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
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=0.000; // increase pelem limits by 0.5%
32 //const double PhantomElement::SCALE_PELEM_EXTENT=0.005; // increase pelem limits by 0.5%
34 const int Phantom::PHM_INVALID = -1;
35 const int Phantom::PHM_HERMAN = 0;
36 const int Phantom::PHM_SHEPP_LOGAN = 1;
37 const int Phantom::PHM_UNITPULSE = 2;
39 const char* Phantom::s_aszPhantomName[] =
46 const char* Phantom::s_aszPhantomTitle[] =
53 const int Phantom::s_iPhantomCount = sizeof(s_aszPhantomName) / sizeof(const char*);
56 // CLASS IDENTIFICATION
66 Phantom::Phantom (const char* const phmName)
69 createFromPhantom (phmName);
80 m_composition = P_PELEMS;
87 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 * createFromFile Add PhantomElements from file
179 * createFromFile (filename)
182 * true if pelem were added
183 * false if an pelem not added
187 Phantom::createFromFile (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::createFromFile]", fname);
209 addPElem (pelemtype, cx, cy, u, v, rot, dens);
218 Phantom::fileWrite (const char* const fname)
220 fstream file (fname, std::ios::out);
223 printDefinitions (file);
224 return ! file.fail();
231 * addPElem (type, cx, cy, u, v, rot, atten)
232 * char *type type of pelem (box, ellipse, etc)
233 * double cx, cy pelem center
234 * double u,v pelem size
235 * double rot rotation angle of pelem (in degrees)
236 * double atten x-ray attenuation cooefficient
240 Phantom::addPElem (const char *type, const double cx, const double cy, const double u, const double v, const double rot, const double atten)
242 PhmElemType pe_type = PhantomElement::convertNameToType (type);
243 if (pe_type == PELEM_INVALID) {
244 sys_error (ERR_WARNING, "Unknown PhantomElement type %s [PhantomElement::PhantomElement]", type);
248 PhantomElement *pelem = new PhantomElement (type, cx, cy, u, v, rot, atten);
249 m_listPElem.push_front (pelem);
251 // update phantom limits
252 if (m_xmin > pelem->xmin()) m_xmin = pelem->xmin();
253 if (m_xmax < pelem->xmax()) m_xmax = pelem->xmax();
254 if (m_ymin > pelem->ymin()) m_ymin = pelem->ymin();
255 if (m_ymax < pelem->ymax()) m_ymax = pelem->ymax();
261 /*----------------------------------------------------------------------*/
262 /* Input-Output Routines */
263 /*----------------------------------------------------------------------*/
267 * print Print vertices of Phantom pelems
274 Phantom::print (std::ostream& os) const
276 os << "Number of PElements: " << m_nPElem << "\n";
277 os << "Limits: xmin=" << m_xmin << ", ymin=" << m_ymin << ", xmax=" << m_xmax << ", ymax=" << m_ymax << "\n";
279 for (PElemConstIterator i = m_listPElem.begin(); i != m_listPElem.end(); i++) {
280 const PhantomElement& rPE = **i;
281 os << "PhantomElement: nPoints=" << rPE.nOutlinePoints();
282 os << ", atten=" << rPE.atten() << " rot=" << convertRadiansToDegrees (rPE.rot()) << "\n";
283 os << "xmin=" << rPE.xmin() << ", ymin=" << rPE.ymin() << ", xmax=" << rPE.xmax() << ", ymax=" << rPE.ymax() << "\n";
286 for (int i = 0; i < rPE.nOutlinePoints(); i++)
287 os << rPE.xOutline()[i] << "," << rPE.yOutline()[i] << "\n";
