1 /*****************************************************************************
5 ** Purpose: Routines for phantom objects
6 ** Progammer: Kevin Rosenberg
7 ** Date Started: Aug 1984
9 ** This is part of the CTSim program
10 ** Copyright (c) 1983-2001 Kevin Rosenberg
12 ** $Id: phantom.cpp,v 1.29 2001/02/09 14:34:16 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 ******************************************************************************/
30 const int PhantomElement::POINTS_PER_CIRCLE = 360;
31 const double PhantomElement::SCALE_PELEM_EXTENT=0.005; // increase pelem limits by 0.5%
33 const int Phantom::PHM_INVALID = -1;
34 const int Phantom::PHM_HERMAN = 0;
35 const int Phantom::PHM_SHEPP_LOGAN = 1;
36 const int Phantom::PHM_UNITPULSE = 2;
38 const char* Phantom::s_aszPhantomName[] =
45 const char* Phantom::s_aszPhantomTitle[] =
52 const int Phantom::s_iPhantomCount = sizeof(s_aszPhantomName) / sizeof(const char*);
55 // CLASS IDENTIFICATION
65 Phantom::Phantom (const char* const phmName)
68 createFromPhantom (phmName);
79 m_composition = P_PELEMS;
86 for (PElemIterator i = m_listPElem.begin(); i != m_listPElem.end(); i++) {
93 Phantom::convertPhantomIDToName (int phmID)
95 static const char *name = "";
97 if (phmID >= 0 && phmID < s_iPhantomCount)
98 return (s_aszPhantomName[phmID]);
104 Phantom::convertPhantomIDToTitle (int phmID)
106 static const char *title = "";
108 if (phmID >= 0 && phmID < s_iPhantomCount)
109 return (s_aszPhantomName[phmID]);
115 Phantom::convertNameToPhantomID (const char* const phmName)
117 int id = PHM_INVALID;
119 for (int i = 0; i < s_iPhantomCount; i++)
120 if (strcasecmp (phmName, s_aszPhantomName[i]) == 0) {
130 Phantom::createFromPhantom (const char* const phmName)
132 int phmid = convertNameToPhantomID (phmName);
133 if (phmid == PHM_INVALID) {
135 m_failMessage = "Invalid phantom name ";
136 m_failMessage += phmName;
141 createFromPhantom (phmid);
146 Phantom::createFromPhantom (const int phmid)
153 case PHM_SHEPP_LOGAN:
157 m_composition = P_UNIT_PULSE;
158 addPElem ("rectangle", 0., 0., 100., 100., 0., 0.); // outline
159 addPElem ("ellipse", 0., 0., 1., 1., 0., 1.); // pulse
163 m_failMessage = "Illegal phantom id ";
164 m_failMessage += phmid;
174 /* METHOD IDENTIFICATION
175 * createFromFile Add PhantomElements from file
178 * createFromFile (filename)
181 * true if pelem were added
182 * false if an pelem not added
186 Phantom::createFromFile (const char* const fname)
188 bool bGoodFile = true;
191 if ((fp = fopen (fname, "r")) == NULL)
197 double cx, cy, u, v, rot, dens;
200 int status = fscanf (fp, "%79s %lf %lf %lf %lf %lf %lf", pelemtype, &cx, &cy, &u, &v, &rot, &dens);
202 if (status == static_cast<int>(EOF))
204 else if (status != 7) {
205 sys_error (ERR_WARNING, "Insufficient fields reading phantom file %s [Phantom::createFromFile]", fname);
208 addPElem (pelemtype, cx, cy, u, v, rot, dens);
217 Phantom::fileWrite (const char* const fname)
219 fstream file (fname, ios::out);
222 printDefinitions (file);
223 return ! file.fail();
230 * addPElem (type, cx, cy, u, v, rot, atten)
231 * char *type type of pelem (box, ellipse, etc)
232 * double cx, cy pelem center
233 * double u,v pelem size
234 * double rot rotation angle of pelem (in degrees)
235 * double atten x-ray attenuation cooefficient
239 Phantom::addPElem (const char *type, const double cx, const double cy, const double u, const double v, const double rot, const double atten)
