xavi
/
libfixmath
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Added 32-bit division option, it is less accurate (inaccuracy of ~0.0035%) and very slow (750% of float) but it does work. 

Changed tan to be saturated (i.e. tan(pi/4) = fix16_max rather than divide by zero error), may revert or implement as stan later.
This commit is contained in:
flatmush 2011-02-28 11:24:38 +00:00
parent 8737eb5fe2
commit ae58c98283
2 changed files with 36 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

35
libfixmath/fix16.c
View File

@ -88,6 +88,7 @@ fix16_t fix16_smul(fix16_t inArg0, fix16_t inArg1) {
fix16_t fix16_div(fix16_t inArg0, fix16_t inArg1) {
#ifndef FIXMATH_NO_64BIT
int64_t tempResult = inArg0;
tempResult <<= 16;
#ifndef FIXMATH_NO_ROUNDING
@ -95,6 +96,21 @@ fix16_t fix16_div(fix16_t inArg0, fix16_t inArg1) {
#endif
tempResult /= inArg1;
return tempResult;
#else
int32_t res = (inArg0 / inArg1) << 16;
int32_t mod = inArg0 % inArg1;
uintptr_t i;
for(i = 0; i < 16; i++) {
mod <<= 1;
res += (mod / inArg1) << (15 - i);
mod %= inArg1;
}
#ifndef FIXMATH_NO_ROUNDING
if((mod << 1) / inArg1)
res++;
#endif
return res;
#endif
}
fix16_t fix16_sdiv(fix16_t inArg0, fix16_t inArg1) {
@ -103,6 +119,7 @@ fix16_t fix16_sdiv(fix16_t inArg0, fix16_t inArg1) {
return fix16_MIN;
return fix16_MAX;
}
#ifndef FIXMATH_NO_64BIT
int64_t tempResult = inArg0;
tempResult <<= 16;
#ifndef FIXMATH_NO_ROUNDING
@ -114,6 +131,24 @@ fix16_t fix16_sdiv(fix16_t inArg0, fix16_t inArg1) {
if(tempResult > fix16_MAX)
return fix16_MAX;
return tempResult;
#else
int32_t res = (inArg0 / inArg1);
if((res < -32768) || (res >= 32768))
return (res < 0 ? fix16_MIN : fix16_MAX);
res <<= 16;
int32_t mod = inArg0 % inArg1;
uintptr_t i;
for(i = 0; i < 16; i++) {
mod <<= 1;
res += (mod / inArg1) << (15 - i);
mod %= inArg1;
}
#ifndef FIXMATH_NO_ROUNDING
if((mod << 1) / inArg1)
res++;
#endif
return res;
#endif
}

2
libfixmath/fix16_trig.c
View File

@ -115,7 +115,7 @@ fix16_t fix16_cos(fix16_t inAngle) {
}
fix16_t fix16_tan(fix16_t inAngle) {
return fix16_div(fix16_sin(inAngle), fix16_cos(inAngle));
return fix16_sdiv(fix16_sin(inAngle), fix16_cos(inAngle));
}
fix16_t fix16_asin(fix16_t inValue) {