291 Phantom::print (std::ostringstream& os) const
293 os << "Number of PElements: " << m_nPElem << "\n";
294 os << "Limits: xmin=" << m_xmin << ", ymin=" << m_ymin << ", xmax=" << m_xmax << ", ymax=" << m_ymax << "\n";
296 for (PElemConstIterator i = m_listPElem.begin(); i != m_listPElem.end(); i++) {
297 const PhantomElement& rPE = **i;
298 os << "PhantomElement: nPoints=" << rPE.nOutlinePoints();
299 os << ", atten=" << rPE.atten() << " rot=" << convertRadiansToDegrees (rPE.rot()) << "\n";
300 os << "xmin=" << rPE.xmin() << ", ymin=" << rPE.ymin() << ", xmax=" << rPE.xmax() << ", ymax=" << rPE.ymax() << "\n";
303 for (int i = 0; i < rPE.nOutlinePoints(); i++)
304 os << rPE.xOutline()[i] << "," << rPE.yOutline()[i] << "\n";
309 Phantom::printDefinitions (std::ostream& os) const
311 for (PElemConstIterator i = m_listPElem.begin(); i != m_listPElem.end(); i++) {
312 const PhantomElement& rPE = **i;
313 rPE.printDefinition (os);
318 Phantom::printDefinitions (std::ostringstream& os) const
320 for (PElemConstIterator i = m_listPElem.begin(); i != m_listPElem.end(); i++) {
321 const PhantomElement& rPE = **i;
322 rPE.printDefinition (os);
328 * show Show vector outline of Phantom to user
336 Phantom::show () const
338 SGPDriver driverSGP ("Phantom Show");
343 std::cout << "Press return to continue";
348 Phantom::show (SGP& sgp) const
350 double wsize = m_xmax - m_xmin;
351 if ((m_ymax - m_ymin) > wsize)
352 wsize = m_ymax - m_ymin;
354 double halfWindow = wsize / 2;
356 double xcent = m_xmin + (m_xmax - m_xmin) / 2;
357 double ycent = m_ymin + (m_ymax - m_ymin) / 2;
359 sgp.setWindow (xcent - halfWindow, ycent - halfWindow, xcent + halfWindow, ycent + halfWindow);
367 * draw Draw vector outline of Phantom
375 Phantom::draw (SGP& sgp) const
377 for (PElemIterator i = m_listPElem.begin(); i != m_listPElem.end(); i++)
378 sgp.polylineAbs ((*i)->xOutline(), (*i)->yOutline(), (*i)->nOutlinePoints());
384 * addStdSheppLogan Make head phantom of Shepp-Logan
387 * S. W. Rowland, "Computer Implementation of Image Reconstruction
388 * Formulas", in "Image Reconstruction from Projections: Implementation
389 * and Applications", edited by G. T. Herman, 1978.
393 Phantom::addStdSheppLogan ()
395 addPElem ("ellipse", 0.0000, 0.0000, 0.6900, 0.9200, 0.0, 1.00);
396 addPElem ("ellipse", 0.0000, -0.0184, 0.6624, 0.8740, 0.0, -0.98);
397 addPElem ("ellipse", 0.2200, 0.0000, 0.1100, 0.3100, -18.0, -0.02);
398 addPElem ("ellipse", -0.2200, 0.0000, 0.1600, 0.4100, 18.0, -0.02);
399 addPElem ("ellipse", 0.0000, 0.3500, 0.2100, 0.2500, 0.0, 0.01);
400 addPElem ("ellipse", 0.0000, 0.1000, 0.0460, 0.0460, 0.0, 0.01);
401 addPElem ("ellipse", 0.0000, -0.1000, 0.0460, 0.0460, 0.0, 0.01);
402 addPElem ("ellipse", -0.0800, -0.6050, 0.0460, 0.0230, 0.0, 0.01);
403 addPElem ("ellipse", 0.0000, -0.6050, 0.0230, 0.0230, 0.0, 0.01);
404 addPElem ("ellipse", 0.0600, -0.6050, 0.0230, 0.0230, 0.0, 0.01);
405 addPElem ("ellipse", 0.5538, -0.3858, 0.0330, 0.2060, -18.0, 0.03);
410 * addStdHerman Standard head phantom of G. T. Herman
413 * G. T. Herman, "Image Reconstructions from Projections: The Fundementals
414 * of Computed Tomography", 1979.
