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) 1983-2000 Kevin Rosenberg
12 ** $Id: phantom.cpp,v 1.9 2000/07/20 11:17:31 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 char Phantom::PHM_HERMAN_STR[]= "herman";
32 const char Phantom::PHM_BHERMAN_STR[]= "bherman";
33 const char Phantom::PHM_ROWLAND_STR[]= "rowland";
34 const char Phantom::PHM_BROWLAND_STR[]= "browland";
35 const char Phantom::PHM_UNITPULSE_STR[]= "unitpulse";
37 const char Phantom::PHM_HERMAN_TITLE_STR[]= "Herman Head";
38 const char Phantom::PHM_BHERMAN_TITLE_STR[]= "Herman Head Bordered";
39 const char Phantom::PHM_ROWLAND_TITLE_STR[]= "Rowland Head";
40 const char Phantom::PHM_BROWLAND_TITLE_STR[]= "Rowland Head Bordered";
41 const char Phantom::PHM_UNITPULSE_TITLE_STR[]= "Unit Pulse";
45 // CLASS IDENTIFICATION
49 Phantom::Phantom (void)
55 Phantom::Phantom (const char* const phmName)
58 createFromPhantom (phmName);
70 m_composition = P_PELEMS;
75 Phantom::~Phantom (void)
77 for (PElemIterator i = m_listPElem.begin(); i != m_listPElem.end(); i++) {
84 Phantom::convertPhantomIDToName (const PhantomID phmID)
86 const char *name = "";
88 if (phmID == PHM_HERMAN)
89 name = PHM_HERMAN_STR;
90 else if (phmID == PHM_BHERMAN)
91 name = PHM_BHERMAN_STR;
92 else if (phmID == PHM_ROWLAND)
93 name = PHM_ROWLAND_STR;
94 else if (phmID == PHM_BROWLAND)
95 name = PHM_BROWLAND_STR;
96 else if (phmID == PHM_UNITPULSE)
97 name = PHM_UNITPULSE_STR;
103 Phantom::convertNameToPhantomID (const char* const phmName)
105 PhantomID id = PHM_INVALID;
107 if (strcasecmp (phmName, PHM_HERMAN_STR) == 0)
109 else if (strcasecmp (phmName, PHM_BHERMAN_STR) == 0)
111 else if (strcasecmp (phmName, PHM_ROWLAND_STR) == 0)
113 else if (strcasecmp (phmName, PHM_BROWLAND_STR) == 0)
115 else if (strcasecmp (phmName, PHM_UNITPULSE_STR) == 0)
123 Phantom::createFromPhantom (const char* const phmName)
125 PhantomID phmid = convertNameToPhantomID (phmName);
126 if (phmid == PHM_INVALID) {
128 m_failMessage = "Invalid phantom name ";
129 m_failMessage += phmName;
134 createFromPhantom (phmid);
139 Phantom::createFromPhantom (const PhantomID phmid)
147 addStdHermanBordered();
153 addStdRowlandBordered ();
156 m_composition = P_UNIT_PULSE;
157 addPElem ("rectangle", 0., 0., 100., 100., 0., 0.); // outline
158 addPElem ("ellipse", 0., 0., 1., 1., 0., 1.); // pulse
162 m_failMessage = "Illegal phantom id ";
163 m_failMessage += phmid;
173 /* METHOD IDENTIFICATION
174 * createFromFile Add PhantomElements from file
177 * createFromFile (filename)
180 * true if pelem were added
181 * false if an pelem not added
185 Phantom::createFromFile (const char* const fname)
187 bool stoploop = false;
191 if ((fp = fopen (fname, "r")) == NULL)
195 double cx, cy, u, v, rot, dens;
197 int n = fscanf (fp, "%79s %lf %lf %lf %lf %lf %lf",
198 pelemtype, &cx, &cy, &u, &v, &rot, &dens);
200 if (n == EOF || n == 0) { /* end of file */
