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/*
-----------------------------------------------------------------------
Copyright: 2010-2018, imec Vision Lab, University of Antwerp
2014-2018, CWI, Amsterdam
Contact: astra@astra-toolbox.com
Website: http://www.astra-toolbox.com/
This file is part of the ASTRA Toolbox.
The ASTRA Toolbox is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
The ASTRA Toolbox is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with the ASTRA Toolbox. If not, see <http://www.gnu.org/licenses/>.
-----------------------------------------------------------------------
*/
#define policy_weight(p,rayindex,volindex,weight) do { if (p.pixelPrior(volindex)) { p.addWeight(rayindex, volindex, weight); p.pixelPosterior(volindex); } } while (false)
template <typename Policy>
void CFanFlatBeamLineKernelProjector2D::project(Policy& p)
{
projectBlock_internal(0, m_pProjectionGeometry->getProjectionAngleCount(),
0, m_pProjectionGeometry->getDetectorCount(), p);
}
template <typename Policy>
void CFanFlatBeamLineKernelProjector2D::projectSingleProjection(int _iProjection, Policy& p)
{
projectBlock_internal(_iProjection, _iProjection + 1,
0, m_pProjectionGeometry->getDetectorCount(), p);
}
template <typename Policy>
void CFanFlatBeamLineKernelProjector2D::projectSingleRay(int _iProjection, int _iDetector, Policy& p)
{
projectBlock_internal(_iProjection, _iProjection + 1,
_iDetector, _iDetector + 1, p);
}
//----------------------------------------------------------------------------------------
// PROJECT BLOCK - vector projection geometry
template <typename Policy>
void CFanFlatBeamLineKernelProjector2D::projectBlock_internal(int _iProjFrom, int _iProjTo, int _iDetFrom, int _iDetTo, Policy& p)
{
// get vector geometry
const CFanFlatVecProjectionGeometry2D* pVecProjectionGeometry;
if (dynamic_cast<CFanFlatProjectionGeometry2D*>(m_pProjectionGeometry)) {
pVecProjectionGeometry = dynamic_cast<CFanFlatProjectionGeometry2D*>(m_pProjectionGeometry)->toVectorGeometry();
} else {
pVecProjectionGeometry = dynamic_cast<CFanFlatVecProjectionGeometry2D*>(m_pProjectionGeometry);
}
// precomputations
const float32 pixelLengthX = m_pVolumeGeometry->getPixelLengthX();
const float32 pixelLengthY = m_pVolumeGeometry->getPixelLengthY();
const float32 inv_pixelLengthX = 1.0f / pixelLengthX;
const float32 inv_pixelLengthY = 1.0f / pixelLengthY;
const int colCount = m_pVolumeGeometry->getGridColCount();
const int rowCount = m_pVolumeGeometry->getGridRowCount();
const int detCount = pVecProjectionGeometry->getDetectorCount();
const float32 Ex = m_pVolumeGeometry->getWindowMinX() + pixelLengthX*0.5f;
const float32 Ey = m_pVolumeGeometry->getWindowMaxY() - pixelLengthY*0.5f;
// loop angles
for (int iAngle = _iProjFrom; iAngle < _iProjTo; ++iAngle) {
// variables
float32 Dx, Dy, Rx, Ry, S, T, weight, c, r, deltac, deltar, offset, RxOverRy, RyOverRx;
float32 lengthPerRow, lengthPerCol, invTminSTimesLengthPerRow, invTminSTimesLengthPerCol;
int iVolumeIndex, iRayIndex, row, col, iDetector;
const SFanProjection * proj = &pVecProjectionGeometry->getProjectionVectors()[iAngle];
float32 detSize = sqrt(proj->fDetUX * proj->fDetUX + proj->fDetUY * proj->fDetUY);
// loop detectors
for (iDetector = _iDetFrom; iDetector < _iDetTo; ++iDetector) {
