From aa61bbfb0158af4c17c75730c0480c22a8e67d99 Mon Sep 17 00:00:00 2001
From: Ryan Dwyer <ryandwyer1@gmail.com>
Date: Sat, 6 Nov 2021 14:03:41 +1000
Subject: [PATCH] Decompile mtx000170e4

---
 src/include/lib/mtx.h |  2 +-
 src/lib/mtx.c         | 75 +++++++++++++++----------------------------
 2 files changed, 27 insertions(+), 50 deletions(-)

diff --git a/src/include/lib/mtx.h b/src/include/lib/mtx.h
index 3a4584692..160d2c610 100644
--- a/src/include/lib/mtx.h
+++ b/src/include/lib/mtx.h
@@ -55,7 +55,7 @@ u32 mtx00016dcc(f32 arg0, f32 arg1);
 u32 mtx00016e98(void);
 void mtx4Align(f32 mtx[4][4], f32 radians, f32 x, f32 y, f32 z);
 void mtx4LoadRotationFrom(f32 src[4][4], f32 dst[4][4]);
-u32 mtx000170e4(void);
+void mtx000170e4(f32 src[4][4], f32 dst[4][4]);
 void mtx0001719c(f32 arg0[4][4], f32 arg1[4][4]);
 u32 mtx000172f0(void);
 void mtx00017588(f32 arg0[4][4], f32 arg1[4][4]);
diff --git a/src/lib/mtx.c b/src/lib/mtx.c
index 66bed5f7f..987109f75 100644
--- a/src/lib/mtx.c
+++ b/src/lib/mtx.c
@@ -863,55 +863,32 @@ void mtx4LoadRotationFrom(f32 src[4][4], f32 dst[4][4])
 	dst[3][3] = 1;
 }
 
-GLOBAL_ASM(
-glabel mtx000170e4
-/*    170e4:	c48c0000 */ 	lwc1	$f12,0x0($a0)
-/*    170e8:	c48e0010 */ 	lwc1	$f14,0x10($a0)
-/*    170ec:	c4820020 */ 	lwc1	$f2,0x20($a0)
-/*    170f0:	460c6102 */ 	mul.s	$f4,$f12,$f12
-/*    170f4:	3c013f80 */ 	lui	$at,0x3f80
-/*    170f8:	44818000 */ 	mtc1	$at,$f16
-/*    170fc:	460e7182 */ 	mul.s	$f6,$f14,$f14
-/*    17100:	46062200 */ 	add.s	$f8,$f4,$f6
-/*    17104:	46021282 */ 	mul.s	$f10,$f2,$f2
-/*    17108:	44801000 */ 	mtc1	$zero,$f2
-/*    1710c:	46085000 */ 	add.s	$f0,$f10,$f8
-/*    17110:	46008003 */ 	div.s	$f0,$f16,$f0
-/*    17114:	46006482 */ 	mul.s	$f18,$f12,$f0
-/*    17118:	e4b20000 */ 	swc1	$f18,0x0($a1)
-/*    1711c:	c4840010 */ 	lwc1	$f4,0x10($a0)
-/*    17120:	46002182 */ 	mul.s	$f6,$f4,$f0
-/*    17124:	e4a60004 */ 	swc1	$f6,0x4($a1)
-/*    17128:	c48a0020 */ 	lwc1	$f10,0x20($a0)
-/*    1712c:	46005202 */ 	mul.s	$f8,$f10,$f0
-/*    17130:	e4a80008 */ 	swc1	$f8,0x8($a1)
-/*    17134:	c4920004 */ 	lwc1	$f18,0x4($a0)
-/*    17138:	46009102 */ 	mul.s	$f4,$f18,$f0
-/*    1713c:	e4a40010 */ 	swc1	$f4,0x10($a1)
-/*    17140:	c4860014 */ 	lwc1	$f6,0x14($a0)
-/*    17144:	46003282 */ 	mul.s	$f10,$f6,$f0
-/*    17148:	e4aa0014 */ 	swc1	$f10,0x14($a1)
-/*    1714c:	c4880024 */ 	lwc1	$f8,0x24($a0)
-/*    17150:	46004482 */ 	mul.s	$f18,$f8,$f0
-/*    17154:	e4b20018 */ 	swc1	$f18,0x18($a1)
-/*    17158:	c4840008 */ 	lwc1	$f4,0x8($a0)
-/*    1715c:	46002182 */ 	mul.s	$f6,$f4,$f0
-/*    17160:	e4a60020 */ 	swc1	$f6,0x20($a1)
-/*    17164:	c48a0018 */ 	lwc1	$f10,0x18($a0)
-/*    17168:	46005202 */ 	mul.s	$f8,$f10,$f0
-/*    1716c:	e4a80024 */ 	swc1	$f8,0x24($a1)
-/*    17170:	c4920028 */ 	lwc1	$f18,0x28($a0)
-/*    17174:	e4b0003c */ 	swc1	$f16,0x3c($a1)
-/*    17178:	e4a20030 */ 	swc1	$f2,0x30($a1)
-/*    1717c:	46009102 */ 	mul.s	$f4,$f18,$f0
-/*    17180:	e4a20034 */ 	swc1	$f2,0x34($a1)
-/*    17184:	e4a20038 */ 	swc1	$f2,0x38($a1)
-/*    17188:	e4a2000c */ 	swc1	$f2,0xc($a1)
-/*    1718c:	e4a2001c */ 	swc1	$f2,0x1c($a1)
-/*    17190:	e4a2002c */ 	swc1	$f2,0x2c($a1)
-/*    17194:	03e00008 */ 	jr	$ra
-/*    17198:	e4a40028 */ 	swc1	$f4,0x28($a1)
-);
+void mtx000170e4(f32 src[4][4], f32 dst[4][4])
+{
+	f32 tmp = (src[0][0] * src[0][0] + src[1][0] * src[1][0] + src[2][0] * src[2][0]);
+	tmp = 1 / tmp;
+
+	dst[0][0] = src[0][0] * tmp;
+	dst[0][1] = src[1][0] * tmp;
+	dst[0][2] = src[2][0] * tmp;
+
+	dst[1][0] = src[0][1] * tmp;
+	dst[1][1] = src[1][1] * tmp;
+	dst[1][2] = src[2][1] * tmp;
+
+	dst[2][0] = src[0][2] * tmp;
+	dst[2][1] = src[1][2] * tmp;
+	dst[2][2] = src[2][2] * tmp;
+
+	dst[3][0] = 0;
+	dst[3][1] = 0;
+	dst[3][2] = 0;
+
+	dst[0][3] = 0;
+	dst[1][3] = 0;
+	dst[2][3] = 0;
+	dst[3][3] = 1;
+}
 
 void mtx0001719c(f32 arg0[4][4], f32 arg1[4][4])
 {