207 addPElem (pelemtype, cx, cy, u, v, rot, dens);
210 } while (stoploop == false);
222 * addPElem (type, cx, cy, u, v, rot, atten)
223 * char *type type of pelem (box, ellipse, etc)
224 * double cx, cy pelem center
225 * double u,v pelem size
226 * double rot rotation angle of pelem (in degrees)
227 * double atten x-ray attenuation cooefficient
231 Phantom::addPElem (const char *type, const double cx, const double cy, const double u, const double v, const double rot, const double atten)
233 PhantomElement *pelem = new PhantomElement (type, cx, cy, u, v, rot, atten);
235 m_listPElem.push_front (pelem);
237 // update phantom limits
238 if (m_xmin > pelem->xmin()) m_xmin = pelem->xmin();
239 if (m_xmax < pelem->xmax()) m_xmax = pelem->xmax();
240 if (m_ymin > pelem->ymin()) m_ymin = pelem->ymin();
241 if (m_ymax < pelem->ymax()) m_ymax = pelem->ymax();
243 if (m_diameter < pelem->diameter())
244 m_diameter = pelem->diameter();
246 // m_diameter = lineLength(m_xmin, m_ymin, m_xmax, m_ymax);
252 /*----------------------------------------------------------------------*/
253 /* Input-Output Routines */
254 /*----------------------------------------------------------------------*/
258 * print Print vertices of Phantom pelems
265 Phantom::print (void) const
267 printf("PRINTING Phantom\n\n");
268 printf("number of pelems in Phantom = %d\n", m_nPElem);
269 printf("limits: xmin=%8.2g ymin=%8.2g xmax=%8.2g ymax=%8.2g\n",
270 m_xmin, m_ymin, m_xmax, m_ymax);
272 for (PElemIterator i = m_listPElem.begin(); i != m_listPElem.end(); i++) {
274 printf("# pts=%3d atten = %7.4f rot = %7.2f (deg)\n",
275 (*i)->nOutlinePoints(), (*i)->atten(), convertRadiansToDegrees ((*i)->rot()));
277 printf("xmin=%7.3g ymin=%7.3g xmax=%7.3g ymax=%7.3g\n",
278 (*i)->xmin(), (*i)->ymin(), (*i)->xmax(), (*i)->ymax());
280 // for (int i = 0; i < m_nPoints; i++)
281 // printf("\t%8.3g %8.3g\n", i->xOutline()[i], i->yOutline()[i]);
287 * show Show vector outline of Phantom to user
295 Phantom::show (void) const
297 double wsize = m_xmax - m_xmin;
298 double xmin = m_xmin;
299 double ymin = m_ymin;
303 if ((m_ymax - m_ymin) > wsize)
304 wsize = m_ymax - m_ymin;
310 printf("Drawing Phantom:\n\n");
311 printf(" data limits: %9.3g, %9.3g, %9.3g, %9.3g\n", m_xmin, m_ymin, m_xmax, m_ymax);
312 printf(" window size: %9.3g, %9.3g, %9.3g, %9.3g\n", xmin, ymin, xmax, ymax);
314 gid = sgp2_init (0, 0, "Phantom Show");
315 sgp2_window (xmin, ymin, xmax, ymax);
325 * draw Draw vector outline of Phantom
333 Phantom::draw (void) const
335 for (PElemIterator i = m_listPElem.begin(); i != m_listPElem.end(); i++)
336 sgp2_polyline_abs ((*i)->xOutline(), (*i)->yOutline(), (*i)->nOutlinePoints());
342 * addStdRowland Make head phantom of S.W. Rowland
345 * S. W. Rowland, "Computer Implementation of Image Reconstruction
346 * Formulas", in "Image Reconstruction from Projections: Implementation
347 * and Applications", edited by G. T. Herman, 1978.
