ref: c67a696a87a35ba3c2fcf10468a6043c2426643c
parent: ee20d9010e49bd243e57aa41ccc32bf5da99e0bf
author: Rangi <remy.oukaour+rangi42@gmail.com>
date: Tue Feb 16 13:07:05 EST 2021
Use macros to convert between radians and fixed-point 65536ths
--- a/src/asm/math.c
+++ b/src/asm/math.c
@@ -22,6 +22,10 @@
#define fx2double(i) ((double)((i) / 65536.0))
#define double2fx(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
@@ -58,7 +62,7 @@
*/
int32_t math_Sin(int32_t i)
{- return double2fx(sin(fx2double(i) * 2 * M_PI / 65536));
+ return double2fx(sin(fdeg2rad(fx2double(i))));
}
/*
@@ -66,7 +70,7 @@
*/
int32_t math_Cos(int32_t i)
{- return double2fx(cos(fx2double(i) * 2 * M_PI / 65536));
+ return double2fx(cos(fdeg2rad(fx2double(i))));
}
/*
@@ -74,7 +78,7 @@
*/
int32_t math_Tan(int32_t i)
{- return double2fx(tan(fx2double(i) * 2 * M_PI / 65536));
+ return double2fx(tan(fdeg2rad(fx2double(i))));
}
/*
@@ -82,7 +86,7 @@
*/
int32_t math_ASin(int32_t i)
{- return double2fx(asin(fx2double(i)) / 2 / M_PI * 65536);
+ return double2fx(rad2fdeg(asin(fx2double(i))));
}
/*
@@ -90,7 +94,7 @@
*/
int32_t math_ACos(int32_t i)
{- return double2fx(acos(fx2double(i)) / 2 / M_PI * 65536);
+ return double2fx(rad2fdeg(acos(fx2double(i))));
}
/*
@@ -98,7 +102,7 @@
*/
int32_t math_ATan(int32_t i)
{- return double2fx(atan(fx2double(i)) / 2 / M_PI * 65536);
+ return double2fx(rad2fdeg(atan(fx2double(i))));
}
/*
@@ -106,7 +110,7 @@
*/
int32_t math_ATan2(int32_t i, int32_t j)
{- return double2fx(atan2(fx2double(i), fx2double(j)) / 2 / M_PI * 65536);
+ return double2fx(rad2fdeg(atan2(fx2double(i), fx2double(j))));
}
/*