1 /*****************************************************************************
5 ** Purpose: Classes for CT scanner
6 ** Programmer: Kevin Rosenberg
9 ** This is part of the CTSim program
10 ** Copyright (c) 1983-2001 Kevin Rosenberg
12 ** $Id: scanner.cpp,v 1.40 2001/09/24 15:16:41 kevin Exp $
14 ** This program is free software; you can redistribute it and/or modify
15 ** it under the terms of the GNU General Public License (version 2) as
16 ** published by the Free Software Foundation.
18 ** This program is distributed in the hope that it will be useful,
19 ** but WITHOUT ANY WARRANTY; without even the implied warranty of
20 ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 ** GNU General Public License for more details.
23 ** You should have received a copy of the GNU General Public License
24 ** along with this program; if not, write to the Free Software
25 ** Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
26 ******************************************************************************/
31 const int Scanner::GEOMETRY_INVALID = -1;
32 const int Scanner::GEOMETRY_PARALLEL = 0;
33 const int Scanner::GEOMETRY_EQUIANGULAR = 1;
34 const int Scanner::GEOMETRY_EQUILINEAR = 2;
36 const char* Scanner::s_aszGeometryName[] =
43 const char* Scanner::s_aszGeometryTitle[] =
50 const int Scanner::s_iGeometryCount = sizeof(s_aszGeometryName) / sizeof(const char*);
54 // DetectorArray Construct a DetectorArray
56 DetectorArray::DetectorArray (const int nDet)
59 m_detValues = new DetectorValue [m_nDet];
64 // ~DetectorArray Free memory allocated to a detector array
66 DetectorArray::~DetectorArray (void)
68 delete [] m_detValues;
74 * Scanner::Scanner Construct a user specified detector structure
77 * Scanner (phm, nDet, nView, nSample)
78 * Phantom& phm PHANTOM that we are making detector for
79 * int geomety Geometry of detector
80 * int nDet Number of detector along detector array
81 * int nView Number of rotated views
82 * int nSample Number of rays per detector
85 Scanner::Scanner (const Phantom& phm, const char* const geometryName,
86 int nDet, int nView, int offsetView,
87 int nSample, const double rot_anglen,
88 const double dFocalLengthRatio,
89 const double dCenterDetectorRatio,
90 const double dViewRatio, const double dScanRatio)
93 m_idGeometry = convertGeometryNameToID (geometryName);
94 if (m_idGeometry == GEOMETRY_INVALID) {
96 m_failMessage = "Invalid geometry name ";
97 m_failMessage += geometryName;
101 if (nView < 1 || nDet < 1) {
103 m_failMessage = "nView & nDet must be greater than 0";
111 m_iOffsetView = offsetView;
113 m_dFocalLengthRatio = dFocalLengthRatio;
114 m_dCenterDetectorRatio = dCenterDetectorRatio;
115 m_dViewRatio = dViewRatio;
116 m_dScanRatio = dScanRatio;
118 m_dViewDiameter = phm.getDiameterBoundaryCircle() * m_dViewRatio;
119 m_dFocalLength = (m_dViewDiameter / 2) * m_dFocalLengthRatio;
120 m_dCenterDetectorLength = (m_dViewDiameter / 2) * m_dCenterDetectorRatio;
121 m_dSourceDetectorLength = m_dFocalLength + m_dCenterDetectorLength;
122 m_dScanDiameter = m_dViewDiameter * m_dScanRatio;
124 m_dXCenter = phm.xmin() + (phm.xmax() - phm.xmin()) / 2;
125 m_dYCenter = phm.ymin() + (phm.ymax() - phm.ymin()) / 2;
126 m_rotLen = rot_anglen;
127 m_rotInc = m_rotLen / m_nView;
128 if (m_idGeometry == GEOMETRY_PARALLEL) {
130 m_detLen = m_dScanDiameter;
131 m_detStart = -m_detLen / 2;
132 m_detInc = m_detLen / m_nDet;
