From d3c3377f13fa4e08a74044ba721b88a64a358e98 Mon Sep 17 00:00:00 2001
From: Lohikar <lohikar@protonmail.com>
Date: Sat, 8 Jul 2017 16:25:12 -0500
Subject: [PATCH] Minor parallax performance tweaks (#2967)

Speeds up parallax's update-values proc a little, but not much.
---
 code/_onclick/hud/parallax.dm         | 50 +++++++++++++++------------
 code/modules/client/client defines.dm |  3 +-
 2 files changed, 29 insertions(+), 24 deletions(-)

diff --git a/code/_onclick/hud/parallax.dm b/code/_onclick/hud/parallax.dm
index a670da71e3c..6ba065620b0 100644
--- a/code/_onclick/hud/parallax.dm
+++ b/code/_onclick/hud/parallax.dm
@@ -4,6 +4,8 @@
 #define PARALLAX_IMAGE_WIDTH 8
 #define PARALLAX_IMAGE_TILES (PARALLAX_IMAGE_WIDTH**2)
 #define GRID_WIDTH 3
+#define PARALLAX_SCALED_WIDTH (PARALLAX_IMAGE_WIDTH*WORLD_ICON_SIZE)
+#define PARALLAX_SCALED_GRID_WIDTH (PARALLAX_SCALED_WIDTH*GRID_WIDTH)
 
 /obj/screen/parallax
 	var/base_offset_x = 0
@@ -81,10 +83,6 @@
 			if(bgobj.parallax_speed)
 				C.parallax_movable += parallax_layer
 
-	if(!C.parallax_offset.len)
-		C.parallax_offset["horizontal"] = 0
-		C.parallax_offset["vertical"] = 0
-
 	C.screen |= C.parallax_dustmaster
 
 /datum/hud/proc/update_parallax()
@@ -114,36 +112,40 @@
 	if(!SSparallax.parallax_initialized)
 		return
 
-	if(!(locate(/turf/space) in trange(C.view,get_turf(C.eye))) && !(locate(/turf/simulated/open) in trange(C.view,get_turf(C.eye))))
-		return
-
 	//ACTUALLY MOVING THE PARALLAX
-	var/turf/posobj = get_turf(C.eye)
+	var/turf/posobj = C.eye ? C.eye:loc : C.mob:loc
+	if (!isturf(posobj))
+		posobj = get_turf(posobj)
+
+	if(!(locate(/turf/space) in RANGE_TURFS(C.view, posobj)) && !(locate(/turf/simulated/open) in RANGE_TURFS(C.view, posobj)))
+		return
 
 	if(!C.previous_turf || (C.previous_turf.z != posobj.z))
 		C.previous_turf = posobj
 
 	//Doing it this way prevents parallax layers from "jumping" when you change Z-Levels.
-	var/offsetx = C.parallax_offset["horizontal"] + posobj.x - C.previous_turf.x
-	var/offsety = C.parallax_offset["vertical"] + posobj.y - C.previous_turf.y
-	C.parallax_offset["horizontal"] = offsetx
-	C.parallax_offset["vertical"] = offsety
+	C.parallax_offset_x += posobj.x - C.previous_turf.x
+	C.parallax_offset_y += posobj.y - C.previous_turf.y
 
 	C.previous_turf = posobj
 
-	for(var/obj/screen/parallax/bgobj in C.parallax_movable)
-		var/accumulated_offset_x = bgobj.base_offset_x - round(offsetx * bgobj.parallax_speed * C.prefs.parallax_speed)
-		var/accumulated_offset_y = bgobj.base_offset_y - round(offsety * bgobj.parallax_speed * C.prefs.parallax_speed)
+	var/offsetx = C.parallax_offset_x * C.prefs.parallax_speed
+	var/offsety = C.parallax_offset_y * C.prefs.parallax_speed
 
-		if(accumulated_offset_x > PARALLAX_IMAGE_WIDTH*WORLD_ICON_SIZE)
-			accumulated_offset_x -= PARALLAX_IMAGE_WIDTH*WORLD_ICON_SIZE*GRID_WIDTH //3x3 grid, 15 tiles * 64 icon_size * 3 grid size
-		if(accumulated_offset_x < -(PARALLAX_IMAGE_WIDTH*WORLD_ICON_SIZE*2))
-			accumulated_offset_x += PARALLAX_IMAGE_WIDTH*WORLD_ICON_SIZE*GRID_WIDTH
+	for(var/thing in C.parallax_movable)
+		var/obj/screen/parallax/bgobj = thing
+		var/accumulated_offset_x = bgobj.base_offset_x - round(offsetx * bgobj.parallax_speed)
+		var/accumulated_offset_y = bgobj.base_offset_y - round(offsety * bgobj.parallax_speed)
 
-		if(accumulated_offset_y > PARALLAX_IMAGE_WIDTH*WORLD_ICON_SIZE)
-			accumulated_offset_y -= PARALLAX_IMAGE_WIDTH*WORLD_ICON_SIZE*GRID_WIDTH
-		if(accumulated_offset_y < -(PARALLAX_IMAGE_WIDTH*WORLD_ICON_SIZE*2))
-			accumulated_offset_y += PARALLAX_IMAGE_WIDTH*WORLD_ICON_SIZE*GRID_WIDTH
+		if(accumulated_offset_x > PARALLAX_SCALED_WIDTH)
+			accumulated_offset_x -= PARALLAX_SCALED_GRID_WIDTH //3x3 grid, 15 tiles * 64 icon_size * 3 grid size
+		if(accumulated_offset_x < -(PARALLAX_SCALED_WIDTH*2))
+			accumulated_offset_x += PARALLAX_SCALED_GRID_WIDTH
+
+		if(accumulated_offset_y > PARALLAX_SCALED_WIDTH)
+			accumulated_offset_y -= PARALLAX_SCALED_GRID_WIDTH
+		if(accumulated_offset_y < -(PARALLAX_SCALED_WIDTH*2))
+			accumulated_offset_y += PARALLAX_SCALED_GRID_WIDTH
 
 		bgobj.screen_loc = "CENTER:[accumulated_offset_x],CENTER:[accumulated_offset_y]"
 
@@ -259,3 +261,5 @@
 #undef PARALLAX2_ICON_NUMBER
 #undef PARALLAX_IMAGE_WIDTH
 #undef PARALLAX_IMAGE_TILES
+#undef PARALLAX_SCALED_WIDTH
+#undef PARALLAX_SCALED_GRID_WIDTH
diff --git a/code/modules/client/client defines.dm b/code/modules/client/client defines.dm
index 9b227dd1865..3eb59afa59b 100644
--- a/code/modules/client/client defines.dm	
+++ b/code/modules/client/client defines.dm	
@@ -66,7 +66,8 @@
 		////////////
 	var/list/parallax = list()
 	var/list/parallax_movable = list()
-	var/list/parallax_offset = list()
+	var/parallax_offset_x = 0
+	var/parallax_offset_y = 0
 	var/turf/previous_turf = null
 	var/obj/screen/plane_master/parallax_master/parallax_master = null
 	var/obj/screen/plane_master/parallax_dustmaster/parallax_dustmaster = null