From 79a78f4c5fc9ab171daae77583119ecf3cebd42e Mon Sep 17 00:00:00 2001
From: gamemasterplc <gamemasterplc@gmail.com>
Date: Wed, 6 Dec 2023 15:13:41 -0600
Subject: [PATCH] Introduce math.h

Makes fix for introducing 0.5 and 3.0 double constants into rels less hacky
---
 include/functions.h                 |  1 -
 include/math.h                      | 43 +++++++++++++++++++++++++++++
 src/REL/subchrselDll/subchrselDll.c |  4 +--
 src/REL/w10Dll/w10Dll.c             |  7 ++---
 4 files changed, 46 insertions(+), 9 deletions(-)
 create mode 100644 include/math.h

diff --git a/include/functions.h b/include/functions.h
index 8a43084f..a906f8c5 100644
--- a/include/functions.h
+++ b/include/functions.h
@@ -78,7 +78,6 @@ void fn_800B4264(s32, s32, s32);
 void fn_8007500C(s32);
 void fn_8006F0D4(s32, f32);
 f32 fn_8006F128(s32);
-f64 fmod(f32, f64);
 void fn_8006F61C(s16, s32);
 void fn_800B42BC(s16);
 s32 fn_8006DBD4(s16);
diff --git a/include/math.h b/include/math.h
new file mode 100644
index 00000000..95c77704
--- /dev/null
+++ b/include/math.h
@@ -0,0 +1,43 @@
+#ifndef _MATH_H
+#define _MATH_H
+
+extern inline float sqrtf(float x)
+{
+	static const double _half=.5;
+	static const double _three=3.0;
+	volatile float y;
+	if(x > 0.0f)
+	{
+		double guess = __frsqrte((double)x);   // returns an approximation to
+		guess = _half*guess*(_three - guess*guess*x);  // now have 12 sig bits
+		guess = _half*guess*(_three - guess*guess*x);  // now have 24 sig bits
+		guess = _half*guess*(_three - guess*guess*x);  // now have 32 sig bits
+		y=(float)(x*guess);
+		return y;
+	}
+	return x;
+}
+
+double atan(double x);
+double copysign(double x, double y);
+double cos(double x);
+double floor(double x);
+double frexp(double x, int *exp);
+double ldexp(double x, int exp);
+double modf(double x, double *intpart);
+double sin(double x);
+double tan(double x);
+double acos(double x);
+double asin(double x);
+double atan2(double y, double x);
+double fmod(double x, double y);
+double log(double x);
+float tanf(float x);
+float sinf(float x);
+float cosf(float x);
+float atan2f(float y, float x);
+float acosf(float x);
+
+#define abs(x) __abs(x)
+
+#endif
\ No newline at end of file
diff --git a/src/REL/subchrselDll/subchrselDll.c b/src/REL/subchrselDll/subchrselDll.c
index 92b5264c..aa5c4c37 100644
--- a/src/REL/subchrselDll/subchrselDll.c
+++ b/src/REL/subchrselDll/subchrselDll.c
@@ -3,9 +3,7 @@
 #include "game/printfunc.h"
 #include "dolphin/pad.h"
 
-//HACK: Force 0.5 and 3.0 double constants to appear in REL
-const double _half = 0.5;
-const double _three = 3.0;
+#include "math.h"
 
 static void SubchrMain(void);
 
diff --git a/src/REL/w10Dll/w10Dll.c b/src/REL/w10Dll/w10Dll.c
index 2ffda651..b3ea6a1f 100644
--- a/src/REL/w10Dll/w10Dll.c
+++ b/src/REL/w10Dll/w10Dll.c
@@ -1,6 +1,8 @@
 #include "include/REL/w10Dll.h"
 #include "game/data.h"
 
+#include "math.h"
+
 //BSS
 s16 lbl_1_bss_22[11];
 s16 lbl_1_bss_20;
@@ -58,11 +60,6 @@ s32 lbl_1_data_6C[2] = {
     DATA_NUM_LISTEND
 };
 
-//RODATA
-//HACK: Force 0.5 and 3.0 double constants to appear in REL
-const double _half = 0.5;
-const double _three = 3.0;
-
 // function is probably global. only inlined in rels?
 inline s32 get_current_board(void) {
     return GWSystem.unk08 & 0x1F;