133 double dDetectorArrayEndOffset = 0;
134 // For even number of detectors, make detInc slightly larger so that center lies
135 // at nDet/2. Also, extend detector array by one detInc so that all of the phantom is scanned
136 if (isEven (m_nDet)) { // Adjust for Even number of detectors
137 m_detInc = m_detLen / (m_nDet - 1); // center detector = (nDet/2)
138 dDetectorArrayEndOffset = m_detInc;
141 double dHalfDetLen = m_detLen / 2;
142 m_initPos.xs1 = m_dXCenter - dHalfDetLen;
143 m_initPos.ys1 = m_dYCenter + m_dFocalLength;
144 m_initPos.xs2 = m_dXCenter + dHalfDetLen + dDetectorArrayEndOffset;
145 m_initPos.ys2 = m_dYCenter + m_dFocalLength;
146 m_initPos.xd1 = m_dXCenter - dHalfDetLen;
147 m_initPos.yd1 = m_dYCenter - m_dCenterDetectorLength;
148 m_initPos.xd2 = m_dXCenter + dHalfDetLen + dDetectorArrayEndOffset;
149 m_initPos.yd2 = m_dYCenter - m_dCenterDetectorLength;
150 m_initPos.angle = m_iOffsetView * m_rotInc;
151 m_detLen += dDetectorArrayEndOffset;
152 } else if (m_idGeometry == GEOMETRY_EQUILINEAR) {
153 if (m_dScanDiameter / 2 >= m_dFocalLength) {
155 m_failMessage = "Invalid geometry: Focal length must be larger than scan length";
159 const double dAngle = asin ((m_dScanDiameter / 2) / m_dFocalLength);
160 const double dHalfDetLen = m_dSourceDetectorLength * tan (dAngle);
162 m_detLen = dHalfDetLen * 2;
163 m_detStart = -dHalfDetLen;
164 m_detInc = m_detLen / m_nDet;
165 double dDetectorArrayEndOffset = 0;
166 if (isEven (m_nDet)) { // Adjust for Even number of detectors
167 m_detInc = m_detLen / (m_nDet - 1); // center detector = (nDet/2)
168 dDetectorArrayEndOffset = m_detInc;
169 m_detLen += dDetectorArrayEndOffset;
172 m_dFanBeamAngle = dAngle * 2;
173 m_initPos.xs1 = m_dXCenter;
174 m_initPos.ys1 = m_dYCenter + m_dFocalLength;
175 m_initPos.xs2 = m_dXCenter;
176 m_initPos.ys2 = m_dYCenter + m_dFocalLength;
177 m_initPos.xd1 = m_dXCenter - dHalfDetLen;
178 m_initPos.yd1 = m_dYCenter - m_dCenterDetectorLength;
179 m_initPos.xd2 = m_dXCenter + dHalfDetLen + dDetectorArrayEndOffset;
180 m_initPos.yd2 = m_dYCenter - m_dCenterDetectorLength;
181 m_initPos.angle = m_iOffsetView * m_rotInc;
182 } else if (m_idGeometry == GEOMETRY_EQUIANGULAR) {
183 if (m_dScanDiameter / 2 > m_dFocalLength) {
185 m_failMessage = "Invalid geometry: Focal length must be larger than scan length";
188 const double dAngle = asin ((m_dScanDiameter / 2) / m_dFocalLength);
190 m_detLen = 2 * dAngle;
191 m_detStart = -dAngle;
192 m_detInc = m_detLen / m_nDet;
193 double dDetectorArrayEndOffset = 0;
194 if (isEven (m_nDet)) { // Adjust for Even number of detectors
195 m_detInc = m_detLen / (m_nDet - 1); // center detector = (nDet/2)
196 dDetectorArrayEndOffset = m_detInc;
198 // adjust for center-detector length
199 double dA1 = acos ((m_dScanDiameter / 2) / m_dCenterDetectorLength);
200 double dAngularScale = 2 * (HALFPI + dAngle - dA1) / m_detLen;
202 m_dAngularDetLen = dAngularScale * (m_detLen + dDetectorArrayEndOffset);
203 m_dAngularDetIncrement = dAngularScale * m_detInc;
204 m_initPos.dAngularDet = -m_dAngularDetLen / 2;
206 m_dFanBeamAngle = dAngle * 2;
207 m_initPos.angle = m_iOffsetView * m_rotInc;
208 m_initPos.xs1 = m_dXCenter;
209 m_initPos.ys1 = m_dYCenter + m_dFocalLength;;
210 m_initPos.xs2 = m_dXCenter;
211 m_initPos.ys2 = m_dYCenter + m_dFocalLength;
212 m_detLen += dDetectorArrayEndOffset;
215 // Calculate incrementatal rotation matrix