418 Phantom::addStdHerman ()
420 addPElem ("ellipse", 0.000, 1.50, 0.375, 0.3000, 90.00, -0.003);
421 addPElem ("ellipse", 0.675, -0.75, 0.225, 0.1500, 140.00, 0.010);
422 addPElem ("ellipse", 0.750, 1.50, 0.375, 0.2250, 50.00, 0.003);
423 addPElem ("segment", 1.375, -7.50, 1.100, 0.6250, 19.20, -0.204);
424 addPElem ("segment", 1.375, -7.50, 1.100, 4.3200, 19.21, 0.204);
425 addPElem ("segment", 0.000, -2.25, 1.125, 0.3750, 0.00, -0.003);
426 addPElem ("segment", 0.000, -2.25, 1.125, 3.0000, 0.00, 0.003);
427 addPElem ("segment", -1.000, 3.75, 1.000, 0.5000, 135.00, -0.003);
428 addPElem ("segment", -1.000, 3.75, 1.000, 3.0000, 135.00, 0.003);
429 addPElem ("segment", 1.000, 3.75, 1.000, 0.5000, 225.00, -0.003);
430 addPElem ("segment", 1.000, 3.75, 1.000, 3.0000, 225.00, 0.003);
431 addPElem ("triangle", 5.025, 3.75, 1.125, 0.5000, 110.75, 0.206);
432 addPElem ("triangle",-5.025, 3.75, 1.125, 0.9000,-110.75, 0.206);
433 addPElem ("ellipse", 0.000, 0.00, 8.625, 6.4687, 90.00, 0.416);
434 addPElem ("ellipse", 0.000, 0.00, 7.875, 5.7187, 90.00, -0.206);
440 * convertToImagefile Make image array from Phantom
443 * pic_to_imagefile (pic, im, nsample)
444 * Phantom& pic Phantom definitions
445 * ImageFile *im Computed pixel array
446 * int nsample Number of samples along each axis for each pixel
447 * (total samples per pixel = nsample * nsample)
451 Phantom::convertToImagefile (ImageFile& im, double dViewRatio, const int in_nsample, const int trace) const
453 convertToImagefile (im, dViewRatio, in_nsample, trace, 0, im.nx(), true);
457 Phantom::convertToImagefile (ImageFile& im, const double dViewRatio, const int in_nsample, const int trace,
458 const int colStart, const int colCount, bool bStoreAtColumnPos) const
460 int iStorageOffset = (bStoreAtColumnPos ? colStart : 0);
461 convertToImagefile (im, im.nx(), dViewRatio, in_nsample, trace, colStart, colCount, iStorageOffset);
465 Phantom::convertToImagefile (ImageFile& im, const int iTotalRasterCols, const double dViewRatio,
466 const int in_nsample, const int trace, const int colStart, const int colCount, int iStorageOffset) const
468 const int nx = im.nx();
469 const int ny = im.ny();
470 if (nx < 2 || ny < 2)
473 int nsample = in_nsample;
477 double dx = m_xmax - m_xmin;
478 double dy = m_ymax - m_ymin;
479 double xcent = m_xmin + dx / 2;
480 double ycent = m_ymin + dy / 2;
481 double dHalflen = dViewRatio * (getDiameterBoundaryCircle() / SQRT2 / 2);
483 double xmin = xcent - dHalflen;
484 double xmax = xcent + dHalflen;
485 double ymin = ycent - dHalflen;
486 double ymax = ycent + dHalflen;
488 // Each pixel holds the average of the intensity of the cell with (ix,iy) at the center of the pixel
489 // Set major increments so that the last cell v[nx-1][ny-1] will start at xmax - xinc, ymax - yinc).
490 // Set minor increments so that sample points are centered in cell
492 double xinc = (xmax - xmin) / (iTotalRasterCols);
493 double yinc = (ymax - ymin) / ny;
495 double kxinc = xinc / nsample; /* interval between samples */
496 double kyinc = yinc / nsample;
497 double kxofs = kxinc / 2; /* offset of 1st point */
498 double kyofs = kyinc / 2;
500 im.setAxisExtent (xmin, xmax, ymin, ymax);
501 im.setAxisIncrement (xinc, yinc);
503 ImageFileArray v = im.getArray();
505 for (int ix = 0; ix < colCount; ix++) {
506 int iColStore = ix + iStorageOffset;
507 ImageFileColumn vCol = v[iColStore];
508 for (int iy = 0; iy < ny; iy++)
512 double x_start = xmin + (colStart * xinc);
513 for (PElemConstIterator pelem = m_listPElem.begin(); pelem != m_listPElem.end(); pelem++) {
514 const PhantomElement& rPElem = **pelem;
