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Fix wrapDegrees family of functions

wrapDegrees() (renamed to modulo360f)
wrapDegrees_0_360
wrapDegrees_180

Minor errors were present in previous versions; see issue #2328
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Zeno- committed Feb 23, 2015
1 parent 51057a5 commit 3b6480c5b0c968ad9f5a7cfb7ca494989be03629
Showing with 80 additions and 51 deletions.
  1. +2 −2 src/network/packethandlers/server.cpp
  2. +37 −7 src/test.cpp
  3. +41 −42 src/util/numeric.h
@@ -543,8 +543,8 @@ void Server::handleCommand_PlayerPos(NetworkPacket* pkt)
v3f position((f32)ps.X / 100.0, (f32)ps.Y / 100.0, (f32)ps.Z / 100.0);
v3f speed((f32)ss.X / 100.0, (f32)ss.Y / 100.0, (f32)ss.Z / 100.0);

pitch = wrapDegrees(pitch);
yaw = wrapDegrees(yaw);
pitch = modulo360f(pitch);
yaw = modulo360f(yaw);

Player *player = m_env->getPlayer(pkt->getPeerId());
if (player == NULL) {
@@ -147,15 +147,45 @@ struct TestBase

struct TestUtilities: public TestBase
{
inline float ref_WrapDegrees180(float f)
{
// This is a slower alternative to the wrapDegrees_180() function;
// used as a reference for testing
float value = fmodf(f + 180, 360);
if (value < 0)
value += 360;
return value - 180;
}

inline float ref_WrapDegrees_0_360(float f)
{
// This is a slower alternative to the wrapDegrees_0_360() function;
// used as a reference for testing
float value = fmodf(f, 360);
if (value < 0)
value += 360;
return value < 0 ? value + 360 : value;
}


void Run()
{
/*infostream<<"wrapDegrees(100.0) = "<<wrapDegrees(100.0)<<std::endl;
infostream<<"wrapDegrees(720.5) = "<<wrapDegrees(720.5)<<std::endl;
infostream<<"wrapDegrees(-0.5) = "<<wrapDegrees(-0.5)<<std::endl;*/
UASSERT(fabs(wrapDegrees(100.0) - 100.0) < 0.001);
UASSERT(fabs(wrapDegrees(720.5) - 0.5) < 0.001);
UASSERT(fabs(wrapDegrees(-0.5) - (-0.5)) < 0.001);
UASSERT(fabs(wrapDegrees(-365.5) - (-5.5)) < 0.001);
UASSERT(fabs(modulo360f(100.0) - 100.0) < 0.001);
UASSERT(fabs(modulo360f(720.5) - 0.5) < 0.001);
UASSERT(fabs(modulo360f(-0.5) - (-0.5)) < 0.001);
UASSERT(fabs(modulo360f(-365.5) - (-5.5)) < 0.001);

for (float f = -720; f <= -360; f += 0.25) {
UASSERT(fabs(modulo360f(f) - modulo360f(f + 360)) < 0.001);
}

for (float f = -1440; f <= 1440; f += 0.25) {
UASSERT(fabs(modulo360f(f) - fmodf(f, 360)) < 0.001);
UASSERT(fabs(wrapDegrees_180(f) - ref_WrapDegrees180(f)) < 0.001);
UASSERT(fabs(wrapDegrees_0_360(f) - ref_WrapDegrees_0_360(f)) < 0.001);
UASSERT(wrapDegrees_0_360(fabs(wrapDegrees_180(f) - wrapDegrees_0_360(f))) < 0.001);
}

UASSERT(lowercase("Foo bAR") == "foo bar");
UASSERT(trim("\n \t\r Foo bAR \r\n\t\t ") == "Foo bAR");
UASSERT(trim("\n \t\r \r\n\t\t ") == "");
@@ -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;
}

/*

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