+
+///////////////////////////////////////////////////////////////////////////////
+//
+// Class ParallelRaysums
+//
+// Used for converting divergent beam raysums into Parallel raysums
+//
+///////////////////////////////////////////////////////////////////////////////
+
+ParallelRaysums::ParallelRaysums (Projections* pProjections)
+: m_iNumCoordinates(0), m_iNumView(pProjections->nView()), m_iNumDet(pProjections->nDet())
+{
+ int iGeometry = pProjections->geometry();
+ double dDetInc = pProjections->detInc();
+ double dDetStart = pProjections->detStart();
+ double dFocalLength = pProjections->focalLength();
+
+ m_iNumCoordinates = m_iNumView * m_iNumDet;
+ m_vecpCoordinates.reserve (m_iNumCoordinates);
+ for (int i = 0; i < m_iNumCoordinates; i++)
+ m_vecpCoordinates[i] = new ParallelRaysumCoordinate;
+
+ int iCoordinate = 0;
+ for (int iV = 0; iV < m_iNumView; iV++) {
+ double dViewAngle = pProjections->getDetectorArray(iV).viewAngle();
+ const DetectorValue* detValues = pProjections->getDetectorArray(iV).detValues();
+
+ double dDetPos = dDetStart;
+ for (int iD = 0; iD < m_iNumDet; iD++) {
+ ParallelRaysumCoordinate* pC = m_vecpCoordinates[iCoordinate++];
+
+ if (iGeometry == Scanner::GEOMETRY_PARALLEL) {
+ pC->m_dTheta = normalizeAngle (dViewAngle);
+ pC->m_dT = dDetPos;
+ } else if (iGeometry == Scanner::GEOMETRY_EQUILINEAR) {
+ double dFanAngle = atan (dDetPos / pProjections->sourceDetectorLength());
+ pC->m_dTheta = normalizeAngle (dViewAngle + dFanAngle);
+ pC->m_dT = dFocalLength * sin(dFanAngle);
+
+ } else if (iGeometry == Scanner::GEOMETRY_EQUIANGULAR) {
+ // fan angle is same as dDetPos
+ pC->m_dTheta = normalizeAngle (dViewAngle + dDetPos);
+ pC->m_dT = dFocalLength * sin (dDetPos);
+ }
+ if (pC->m_dTheta >= PI) { // convert T/Theta to 0-PI interval
+ pC->m_dTheta -= PI;
+ pC->m_dT = -pC->m_dT - pProjections->detInc();
+ }
+ pC->m_dRaysum = detValues[iD];
+ dDetPos += dDetInc;
+ }
+ }
+}
+
+ParallelRaysums::~ParallelRaysums()
+{
+ for (int i = 0; i < m_iNumCoordinates; i++)
+ delete m_vecpCoordinates[i];
+}
+
+ParallelRaysums::CoordinateContainer&
+ParallelRaysums::getSortedByTheta()
+{
+ if (m_vecpSortedByTheta.size() == 0) {
+ m_vecpSortedByTheta.resize (m_iNumCoordinates);
+ for (int i = 0; i < m_iNumCoordinates; i++)
+ m_vecpSortedByTheta[i] = m_vecpCoordinates[i];
+ std::sort (m_vecpSortedByTheta.begin(), m_vecpSortedByTheta.end(), ParallelRaysumCoordinate::compareByTheta);
+ }
+
+ return m_vecpSortedByTheta;
+}
+
+ParallelRaysums::CoordinateContainer&
+ParallelRaysums::getSortedByT()
+{
+ if (m_vecpSortedByT.size() == 0) {
+ m_vecpSortedByT.resize (m_iNumCoordinates);
+ for (int i = 0; i < m_iNumCoordinates; i++)
+ m_vecpSortedByT[i] = m_vecpCoordinates[i];
+ std::sort (m_vecpSortedByT.begin(), m_vecpSortedByT.end(), ParallelRaysumCoordinate::compareByT);
+ }
+
+ return m_vecpSortedByT;
+}
+
+
+void
+ParallelRaysums::getLimits (double* dMinT, double* dMaxT, double* dMinTheta, double* dMaxTheta) const
+{
+ if (m_iNumCoordinates <= 0)
+ return;
+
+ *dMinT = *dMaxT = m_vecpCoordinates[0]->m_dT;
+ *dMinTheta = *dMaxTheta = m_vecpCoordinates[0]->m_dTheta;
+
+ for (int i = 0; i < m_iNumCoordinates; i++) {
+ double dT = m_vecpCoordinates[i]->m_dT;
+ double dTheta = m_vecpCoordinates[i]->m_dTheta;
+
+ if (dT < *dMinT)
+ *dMinT = dT;
+ else if (dT > *dMaxT)
+ *dMaxT = dT;
+
+ if (dTheta < *dMinTheta)
+ *dMinTheta = dTheta;
+ else if (dTheta > *dMaxTheta)
+ *dMaxTheta = dTheta;
+ }