241 PhantomElement *pelem = new PhantomElement (type, cx, cy, u, v, rot, atten);
243 m_listPElem.push_front (pelem);
245 // update phantom limits
246 if (m_xmin > pelem->xmin()) m_xmin = pelem->xmin();
247 if (m_xmax < pelem->xmax()) m_xmax = pelem->xmax();
248 if (m_ymin > pelem->ymin()) m_ymin = pelem->ymin();
249 if (m_ymax < pelem->ymax()) m_ymax = pelem->ymax();
255 /*----------------------------------------------------------------------*/
256 /* Input-Output Routines */
257 /*----------------------------------------------------------------------*/
261 * print Print vertices of Phantom pelems
268 Phantom::print (std::ostream& os) const
270 os << "Number of PElements: " << m_nPElem << "\n";
271 os << "Limits: xmin=" << m_xmin << ", ymin=" << m_ymin << ", xmax=" << m_xmax << ", ymax=" << m_ymax << "\n";
273 for (PElemConstIterator i = m_listPElem.begin(); i != m_listPElem.end(); i++) {
274 const PhantomElement& rPE = **i;
275 os << "PhantomElement: nPoints=" << rPE.nOutlinePoints();
276 os << ", atten=" << rPE.atten() << " rot=" << convertRadiansToDegrees (rPE.rot()) << "\n";
277 os << "xmin=" << rPE.xmin() << ", ymin=" << rPE.ymin() << ", xmax=" << rPE.xmax() << ", ymax=" << rPE.ymax() << "\n";
280 for (int i = 0; i < rPE.nOutlinePoints(); i++)
281 os << rPE.xOutline()[i] << "," << rPE.yOutline()[i] << "\n";
285 Phantom::print (std::ostringstream& os) const
287 os << "Number of PElements: " << m_nPElem << "\n";
288 os << "Limits: xmin=" << m_xmin << ", ymin=" << m_ymin << ", xmax=" << m_xmax << ", ymax=" << m_ymax << "\n";
290 for (PElemConstIterator i = m_listPElem.begin(); i != m_listPElem.end(); i++) {
291 const PhantomElement& rPE = **i;
292 os << "PhantomElement: nPoints=" << rPE.nOutlinePoints();
293 os << ", atten=" << rPE.atten() << " rot=" << convertRadiansToDegrees (rPE.rot()) << "\n";
294 os << "xmin=" << rPE.xmin() << ", ymin=" << rPE.ymin() << ", xmax=" << rPE.xmax() << ", ymax=" << rPE.ymax() << "\n";
297 for (int i = 0; i < rPE.nOutlinePoints(); i++)
298 os << rPE.xOutline()[i] << "," << rPE.yOutline()[i] << "\n";
303 Phantom::printDefinitions (std::ostream& os) const
305 for (PElemConstIterator i = m_listPElem.begin(); i != m_listPElem.end(); i++) {
306 const PhantomElement& rPE = **i;
307 rPE.printDefinition (os);
312 Phantom::printDefinitions (std::ostringstream& os) const
314 for (PElemConstIterator i = m_listPElem.begin(); i != m_listPElem.end(); i++) {
315 const PhantomElement& rPE = **i;
316 rPE.printDefinition (os);
322 * show Show vector outline of Phantom to user
330 Phantom::show () const
332 SGPDriver driverSGP ("Phantom Show");
337 std::cout << "Press return to continue";
342 Phantom::show (SGP& sgp) const
344 double wsize = m_xmax - m_xmin;
345 if ((m_ymax - m_ymin) > wsize)
346 wsize = m_ymax - m_ymin;
348 double halfWindow = wsize / 2;
350 double xcent = m_xmin + (m_xmax - m_xmin) / 2;
351 double ycent = m_ymin + (m_ymax - m_ymin) / 2;
353 sgp.setWindow (xcent - halfWindow, ycent - halfWindow, xcent + halfWindow, ycent + halfWindow);
361 * draw Draw vector outline of Phantom
369 Phantom::draw (SGP& sgp) const
371 for (PElemIterator i = m_listPElem.begin(); i != m_listPElem.end(); i++)
372 sgp.polylineAbs ((*i)->xOutline(), (*i)->yOutline(), (*i)->nOutlinePoints());
378 * addStdSheppLogan Make head phantom of Shepp-Logan
381 * S. W. Rowland, "Computer Implementation of Image Reconstruction
382 * Formulas", in "Image Reconstruction from Projections: Implementation
383 * and Applications", edited by G. T. Herman, 1978.