217 xlat_mtx2 (m_rotmtxIncrement, -m_dXCenter, -m_dYCenter);
218 rot_mtx2 (temp, m_rotInc);
219 mult_mtx2 (m_rotmtxIncrement, temp, m_rotmtxIncrement);
220 xlat_mtx2 (temp, m_dXCenter, m_dYCenter);
221 mult_mtx2 (m_rotmtxIncrement, temp, m_rotmtxIncrement);
225 Scanner::~Scanner (void)
231 Scanner::convertGeometryIDToName (const int geomID)
233 const char *name = "";
235 if (geomID >= 0 && geomID < s_iGeometryCount)
236 return (s_aszGeometryName[geomID]);
242 Scanner::convertGeometryIDToTitle (const int geomID)
244 const char *title = "";
246 if (geomID >= 0 && geomID < s_iGeometryCount)
247 return (s_aszGeometryName[geomID]);
253 Scanner::convertGeometryNameToID (const char* const geomName)
255 int id = GEOMETRY_INVALID;
257 for (int i = 0; i < s_iGeometryCount; i++)
258 if (strcasecmp (geomName, s_aszGeometryName[i]) == 0) {
268 * collectProjections Calculate projections for a Phantom
271 * collectProjections (proj, phm, start_view, nView, bStoreViewPos, trace)
272 * Projectrions& proj Projection storage
273 * Phantom& phm Phantom for which we collect projections
274 * bool bStoreViewPos TRUE then storage proj at normal view position
275 * int trace Trace level
280 Scanner::collectProjections (Projections& proj, const Phantom& phm, const int trace, SGP* pSGP)
282 collectProjections (proj, phm, m_startView, proj.nView(), m_iOffsetView, true, trace, pSGP);
286 Scanner::collectProjections (Projections& proj, const Phantom& phm, const int iStartView,
287 const int iNumViews, const int iOffsetView, bool bStoreAtViewPosition,
288 const int trace, SGP* pSGP)
290 int iStorageOffset = (bStoreAtViewPosition ? iStartView : 0);
291 collectProjections (proj, phm, iStartView, iNumViews, iOffsetView, iStorageOffset, trace, pSGP);
295 Scanner::collectProjections (Projections& proj, const Phantom& phm, const int iStartView,
296 const int iNumViews, const int iOffsetView, int iStorageOffset,
297 const int trace, SGP* pSGP)
300 double start_angle = (iStartView + iOffsetView) * proj.rotInc();
302 // Calculate initial rotation matrix
303 GRFMTX_2D rotmtx_initial, temp;
304 xlat_mtx2 (rotmtx_initial, -m_dXCenter, -m_dYCenter);
305 rot_mtx2 (temp, start_angle);
306 mult_mtx2 (rotmtx_initial, temp, rotmtx_initial);
307 xlat_mtx2 (temp, m_dXCenter, m_dYCenter);
308 mult_mtx2 (rotmtx_initial, temp, rotmtx_initial);
310 double xd1=0, yd1=0, xd2=0, yd2=0;
311 if (m_idGeometry != GEOMETRY_EQUIANGULAR) {
316 xform_mtx2 (rotmtx_initial, xd1, yd1); // rotate detector endpoints
317 xform_mtx2 (rotmtx_initial, xd2, yd2); // to initial view_angle
320 double xs1 = m_initPos.xs1;
321 double ys1 = m_initPos.ys1;
322 double xs2 = m_initPos.xs2;
323 double ys2 = m_initPos.ys2;
324 xform_mtx2 (rotmtx_initial, xs1, ys1); // rotate source endpoints to
325 xform_mtx2 (rotmtx_initial, xs2, ys2); // initial view angle
329 for (iView = 0, viewAngle = start_angle; iView < iNumViews; iView++, viewAngle += proj.rotInc()) {
330 int iStoragePosition = iView + iStorageOffset;
332 DetectorArray& detArray = proj.getDetectorArray( iStoragePosition );
335 if (pSGP && m_trace >= Trace::TRACE_PHANTOM) {
337 double dWindowSize = dmax (m_detLen, m_dSourceDetectorLength) * 2;
338 double dHalfWindowSize = dWindowSize / 2;
339 m_dXMinWin = m_dXCenter - dHalfWindowSize;
340 m_dXMaxWin = m_dXCenter + dHalfWindowSize;
341 m_dYMinWin = m_dYCenter - dHalfWindowSize;
342 m_dYMaxWin = m_dYCenter + dHalfWindowSize;
344 m_pSGP->setWindow (m_dXMinWin, m_dYMinWin, m_dXMaxWin, m_dYMaxWin);
