float32 FindMinSeparation()

in Box2D/Collision/b2TimeOfImpact.cpp [126:192]
51 lines of code
4 McCabe index (conditional complexity)

	float32 FindMinSeparation(int32* indexA, int32* indexB, float32 t) const
	{
		b2Transform xfA, xfB;
		m_sweepA.GetTransform(&xfA, t);
		m_sweepB.GetTransform(&xfB, t);

		switch (m_type)
		{
		case e_points:
			{
				b2Vec2 axisA = b2MulT(xfA.q,  m_axis);
				b2Vec2 axisB = b2MulT(xfB.q, -m_axis);

				*indexA = m_proxyA->GetSupport(axisA);
				*indexB = m_proxyB->GetSupport(axisB);

				b2Vec2 localPointA = m_proxyA->GetVertex(*indexA);
				b2Vec2 localPointB = m_proxyB->GetVertex(*indexB);
				
				b2Vec2 pointA = b2Mul(xfA, localPointA);
				b2Vec2 pointB = b2Mul(xfB, localPointB);

				float32 separation = b2Dot(pointB - pointA, m_axis);
				return separation;
			}

		case e_faceA:
			{
				b2Vec2 normal = b2Mul(xfA.q, m_axis);
				b2Vec2 pointA = b2Mul(xfA, m_localPoint);

				b2Vec2 axisB = b2MulT(xfB.q, -normal);
				
				*indexA = -1;
				*indexB = m_proxyB->GetSupport(axisB);

				b2Vec2 localPointB = m_proxyB->GetVertex(*indexB);
				b2Vec2 pointB = b2Mul(xfB, localPointB);

				float32 separation = b2Dot(pointB - pointA, normal);
				return separation;
			}

		case e_faceB:
			{
				b2Vec2 normal = b2Mul(xfB.q, m_axis);
				b2Vec2 pointB = b2Mul(xfB, m_localPoint);

				b2Vec2 axisA = b2MulT(xfA.q, -normal);

				*indexB = -1;
				*indexA = m_proxyA->GetSupport(axisA);

				b2Vec2 localPointA = m_proxyA->GetVertex(*indexA);
				b2Vec2 pointA = b2Mul(xfA, localPointA);

				float32 separation = b2Dot(pointA - pointB, normal);
				return separation;
			}

		default:
			b2Assert(false);
			*indexA = -1;
			*indexB = -1;
			return 0.0f;
		}
	}