387 Phantom::addStdSheppLogan ()
389 addPElem ("ellipse", 0.0000, 0.0000, 0.6900, 0.9200, 0.0, 1.00);
390 addPElem ("ellipse", 0.0000, -0.0184, 0.6624, 0.8740, 0.0, -0.98);
391 addPElem ("ellipse", 0.2200, 0.0000, 0.1100, 0.3100, -18.0, -0.02);
392 addPElem ("ellipse", -0.2200, 0.0000, 0.1600, 0.4100, 18.0, -0.02);
393 addPElem ("ellipse", 0.0000, 0.3500, 0.2100, 0.2500, 0.0, 0.01);
394 addPElem ("ellipse", 0.0000, 0.1000, 0.0460, 0.0460, 0.0, 0.01);
395 addPElem ("ellipse", 0.0000, -0.1000, 0.0460, 0.0460, 0.0, 0.01);
396 addPElem ("ellipse", -0.0800, -0.6050, 0.0460, 0.0230, 0.0, 0.01);
397 addPElem ("ellipse", 0.0000, -0.6050, 0.0230, 0.0230, 0.0, 0.01);
398 addPElem ("ellipse", 0.0600, -0.6050, 0.0230, 0.0230, 0.0, 0.01);
399 addPElem ("ellipse", 0.5538, -0.3858, 0.0330, 0.2060, -18.0, 0.03);
404 * addStdHerman Standard head phantom of G. T. Herman
407 * G. T. Herman, "Image Reconstructions from Projections: The Fundementals
408 * of Computed Tomography", 1979.
412 Phantom::addStdHerman ()
414 addPElem ("ellipse", 0.000, 1.50, 0.375, 0.3000, 90.00, -0.003);
415 addPElem ("ellipse", 0.675, -0.75, 0.225, 0.1500, 140.00, 0.010);
416 addPElem ("ellipse", 0.750, 1.50, 0.375, 0.2250, 50.00, 0.003);
417 addPElem ("segment", 1.375, -7.50, 1.100, 0.6250, 19.20, -0.204);
418 addPElem ("segment", 1.375, -7.50, 1.100, 4.3200, 19.21, 0.204);
419 addPElem ("segment", 0.000, -2.25, 1.125, 0.3750, 0.00, -0.003);
420 addPElem ("segment", 0.000, -2.25, 1.125, 3.0000, 0.00, 0.003);
421 addPElem ("segment", -1.000, 3.75, 1.000, 0.5000, 135.00, -0.003);
422 addPElem ("segment", -1.000, 3.75, 1.000, 3.0000, 135.00, 0.003);
423 addPElem ("segment", 1.000, 3.75, 1.000, 0.5000, 225.00, -0.003);
424 addPElem ("segment", 1.000, 3.75, 1.000, 3.0000, 225.00, 0.003);
425 addPElem ("triangle", 5.025, 3.75, 1.125, 0.5000, 110.75, 0.206);
426 addPElem ("triangle",-5.025, 3.75, 1.125, 0.9000,-110.75, 0.206);
427 addPElem ("ellipse", 0.000, 0.00, 8.625, 6.4687, 90.00, 0.416);
428 addPElem ("ellipse", 0.000, 0.00, 7.875, 5.7187, 90.00, -0.206);
434 * convertToImagefile Make image array from Phantom
437 * pic_to_imagefile (pic, im, nsample)
438 * Phantom& pic Phantom definitions
439 * ImageFile *im Computed pixel array
440 * int nsample Number of samples along each axis for each pixel
441 * (total samples per pixel = nsample * nsample)
445 Phantom::convertToImagefile (ImageFile& im, double dViewRatio, const int in_nsample, const int trace) const
447 convertToImagefile (im, dViewRatio, in_nsample, trace, 0, im.nx(), true);
451 Phantom::convertToImagefile (ImageFile& im, const double dViewRatio, const int in_nsample, const int trace, const int colStart, const int colCount, bool bStoreAtColumnPos) const
455 if (nx < 2 || ny < 2)
458 int nsample = in_nsample;
462 double dx = m_xmax - m_xmin;
463 double dy = m_ymax - m_ymin;
464 double xcent = m_xmin + dx / 2;
465 double ycent = m_ymin + dy / 2;
466 double dHalflen = dViewRatio * (getDiameterBoundaryCircle() / SQRT2 / 2);
468 double xmin = xcent - dHalflen;
469 double xmax = xcent + dHalflen;
470 double ymin = ycent - dHalflen;
471 double ymax = ycent + dHalflen;
473 // Each pixel holds the average of the intensity of the cell with (ix,iy) at the center of the pixel
474 // Set major increments so that the last cell v[nx-1][ny-1] will start at xmax - xinc, ymax - yinc).
