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) 1983-2009 Kevin Rosenberg
12 ** This program is free software; you can redistribute it and/or modify
13 ** it under the terms of the GNU General Public License (version 2) as
14 ** published by the Free Software Foundation.
16 ** This program is distributed in the hope that it will be useful,
17 ** but WITHOUT ANY WARRANTY; without even the implied warranty of
18 ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 ** GNU General Public License for more details.
21 ** You should have received a copy of the GNU General Public License
22 ** along with this program; if not, write to the Free Software
23 ** Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
24 ******************************************************************************/
28 const int PhantomElement::POINTS_PER_CIRCLE = 360;
29 const double PhantomElement::SCALE_PELEM_EXTENT=0.000; // increase pelem limits by 0.5%
30 //const double PhantomElement::SCALE_PELEM_EXTENT=0.005; // increase pelem limits by 0.5%
32 const int Phantom::PHM_INVALID = -1;
33 const int Phantom::PHM_HERMAN = 0;
34 const int Phantom::PHM_SHEPP_LOGAN = 1;
35 const int Phantom::PHM_UNITPULSE = 2;
37 const char* Phantom::s_aszPhantomName[] =
44 const char* Phantom::s_aszPhantomTitle[] =
51 const int Phantom::s_iPhantomCount = sizeof(s_aszPhantomName) / sizeof(const char*);
54 // CLASS IDENTIFICATION
64 Phantom::Phantom (const char* const phmName)
67 createFromPhantom (phmName);
78 m_composition = P_PELEMS;
86 for (PElemIterator i = m_listPElem.begin(); i != m_listPElem.end(); i++) {
94 Phantom::convertPhantomIDToName (int phmID)
96 static const char *name = "";
98 if (phmID >= 0 && phmID < s_iPhantomCount)
99 return (s_aszPhantomName[phmID]);
105 Phantom::convertPhantomIDToTitle (int phmID)
107 static const char *title = "";
109 if (phmID >= 0 && phmID < s_iPhantomCount)
110 return (s_aszPhantomName[phmID]);
116 Phantom::convertNameToPhantomID (const char* const phmName)
118 int id = PHM_INVALID;
120 for (int i = 0; i < s_iPhantomCount; i++) {
121 if (strcasecmp (phmName, s_aszPhantomName[i]) == 0) {
131 Phantom::createFromPhantom (const char* const phmName)
133 int phmid = convertNameToPhantomID (phmName);
134 if (phmid == PHM_INVALID) {
136 m_failMessage = "Invalid phantom name ";
137 m_failMessage += phmName;
142 createFromPhantom (phmid);
147 Phantom::createFromPhantom (const int phmid)
154 case PHM_SHEPP_LOGAN:
158 m_composition = P_UNIT_PULSE;
159 addPElem ("rectangle", 0., 0., 100., 100., 0., 0.); // outline
160 addPElem ("ellipse", 0., 0., 1., 1., 0., 1.); // pulse
164 m_failMessage = "Illegal phantom id ";
165 m_failMessage += phmid;
175 /* METHOD IDENTIFICATION
176 * createFromPhmFile Add PhantomElements from file
179 * createFromPhmFile (filename)
182 * true if pelem were added
183 * false if an pelem not added
187 Phantom::createFromPhmFile (const char* const fname)
189 bool bGoodFile = true;
192 if ((fp = fopen (fname, "r")) == NULL)