517 for (ix = 0, x = x_start; ix < colCount; ix++, x += xinc) {
518 int iColStore = ix + iStorageOffset;
519 ImageFileColumn vCol = v[iColStore];
520 for (iy = 0, y = ymin; iy < ny; iy++, y += yinc) {
522 for (kx = 0, xi = x + kxofs; kx < nsample; kx++, xi += kxinc) {
523 for (ky = 0, yi = y + kyofs; ky < nsample; ky++, yi += kyinc)
524 if (rPElem.isPointInside (xi, yi, PHM_COORD))
525 dAtten += rPElem.atten();
534 double factor = 1.0 / static_cast<double>(nsample * nsample);
537 for (int ix = 0; ix < colCount; ix++) {
538 int iColStore = ix + iStorageOffset;
539 ImageFileColumn vCol = v[iColStore];
540 for (int iy = 0; iy < ny; iy++)
546 ////////////////////////////////////////////////////////////////////////////////////////////////////////
547 // CLASS IDENTIFICATION
553 ////////////////////////////////////////////////////////////////////////////////////////////////////////
556 PhantomElement::PhantomElement (const char *type, const double cx, const double cy, const double u, const double v, const double rot, const double atten)
557 : m_cx(cx), m_cy(cy), m_u(u), m_v(v), m_atten(atten), m_nPoints(0), m_xOutline(0), m_yOutline(0)
559 m_rot = convertDegreesToRadians (rot); // convert angle to radians
561 m_type = convertNameToType (type);
563 makeTransformMatrices (); // calc transform matrices between phantom and normalized phantomelement
564 makeVectorOutline (); // calculate vector outline of pelem
566 m_rectLimits[0] = m_xmin; m_rectLimits[1] = m_ymin;
567 m_rectLimits[2] = m_xmax; m_rectLimits[3] = m_ymax;
572 PhantomElement::~PhantomElement ()
579 PhantomElement::printDefinition (std::ostream& os) const
581 os << convertTypeToName (m_type) << " " << m_cx << " " << m_cy << " " << m_u << " "
582 << m_v << " " << convertRadiansToDegrees (m_rot) << " " << m_atten << "\n";
586 PhantomElement::printDefinition (std::ostringstream& os) const
588 os << convertTypeToName (m_type) << " " << m_cx << " " << m_cy << " " << m_u << " "
589 << m_v << " " << convertRadiansToDegrees (m_rot) << " " << m_atten << "\n";
593 PhantomElement::convertNameToType (const char* const typeName)
595 PhmElemType type = PELEM_INVALID;
597 if (strcasecmp (typeName, "rectangle") == 0)
598 type = PELEM_RECTANGLE;
599 else if (strcasecmp (typeName, "triangle") == 0)
600 type = PELEM_TRIANGLE;
601 else if (strcasecmp (typeName, "ellipse") == 0)
602 type = PELEM_ELLIPSE;
603 else if (strcasecmp (typeName, "sector") == 0)
605 else if (strcasecmp (typeName, "segment") == 0)
606 type = PELEM_SEGMENT;
612 PhantomElement::convertTypeToName (PhmElemType iType)
614 static const char* pszType = "Unknown";
616 if (iType == PELEM_RECTANGLE)
617 pszType = "rectangle";
618 else if (iType == PELEM_TRIANGLE)
619 pszType = "triangle";
620 else if (iType == PELEM_ELLIPSE)
622 else if (iType == PELEM_SECTOR)
624 else if (iType == PELEM_SEGMENT)
632 PhantomElement::makeTransformMatrices ()
636 // To map normalized Pelem coords to world Phantom
639 // translate by (cx, cy)
641 scale_mtx2 (m_xformObjToPhm, m_u, m_v);
642 rot_mtx2 (temp, m_rot);
643 mult_mtx2 (m_xformObjToPhm, temp, m_xformObjToPhm);
644 xlat_mtx2 (temp, m_cx, m_cy);
645 mult_mtx2 (m_xformObjToPhm, temp, m_xformObjToPhm);
647 // to map world Phantom coodinates to normalized PElem coords
648 // translate by (-cx, -cy)
650 // scale by (1/u, 1/v)
652 xlat_mtx2 (m_xformPhmToObj, -m_cx, -m_cy);
653 rot_mtx2 (temp, -m_rot);
654 mult_mtx2 (m_xformPhmToObj, temp, m_xformPhmToObj);
655 scale_mtx2 (temp, 1 / m_u, 1 / m_v);
656 mult_mtx2 (m_xformPhmToObj, temp, m_xformPhmToObj);
661 * pelem_make_points INTERNAL routine to calculate point array for an pelem