475 // Set minor increments so that sample points are centered in cell
477 double xinc = (xmax - xmin) / nx;
478 double yinc = (ymax - ymin) / ny;
480 double kxinc = xinc / nsample; /* interval between samples */
481 double kyinc = yinc / nsample;
482 double kxofs = kxinc / 2; /* offset of 1st point */
483 double kyofs = kyinc / 2;
485 im.setAxisExtent (xmin, xmax, ymin, ymax);
486 im.setAxisIncrement (xinc, yinc);
488 ImageFileArray v = im.getArray();
490 for (int ix = 0; ix < colCount; ix++)
491 for (int iy = 0; iy < ny; iy++) {
493 if (bStoreAtColumnPos)
494 iColStore += colStart;
495 v[iColStore][iy] = 0;
498 double x_start = xmin + (colStart * xinc);
499 for (PElemConstIterator pelem = m_listPElem.begin(); pelem != m_listPElem.end(); pelem++) {
500 const PhantomElement& rPElem = **pelem;
503 for (ix = 0, x = x_start; ix < colCount; ix++, x += xinc) {
505 if (bStoreAtColumnPos)
506 iColStore += colStart;
507 for (iy = 0, y = ymin; iy < ny; iy++, y += yinc) {
508 for (kx = 0, xi = x + kxofs; kx < nsample; kx++, xi += kxinc) {
509 for (ky = 0, yi = y + kyofs; ky < nsample; ky++, yi += kyinc)
510 if (rPElem.isPointInside (xi, yi, PHM_COORD) == TRUE)
511 v[iColStore][iy] += rPElem.atten();
519 double factor = 1.0 / static_cast<double>(nsample * nsample);
522 for (int ix = 0; ix < colCount; ix++) {
524 if (bStoreAtColumnPos)
525 iColStore += colStart;
526 for (int iy = 0; iy < ny; iy++)
527 v[iColStore][iy] *= factor;
532 ////////////////////////////////////////////////////////////////////////////////////////////////////////
533 // CLASS IDENTIFICATION
539 ////////////////////////////////////////////////////////////////////////////////////////////////////////
542 PhantomElement::PhantomElement (const char *type, const double cx, const double cy, const double u, const double v, const double rot, const double atten)
543 : m_cx(cx), m_cy(cy), m_u(u), m_v(v), m_atten(atten), m_nPoints(0), m_xOutline(0), m_yOutline(0)
545 m_rot = convertDegreesToRadians (rot); // convert angle to radians
547 m_type = convertNameToType (type);
549 makeTransformMatrices (); // calc transform matrices between phantom and normalized phantomelement
550 makeVectorOutline (); // calculate vector outline of pelem
552 m_rectLimits[0] = m_xmin; m_rectLimits[1] = m_ymin;
553 m_rectLimits[2] = m_xmax; m_rectLimits[3] = m_ymax;
558 PhantomElement::~PhantomElement ()
565 PhantomElement::printDefinition (std::ostream& os) const
567 os << convertTypeToName (m_type) << " " << m_cx << " " << m_cy << " " << m_u << " "
568 << m_v << " " << convertRadiansToDegrees (m_rot) << " " << m_atten << "\n";
572 PhantomElement::printDefinition (std::ostringstream& os) const
574 os << convertTypeToName (m_type) << " " << m_cx << " " << m_cy << " " << m_u << " "
575 << m_v << " " << convertRadiansToDegrees (m_rot) << " " << m_atten << "\n";
579 PhantomElement::convertNameToType (const char* const typeName)
581 PhmElemType type = PELEM_INVALID;