iRayIndex = iAngle * detCount + iDetector;
// POLICY: RAY PRIOR
if (!p.rayPrior(iRayIndex)) continue;
Dx = proj->fDetSX + (iDetector+0.5f) * proj->fDetUX;
Dy = proj->fDetSY + (iDetector+0.5f) * proj->fDetUY;
Rx = proj->fSrcX - Dx;
Ry = proj->fSrcY - Dy;
bool vertical = fabs(Rx) < fabs(Ry);
bool isin = false;
// vertically
if (vertical) {
RxOverRy = Rx/Ry;
lengthPerRow = detSize * pixelLengthX * sqrt(Rx*Rx + Ry*Ry) / abs(Ry);
deltac = -pixelLengthY * RxOverRy * inv_pixelLengthX;
S = 0.5f - 0.5f*fabs(RxOverRy);
T = 0.5f + 0.5f*fabs(RxOverRy);
invTminSTimesLengthPerRow = lengthPerRow / (T - S);
// calculate c for row 0
c = (Dx + (Ey - Dy)*RxOverRy - Ex) * inv_pixelLengthX;
// for each row
for (row = 0; row < rowCount; ++row, c += deltac) {
col = int(floor(c+0.5f));
if (col < -1 || col > colCount) { if (!isin) continue; else break; }
offset = c - float32(col);
// left
if (offset < -S) {
weight = (offset + T) * invTminSTimesLengthPerRow;
iVolumeIndex = row * colCount + col - 1;
if (col > 0) { policy_weight(p, iRayIndex, iVolumeIndex, lengthPerRow-weight); }
iVolumeIndex++;
if (col >= 0 && col < colCount) { policy_weight(p, iRayIndex, iVolumeIndex, weight); }
}
// right
else if (S < offset) {
weight = (offset - S) * invTminSTimesLengthPerRow;
iVolumeIndex = row * colCount + col;
if (col >= 0 && col < colCount) { policy_weight(p, iRayIndex, iVolumeIndex, lengthPerRow-weight); }
iVolumeIndex++;
if (col + 1 < colCount) { policy_weight(p, iRayIndex, iVolumeIndex, weight); }
}
// centre
else if (col >= 0 && col < colCount) {
iVolumeIndex = row * colCount + col;
policy_weight(p, iRayIndex, iVolumeIndex, lengthPerRow);
}
isin = true;
}
}
// horizontally
else {
RyOverRx = Ry/Rx;
lengthPerCol = detSize * pixelLengthY * sqrt(Rx*Rx + Ry*Ry) / abs(Rx);
deltar = -pixelLengthX * RyOverRx * inv_pixelLengthY;
S = 0.5f - 0.5f*fabs(RyOverRx);
T = 0.5f + 0.5f*fabs(RyOverRx);
invTminSTimesLengthPerCol = lengthPerCol / (T - S);
// calculate r for col 0
r = -(Dy + (Ex - Dx)*RyOverRx - Ey) * inv_pixelLengthY;
// for each col
for (col = 0; col < colCount; ++col, r += deltar) {
row = int(floor(r+0.5f));
if (row < -1 || row > rowCount) { if (!isin) continue; else break; }
offset = r - float32(row);
// up
if (offset < -S) {
weight = (offset + T) * invTminSTimesLengthPerCol;
iVolumeIndex = (row-1) * colCount + col;
if (row > 0) { policy_weight(p, iRayIndex, iVolumeIndex, lengthPerCol-weight); }
iVolumeIndex += colCount;
if (row >= 0 && row < rowCount) { policy_weight(p, iRayIndex, iVolumeIndex, weight); }
}
// down
else if (S < offset) {
weight = (offset - S) * invTminSTimesLengthPerCol;
iVolumeIndex = row * colCount + col;
if (row >= 0 && row < rowCount) { policy_weight(p, iRayIndex, iVolumeIndex, lengthPerCol-weight); }
iVolumeIndex += colCount;
if (row + 1 < rowCount) { policy_weight(p, iRayIndex, iVolumeIndex, weight); }
}
// centre
else if (row >= 0 && row < rowCount) {
iVolumeIndex = row * colCount + col;
policy_weight(p, iRayIndex, iVolumeIndex, lengthPerCol);
}
isin = true;
}
}
// POLICY: RAY POSTERIOR
p.rayPosterior(iRayIndex);
} // end loop detector
} // end loop angles
// Delete created vec geometry if required
if (dynamic_cast<CFanFlatProjectionGeometry2D*>(m_pProjectionGeometry))
delete pVecProjectionGeometry;
}
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