diff --git a/src/game/bg.c b/src/game/bg.c
index 13505786c..454e4a0fd 100644
--- a/src/game/bg.c
+++ b/src/game/bg.c
@@ -1865,7 +1865,7 @@ glabel func0f158d9c
 );
 
 GLOBAL_ASM(
-glabel func0f1598b4
+glabel bg0f1598b4
 .late_rodata
 glabel var7f1b75c4
 .word 0x3f333333
@@ -2295,6 +2295,102 @@ glabel var7f1b75c4
 /*  f159f18:	27bd03d8 */ 	addiu	$sp,$sp,0x3d8
 );
 
+// Mismatch: Regalloc and some reordered instructions
+//Gfx *bg0f1598b4(Gfx *gdl, Gfx *gdl2, struct gfxvtx *vertices, s16 arg3[3])
+//{
+//	s32 i;
+//	s32 stack;
+//	struct bgthing thing;
+//	struct stagetableentry *stage = stageGetCurrent();
+//	s16 sp120[16][3];
+//	s32 spe0[16];
+//	s32 spa0[16];
+//
+//	thing.unk00c = g_Vars.currentplayer->eraserbgdist;
+//	thing.unk010 = thing.unk00c * thing.unk00c;
+//	thing.unk018 = thing.unk00c * 0.25f;
+//	thing.unk01c = g_Vars.currentplayer->eraserpropdist / thing.unk00c;
+//
+//	if (thing.unk01c > 0.7f) {
+//		thing.unk01c = 0.7f;
+//	}
+//
+//	thing.unk014 = 0.250f;
+//	thing.unk020 = stage->unk2c;
+//	thing.unk024 = thing.unk020 * thing.unk020;
+//	thing.unk000 = arg3[0];
+//	thing.unk004 = arg3[1];
+//	thing.unk008 = arg3[2];
+//	thing.unk24a = 0;
+//	thing.unk248 = 0;
+//
+//	while (true) {
+//		if (gdl2->dma.cmd == G_ENDDL) {
+//			break;
+//		}
+//
+//		if (gdl2->dma.cmd == G_MTX) {
+//			// empty
+//		} else if (gdl2->dma.cmd == G_VTX) {
+//			s32 index = gdl2->bytes[1] & 0xf;
+//			s32 numvertices = (((u32)gdl2->bytes[1] >> 4)) + 1;
+//			s32 offset = (gdl2->words.w1 & 0xffffff);
+//			struct gfxvtx *vtx = (struct gfxvtx *)((u32)vertices + offset);
+//			u32 stack[4];
+//
+//			for (i = 0; i < numvertices; i++) {
+//				sp120[index + i][0] = vtx->x;
+//				sp120[index + i][1] = vtx->y;
+//				sp120[index + i][2] = vtx->z;
+//
+//				func0f158884(&spa0[i], sp120[index + i], &spe0[index + i], &thing);
+//
+//				vtx++;
+//			}
+//		} else if (gdl2->dma.cmd == G_TRI1) {
+//			s16 x = gdl2->tri.tri.v[0] / 10;
+//			s16 y = gdl2->tri.tri.v[1] / 10;
+//			s16 z = gdl2->tri.tri.v[2] / 10;
+//
+//			gdl = func0f158d9c(gdl, &thing, sp120[x], sp120[y], sp120[z], spe0[x], spe0[y], spe0[z], spa0[x], spa0[y], spa0[z]);
+//		} else if (gdl2->dma.cmd == G_TRI4) {
+//			s16 x;
+//			s16 y;
+//			s16 z;
+//
+//			x = gdl2->tri4.x1;
+//			y = gdl2->tri4.y1;
+//			z = gdl2->tri4.z1;
+//
+//			gdl = func0f158d9c(gdl, &thing, sp120[x], sp120[y], sp120[z], spe0[x], spe0[y], spe0[z], spa0[x], spa0[y], spa0[z]);
+//
+//			x = gdl2->tri4.x2;
+//			y = gdl2->tri4.y2;
+//			z = gdl2->tri4.z2;
+//
+//			gdl = func0f158d9c(gdl, &thing, sp120[x], sp120[y], sp120[z], spe0[x], spe0[y], spe0[z], spa0[x], spa0[y], spa0[z]);
+//
+//			x = gdl2->tri4.x3;
+//			y = gdl2->tri4.y3;
+//			z = gdl2->tri4.z3;
+//
+//			gdl = func0f158d9c(gdl, &thing, sp120[x], sp120[y], sp120[z], spe0[x], spe0[y], spe0[z], spa0[x], spa0[y], spa0[z]);
+//
+//			x = gdl2->tri4.x4;
+//			y = gdl2->tri4.y4;
+//			z = gdl2->tri4.z4;
+//
+//			gdl = func0f158d9c(gdl, &thing, sp120[x], sp120[y], sp120[z], spe0[x], spe0[y], spe0[z], spa0[x], spa0[y], spa0[z]);
+//		}
+//
+//		gdl2++;
+//	}
+//
+//	gdl = func0f158184(gdl, &thing);
+//
+//	return gdl;
+//}
+
 Gfx *bgRenderRoomXrayPass(Gfx *gdl, s32 roomnum, struct roomgfxdata18 *arg2, bool recurse, s16 arg4[3])
 {
 	struct player *player = g_Vars.currentplayer;
@@ -2305,7 +2401,7 @@ Gfx *bgRenderRoomXrayPass(Gfx *gdl, s32 roomnum, struct roomgfxdata18 *arg2, boo
 