198 double cx, cy, u, v, rot, dens;
201 int status = fscanf (fp, "%79s %lf %lf %lf %lf %lf %lf", pelemtype, &cx, &cy, &u, &v, &rot, &dens);
203 if (status == static_cast<int>(EOF))
205 else if (status != 7) {
206 sys_error (ERR_WARNING, "Insufficient fields reading phantom file %s [Phantom::createFromPhmFile]", fname);
209 addPElem (pelemtype, cx, cy, u, v, rot, dens);
218 Phantom::createFromImageFile (const char* const fname)
220 bool bGoodFile = true;
222 m_im = new ImageFile ();
223 if (! m_im || ! m_im->fileRead (fname)) {
224 sys_error (ERR_SEVERE, "Unable to read image file %s", fname);
234 if (! m_im->getAxisExtent(m_xmin, m_xmax, m_ymin, m_ymax)) {
235 m_xmax = m_im->nx() / 2.; m_xmin = -m_xmax;
236 m_ymax = m_im->ny() / 2.; m_ymin = -m_ymax;
244 Phantom::fileWrite (const char* const fname)
246 fstream file (fname, std::ios::out);
249 printDefinitions (file);
250 return ! file.fail();
257 * addPElem (type, cx, cy, u, v, rot, atten)
258 * char *type type of pelem (box, ellipse, etc)
259 * double cx, cy pelem center
260 * double u,v pelem size
261 * double rot rotation angle of pelem (in degrees)
262 * double atten x-ray attenuation cooefficient
266 Phantom::addPElem (const char *type, const double cx, const double cy, const double u, const double v, const double rot, const double atten)
268 PhmElemType pe_type = PhantomElement::convertNameToType (type);
269 if (pe_type == PELEM_INVALID) {
270 sys_error (ERR_WARNING, "Unknown PhantomElement type %s [PhantomElement::PhantomElement]", type);
274 PhantomElement *pelem = new PhantomElement (type, cx, cy, u, v, rot, atten);
275 m_listPElem.push_front (pelem);
277 // update phantom limits
278 if (m_xmin > pelem->xmin()) m_xmin = pelem->xmin();
279 if (m_xmax < pelem->xmax()) m_xmax = pelem->xmax();
280 if (m_ymin > pelem->ymin()) m_ymin = pelem->ymin();
281 if (m_ymax < pelem->ymax()) m_ymax = pelem->ymax();
287 /*----------------------------------------------------------------------*/
288 /* Input-Output Routines */
289 /*----------------------------------------------------------------------*/
293 * print Print vertices of Phantom pelems
300 Phantom::print (std::ostream& os) const
302 os << "Number of PElements: " << m_nPElem << "\n";
303 os << "Limits: xmin=" << m_xmin << ", ymin=" << m_ymin << ", xmax=" << m_xmax << ", ymax=" << m_ymax << "\n";
305 for (PElemConstIterator i = m_listPElem.begin(); i != m_listPElem.end(); i++) {
306 const PhantomElement& rPE = **i;
307 os << "PhantomElement: nPoints=" << rPE.nOutlinePoints();
308 os << ", atten=" << rPE.atten() << " rot=" << convertRadiansToDegrees (rPE.rot()) << "\n";
309 os << "xmin=" << rPE.xmin() << ", ymin=" << rPE.ymin() << ", xmax=" << rPE.xmax() << ", ymax=" << rPE.ymax() << "\n";
312 for (int i = 0; i < rPE.nOutlinePoints(); i++)
313 os << rPE.xOutline()[i] << "," << rPE.yOutline()[i] << "\n";
317 Phantom::print (std::ostringstream& os) const
319 os << "Number of PElements: " << m_nPElem << "\n";
