob is null here, we deserve the runtime