 	switch (arg2->type) {
 	case 0:
-		gdl = func0f1598b4(gdl, arg2->gdl, arg2->vertices, arg4);
+		gdl = bg0f1598b4(gdl, arg2->gdl, arg2->vertices, arg4);
 
 		if (recurse) {
 			gdl = bgRenderRoomXrayPass(gdl, roomnum, arg2->next, true, arg4);
diff --git a/src/include/game/bg.h b/src/include/game/bg.h
index cceff91c5..a7955d15b 100644
--- a/src/include/game/bg.h
+++ b/src/include/game/bg.h
@@ -8,11 +8,11 @@ void roomUnpauseProps(u32 roomnum, bool tintedglassonly);
 void roomSetOnscreen(s32 room, s32 draworder, struct screenbox *arg2);
 void func0f158108(s32 roomnum, u8 *arg1, u8 *arg2);
 struct var800a4640_00 *func0f158140(s32 roomnum);
-u32 func0f158184(void);
+Gfx *func0f158184(Gfx *gdl, struct bgthing *arg1);
 u32 func0f158400(void);
-u32 func0f158884(void);
-u32 func0f158d9c(void);
-Gfx *func0f1598b4(Gfx *gdl, Gfx *gdl2, struct gfxvtx *vertices, s16 arg3[3]);
+void func0f158884(s32 *arg0, s16 arg1[3], s32 *arg2, struct bgthing *arg3);
+Gfx *func0f158d9c(Gfx *gdl, struct bgthing *arg1, s16 arg2[3], s16 arg3[3], s16 arg4[3], s32 arg5, s32 arg6, s32 arg7, s32 arg8, s32 arg9, s32 arg10);
+Gfx *bg0f1598b4(Gfx *gdl, Gfx *gdl2, struct gfxvtx *vertices, s16 arg3[3]);
 Gfx *bgRenderRoomXrayPass(Gfx *gdl, s32 roomnum, struct roomgfxdata18 *arg2, bool recurse, s16 arg4[3]);
 Gfx *bgRenderRoomInXray(Gfx *gdl, s32 roomnum);
 Gfx *bgRenderSceneInXray(Gfx *gdl);
diff --git a/src/include/gbiex.h b/src/include/gbiex.h
index 13c5a47fb..e9ff8496d 100644
--- a/src/include/gbiex.h
+++ b/src/include/gbiex.h
@@ -5,7 +5,7 @@
 #include "types.h"
 
 #define G_SETCOLOR 0x07
-#define G_TRI4     0xb1
+#define G_TRI4     -79
 
 /**
  * 04	rsp_uc05_vertex
diff --git a/src/include/types.h b/src/include/types.h
index c289ca888..b52d982e6 100644
--- a/src/include/types.h
+++ b/src/include/types.h
@@ -2353,7 +2353,7 @@ struct player {
 	/*0x0014*/ s32 memcamroom;
 	/*0x0018*/ struct coord eraserpos;
 	/*0x0024*/ f32 eraserpropdist;
-	/*0x0028*/ u32 eraserbgdist;
+	/*0x0028*/ f32 eraserbgdist;
 	/*0x002c*/ u32 eraserdepth;
 	/*0x0030*/ bool isfalling;
 	/*0x0034*/ s32 fallstart; // lvframe60 when player started falling
@@ -6350,4 +6350,20 @@ struct var800a6538 {
 	f32 unk04;
 };
 
+struct bgthing {
+	s32 unk000;
+	s32 unk004;
+	s32 unk008;
+	f32 unk00c;
+	f32 unk010;
+	f32 unk014;
+	f32 unk018;
+	f32 unk01c;
+	s32 unk020;
+	s32 unk024;
+	u8 unk028[0x220];
+	s16 unk248;
+	s16 unk24a;
+};
+
 #endif