351 Phantom::addStdRowland (void)
353 addPElem ("ellipse", 0.0000, 0.0000, 0.6900, 0.9200, 0.0, 1.00);
354 addPElem ("ellipse", 0.0000, -0.0184, 0.6624, 0.8740, 0.0, -0.98);
355 addPElem ("ellipse", 0.2200, 0.0000, 0.1100, 0.3100, -18.0, -0.02);
356 addPElem ("ellipse", -0.2200, 0.0000, 0.1600, 0.4100, 18.0, -0.02);
357 addPElem ("ellipse", 0.0000, 0.3500, 0.2100, 0.2500, 0.0, 0.01);
358 addPElem ("ellipse", 0.0000, 0.1000, 0.0460, 0.0460, 0.0, 0.01);
359 addPElem ("ellipse", 0.0000, -0.1000, 0.0460, 0.0460, 0.0, 0.01);
360 addPElem ("ellipse", -0.0800, -0.6050, 0.0460, 0.0230, 0.0, 0.01);
361 addPElem ("ellipse", 0.0000, -0.6050, 0.0230, 0.0230, 0.0, 0.01);
362 addPElem ("ellipse", 0.0600, -0.6050, 0.0230, 0.0230, 0.0, 0.01);
363 addPElem ("ellipse", 0.5538, -0.3858, 0.0330, 0.2060, -18.0, 0.03);
367 Phantom::addStdRowlandBordered (void)
370 addPElem ("ellipse", 0.000, 0.0000, 0.7500, 1.000, 0.0, 0.00);
374 * addStdHerman Standard head phantom of G. T. Herman
377 * G. T. Herman, "Image Reconstructions from Projections: The Fundementals
378 * of Computed Tomography", 1979.
382 Phantom::addStdHerman (void)
384 addPElem ("ellipse", 0.000, 1.50, 0.375, 0.3000, 90.00, -0.003);
385 addPElem ("ellipse", 0.675, -0.75, 0.225, 0.1500, 140.00, 0.010);
386 addPElem ("ellipse", 0.750, 1.50, 0.375, 0.2250, 50.00, 0.003);
387 addPElem ("segment", 1.375, -7.50, 1.100, 0.6250, 19.20, -0.204);
388 addPElem ("segment", 1.375, -7.50, 1.100, 4.3200, 19.21, 0.204);
389 addPElem ("segment", 0.000, -2.25, 1.125, 0.3750, 0.00, -0.003);
390 addPElem ("segment", 0.000, -2.25, 1.125, 3.0000, 0.00, 0.003);
391 addPElem ("segment", -1.000, 3.75, 1.000, 0.5000, 135.00, -0.003);
392 addPElem ("segment", -1.000, 3.75, 1.000, 3.0000, 135.00, 0.003);
393 addPElem ("segment", 1.000, 3.75, 1.000, 0.5000, 225.00, -0.003);
394 addPElem ("segment", 1.000, 3.75, 1.000, 3.0000, 225.00, 0.003);
395 addPElem ("triangle", 5.025, 3.75, 1.125, 0.5000, 110.75, 0.206);
396 addPElem ("triangle",-5.025, 3.75, 1.125, 0.9000,-110.75, 0.206);
397 addPElem ("ellipse", 0.000, 0.00, 8.625, 6.4687, 90.00, 0.416);
398 addPElem ("ellipse", 0.000, 0.00, 7.875, 5.7187, 90.00, -0.206);
402 Phantom::addStdHermanBordered (void)
405 addPElem ("ellipse", 0.000, 0.000, 8.650, 8.650, 0.00, 0.000);
410 * convertToImagefile Make image array from Phantom
413 * pic_to_imagefile (pic, im, nsample)
414 * Phantom& pic Phantom definitions
415 * ImageFile *im Computed pixel array
416 * int nsample Number of samples along each axis for each pixel
417 * (total samples per pixel = nsample * nsample)
421 Phantom::convertToImagefile (ImageFile& im, const int in_nsample, const int trace) const
423 convertToImagefile (im, in_nsample, trace, 0, im.nx());
427 Phantom::convertToImagefile (ImageFile& im, const int in_nsample, const int trace, const int colStart, const int colCount) const
431 if (nx < 2 || ny < 2)
434 int nsample = in_nsample;
438 double dx = m_xmax - m_xmin;
439 double dy = m_ymax - m_ymin;
440 double xcent = m_xmin + dx / 2;
441 double ycent = m_ymin + dy / 2;
442 double phmlen = (dx > dy ? dx : dy);
444 double phmradius = phmlen / 2;
446 double xmin = xcent - phmradius;
447 double xmax = xcent + phmradius;
448 double ymin = ycent - phmradius;
449 double ymax = ycent + phmradius;
451 // Each pixel holds the average of the intensity of the cell with (ix,iy) at the center of the pixel
452 // Set major increments so that the last cell v[nx-1][ny-1] will start at xmax - xinc, ymax - yinc).