320 os << "Limits: xmin=" << m_xmin << ", ymin=" << m_ymin << ", xmax=" << m_xmax << ", ymax=" << m_ymax << "\n";
322 for (PElemConstIterator i = m_listPElem.begin(); i != m_listPElem.end(); i++) {
323 const PhantomElement& rPE = **i;
324 os << "PhantomElement: nPoints=" << rPE.nOutlinePoints();
325 os << ", atten=" << rPE.atten() << " rot=" << convertRadiansToDegrees (rPE.rot()) << "\n";
326 os << "xmin=" << rPE.xmin() << ", ymin=" << rPE.ymin() << ", xmax=" << rPE.xmax() << ", ymax=" << rPE.ymax() << "\n";
329 for (int i = 0; i < rPE.nOutlinePoints(); i++)
330 os << rPE.xOutline()[i] << "," << rPE.yOutline()[i] << "\n";
335 Phantom::printDefinitions (std::ostream& os) const
337 for (PElemConstIterator i = m_listPElem.begin(); i != m_listPElem.end(); i++) {
338 const PhantomElement& rPE = **i;
339 rPE.printDefinition (os);
344 Phantom::printDefinitions (std::ostringstream& os) const
346 for (PElemConstIterator i = m_listPElem.begin(); i != m_listPElem.end(); i++) {
347 const PhantomElement& rPE = **i;
348 rPE.printDefinition (os);
354 * show Show vector outline of Phantom to user
362 Phantom::show () const
364 SGPDriver driverSGP ("Phantom Show");
369 std::cout << "Press return to continue";
374 Phantom::show (SGP& sgp) const
376 double wsize = m_xmax - m_xmin;
377 if ((m_ymax - m_ymin) > wsize)
378 wsize = m_ymax - m_ymin;
380 double halfWindow = wsize / 2;
382 double xcent = m_xmin + (m_xmax - m_xmin) / 2;
383 double ycent = m_ymin + (m_ymax - m_ymin) / 2;
385 sgp.setWindow (xcent - halfWindow, ycent - halfWindow, xcent + halfWindow, ycent + halfWindow);
393 * draw Draw vector outline of Phantom
401 Phantom::draw (SGP& sgp) const
403 for (PElemIterator i = m_listPElem.begin(); i != m_listPElem.end(); i++)
404 sgp.polylineAbs ((*i)->xOutline(), (*i)->yOutline(), (*i)->nOutlinePoints());
410 * addStdSheppLogan Make head phantom of Shepp-Logan
413 * S. W. Rowland, "Computer Implementation of Image Reconstruction
414 * Formulas", in "Image Reconstruction from Projections: Implementation
415 * and Applications", edited by G. T. Herman, 1978.
419 Phantom::addStdSheppLogan ()
421 addPElem ("ellipse", 0.0000, 0.0000, 0.6900, 0.9200, 0.0, 1.00);
422 addPElem ("ellipse", 0.0000, -0.0184, 0.6624, 0.8740, 0.0, -0.98);
423 addPElem ("ellipse", 0.2200, 0.0000, 0.1100, 0.3100, -18.0, -0.02);
424 addPElem ("ellipse", -0.2200, 0.0000, 0.1600, 0.4100, 18.0, -0.02);
425 addPElem ("ellipse", 0.0000, 0.3500, 0.2100, 0.2500, 0.0, 0.01);
426 addPElem ("ellipse", 0.0000, 0.1000, 0.0460, 0.0460, 0.0, 0.01);
427 addPElem ("ellipse", 0.0000, -0.1000, 0.0460, 0.0460, 0.0, 0.01);
428 addPElem ("ellipse", -0.0800, -0.6050, 0.0460, 0.0230, 0.0, 0.01);
429 addPElem ("ellipse", 0.0000, -0.6050, 0.0230, 0.0230, 0.0, 0.01);
430 addPElem ("ellipse", 0.0600, -0.6050, 0.0230, 0.0230, 0.0, 0.01);
431 addPElem ("ellipse", 0.5538, -0.3858, 0.0330, 0.2060, -18.0, 0.03);
436 * addStdHerman Standard head phantom of G. T. Herman
439 * G. T. Herman, "Image Reconstructions from Projections: The Fundementals
440 * of Computed Tomography", 1979.