583 if (strcasecmp (typeName, "rectangle") == 0)
584 type = PELEM_RECTANGLE;
585 else if (strcasecmp (typeName, "triangle") == 0)
586 type = PELEM_TRIANGLE;
587 else if (strcasecmp (typeName, "ellipse") == 0)
588 type = PELEM_ELLIPSE;
589 else if (strcasecmp (typeName, "sector") == 0)
591 else if (strcasecmp (typeName, "segment") == 0)
592 type = PELEM_SEGMENT;
594 sys_error (ERR_WARNING, "Unknown PhantomElement type %s [PhantomElement::PhantomElement]", type);
600 PhantomElement::convertTypeToName (PhmElemType iType)
602 static char* pszType = "Unknown";
604 if (iType == PELEM_RECTANGLE)
605 pszType = "rectangle";
606 else if (iType == PELEM_TRIANGLE)
607 pszType = "triangle";
608 else if (iType == PELEM_ELLIPSE)
610 else if (iType == PELEM_SECTOR)
612 else if (iType == PELEM_SEGMENT)
620 PhantomElement::makeTransformMatrices ()
624 // To map normalized Pelem coords to world Phantom
627 // translate by (cx, cy)
629 scale_mtx2 (m_xformObjToPhm, m_u, m_v);
630 rot_mtx2 (temp, m_rot);
631 mult_mtx2 (m_xformObjToPhm, temp, m_xformObjToPhm);
632 xlat_mtx2 (temp, m_cx, m_cy);
633 mult_mtx2 (m_xformObjToPhm, temp, m_xformObjToPhm);
635 // to map world Phantom coodinates to normalized PElem coords
636 // translate by (-cx, -cy)
638 // scale by (1/u, 1/v)
640 xlat_mtx2 (m_xformPhmToObj, -m_cx, -m_cy);
641 rot_mtx2 (temp, -m_rot);
642 mult_mtx2 (m_xformPhmToObj, temp, m_xformPhmToObj);
643 scale_mtx2 (temp, 1 / m_u, 1 / m_v);
644 mult_mtx2 (m_xformPhmToObj, temp, m_xformPhmToObj);
649 * pelem_make_points INTERNAL routine to calculate point array for an pelem
652 * makepelempts (pelem)
653 * PELEM *pelem pelem whose points we are calculating
656 * Called by phm_add_pelem()
660 PhantomElement::makeVectorOutline ()
662 double radius, theta, start, stop;
668 case PELEM_RECTANGLE:
670 m_xOutline = new double [m_nPoints];
671 m_yOutline = new double [m_nPoints];
672 m_xOutline[0] =-m_u; m_yOutline[0] =-m_v;
673 m_xOutline[1] = m_u; m_yOutline[1] =-m_v;
674 m_xOutline[2] = m_u; m_yOutline[2] = m_v;
675 m_xOutline[3] =-m_u; m_yOutline[3] = m_v;
676 m_xOutline[4] =-m_u; m_yOutline[4] =-m_v;
680 m_xOutline = new double [m_nPoints];
681 m_yOutline = new double [m_nPoints];
682 m_xOutline[0] =-m_u; m_yOutline[0] = 0.0;
683 m_xOutline[1] = m_u; m_yOutline[1] = 0.0;
684 m_xOutline[2] = 0.0; m_yOutline[2] = m_v;
685 m_xOutline[3] =-m_u; m_yOutline[3] = 0.0;
688 cpts = numCirclePoints (TWOPI);
690 m_xOutline = new double [m_nPoints];
691 m_yOutline = new double [m_nPoints];
692 calcEllipsePoints (m_xOutline, m_yOutline, cpts, m_u, m_v);
695 radius = sqrt(m_u * m_u + m_v * m_v);
696 theta = atan(m_u / m_v); // angle with y-axis
697 start = 3.0 * HALFPI - theta;
698 stop = 3.0 * HALFPI + theta;
699 cpts = numCirclePoints (stop - start);
700 m_nPoints = 3 + cpts;
701 m_xOutline = new double [m_nPoints];
702 m_yOutline = new double [m_nPoints];
704 m_xOutline[0] = 0.0; m_yOutline[0] = m_v;
705 m_xOutline[1] =-m_u; m_yOutline[1] = 0.0;