453 // Set minor increments so that sample points are centered in cell
455 double xinc = (xmax - xmin) / nx;
456 double yinc = (ymax - ymin) / ny;
458 double kxinc = xinc / nsample; /* interval between samples */
459 double kyinc = yinc / nsample;
460 double kxofs = kxinc / 2; /* offset of 1st point */
461 double kyofs = kyinc / 2;
463 im.setAxisExtent (xmin, xmax, ymin, ymax);
464 im.setAxisIncrement (xinc, yinc);
466 ImageFileArray v = im.getArray();
468 for (int ix = 0; ix < colCount; ix++)
469 for (int iy = 0; iy < ny; iy++)
472 double x_start = xmin + (colStart * xinc);
473 for (PElemConstIterator pelem = m_listPElem.begin(); pelem != m_listPElem.end(); pelem++) {
474 const PhantomElement& rPElem = **pelem;
477 for (ix = 0, x = x_start; ix < colCount; ix++, x += xinc) {
478 for (iy = 0, y = ymin; iy < ny; iy++, y += yinc) {
479 for (kx = 0, xi = x + kxofs; kx < nsample; kx++, xi += kxinc) {
480 for (ky = 0, yi = y + kyofs; ky < nsample; ky++, yi += kyinc)
481 if (rPElem.isPointInside (xi, yi, PHM_COORD) == TRUE)
482 v[ix][iy] += rPElem.atten();
490 double factor = 1.0 / (nsample * nsample);
492 for (int ix = 0; ix < colCount; ix++)
493 for (int iy = 0; iy < ny; iy++)
498 ////////////////////////////////////////////////////////////////////////////////////////////////////////
499 // CLASS IDENTIFICATION
505 ////////////////////////////////////////////////////////////////////////////////////////////////////////
508 PhantomElement::PhantomElement (const char *type, const double cx, const double cy, const double u, const double v, const double rot, const double atten)
509 : m_cx(cx), m_cy(cy), m_u(u), m_v(v), m_atten(atten), m_nPoints(0), m_xOutline(0), m_yOutline(0)
511 m_rot = convertDegreesToRadians (rot); // convert angle to radians
513 m_type = convertNameToType (type);
515 makeTransformMatrices (); // calc transform matrices between phantom and normalized phantomelement
516 makeVectorOutline (); // calculate vector outline of pelem
518 // Find maximum diameter of Object
520 for (int i = 0; i < m_nPoints; i++) {
521 double r2 = (m_xOutline[i] * m_xOutline[i]) + (m_yOutline[i] * m_yOutline[i]);
525 m_diameter = 2 * sqrt( r2Max );
527 m_rectLimits[0] = m_xmin; m_rectLimits[1] = m_ymin;
528 m_rectLimits[2] = m_xmax; m_rectLimits[3] = m_ymax;
532 PhantomElement::~PhantomElement (void)
539 PhantomElement::convertNameToType (const char* const typeName)
541 PhmElemType type = PELEM_INVALID;
543 if (strcasecmp (typeName, "rectangle") == 0)
544 type = PELEM_RECTANGLE;
545 else if (strcasecmp (typeName, "triangle") == 0)
546 type = PELEM_TRIANGLE;
547 else if (strcasecmp (typeName, "ellipse") == 0)
548 type = PELEM_ELLIPSE;
549 else if (strcasecmp (typeName, "sector") == 0)
551 else if (strcasecmp (typeName, "segment") == 0)