444 Phantom::addStdHerman ()
446 addPElem ("ellipse", 0.000, 1.50, 0.375, 0.3000, 90.00, -0.003);
447 addPElem ("ellipse", 0.675, -0.75, 0.225, 0.1500, 140.00, 0.010);
448 addPElem ("ellipse", 0.750, 1.50, 0.375, 0.2250, 50.00, 0.003);
449 addPElem ("segment", 1.375, -7.50, 1.100, 0.6250, 19.20, -0.204);
450 addPElem ("segment", 1.375, -7.50, 1.100, 4.3200, 19.21, 0.204);
451 addPElem ("segment", 0.000, -2.25, 1.125, 0.3750, 0.00, -0.003);
452 addPElem ("segment", 0.000, -2.25, 1.125, 3.0000, 0.00, 0.003);
453 addPElem ("segment", -1.000, 3.75, 1.000, 0.5000, 135.00, -0.003);
454 addPElem ("segment", -1.000, 3.75, 1.000, 3.0000, 135.00, 0.003);
455 addPElem ("segment", 1.000, 3.75, 1.000, 0.5000, 225.00, -0.003);
456 addPElem ("segment", 1.000, 3.75, 1.000, 3.0000, 225.00, 0.003);
457 addPElem ("triangle", 5.025, 3.75, 1.125, 0.5000, 110.75, 0.206);
458 addPElem ("triangle",-5.025, 3.75, 1.125, 0.9000,-110.75, 0.206);
459 addPElem ("ellipse", 0.000, 0.00, 8.625, 6.4687, 90.00, 0.416);
460 addPElem ("ellipse", 0.000, 0.00, 7.875, 5.7187, 90.00, -0.206);
466 * convertToImagefile Make image array from Phantom
469 * pic_to_imagefile (pic, im, nsample)
470 * Phantom& pic Phantom definitions
471 * ImageFile *im Computed pixel array
472 * int nsample Number of samples along each axis for each pixel
473 * (total samples per pixel = nsample * nsample)
477 Phantom::convertToImagefile (ImageFile& im, double dViewRatio, const int in_nsample, const int trace) const
479 convertToImagefile (im, dViewRatio, in_nsample, trace, 0, im.nx(), true);
483 Phantom::convertToImagefile (ImageFile& im, const double dViewRatio, const int in_nsample, const int trace,
484 const int colStart, const int colCount, bool bStoreAtColumnPos) const
486 int iStorageOffset = (bStoreAtColumnPos ? colStart : 0);
487 convertToImagefile (im, im.nx(), dViewRatio, in_nsample, trace, colStart, colCount, iStorageOffset);
491 Phantom::convertToImagefile (ImageFile& im, const int iTotalRasterCols, const double dViewRatio,
492 const int in_nsample, const int trace, const int colStart, const int colCount, int iStorageOffset) const
494 const int nx = im.nx();
495 const int ny = im.ny();
496 if (nx < 2 || ny < 2)
499 int nsample = in_nsample;
503 double dx = m_xmax - m_xmin;
504 double dy = m_ymax - m_ymin;
505 double xcent = m_xmin + dx / 2;
506 double ycent = m_ymin + dy / 2;
507 double dHalflen = dViewRatio * (getDiameterBoundaryCircle() / SQRT2 / 2);
509 double xmin = xcent - dHalflen;
510 double xmax = xcent + dHalflen;
511 double ymin = ycent - dHalflen;
512 double ymax = ycent + dHalflen;
514 // Each pixel holds the average of the intensity of the cell with (ix,iy) at the center of the pixel
515 // Set major increments so that the last cell v[nx-1][ny-1] will start at xmax - xinc, ymax - yinc).