706 calcArcPoints (&m_xOutline[2], &m_yOutline[2], cpts, 0.0, m_v, radius, start, stop);
707 m_xOutline[cpts + 2] = 0.0;
708 m_yOutline[cpts + 2] = m_v;
711 radius = sqrt(m_u * m_u + m_v * m_v);
712 theta = atan (m_u / m_v); // angle with y-axis
713 start = 3.0 * HALFPI - theta;
714 stop = 3.0 * HALFPI + theta;
716 cpts = numCirclePoints (stop - start);
717 m_nPoints = cpts + 1;
718 m_xOutline = new double [m_nPoints];
719 m_yOutline = new double [m_nPoints];
721 calcArcPoints (m_xOutline, m_yOutline, cpts, 0.0, m_v, radius, start, stop);
722 m_xOutline[cpts] = -m_u;
723 m_yOutline[cpts] = 0.0;
726 sys_error(ERR_WARNING, "illegal pelem type %d [makeVectorOutline]", m_type);
730 rotate2d (m_xOutline, m_yOutline, m_nPoints, m_rot);
731 xlat2d (m_xOutline, m_yOutline, m_nPoints, m_cx, m_cy);
733 minmax_array (m_xOutline, m_nPoints, m_xmin, m_xmax);
734 minmax_array (m_yOutline, m_nPoints, m_ymin, m_ymax);
736 // increase pelem extent by SCALE_PELEM_EXTENT to eliminate chance of
737 // missing actual pelem maximum due to polygonal sampling
739 xfact = (m_xmax - m_xmin) * SCALE_PELEM_EXTENT;
740 yfact = (m_ymax - m_ymin) * SCALE_PELEM_EXTENT;
750 * calc_arc Calculate outline of a arc of a circle
753 * calc_arc (x, y, xcent, ycent, pts, r, start, stop)
754 * double x[], y[]; Array of points
755 * int pts Number of points in array
756 * double xcent, ycent Center of cirlce
757 * double r Radius of circle
758 * double start, stop Beginning & ending angles
762 PhantomElement::calcArcPoints (double x[], double y[], const int pts, const double xcent, const double ycent, const double r, const double start, const double stop)
765 sys_error (ERR_WARNING, "negative or zero radius in calc_arc()");
767 double theta = (stop - start) / (pts - 1); // angle incr. between points
768 double c = cos(theta);
769 double s = sin(theta);
771 x[0] = r * cos (start) + xcent;
772 y[0] = r * sin (start) + ycent;
774 double xp = x[0] - xcent;
775 double yp = y[0] - ycent;
776 for (int i = 1; i < pts; i++) {
777 double xc = c * xp - s * yp;
778 double yc = s * xp + c * yp;
787 // PhantomElement::calcEllipsePoints Calculate outline of a ellipse
790 // calcEllipsePoints ()
795 PhantomElement::calcEllipsePoints (double x[], double y[], const int pts, const double u, const double v)
797 calcArcPoints (x, y, m_nPoints, 0.0, 0.0, 1.0, 0.0, TWOPI); // make a unit circle
798 scale2d (x, y, m_nPoints, m_u, m_v); // scale to ellipse
803 * circle_pts Calculate number of points to use for circle segment
806 * n = circle_pts (theta)
807 * int n Number of points to use for arc
808 * double theta Length of arc in radians
812 PhantomElement::numCirclePoints (double theta)
814 theta = clamp (theta, 0., TWOPI);
816 return static_cast<int> (POINTS_PER_CIRCLE * theta / TWOPI + 1.5);
821 PhantomElement::clipLineWorldCoords (double& x1, double& y1, double& x2, double &y2) const
823 /* check if ray is outside of pelem extents */
824 double cx1 = x1, cy1 = y1, cx2 = x2, cy2 = y2;
