Rename math.c/mymath.h to fixpoint.c/.h

This also changes the functions' prefix
from "math_" to "fix_".

src/asm/fixpoint.c

@@ -0,0 +1,170 @@
+/*
+ * This file is part of RGBDS.
+ *
+ * Copyright (c) 1997-2021, Carsten Sorensen and RGBDS contributors.
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+/*
+ * Fixed-point math routines
+ */
+
+#include <inttypes.h>
+#include <math.h>
+#include <stdint.h>
+#include <stdio.h>
+
+#include "asm/fixpoint.h"
+#include "asm/symbol.h"
+#include "asm/warning.h"
+
+#define fix2double(i)	((double)((i) / 65536.0))
+#define double2fix(d)	((int32_t)round((d) * 65536.0))
+
+// pi radians == 32768 fixed-point "degrees"
+#define fdeg2rad(f)	((f) * (M_PI / 32768.0))
+#define rad2fdeg(r)	((r) * (32768.0 / M_PI))
+
+#ifndef M_PI
+#define M_PI 3.14159265358979323846
+#endif
+
+/*
+ * Return the _PI symbol value
+ */
+int32_t fix_Callback_PI(void)
+{
+	warning(WARNING_OBSOLETE, "`_PI` is deprecated; use 3.14159\n");
+
+	return double2fix(M_PI);
+}
+
+/*
+ * Print a fixed point value
+ */
+void fix_Print(int32_t i)
+{
+	uint32_t u = i;
+	const char *sign = "";
+
+	if (i < 0) {
+		u = -u;
+		sign = "-";
+	}
+
+	printf("%s%" PRIu32 ".%05" PRIu32, sign, u >> 16,
+	       ((uint32_t)(fix2double(u) * 100000 + 0.5)) % 100000);
+}
+
+/*
+ * Calculate sine
+ */
+int32_t fix_Sin(int32_t i)
+{
+	return double2fix(sin(fdeg2rad(fix2double(i))));
+}
+
+/*
+ * Calculate cosine
+ */
+int32_t fix_Cos(int32_t i)
+{
+	return double2fix(cos(fdeg2rad(fix2double(i))));
+}
+
+/*
+ * Calculate tangent
+ */
+int32_t fix_Tan(int32_t i)
+{
+	return double2fix(tan(fdeg2rad(fix2double(i))));
+}
+
+/*
+ * Calculate arcsine
+ */
+int32_t fix_ASin(int32_t i)
+{
+	return double2fix(rad2fdeg(asin(fix2double(i))));
+}
+
+/*
+ * Calculate arccosine
+ */
+int32_t fix_ACos(int32_t i)
+{
+	return double2fix(rad2fdeg(acos(fix2double(i))));
+}
+
+/*
+ * Calculate arctangent
+ */
+int32_t fix_ATan(int32_t i)
+{
+	return double2fix(rad2fdeg(atan(fix2double(i))));
+}
+
+/*
+ * Calculate atan2
+ */
+int32_t fix_ATan2(int32_t i, int32_t j)
+{
+	return double2fix(rad2fdeg(atan2(fix2double(i), fix2double(j))));
+}
+
+/*
+ * Multiplication
+ */
+int32_t fix_Mul(int32_t i, int32_t j)
+{
+	return double2fix(fix2double(i) * fix2double(j));
+}
+
+/*
+ * Division
+ */
+int32_t fix_Div(int32_t i, int32_t j)
+{
+	return double2fix(fix2double(i) / fix2double(j));
+}
+
+/*
+ * Power
+ */
+int32_t fix_Pow(int32_t i, int32_t j)
+{
+	return double2fix(pow(fix2double(i), fix2double(j)));
+}
+
+/*
+ * Logarithm
+ */
+int32_t fix_Log(int32_t i, int32_t j)
+{
+	return double2fix(log(fix2double(i)) / log(fix2double(j)));
+}
+
+/*
+ * Round
+ */
+int32_t fix_Round(int32_t i)
+{
+	return double2fix(round(fix2double(i)));
+}
+
+/*
+ * Ceil
+ */
+int32_t fix_Ceil(int32_t i)
+{
+	return double2fix(ceil(fix2double(i)));
+}
+
+/*
+ * Floor
+ */
+int32_t fix_Floor(int32_t i)
+{
+	return double2fix(floor(fix2double(i)));
+}