516 // Set minor increments so that sample points are centered in cell
518 double xinc = (xmax - xmin) / (iTotalRasterCols);
519 double yinc = (ymax - ymin) / ny;
521 double kxinc = xinc / nsample; /* interval between samples */
522 double kyinc = yinc / nsample;
523 double kxofs = kxinc / 2; /* offset of 1st point */
524 double kyofs = kyinc / 2;
526 im.setAxisExtent (xmin, xmax, ymin, ymax);
527 im.setAxisIncrement (xinc, yinc);
529 ImageFileArray v = im.getArray();
531 for (int ix = 0; ix < colCount; ix++) {
532 int iColStore = ix + iStorageOffset;
533 ImageFileColumn vCol = v[iColStore];
534 for (int iy = 0; iy < ny; iy++)
539 double x_start = xmin + (colStart * xinc);
540 for (PElemConstIterator pelem = m_listPElem.begin(); pelem != m_listPElem.end(); pelem++) {
541 const PhantomElement& rPElem = **pelem;
542 #pragma omp parallel for
543 for (int ix = 0; ix < colCount; ix++) {
544 double x = x_start + ix * xinc;
545 int iColStore = ix + iStorageOffset;
546 ImageFileColumn vCol = v[iColStore];
549 for (int iy = 0; iy < ny; iy++, y += yinc) {
551 double xi = x + kxofs;
552 for (int kx = 0; kx < nsample; kx++, xi += kxinc) {
553 double yi = y + kyofs;
554 for (int ky = 0; ky < nsample; ky++, yi += kyinc) {
555 if (rPElem.isPointInside (xi, yi, PHM_COORD))
556 dAtten += rPElem.atten();
566 double x_start = xmin + (colStart * xinc);
567 for (PElemConstIterator pelem = m_listPElem.begin(); pelem != m_listPElem.end(); pelem++) {
568 const PhantomElement& rPElem = **pelem;
571 for (ix = 0, x = x_start; ix < colCount; ix++, x += xinc) {
572 int iColStore = ix + iStorageOffset;
573 ImageFileColumn vCol = v[iColStore];
574 for (iy = 0, y = ymin; iy < ny; iy++, y += yinc) {
576 for (kx = 0, xi = x + kxofs; kx < nsample; kx++, xi += kxinc) {
577 for (ky = 0, yi = y + kyofs; ky < nsample; ky++, yi += kyinc)
578 if (rPElem.isPointInside (xi, yi, PHM_COORD))
579 dAtten += rPElem.atten();
588 double factor = 1.0 / static_cast<double>(nsample * nsample);
590 #pragma omp parallel for
592 for (int ix = 0; ix < colCount; ix++) {
593 int iColStore = ix + iStorageOffset;
594 ImageFileColumn vCol = v[iColStore];
595 for (int iy = 0; iy < ny; iy++)
601 ////////////////////////////////////////////////////////////////////////////////////////////////////////
602 // CLASS IDENTIFICATION
608 ////////////////////////////////////////////////////////////////////////////////////////////////////////
611 PhantomElement::PhantomElement (const char *type, const double cx, const double cy, const double u, const double v, const double rot, const double atten)
612 : m_cx(cx), m_cy(cy), m_u(u), m_v(v), m_atten(atten), m_nPoints(0), m_xOutline(0), m_yOutline(0)
614 m_rot = convertDegreesToRadians (rot); // convert angle to radians
616 m_type = convertNameToType (type);
618 makeTransformMatrices (); // calc transform matrices between phantom and normalized phantomelement
619 makeVectorOutline (); // calculate vector outline of pelem
621 m_rectLimits[0] = m_xmin; m_rectLimits[1] = m_ymin;
622 m_rectLimits[2] = m_xmax; m_rectLimits[3] = m_ymax;
627 PhantomElement::~PhantomElement ()