345 m_pSGP->setRasterOp (RO_COPY);
347 m_pSGP->setColor (C_RED);
348 m_pSGP->moveAbs (0., 0.);
349 m_pSGP->drawCircle (m_dViewDiameter / 2);
351 m_pSGP->moveAbs (0., 0.);
352 m_pSGP->setColor (C_GREEN);
353 m_pSGP->drawCircle (m_dFocalLength);
354 m_pSGP->setColor (C_BLUE);
355 m_pSGP->setTextPointSize (9);
357 m_dTextHeight = m_pSGP->getCharHeight ();
359 traceShowParam ("Phantom:", "%s", PROJECTION_TRACE_ROW_PHANT_ID, C_BLACK, phm.name().c_str());
360 traceShowParam ("Geometry:", "%s", PROJECTION_TRACE_ROW_GEOMETRY, C_BLUE, convertGeometryIDToName(m_idGeometry));
361 traceShowParam ("Focal Length Ratio:", "%.2f", PROJECTION_TRACE_ROW_FOCAL_LENGTH, C_BLUE, m_dFocalLengthRatio);
362 // traceShowParam ("Field Of View Ratio:", "%.2f", PROJECTION_TRACE_ROW_FIELD_OF_VIEW, C_BLUE, m_dFieldOfViewRatio);
363 traceShowParam ("Num Detectors:", "%d", PROJECTION_TRACE_ROW_NDET, C_BLUE, proj.nDet());
364 traceShowParam ("Num Views:", "%d", PROJECTION_TRACE_ROW_NVIEW, C_BLUE, proj.nView());
365 traceShowParam ("Samples / Ray:", "%d", PROJECTION_TRACE_ROW_SAMPLES, C_BLUE, m_nSample);
367 m_pSGP->setMarker (SGP::MARKER_BDIAMOND);
372 if (m_pSGP && m_trace >= Trace::TRACE_PHANTOM) {
373 m_pSGP->setColor (C_BLACK);
374 m_pSGP->setPenWidth (2);
375 if (m_idGeometry == GEOMETRY_PARALLEL) {
376 m_pSGP->moveAbs (xs1, ys1);
377 m_pSGP->lineAbs (xs2, ys2);
378 m_pSGP->moveAbs (xd1, yd1);
379 m_pSGP->lineAbs (xd2, yd2);
380 } else if (m_idGeometry == GEOMETRY_EQUILINEAR) {
381 m_pSGP->setPenWidth (4);
382 m_pSGP->moveAbs (xs1, ys1);
383 m_pSGP->lineAbs (xs2, ys2);
384 m_pSGP->setPenWidth (2);
385 m_pSGP->moveAbs (xd1, yd1);
386 m_pSGP->lineAbs (xd2, yd2);
387 } else if (m_idGeometry == GEOMETRY_EQUIANGULAR) {
388 m_pSGP->setPenWidth (4);
389 m_pSGP->moveAbs (xs1, ys1);
390 m_pSGP->lineAbs (xs2, ys2);
391 m_pSGP->setPenWidth (2);
392 m_pSGP->moveAbs (0., 0.);
393 m_pSGP->drawArc (m_dCenterDetectorLength, viewAngle + 3 * HALFPI - (m_dAngularDetLen/2), viewAngle + 3 * HALFPI + (m_dAngularDetLen/2));
395 m_pSGP->setPenWidth (1);
397 if (m_trace > Trace::TRACE_CONSOLE)
398 traceShowParam ("Current View:", "%d (%.0f%%)", PROJECTION_TRACE_ROW_CURR_VIEW, C_RED, iView + iStartView, (iView + iStartView) / static_cast<double>(m_nView) * 100.);
400 if (m_trace == Trace::TRACE_CONSOLE)
401 std::cout << "Current View: " << iView+iStartView << std::endl;
403 projectSingleView (phm, detArray, xd1, yd1, xd2, yd2, xs1, ys1, xs2, ys2, viewAngle + 3 * HALFPI);
404 detArray.setViewAngle (viewAngle);
407 if (m_pSGP && m_trace >= Trace::TRACE_PHANTOM) {
408 // rs_plot (detArray, xd1, yd1, dXCenter, dYCenter, theta);
411 xform_mtx2 (m_rotmtxIncrement, xs1, ys1);
412 xform_mtx2 (m_rotmtxIncrement, xs2, ys2);
413 if (m_idGeometry != GEOMETRY_EQUIANGULAR) {
414 xform_mtx2 (m_rotmtxIncrement, xd1, yd1); // rotate detector endpoints
415 xform_mtx2 (m_rotmtxIncrement, xd2, yd2);
417 } /* for each iView */
422 * rayview Calculate raysums for a view at any angle
425 * rayview (phm, detArray, xd1, nSample, yd1, xd2, yd2, xs1, ys1, xs2, ys2)
426 * Phantom& phm Phantom to scan
427 * DETARRAY *detArray Storage of values for detector array
428 * Scanner& det Scanner parameters
429 * double xd1, yd1, xd2, yd2 Beginning & ending detector positions
430 * double xs1, ys1, xs2, ys2 Beginning & ending source positions
433 * For each detector, have there are a variable number of rays traced.
