[NO GBP] Fixes black character previews (#91616)

code/__DEFINES/layers.dm

@@ -59,15 +59,17 @@
 #define EMISSIVE_SPACE_LAYER 3
 #define EMISSIVE_WALL_LAYER 4
 
-#define EMISSIVE_BLOOM_PLATE 15
+#define EMISSIVE_BLOOM_MASK_PLATE 15
+#define EMISSIVE_BLOOM_MASK_TARGET "*EMISSIVE_BLOOM_MASK_PLATE"
+#define EMISSIVE_BLOOM_PLATE 16
 
 //-------------------- Game plane assembly ---------------------
 
-#define RENDER_PLANE_GAME 16
+#define RENDER_PLANE_GAME 17
 /// If fov is enabled we'll draw game to this and do shit to it
-#define RENDER_PLANE_GAME_MASKED 17
+#define RENDER_PLANE_GAME_MASKED 18
 /// The bit of the game plane that is let alone is sent here
-#define RENDER_PLANE_GAME_UNMASKED 18
+#define RENDER_PLANE_GAME_UNMASKED 19
 
 //-------------------- Lighting ---------------------
 

code/_onclick/hud/rendering/plane_masters/plane_master_subtypes.dm

@@ -345,7 +345,8 @@
 	add_relay_to(GET_NEW_PLANE(EMISSIVE_RENDER_PLATE, offset), relay_color = list(1,1,1,0, 1,1,1,0, 1,1,1,0, 0,0,0,1, 0,0,0,0))
 	/// But for the bloom plate we convert only the red color into full white, this way we can have emissives in green channel unaffected by bloom
 	/// which allows us to selectively bloom only a part of our emissives
-	add_relay_to(GET_NEW_PLANE(EMISSIVE_BLOOM_PLATE, offset), relay_color = list(1,1,1,0, 0,0,0,0, 0,0,0,0, 0,0,0,1, 0,0,0,0))
+	add_relay_to(GET_NEW_PLANE(EMISSIVE_BLOOM_PLATE, offset), relay_color = list(255,255,255,0, 0,0,0,0, 0,0,0,0, 0,0,0,1, 0,0,0,0))
+	add_relay_to(GET_NEW_PLANE(EMISSIVE_BLOOM_MASK_PLATE, offset), relay_color = list(1,1,1,1, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0))
 
 /atom/movable/screen/plane_master/pipecrawl
 	name = "Pipecrawl"

code/_onclick/hud/rendering/render_plate.dm

@@ -376,12 +376,20 @@
 	plane = RENDER_PLANE_NON_GAME
 	render_relay_planes = list(RENDER_PLANE_MASTER)
 
+/atom/movable/screen/plane_master/rendering_plate/emissive_bloom_mask
+	name = "Emissive bloom mask plate"
+	documentation = "A holder plate used purely as a way to full-white bloom emissives before applying them as a mask onto the emissive bloom plate."
+	plane = EMISSIVE_BLOOM_MASK_PLATE
+	appearance_flags = PLANE_MASTER|NO_CLIENT_COLOR
+	mouse_opacity = MOUSE_OPACITY_TRANSPARENT
+	render_relay_planes = list()
+	render_target = EMISSIVE_BLOOM_MASK_TARGET
+	critical = PLANE_CRITICAL_DISPLAY
+
 /atom/movable/screen/plane_master/rendering_plate/emissive_bloom
 	name = "Emissive bloom plate"
-	documentation = "Plate used to bloom emissives before adding them onto the overlay lighting plane. This relies on game rendering plate,\
+	documentation = "Plate used to bloom emissives before adding them onto the overlay lighting plane. We do this by multiplying the game plate\
-		which assembles all in-world planes affected by lighting, is above the emissive plane - which allows us to bypass having to fullbright\
+		onto a fullbright emissive, then alpha masking it by emissive's color to solve the problem of blockers, both alone and covered by emissives."
-		the emissive plane on a separate plate before alpha masking the rendering plate copy via multiplying fullbright emissive created here\
-		with the game plate, which technically achieves the same effect. Odd, but it works, and is significantly graphically cheaper."
 	plane = EMISSIVE_BLOOM_PLATE
 	appearance_flags = PLANE_MASTER|NO_CLIENT_COLOR
 	mouse_opacity = MOUSE_OPACITY_TRANSPARENT
@@ -391,7 +399,8 @@
 
 /atom/movable/screen/plane_master/rendering_plate/emissive_bloom/Initialize(mapload, datum/hud/hud_owner, datum/plane_master_group/home, offset)
 	. = ..()
-	add_filter("emissive_bloom", 1, bloom_filter(threshold = COLOR_BLACK, size = 2, offset = 1))
+	add_filter("emissive_mask", 1, alpha_mask_filter(render_source = OFFSET_RENDER_TARGET(EMISSIVE_BLOOM_MASK_TARGET, offset)))
+	add_filter("emissive_bloom", 2, bloom_filter(threshold = COLOR_BLACK, size = 2, offset = 1))
 
 /atom/movable/screen/plane_master/rendering_plate/turf_lighting
 	name = "Turf lighting post-processing plate"