825 if (! clip_rect (cx1, cy1, cx2, cy2, m_rectLimits))
828 // convert phantom coordinates to pelem coordinates
829 xform_mtx2 (m_xformPhmToObj, x1, y1);
830 xform_mtx2 (m_xformPhmToObj, x2, y2);
832 if (! clipLineNormalizedCoords (x1, y1, x2, y2))
835 // convert standard pelem coordinates back to phantom coordinates
836 xform_mtx2 (m_xformObjToPhm, x1, y1);
837 xform_mtx2 (m_xformObjToPhm, x2, y2);
844 * pelem_clip_line Clip pelem against an arbitrary line
847 * pelem_clip_line (pelem, x1, y1, x2, y2)
848 * PhantomElement& pelem; Pelem to be clipped
849 * double *x1, *y1, *x2, *y2 Endpoints of line to be clipped
852 * true if line passes through pelem
853 * (x1, y1, x2, y2 hold coordinates of new line)
854 * false if line do not pass through pelem
855 * (x1, y1, x2, y2 are undefined)
859 PhantomElement::clipLineNormalizedCoords (double& x1, double& y1, double& x2, double& y2) const
864 case PELEM_RECTANGLE:
866 rect[0] = -1.0; rect[1] = -1.0;
867 rect[2] = 1.0; rect[3] = 1.0;
868 accept = clip_rect (x1, y1, x2, y2, rect);
871 accept = clip_circle (x1, y1, x2, y2, 0.0, 0.0, 1.0, 0.0, 0.0);
874 accept = clip_triangle (x1, y1, x2, y2, 1.0, 1.0, true);
877 accept = clip_segment (x1, y1, x2, y2, m_u, m_v);
880 accept = clip_sector (x1, y1, x2, y2, m_u, m_v);
883 sys_error (ERR_WARNING, "Illegal pelem type %d [pelem_clip_line]", m_type);
891 // METHOD IDENTIFICATION
892 // PhantomElement::isPointInside Check if point is inside pelem
895 // is_point_inside (pelem, x, y, coord_type)
896 // double x, y Point to see if lies in pelem
897 // int coord_type Coordinate type (PELEM_COORD or PHM_COORD)
900 // true if point lies within pelem
901 // false if point lies outside of pelem
904 PhantomElement::isPointInside (double x, double y, const CoordType coord_type) const
906 if (coord_type == PHM_COORD) {
907 xform_mtx2 (m_xformPhmToObj, x, y);
908 } else if (coord_type != PELEM_COORD) {
909 sys_error(ERR_WARNING, "Illegal coordinate type in pelem_is_point_inside");
914 case PELEM_RECTANGLE:
915 if (x > 1. || x < -1. || y > 1. || y < -1.)
921 if (y < 0. || y > 1. - x || y > 1. + x)
927 if (x > 1. || x < -1. || y > 1. || y < -1.)
929 if (x * x + y * y > 1.) // check if inside unit circle
935 // for clipping segments & sectors, must NOT scale by (1/u, 1/v)
936 // because this destroys information about size of arc component
939 if (x > 1. || x < -1. || y > 0.)
940 return (false); // clip against y > 0
941 x *= m_u; // put back u & v scale
943 if (x * x + (y-m_v) * (y-m_v) > m_u * m_u + m_v * m_v)
944 return (false); // clip against circle, r = sqrt(@)
949 if (x > 1. || x < -1. || y > 1.) // extent
951 if (y > 1. - x || y > 1. + x) // triangle
952 return (false); // clip against triangle
953 x *= m_u; // circle: put back u & v scale
955 if (x * x + (y-m_v) * (y-m_v) > m_u * m_u + m_v * m_v)
956 return (false); // clip against circle
961 sys_error (ERR_WARNING, "Illegal pelem type in pelem_is_point_inside()");