552 type = PELEM_SEGMENT;
554 sys_error (ERR_WARNING, "Unknown PhantomElement type %s [PhantomElement::PhantomElement]", type);
560 PhantomElement::makeTransformMatrices (void)
564 // To map normalized Pelem coords to world Phantom
567 // translate by (cx, cy)
569 scale_mtx2 (m_xformObjToPhm, m_u, m_v);
570 rot_mtx2 (temp, m_rot);
571 mult_mtx2 (m_xformObjToPhm, temp, m_xformObjToPhm);
572 xlat_mtx2 (temp, m_cx, m_cy);
573 mult_mtx2 (m_xformObjToPhm, temp, m_xformObjToPhm);
575 // to map world Phantom coodinates to normalized PElem coords
576 // translate by (-cx, -cy)
578 // scale by (1/u, 1/v)
580 xlat_mtx2 (m_xformPhmToObj, -m_cx, -m_cy);
581 rot_mtx2 (temp, -m_rot);
582 mult_mtx2 (m_xformPhmToObj, temp, m_xformPhmToObj);
583 scale_mtx2 (temp, 1 / m_u, 1 / m_v);
584 mult_mtx2 (m_xformPhmToObj, temp, m_xformPhmToObj);
589 * pelem_make_points INTERNAL routine to calculate point array for an pelem
592 * makepelempts (pelem)
593 * PELEM *pelem pelem whose points we are calculating
596 * Called by phm_add_pelem()
600 PhantomElement::makeVectorOutline (void)
602 double radius, theta, start, stop;
608 case PELEM_RECTANGLE:
610 m_xOutline = new double [m_nPoints];
611 m_yOutline = new double [m_nPoints];
612 m_xOutline[0] =-m_u; m_yOutline[0] =-m_v;
613 m_xOutline[1] = m_u; m_yOutline[1] =-m_v;
614 m_xOutline[2] = m_u; m_yOutline[2] = m_v;
615 m_xOutline[3] =-m_u; m_yOutline[3] = m_v;
616 m_xOutline[4] =-m_u; m_yOutline[4] =-m_v;
620 m_xOutline = new double [m_nPoints];
621 m_yOutline = new double [m_nPoints];
622 m_xOutline[0] =-m_u; m_yOutline[0] = 0.0;
623 m_xOutline[1] = m_u; m_yOutline[1] = 0.0;
624 m_xOutline[2] = 0.0; m_yOutline[2] = m_v;
625 m_xOutline[3] =-m_u; m_yOutline[3] = 0.0;
628 cpts = numCirclePoints (TWOPI);
630 m_xOutline = new double [m_nPoints];
631 m_yOutline = new double [m_nPoints];
632 calcEllipsePoints (m_xOutline, m_yOutline, cpts, m_u, m_v);
635 radius = sqrt(m_u * m_u + m_v * m_v);
636 theta = atan(m_u / m_v); // angle with y-axis
637 start = 3.0 * HALFPI - theta;
638 stop = 3.0 * HALFPI + theta;
639 cpts = numCirclePoints (stop - start);
640 m_nPoints = 3 + cpts;
641 m_xOutline = new double [m_nPoints];
642 m_yOutline = new double [m_nPoints];
644 m_xOutline[0] = 0.0; m_yOutline[0] = m_v;
645 m_xOutline[1] =-m_u; m_yOutline[1] = 0.0;
646 calcArcPoints (&m_xOutline[2], &m_yOutline[2], cpts, 0.0, m_v, radius, start, stop);
647 m_xOutline[cpts + 2] = 0.0;
648 m_yOutline[cpts + 2] = m_v;
651 radius = sqrt(m_u * m_u + m_v * m_v);
652 theta = atan (m_u / m_v); // angle with y-axis
653 start = 3.0 * HALFPI - theta;
654 stop = 3.0 * HALFPI + theta;
656 cpts = numCirclePoints (stop - start);
657 m_nPoints = cpts + 1;
658 m_xOutline = new double [m_nPoints];