434 * The source of each ray is the center of the source x-ray cell. The
435 * detector positions are equally spaced within the cell
437 * The increments between rays are calculated so that the cells start
438 * at the beginning of a detector cell and they end on the endpoint
439 * of the cell. Thus, the last cell starts at (xd2-ddx),(yd2-ddy).
440 * The exception to this is if there is only one ray per detector.
441 * In that case, the detector position is the center of the detector cell.
445 Scanner::projectSingleView (const Phantom& phm, DetectorArray& detArray, const double xd1, const double yd1, const double xd2, const double yd2, const double xs1, const double ys1, const double xs2, const double ys2, const double dDetAngle)
448 double sdx = (xs2 - xs1) / detArray.nDet(); // change in coords
449 double sdy = (ys2 - ys1) / detArray.nDet(); // between source
450 double xs_maj = xs1 + (sdx / 2); // put ray source in center of cell
451 double ys_maj = ys1 + (sdy / 2);
453 double ddx=0, ddy=0, ddx2=0, ddy2=0, ddx2_ofs=0, ddy2_ofs=0, xd_maj=0, yd_maj=0;
454 double dAngleInc=0, dAngleSampleInc=0, dAngleSampleOffset=0, dAngleMajor=0;
455 if (m_idGeometry == GEOMETRY_EQUIANGULAR) {
456 dAngleInc = m_dAngularDetIncrement;
457 dAngleSampleInc = dAngleInc / m_nSample;
458 dAngleSampleOffset = dAngleSampleInc / 2;
459 dAngleMajor = dDetAngle - (m_dAngularDetLen/2) + dAngleSampleOffset;
461 ddx = (xd2 - xd1) / detArray.nDet(); // change in coords
462 ddy = (yd2 - yd1) / detArray.nDet(); // between detectors
463 ddx2 = ddx / m_nSample; // Incr. between rays with detector cell
464 ddy2 = ddy / m_nSample; // Doesn't include detector endpoints
465 ddx2_ofs = ddx2 / 2; // offset of 1st ray from start of detector cell
468 xd_maj = xd1 + ddx2_ofs; // Incr. between detector cells
469 yd_maj = yd1 + ddy2_ofs;
472 DetectorValue* detval = detArray.detValues();
474 if (phm.getComposition() == P_UNIT_PULSE) { // put unit pulse in center of view
475 for (int d = 0; d < detArray.nDet(); d++)
477 detval[ detArray.nDet() / 2 ] = 1;
479 for (int d = 0; d < detArray.nDet(); d++) {
482 double xd=0, yd=0, dAngle=0;
483 if (m_idGeometry == GEOMETRY_EQUIANGULAR) {
484 dAngle = dAngleMajor;
490 for (unsigned int i = 0; i < m_nSample; i++) {
491 if (m_idGeometry == GEOMETRY_EQUIANGULAR) {
492 xd = m_dCenterDetectorLength * cos (dAngle);
493 yd = m_dCenterDetectorLength * sin (dAngle);
497 if (m_pSGP && m_trace >= Trace::TRACE_PROJECTIONS) {
498 m_pSGP->setColor (C_YELLOW);
499 m_pSGP->setRasterOp (RO_AND);
500 m_pSGP->moveAbs (xs, ys);
501 m_pSGP->lineAbs (xd, yd);
505 sum += projectSingleLine (phm, xd, yd, xs, ys);
508 // if (m_trace >= Trace::TRACE_CLIPPING) {
509 // traceShowParam ("Attenuation:", "%s", PROJECTION_TRACE_ROW_ATTEN, C_LTMAGENTA, " ");
510 // traceShowParam ("Attenuation:", "%.3f", PROJECTION_TRACE_ROW_ATTEN, C_LTMAGENTA, sum);
513 if (m_idGeometry == GEOMETRY_EQUIANGULAR)
514 dAngle += dAngleSampleInc;
519 } // for each sample in detector
521 detval[d] = sum / m_nSample;
524 if (m_idGeometry == GEOMETRY_EQUIANGULAR)
525 dAngleMajor += dAngleInc;
