oss/luanti
oss/luanti
1
0
Fork 0
mirror of https://github.com/luanti-org/luanti.git synced 2025-06-27 16:36:03 +00:00
Code Wiki Activity

Fix wrapDegrees family of functions

Browse source 
wrapDegrees() (renamed to modulo360f)
wrapDegrees_0_360
wrapDegrees_180

Minor errors were present in previous versions; see issue #2328
This commit is contained in:
Craig Robbins 2015-02-23 16:25:14 +10:00
parent 51057a56f5
commit 3b6480c5b0
3 changed files with 80 additions and 51 deletions
Download patch file Download diff file Expand all files Collapse all files

83
src/util/numeric.h
View file

@ -184,57 +184,56 @@ inline void sortBoxVerticies(v3s16 &p1, v3s16 &p2) {
}
/*
See test.cpp for example cases.
wraps degrees to the range of -360...360
NOTE: Wrapping to 0...360 is not used because pitch needs negative values.
*/
inline float wrapDegrees(float f)
/** Returns \p f wrapped to the range [-360, 360]
*
* See test.cpp for example cases.
*
* \note This is also used in cases where degrees wrapped to the range [0, 360]
* is innapropriate (e.g. pitch needs negative values)
*
* \internal functionally equivalent -- although precision may vary slightly --
* to fmodf((f), 360.0f) however empirical tests indicate that this approach is
* faster.
*/
inline float modulo360f(float f)
{
// Take examples of f=10, f=720.5, f=-0.5, f=-360.5
// This results in
// 10, 720, -1, -361
int i = floor(f);
// 0, 2, 0, -1
int l = i / 360;
// NOTE: This would be used for wrapping to 0...360
// 0, 2, -1, -2
/*if(i < 0)
l -= 1;*/
// 0, 720, 0, -360
int k = l * 360;
// 10, 0.5, -0.5, -0.5
f -= float(k);
return f;
int sign;
int whole;
float fraction;
if (f < 0) {
f = -f;
sign = -1;
} else {
sign = 1;
}
whole = f;
fraction = f - whole;
whole %= 360;
return sign * (whole + fraction);
}
/* Wrap to 0...360 */
/** Returns \p f wrapped to the range [0, 360]
*/
inline float wrapDegrees_0_360(float f)
{
// Take examples of f=10, f=720.5, f=-0.5, f=-360.5
// This results in
// 10, 720, -1, -361
int i = floor(f);
// 0, 2, 0, -1
int l = i / 360;
// Wrap to 0...360
// 0, 2, -1, -2
if(i < 0)
l -= 1;
// 0, 720, 0, -360
int k = l * 360;
// 10, 0.5, -0.5, -0.5
f -= float(k);
return f;
float value = modulo360f(f);
return value < 0 ? value + 360 : value;
}
/* Wrap to -180...180 */
/** Returns \p f wrapped to the range [-180, 180]
*/
inline float wrapDegrees_180(float f)
{
f += 180;
f = wrapDegrees_0_360(f);
f -= 180;
return f;
float value = modulo360f(f + 180);
if (value < 0)
value += 360;
return value - 180;
}
/*