Function UpdateProjectionParameters

trinity/Tr2Renderer.cpp:71–84

float s_orthoHeight = 0.0f;

void UpdateProjectionParameters( const Matrix& proj )
{
	// Use the fact that:
	// aspect = m_22 / m_11;
	// m_33 = z_f/(z_f-z_n), m_43 = -z_n*z_f/(z_f-z_n)
	// => front = z_n = -m_43/m_33
	// => back = z_f = -m_43/(1+m_43/z_n)
	// m_22 = cotan(fov/2) = 1 / tan(fov/2)
	// => fov = 2*tan(1/m_22)
	s_aspectRatio = ( proj._11 ? proj._22 / proj._11 : 0.0f );
	s_fieldOfView = ( proj._22 ? 2.0f * atan( 1.0f / proj._22 ) : 0.0f );
	s_frontClip = ( proj._33 ? proj._43 / proj._33 : 0.0f );
	s_backClip = proj._43 / ( 1.0f + proj._33 );
}

Matrix s_worldTransform;
Matrix s_inverseWorldTransform;