530 } /* for each detector */
531 } /* if not unit pulse */
536 Scanner::traceShowParam (const char *szLabel, const char *fmt, int row, int color, ...)
539 va_start(arg, color);
541 traceShowParamRasterOp (RO_COPY, szLabel, fmt, row, color, arg);
543 traceShowParamRasterOp (0, szLabel, fmt, row, color, arg);
549 Scanner::traceShowParamXOR (const char *szLabel, const char *fmt, int row, int color, ...)
552 va_start(arg, color);
554 traceShowParamRasterOp (RO_XOR, szLabel, fmt, row, color, arg);
556 traceShowParamRasterOp (0, szLabel, fmt, row, color, arg);
562 Scanner::traceShowParamRasterOp (int iRasterOp, const char *szLabel, const char *fmt, int row, int color, va_list args)
566 vsnprintf (szValue, sizeof(szValue), fmt, args);
570 m_pSGP->setRasterOp (iRasterOp);
571 m_pSGP->setTextColor (color, -1);
572 double dValueOffset = (m_dXMaxWin - m_dXMinWin) / 4;
574 double dYPos = m_dYMaxWin - (row * m_dTextHeight);
575 double dXPos = m_dXMinWin;
576 m_pSGP->moveAbs (dXPos, dYPos);
577 m_pSGP->drawText (szLabel);
578 m_pSGP->moveAbs (dXPos + dValueOffset, dYPos);
579 m_pSGP->drawText (szValue);
582 double dYPos = m_dYMaxWin - (row * m_dTextHeight);
583 double dXPos = m_dXMinWin + (m_dXMaxWin - m_dXMinWin) * 0.5;
584 m_pSGP->moveAbs (dXPos, dYPos);
585 m_pSGP->drawText (szLabel);
586 m_pSGP->moveAbs (dXPos + dValueOffset, dYPos);
587 m_pSGP->drawText (szValue);
592 cio_put_str (szLabel);
593 cio_put_str (szValue);
601 * projectSingleLine INTERNAL: Calculates raysum along a line for a Phantom
604 * rsum = phm_ray_attenuation (phm, x1, y1, x2, y2)
605 * double rsum Ray sum of Phantom along given line
606 * Phantom& phm; Phantom from which to calculate raysum
607 * double *x1, *y1, *x2, y2 Endpoints of ray path (in Phantom coords)
611 Scanner::projectSingleLine (const Phantom& phm, const double x1, const double y1, const double x2, const double y2)
613 // check ray against each pelem in Phantom
615 for (PElemConstIterator i = phm.listPElem().begin(); i != phm.listPElem().end(); i++)
616 rsum += projectLineAgainstPElem (**i, x1, y1, x2, y2);
623 * pelem_ray_attenuation Calculate raysum of an pelem along one line
626 * rsum = pelem_ray_attenuation (pelem, x1, y1, x2, y2)
627 * double rsum Computed raysum
628 * PhantomElement& pelem Pelem to scan
629 * double x1, y1, x2, y2 Endpoints of raysum line
633 Scanner::projectLineAgainstPElem (const PhantomElement& pelem, double x1, double y1, double x2, double y2)
635 if (! pelem.clipLineWorldCoords (x1, y1, x2, y2)) {
636 if (m_trace == Trace::TRACE_CLIPPING)
637 cio_tone (1000., 0.05);
642 if (m_pSGP && m_trace == Trace::TRACE_CLIPPING) {
643 m_pSGP->setRasterOp (RO_XOR);
644 m_pSGP->moveAbs (x1, y1);
645 m_pSGP->lineAbs (x2, y2);
646 cio_tone (8000., 0.05);
647 m_pSGP->moveAbs (x1, y1);
648 m_pSGP->lineAbs (x2, y2);
649 m_pSGP->setRasterOp (RO_SET);
653 double len = lineLength (x1, y1, x2, y2);
654 return (len * pelem.atten());