From 550f1d3182d443f2833a2f0280ce7331d67e56f3 Mon Sep 17 00:00:00 2001
From: joshuarwood <joshua.randall.wood@gmail.com>
Date: Fri, 7 Nov 2025 15:18:02 -0600
Subject: [PATCH 1/2] add flag to ignore line-of-sight hits for transparent
 background surfaces

---
 src/game/bg.c       |  4 ++++
 src/game/prop.c     | 13 ++++++++-----
 src/include/types.h |  3 +++
 3 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/src/game/bg.c b/src/game/bg.c
index d1569bdc4..8a2a53615 100644
--- a/src/game/bg.c
+++ b/src/game/bg.c
@@ -4590,6 +4590,10 @@ bool bgTestHitInRoom(struct coord *frompos, struct coord *topos, s32 roomnum, st
 	numbatches = g_Rooms[roomnum].numvtxbatches;
 
 	for (i = 0; i < numbatches; batch++, i++) {
+#ifndef PLATFORM_N64
+		if (hitthing->ignore_xlu && batch->type == VTXBATCHTYPE_XLU)
+			continue;
+#endif
 		j = bg0f1612e4(&batch->bbmin, &batch->bbmax, &from, &dist, &sp94, &hitthing->pos);
 
 		if (j == 0) {
diff --git a/src/game/prop.c b/src/game/prop.c
index ae18152d0..05118904e 100644
--- a/src/game/prop.c
+++ b/src/game/prop.c
@@ -983,7 +983,7 @@ struct prop *shotCalculateHits(s32 handnum, bool isshooting, struct coord *gunpo
 bool shotTestLos(struct coord *gunpos2d, struct coord *gundir2d, struct coord *gunpos3d, struct coord *gundir3d, struct coord *endpos3d)
 {
 	struct prop **propptr;
-	struct hitthing sp664;
+	struct hitthing hitthing;
 	struct coord delta;
 	struct shotdata shotdata;
 	s32 i;
@@ -993,6 +993,9 @@ bool shotTestLos(struct coord *gunpos2d, struct coord *gundir2d, struct coord *g
 	RoomNum *roomsptr;
 	struct prop *prop;
 
+	// ignore transparent surfaces
+	hitthing.ignore_xlu = 1;
+
 	shotdata.gunpos3d.x = gunpos3d->x;
 	shotdata.gunpos3d.y = gunpos3d->y;
 	shotdata.gunpos3d.z = gunpos3d->z;
@@ -1040,11 +1043,11 @@ bool shotTestLos(struct coord *gunpos2d, struct coord *gundir2d, struct coord *g
 
 	// Check for BG hits first
 	for (i = 0; rooms[i] != -1; i++) {
-		if (bgTestHitInRoom(&shotdata.gunpos3d, endpos3d, rooms[i], &sp664)) {
+		if (bgTestHitInRoom(&shotdata.gunpos3d, endpos3d, rooms[i], &hitthing)) {
 			// check if it's far enough away from the end point
-			if (fabsf(sp664.pos.x - endpos3d->x) >= 0.1f ||
-					fabsf(sp664.pos.y - endpos3d->y) >= 0.1f ||
-					fabsf(sp664.pos.z - endpos3d->z) >= 0.1f) {
+			if (fabsf(hitthing.pos.x - endpos3d->x) >= 0.1f ||
+					fabsf(hitthing.pos.y - endpos3d->y) >= 0.1f ||
+					fabsf(hitthing.pos.z - endpos3d->z) >= 0.1f) {
 				return false;
 			}
 		}
diff --git a/src/include/types.h b/src/include/types.h
index 2bd8fdd2c..5c5c19338 100644
--- a/src/include/types.h
+++ b/src/include/types.h
@@ -5750,6 +5750,9 @@ struct hitthing {
 	s16 unk28;
 	s16 texturenum;
 	s16 unk2c;
+#ifndef PLATFORM_N64
+	s16 ignore_xlu;
+#endif
 };
 
 struct hit {

From f5cbfe66929a0de82debbbad8d686b232865cd1f Mon Sep 17 00:00:00 2001
From: joshuarwood <joshua.randall.wood@gmail.com>
Date: Fri, 7 Nov 2025 18:38:27 -0600
Subject: [PATCH 2/2] disable xlu surface hits with a global to avoid
 initialization errors with struct flag

---
 src/game/bg.c       | 12 +++++++++++-
 src/game/prop.c     |  3 ---
 src/include/types.h |  3 ---
 3 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/src/game/bg.c b/src/game/bg.c
index 8a2a53615..ea4d08784 100644
--- a/src/game/bg.c
+++ b/src/game/bg.c
@@ -135,6 +135,9 @@ s32 g_BgMostAttemptedDrawSlots = 0;
 s32 g_BgNumRoomLoadCandidates = 0;
 u16 g_BgFrameCount = 0xfffe;
 s32 g_BgNumPortalCameraCacheItems = 0;
+#ifndef PLATFORM_N64
+bool g_BgHitXluDisabled = false;
+#endif
 
 void bgUnpausePropsInRoom(u32 roomnum, bool tintedglassonly)
 {
@@ -4591,7 +4594,7 @@ bool bgTestHitInRoom(struct coord *frompos, struct coord *topos, s32 roomnum, st
 
 	for (i = 0; i < numbatches; batch++, i++) {
 #ifndef PLATFORM_N64
-		if (hitthing->ignore_xlu && batch->type == VTXBATCHTYPE_XLU)
+		if (g_BgHitXluDisabled && batch->type == VTXBATCHTYPE_XLU)
 			continue;
 #endif
 		j = bg0f1612e4(&batch->bbmin, &batch->bbmax, &from, &dist, &sp94, &hitthing->pos);
@@ -6421,6 +6424,10 @@ void bgCalculateGlaresForVisibleRooms(void)
 
 	g_NumRoomsWithGlares = 0;
 
+	// disable line-of-sight hits for transparent background
+	// surfaces before testing for light obstructions
+	g_BgHitXluDisabled = true;
+
 	if (!g_Vars.mplayerisrunning) {
 		for (i = 1; i < g_Vars.roomcount; i++) {
 			if (g_Rooms[i].flags & ROOMFLAG_ONSCREEN) {
@@ -6431,6 +6438,9 @@ void bgCalculateGlaresForVisibleRooms(void)
 			}
 		}
 	}
+
+	// re-enable background hits for transparent surfaces
+	g_BgHitXluDisabled = false;
 }
 
 #endif
diff --git a/src/game/prop.c b/src/game/prop.c
index 05118904e..5cb22009b 100644
--- a/src/game/prop.c
+++ b/src/game/prop.c
@@ -993,9 +993,6 @@ bool shotTestLos(struct coord *gunpos2d, struct coord *gundir2d, struct coord *g
 	RoomNum *roomsptr;
 	struct prop *prop;
 
-	// ignore transparent surfaces
-	hitthing.ignore_xlu = 1;
-
 	shotdata.gunpos3d.x = gunpos3d->x;
 	shotdata.gunpos3d.y = gunpos3d->y;
 	shotdata.gunpos3d.z = gunpos3d->z;
diff --git a/src/include/types.h b/src/include/types.h
index 5c5c19338..2bd8fdd2c 100644
--- a/src/include/types.h
+++ b/src/include/types.h
@@ -5750,9 +5750,6 @@ struct hitthing {
 	s16 unk28;
 	s16 texturenum;
 	s16 unk2c;
-#ifndef PLATFORM_N64
-	s16 ignore_xlu;
-#endif
 };
 
 struct hit {