664 * makepelempts (pelem)
665 * PELEM *pelem pelem whose points we are calculating
668 * Called by phm_add_pelem()
672 PhantomElement::makeVectorOutline ()
674 double radius, theta, start, stop;
680 case PELEM_RECTANGLE:
682 m_xOutline = new double [m_nPoints];
683 m_yOutline = new double [m_nPoints];
684 m_xOutline[0] =-m_u; m_yOutline[0] =-m_v;
685 m_xOutline[1] = m_u; m_yOutline[1] =-m_v;
686 m_xOutline[2] = m_u; m_yOutline[2] = m_v;
687 m_xOutline[3] =-m_u; m_yOutline[3] = m_v;
688 m_xOutline[4] =-m_u; m_yOutline[4] =-m_v;
692 m_xOutline = new double [m_nPoints];
693 m_yOutline = new double [m_nPoints];
694 m_xOutline[0] =-m_u; m_yOutline[0] = 0.0;
695 m_xOutline[1] = m_u; m_yOutline[1] = 0.0;
696 m_xOutline[2] = 0.0; m_yOutline[2] = m_v;
697 m_xOutline[3] =-m_u; m_yOutline[3] = 0.0;
700 cpts = numCirclePoints (TWOPI);
702 m_xOutline = new double [m_nPoints];
703 m_yOutline = new double [m_nPoints];
704 calcEllipsePoints (m_xOutline, m_yOutline, cpts, m_u, m_v);
707 radius = sqrt(m_u * m_u + m_v * m_v);
708 theta = atan(m_u / m_v); // angle with y-axis
709 start = 3.0 * HALFPI - theta;
710 stop = 3.0 * HALFPI + theta;
711 cpts = numCirclePoints (stop - start);
712 m_nPoints = 3 + cpts;
713 m_xOutline = new double [m_nPoints];
714 m_yOutline = new double [m_nPoints];
716 m_xOutline[0] = 0.0; m_yOutline[0] = m_v;
717 m_xOutline[1] =-m_u; m_yOutline[1] = 0.0;
718 calcArcPoints (&m_xOutline[2], &m_yOutline[2], cpts, 0.0, m_v, radius, start, stop);
719 m_xOutline[cpts + 2] = 0.0;
720 m_yOutline[cpts + 2] = m_v;
723 radius = sqrt(m_u * m_u + m_v * m_v);
724 theta = atan (m_u / m_v); // angle with y-axis
725 start = 3.0 * HALFPI - theta;
726 stop = 3.0 * HALFPI + theta;
728 cpts = numCirclePoints (stop - start);
729 m_nPoints = cpts + 1;
730 m_xOutline = new double [m_nPoints];
731 m_yOutline = new double [m_nPoints];
733 calcArcPoints (m_xOutline, m_yOutline, cpts, 0.0, m_v, radius, start, stop);
734 m_xOutline[cpts] = -m_u;
735 m_yOutline[cpts] = 0.0;
738 sys_error(ERR_WARNING, "Illegal phantom element type %d [makeVectorOutline]", m_type);
742 rotate2d (m_xOutline, m_yOutline, m_nPoints, m_rot);
743 xlat2d (m_xOutline, m_yOutline, m_nPoints, m_cx, m_cy);
745 minmax_array (m_xOutline, m_nPoints, m_xmin, m_xmax);
746 minmax_array (m_yOutline, m_nPoints, m_ymin, m_ymax);
748 // increase pelem extent by SCALE_PELEM_EXTENT to eliminate chance of
749 // missing actual pelem maximum due to polygonal sampling
751 xfact = (m_xmax - m_xmin) * SCALE_PELEM_EXTENT;
752 yfact = (m_ymax - m_ymin) * SCALE_PELEM_EXTENT;
762 * calc_arc Calculate outline of a arc of a circle
765 * calc_arc (x, y, xcent, ycent, pts, r, start, stop)
766 * double x[], y[]; Array of points
767 * int pts Number of points in array
768 * double xcent, ycent Center of cirlce
769 * double r Radius of circle
770 * double start, stop Beginning & ending angles
774 PhantomElement::calcArcPoints (double x[], double y[], const int pts, const double xcent, const double ycent, const double r, const double start, const double stop)
777 sys_error (ERR_WARNING, "negative or zero radius in calc_arc()");
779 double theta = (stop - start) / (pts - 1); // angle incr. between points
780 double c = cos(theta);
781 double s = sin(theta);
783 x[0] = r * cos (start) + xcent;
784 y[0] = r * sin (start) + ycent;
786 double xp = x[0] - xcent;
787 double yp = y[0] - ycent;
788 for (int i = 1; i < pts; i++) {
789 double xc = c * xp - s * yp;
790 double yc = s * xp + c * yp;
799 // PhantomElement::calcEllipsePoints Calculate outline of a ellipse
802 // calcEllipsePoints ()