634 PhantomElement::printDefinition (std::ostream& os) const
636 os << convertTypeToName (m_type) << " " << m_cx << " " << m_cy << " " << m_u << " "
637 << m_v << " " << convertRadiansToDegrees (m_rot) << " " << m_atten << "\n";
641 PhantomElement::printDefinition (std::ostringstream& os) const
643 os << convertTypeToName (m_type) << " " << m_cx << " " << m_cy << " " << m_u << " "
644 << m_v << " " << convertRadiansToDegrees (m_rot) << " " << m_atten << "\n";
648 PhantomElement::convertNameToType (const char* const typeName)
650 PhmElemType type = PELEM_INVALID;
652 if (strcasecmp (typeName, "rectangle") == 0)
653 type = PELEM_RECTANGLE;
654 else if (strcasecmp (typeName, "triangle") == 0)
655 type = PELEM_TRIANGLE;
656 else if (strcasecmp (typeName, "ellipse") == 0)
657 type = PELEM_ELLIPSE;
658 else if (strcasecmp (typeName, "sector") == 0)
660 else if (strcasecmp (typeName, "segment") == 0)
661 type = PELEM_SEGMENT;
667 PhantomElement::convertTypeToName (PhmElemType iType)
669 static const char* pszType = "Unknown";
671 if (iType == PELEM_RECTANGLE)
672 pszType = "rectangle";
673 else if (iType == PELEM_TRIANGLE)
674 pszType = "triangle";
675 else if (iType == PELEM_ELLIPSE)
677 else if (iType == PELEM_SECTOR)
679 else if (iType == PELEM_SEGMENT)
687 PhantomElement::makeTransformMatrices ()
691 // To map normalized Pelem coords to world Phantom
694 // translate by (cx, cy)
696 scale_mtx2 (m_xformObjToPhm, m_u, m_v);
697 rot_mtx2 (temp, m_rot);
698 mult_mtx2 (m_xformObjToPhm, temp, m_xformObjToPhm);
699 xlat_mtx2 (temp, m_cx, m_cy);
700 mult_mtx2 (m_xformObjToPhm, temp, m_xformObjToPhm);
702 // to map world Phantom coodinates to normalized PElem coords
703 // translate by (-cx, -cy)
705 // scale by (1/u, 1/v)
707 xlat_mtx2 (m_xformPhmToObj, -m_cx, -m_cy);
708 rot_mtx2 (temp, -m_rot);
709 mult_mtx2 (m_xformPhmToObj, temp, m_xformPhmToObj);
710 scale_mtx2 (temp, 1 / m_u, 1 / m_v);
711 mult_mtx2 (m_xformPhmToObj, temp, m_xformPhmToObj);
716 * pelem_make_points INTERNAL routine to calculate point array for an pelem
719 * makepelempts (pelem)
720 * PELEM *pelem pelem whose points we are calculating
723 * Called by phm_add_pelem()
727 PhantomElement::makeVectorOutline ()
729 double radius, theta, start, stop;
735 case PELEM_RECTANGLE:
737 m_xOutline = new double [m_nPoints];
738 m_yOutline = new double [m_nPoints];
739 m_xOutline[0] =-m_u; m_yOutline[0] =-m_v;
740 m_xOutline[1] = m_u; m_yOutline[1] =-m_v;
741 m_xOutline[2] = m_u; m_yOutline[2] = m_v;
742 m_xOutline[3] =-m_u; m_yOutline[3] = m_v;
743 m_xOutline[4] =-m_u; m_yOutline[4] =-m_v;
747 m_xOutline = new double [m_nPoints];
748 m_yOutline = new double [m_nPoints];
749 m_xOutline[0] =-m_u; m_yOutline[0] = 0.0;
750 m_xOutline[1] = m_u; m_yOutline[1] = 0.0;
751 m_xOutline[2] = 0.0; m_yOutline[2] = m_v;
752 m_xOutline[3] =-m_u; m_yOutline[3] = 0.0;
755 cpts = numCirclePoints (TWOPI);
757 m_xOutline = new double [m_nPoints];
758 m_yOutline = new double [m_nPoints];
759 calcEllipsePoints (m_xOutline, m_yOutline, cpts, m_u, m_v);
762 radius = sqrt(m_u * m_u + m_v * m_v);
763 theta = atan(m_u / m_v); // angle with y-axis
