Expected behaviour of Radians roll-around?

[thomthom]

I was setting up tests for the current behaviour or Radians:

Sketchup-API-C-Wrapper/src/SUAPI-CppWrapper/Geometry.cpp

Lines 47 to 58 in 94aa35c

	Radians::Radians(const double &rhs):
	m_val(rhs)
	{
	if(rhs > (2*PI)) {
	int numPi = rhs / (2*PI); // Get number of times 2pi fits in to rhs
	m_val = rhs - (numPi*2*PI);
	}
	else if(rhs < 0.0) {
	int numPi = (rhs / (2*PI)) - 1; // Get number of times 2pi fits in to rhs
	m_val = rhs - (numPi*2*PI);
	}
	}

From what I understand of the code it's trying to cap the value by rolling around 2*PI.

For 7.0 I get 0.71681469282041377 which I'd expect.
For -7.0 I get 5.5663706143591725 which I did not expect.

I would have thought I should get -0.71681469282041377.

Am I wrong? Can you explain the intent so I can fill in test unit for this?

[thomthom]

This version returns the result I originally expected:

Radians::Radians(const double &rhs):
  m_val(rhs)
{
  if(rhs > (2 * PI)) {
    m_val = std::fmod(rhs, 2 * PI);
  }
  else if(rhs < 0.0) {
    m_val = std::fmod(rhs, -(2 * PI));
  }
}

[TommyKaneko]

So Radians always produces a positive number between 0 and 2*PI. A negative number will be converted to its positive equivalent. So 5.5663706143591725 is the same as -0.71681469282041377

On a side note - I think there is mixing of types - ie 2*PI should be 2.0*PI on line 50, 52 and 56.

[thomthom]

So Radians always produces a positive number between 0 and 2*PI. A negative number will be converted to its positive equivalent. So 5.5663706143591725 is the same as -0.71681469282041377.

Gotcha. I'll correct my test and implementation.

[thomthom]

Corrected in 89089d2