807 PhantomElement::calcEllipsePoints (double x[], double y[], const int pts, const double u, const double v)
809 calcArcPoints (x, y, m_nPoints, 0.0, 0.0, 1.0, 0.0, TWOPI); // make a unit circle
810 scale2d (x, y, m_nPoints, m_u, m_v); // scale to ellipse
815 * circle_pts Calculate number of points to use for circle segment
818 * n = circle_pts (theta)
819 * int n Number of points to use for arc
820 * double theta Length of arc in radians
824 PhantomElement::numCirclePoints (double theta)
826 theta = clamp (theta, 0., TWOPI);
828 return static_cast<int> (POINTS_PER_CIRCLE * theta / TWOPI + 1.5);
833 PhantomElement::clipLineWorldCoords (double& x1, double& y1, double& x2, double &y2) const
835 /* check if ray is outside of pelem extents */
836 double cx1 = x1, cy1 = y1, cx2 = x2, cy2 = y2;
837 if (! clip_rect (cx1, cy1, cx2, cy2, m_rectLimits))
840 // convert phantom coordinates to pelem coordinates
841 xform_mtx2 (m_xformPhmToObj, x1, y1);
842 xform_mtx2 (m_xformPhmToObj, x2, y2);
844 if (! clipLineNormalizedCoords (x1, y1, x2, y2))
847 // convert standard pelem coordinates back to phantom coordinates
848 xform_mtx2 (m_xformObjToPhm, x1, y1);
849 xform_mtx2 (m_xformObjToPhm, x2, y2);
856 * pelem_clip_line Clip pelem against an arbitrary line
859 * pelem_clip_line (pelem, x1, y1, x2, y2)
860 * PhantomElement& pelem; Pelem to be clipped
861 * double *x1, *y1, *x2, *y2 Endpoints of line to be clipped
864 * true if line passes through pelem
865 * (x1, y1, x2, y2 hold coordinates of new line)
866 * false if line do not pass through pelem
867 * (x1, y1, x2, y2 are undefined)
871 PhantomElement::clipLineNormalizedCoords (double& x1, double& y1, double& x2, double& y2) const
876 case PELEM_RECTANGLE:
878 rect[0] = -1.0; rect[1] = -1.0;
879 rect[2] = 1.0; rect[3] = 1.0;
880 accept = clip_rect (x1, y1, x2, y2, rect);
883 accept = clip_circle (x1, y1, x2, y2, 0.0, 0.0, 1.0, 0.0, 0.0);
886 accept = clip_triangle (x1, y1, x2, y2, 1.0, 1.0, true);
889 accept = clip_segment (x1, y1, x2, y2, m_u, m_v);
892 accept = clip_sector (x1, y1, x2, y2, m_u, m_v);
895 sys_error (ERR_WARNING, "Illegal pelem type %d [pelem_clip_line]", m_type);
903 // METHOD IDENTIFICATION
904 // PhantomElement::isPointInside Check if point is inside pelem
907 // is_point_inside (pelem, x, y, coord_type)
908 // double x, y Point to see if lies in pelem
909 // int coord_type Coordinate type (PELEM_COORD or PHM_COORD)
912 // true if point lies within pelem
913 // false if point lies outside of pelem
916 PhantomElement::isPointInside (double x, double y, const CoordType coord_type) const
918 if (coord_type == PHM_COORD) {
919 xform_mtx2 (m_xformPhmToObj, x, y);
920 } else if (coord_type != PELEM_COORD) {
921 sys_error(ERR_WARNING, "Illegal coordinate type in pelem_is_point_inside");
926 case PELEM_RECTANGLE:
927 if (x > 1. || x < -1. || y > 1. || y < -1.)
933 if (y < 0. || y > 1. - x || y > 1. + x)
939 if (x > 1. || x < -1. || y > 1. || y < -1.)
941 if (x * x + y * y > 1.) // check if inside unit circle
947 // for clipping segments & sectors, must NOT scale by (1/u, 1/v)
948 // because this destroys information about size of arc component
951 if (x > 1. || x < -1. || y > 0.)
952 return (false); // clip against y > 0
953 x *= m_u; // 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, r = sqrt(@)
961 if (x > 1. || x < -1. || y > 1.) // extent
963 if (y > 1. - x || y > 1. + x) // triangle
964 return (false); // clip against triangle
965 x *= m_u; // circle: put back u & v scale
967 if (x * x + (y-m_v) * (y-m_v) > m_u * m_u + m_v * m_v)
968 return (false); // clip against circle
973 sys_error (ERR_WARNING, "Illegal pelem type in pelem_is_point_inside()");