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Match fp_math.c (#2116)

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cadmic 2024-09-03 22:12:44 -07:00 • committed by GitHub
parent 6e5ea8c7aa
commit 87914c6cc6
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4 changed files with 90 additions and 8 deletions
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2
src/code/fp.s
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@ -6,6 +6,7 @@
.balign 16
#if PLATFORM_GC
DATA(qNaN0x3FFFFF)
.word 0x7FBFFFFF
ENDDATA(qNaN0x3FFFFF)
@ -17,6 +18,7 @@ ENDDATA(qNaN0x10000)
DATA(sNaN0x3FFFFF)
.word 0x7FFFFFFF
ENDDATA(sNaN0x3FFFFF)
#endif
.section .text

83
src/code/fp_math.c
View file

@ -1,7 +1,9 @@
#include "z64math.h"
#include "macros.h"
#if PLATFORM_GC
s32 gUseAtanContFrac;
#endif
/**
* @param angle radians
@ -22,6 +24,16 @@ f32 Math_FCeilF(f32 x) {
return ceilf(x);
}
#if PLATFORM_N64
f64 Math_FAbs(f64 x) {
return x < 0.0 ? -x : x;
}
f32 Math_FAbsF(f32 x) {
return x < 0.0f ? -x : x;
}
#endif
f32 Math_FRoundF(f32 x) {
return roundf(x);
}
@ -34,6 +46,7 @@ f32 Math_FNearbyIntF(f32 x) {
return nearbyintf(x);
}
#if PLATFORM_GC
/* Arctangent approximation using a Taylor series (one quadrant) */
f32 Math_FAtanTaylorQF(f32 x) {
static const f32 coeffs[] = {
@ -89,6 +102,7 @@ f32 Math_FAtanTaylorF(f32 x) {
return -q;
}
}
#endif
/* Arctangent approximation using a continued fraction */
f32 Math_FAtanContFracF(f32 x) {
@ -98,6 +112,17 @@ f32 Math_FAtanContFracF(f32 x) {
f32 sq;
s32 i;
#if PLATFORM_N64
if (x > 1.0f) {
sector = 1;
x = 1.0f / x;
} else if (x < -1.0f) {
sector = -1;
x = 1.0f / x;
} else {
sector = 0;
}
#else
if (x >= -1.0f && x <= 1.0f) {
sector = 0;
} else if (x > 1.0f) {
@ -109,16 +134,35 @@ f32 Math_FAtanContFracF(f32 x) {
} else {
return qNaN0x10000;
}
#endif
sq = SQ(x);
conv = 0.0f;
#if PLATFORM_N64
z = 24.0f;
i = 24;
#else
z = 8.0f;
for (i = 8; i != 0; i--) {
i = 8;
#endif
while (i != 0) {
conv = SQ(z) * sq / (2.0f * z + 1.0f + conv);
z -= 1.0f;
i--;
}
conv = x / (1.0f + conv);
#if PLATFORM_N64
if (sector > 0) {
return M_PI / 2 - (x / (1.0f + conv));
} else if (sector < 0) {
return -M_PI / 2 - (x / (1.0f + conv));
} else {
return x / (1.0f + conv);
}
#else
conv = x / (1.0f + conv);
if (sector == 0) {
return conv;
} else if (sector > 0) {
@ -126,8 +170,10 @@ f32 Math_FAtanContFracF(f32 x) {
} else {
return -M_PI / 2 - conv;
}
#endif
}
#if PLATFORM_GC
/**
* @return arctan(x) in radians, in (-pi/2,pi/2) range
*/
@ -138,11 +184,33 @@ f32 Math_FAtanF(f32 x) {
return Math_FAtanContFracF(x);
}
}
#endif
/**
* @return angle to (x,y) from vector (1,0) around (0,0) in radians, in (-pi,pi] range
*/
f32 Math_FAtan2F(f32 y, f32 x) {
#if PLATFORM_N64
if (y == 0.0f && x == 0.0f) {
return 0.0f;
}
if (x == 0.0f) {
if (y < 0.0f) {
return -M_PI / 2;
} else {
return M_PI / 2;
}
} else if (x < 0.0f) {
if (y < 0.0f) {
return -(M_PI - Math_FAtanContFracF(fabs(y / x)));
} else {
return M_PI - Math_FAtanContFracF(fabs(y / x));
}
} else { // x > 0.0f
return Math_FAtanContFracF(y / x);
}
#else
if (x == 0.0f) {
if (y == 0.0f) {
return 0.0f;
@ -155,11 +223,14 @@ f32 Math_FAtan2F(f32 y, f32 x) {
}
} else if (x >= 0.0f) {
return Math_FAtanF(y / x);
} else if (y < 0.0f) {
return Math_FAtanF(y / x) - M_PI;
} else {
return M_PI - Math_FAtanF(-(y / x));
} else { // x < 0.0f
if (y < 0.0f) {
return Math_FAtanF(y / x) - M_PI;
} else {
return M_PI - Math_FAtanF(-(y / x));
}
}
#endif
}
/**