764 start = 3.0 * HALFPI - theta;
765 stop = 3.0 * HALFPI + theta;
766 cpts = numCirclePoints (stop - start);
767 m_nPoints = 3 + cpts;
768 m_xOutline = new double [m_nPoints];
769 m_yOutline = new double [m_nPoints];
771 m_xOutline[0] = 0.0; m_yOutline[0] = m_v;
772 m_xOutline[1] =-m_u; m_yOutline[1] = 0.0;
773 calcArcPoints (&m_xOutline[2], &m_yOutline[2], cpts, 0.0, m_v, radius, start, stop);
774 m_xOutline[cpts + 2] = 0.0;
775 m_yOutline[cpts + 2] = m_v;
778 radius = sqrt(m_u * m_u + m_v * m_v);
779 theta = atan (m_u / m_v); // angle with y-axis
780 start = 3.0 * HALFPI - theta;
781 stop = 3.0 * HALFPI + theta;
783 cpts = numCirclePoints (stop - start);
784 m_nPoints = cpts + 1;
785 m_xOutline = new double [m_nPoints];
786 m_yOutline = new double [m_nPoints];
788 calcArcPoints (m_xOutline, m_yOutline, cpts, 0.0, m_v, radius, start, stop);
789 m_xOutline[cpts] = -m_u;
790 m_yOutline[cpts] = 0.0;
793 sys_error(ERR_WARNING, "Illegal phantom element type %d [makeVectorOutline]", m_type);
797 rotate2d (m_xOutline, m_yOutline, m_nPoints, m_rot);
798 xlat2d (m_xOutline, m_yOutline, m_nPoints, m_cx, m_cy);
800 minmax_array (m_xOutline, m_nPoints, m_xmin, m_xmax);
801 minmax_array (m_yOutline, m_nPoints, m_ymin, m_ymax);
803 // increase pelem extent by SCALE_PELEM_EXTENT to eliminate chance of
804 // missing actual pelem maximum due to polygonal sampling
806 xfact = (m_xmax - m_xmin) * SCALE_PELEM_EXTENT;
807 yfact = (m_ymax - m_ymin) * SCALE_PELEM_EXTENT;
817 * calc_arc Calculate outline of a arc of a circle
820 * calc_arc (x, y, xcent, ycent, pts, r, start, stop)
821 * double x[], y[]; Array of points
822 * int pts Number of points in array
823 * double xcent, ycent Center of cirlce
824 * double r Radius of circle
825 * double start, stop Beginning & ending angles
829 PhantomElement::calcArcPoints (double x[], double y[], const int pts, const double xcent, const double ycent, const double r, const double start, const double stop)
832 sys_error (ERR_WARNING, "negative or zero radius in calc_arc()");
834 double theta = (stop - start) / (pts - 1); // angle incr. between points
835 double c = cos(theta);
836 double s = sin(theta);
838 x[0] = r * cos (start) + xcent;
839 y[0] = r * sin (start) + ycent;
841 double xp = x[0] - xcent;
842 double yp = y[0] - ycent;
843 for (int i = 1; i < pts; i++) {
844 double xc = c * xp - s * yp;
845 double yc = s * xp + c * yp;
854 // PhantomElement::calcEllipsePoints Calculate outline of a ellipse
857 // calcEllipsePoints ()
862 PhantomElement::calcEllipsePoints (double x[], double y[], const int pts, const double u, const double v)
864 calcArcPoints (x, y, m_nPoints, 0.0, 0.0, 1.0, 0.0, TWOPI); // make a unit circle
865 scale2d (x, y, m_nPoints, m_u, m_v); // scale to ellipse
870 * circle_pts Calculate number of points to use for circle segment
873 * n = circle_pts (theta)
874 * int n Number of points to use for arc
875 * double theta Length of arc in radians
879 PhantomElement::numCirclePoints (double theta)
881 theta = clamp (theta, 0., TWOPI);
883 return static_cast<int> (POINTS_PER_CIRCLE * theta / TWOPI + 1.5);
