Method PrepareRender

trinity/Eve/EveLensflare.cpp:192–266

-------------------------------------------------------------------------------- Description: Is a lot like ::Update but needs the current frame's frustum! Basiclly calculates the transform for the billboard geomtry to become a 2d sprite. Calculation itself is a little bit strange, but totally EVE legacy! Arguments: frustum - the current view frustum of the current frame --------------------------

//   frustum - the current view frustum of the current frame
// --------------------------------------------------------------------------------
void EveLensflare::PrepareRender( const TriFrustum& frustum )
{
	// debug
	if( !m_display )
	{
		return;
	}

	// calc direction to the sun (usually normalized m_position)
	if( LengthSq( m_position ) == 0.f )
	{
		Vector3 curPos( 0.f, 0.f, 0.f );
		curPos -= frustum.m_viewPos;
		m_direction = Normalize( curPos );
	}
	else
	{
		Vector3 invPos = -m_position;
		m_direction = Normalize( invPos );
	}

	Vector3 cameraSpacePos = frustum.m_viewDir * ( -1.f * m_cameraFactor );
	cameraSpacePos += frustum.m_viewPos;

	// build the matrix that will rotate the flares into position
	// by using the position of the camera and the direction to the world pos
	Vector3 negDirVec = -m_direction;
	TriMatrixArcFromForward( &m_transform, &negDirVec );
	m_transform._41 = cameraSpacePos.x;
	m_transform._42 = cameraSpacePos.y;
	m_transform._43 = cameraSpacePos.z;
	m_transform._44 = 1.0f;

	// pass important data to shader
	m_directionVar = Vector4( m_direction, m_sunSize );

	Vector4 direction( m_direction.x, m_direction.y, m_direction.z, 0 );
	direction = Transform( direction, Tr2Renderer::GetViewTransform() );
	direction = Transform( direction, frustum.m_projectionMatrix );
	direction.x /= direction.w;
	direction.y /= direction.w;
	float distanceToEdge = 1 - std::min( 1 - std::abs( direction.x ), 1 - std::abs( direction.y ) );
	float distanceToCenter = Length( *reinterpret_cast<Vector2*>( &direction ) );
	float radialAngle = atan2( direction.y, direction.x ) + TRI_PI;

	for( auto it = m_distanceToEdgeCurves.begin(); it != m_distanceToEdgeCurves.end(); ++it )
	{
		( *it )->UpdateValue( distanceToEdge );
	}

	for( auto it = m_distanceToCenterCurves.begin(); it != m_distanceToCenterCurves.end(); ++it )
	{
		( *it )->UpdateValue( distanceToCenter );
	}

	for( auto it = m_radialAngleCurves.begin(); it != m_radialAngleCurves.end(); ++it )
	{
		( *it )->UpdateValue( radialAngle );