888 PhantomElement::clipLineWorldCoords (double& x1, double& y1, double& x2, double &y2) const
890 /* check if ray is outside of pelem extents */
891 double cx1 = x1, cy1 = y1, cx2 = x2, cy2 = y2;
892 if (! clip_rect (cx1, cy1, cx2, cy2, m_rectLimits))
895 // convert phantom coordinates to pelem coordinates
896 xform_mtx2 (m_xformPhmToObj, x1, y1);
897 xform_mtx2 (m_xformPhmToObj, x2, y2);
899 if (! clipLineNormalizedCoords (x1, y1, x2, y2))
902 // convert standard pelem coordinates back to phantom coordinates
903 xform_mtx2 (m_xformObjToPhm, x1, y1);
904 xform_mtx2 (m_xformObjToPhm, x2, y2);
911 * pelem_clip_line Clip pelem against an arbitrary line
914 * pelem_clip_line (pelem, x1, y1, x2, y2)
915 * PhantomElement& pelem; Pelem to be clipped
916 * double *x1, *y1, *x2, *y2 Endpoints of line to be clipped
919 * true if line passes through pelem
920 * (x1, y1, x2, y2 hold coordinates of new line)
921 * false if line do not pass through pelem
922 * (x1, y1, x2, y2 are undefined)
926 PhantomElement::clipLineNormalizedCoords (double& x1, double& y1, double& x2, double& y2) const
931 case PELEM_RECTANGLE:
933 rect[0] = -1.0; rect[1] = -1.0;
934 rect[2] = 1.0; rect[3] = 1.0;
935 accept = clip_rect (x1, y1, x2, y2, rect);
938 accept = clip_circle (x1, y1, x2, y2, 0.0, 0.0, 1.0, 0.0, 0.0);
941 accept = clip_triangle (x1, y1, x2, y2, 1.0, 1.0, true);
944 accept = clip_segment (x1, y1, x2, y2, m_u, m_v);
947 accept = clip_sector (x1, y1, x2, y2, m_u, m_v);
950 sys_error (ERR_WARNING, "Illegal pelem type %d [pelem_clip_line]", m_type);
958 // METHOD IDENTIFICATION
959 // PhantomElement::isPointInside Check if point is inside pelem
962 // is_point_inside (pelem, x, y, coord_type)
963 // double x, y Point to see if lies in pelem
964 // int coord_type Coordinate type (PELEM_COORD or PHM_COORD)
967 // true if point lies within pelem
968 // false if point lies outside of pelem
971 PhantomElement::isPointInside (double x, double y, const CoordType coord_type) const
973 if (coord_type == PHM_COORD) {
974 xform_mtx2 (m_xformPhmToObj, x, y);
975 } else if (coord_type != PELEM_COORD) {
976 sys_error(ERR_WARNING, "Illegal coordinate type in pelem_is_point_inside");
981 case PELEM_RECTANGLE:
982 if (x > 1. || x < -1. || y > 1. || y < -1.)
988 if (y < 0. || y > 1. - x || y > 1. + x)
994 if (x > 1. || x < -1. || y > 1. || y < -1.)
996 if (x * x + y * y > 1.) // check if inside unit circle
1002 // for clipping segments & sectors, must NOT scale by (1/u, 1/v)
1003 // because this destroys information about size of arc component
1006 if (x > 1. || x < -1. || y > 0.)
1007 return (false); // clip against y > 0
1008 x *= m_u; // put back u & v scale
1010 if (x * x + (y-m_v) * (y-m_v) > m_u * m_u + m_v * m_v)
1011 return (false); // clip against circle, r = sqrt(@)
1016 if (x > 1. || x < -1. || y > 1.) // extent
1018 if (y > 1. - x || y > 1. + x) // triangle
1019 return (false); // clip against triangle
1020 x *= m_u; // circle: put back u & v scale
1022 if (x * x + (y-m_v) * (y-m_v) > m_u * m_u + m_v * m_v)
1023 return (false); // clip against circle
1028 sys_error (ERR_WARNING, "Illegal pelem type in pelem_is_point_inside()");