659 m_yOutline = new double [m_nPoints];
661 calcArcPoints (m_xOutline, m_yOutline, cpts, 0.0, m_v, radius, start, stop);
662 m_xOutline[cpts] = -m_u;
663 m_yOutline[cpts] = 0.0;
666 sys_error(ERR_WARNING, "illegal pelem type %d [makeVectorOutline]", m_type);
670 rotate2d (m_xOutline, m_yOutline, m_nPoints, m_rot);
671 xlat2d (m_xOutline, m_yOutline, m_nPoints, m_cx, m_cy);
673 minmax_array (m_xOutline, m_nPoints, m_xmin, m_xmax);
674 minmax_array (m_yOutline, m_nPoints, m_ymin, m_ymax);
676 // increase pelem extent by SCALE_PELEM_EXTENT to eliminate chance of
677 // missing actual pelem maximum due to polygonal sampling
679 xfact = (m_xmax - m_xmin) * SCALE_PELEM_EXTENT;
680 yfact = (m_ymax - m_ymin) * SCALE_PELEM_EXTENT;
690 * calc_arc Calculate outline of a arc of a circle
693 * calc_arc (x, y, xcent, ycent, pts, r, start, stop)
694 * double x[], y[]; Array of points
695 * int pts Number of points in array
696 * double xcent, ycent Center of cirlce
697 * double r Radius of circle
698 * double start, stop Beginning & ending angles
702 PhantomElement::calcArcPoints (double x[], double y[], const int pts, const double xcent, const double ycent, const double r, const double start, const double stop)
705 sys_error (ERR_WARNING, "negative or zero radius in calc_arc()");
707 double theta = (stop - start) / (pts - 1); // angle incr. between points
708 double c = cos(theta);
709 double s = sin(theta);
711 x[0] = r * cos (start) + xcent;
712 y[0] = r * sin (start) + ycent;
714 double xp = x[0] - xcent;
715 double yp = y[0] - ycent;
716 for (int i = 1; i < pts; i++) {
717 double xc = c * xp - s * yp;
718 double yc = s * xp + c * yp;
727 // PhantomElement::calcEllipsePoints Calculate outline of a ellipse
730 // calcEllipsePoints ()
735 PhantomElement::calcEllipsePoints (double x[], double y[], const int pts, const double u, const double v)
737 calcArcPoints (x, y, m_nPoints, 0.0, 0.0, 1.0, 0.0, TWOPI); // make a unit circle
738 scale2d (x, y, m_nPoints, m_u, m_v); // scale to ellipse
743 * circle_pts Calculate number of points to use for circle segment
746 * n = circle_pts (theta)
747 * int n Number of points to use for arc
748 * double theta Length of arc in radians
752 PhantomElement::numCirclePoints (double theta)
754 theta = clamp (theta, 0., TWOPI);
756 return static_cast<int> (POINTS_PER_CIRCLE * theta / TWOPI + 1.5);
761 PhantomElement::clipLineWorldCoords (double& x1, double& y1, double& x2, double &y2) const
763 /* check if ray is outside of pelem extents */
764 double cx1 = x1, cy1 = y1, cx2 = x2, cy2 = y2;
765 if (! clip_rect (cx1, cy1, cx2, cy2, m_rectLimits))
768 // convert phantom coordinates to pelem coordinates
769 xform_mtx2 (m_xformPhmToObj, x1, y1);
770 xform_mtx2 (m_xformPhmToObj, x2, y2);
772 if (! clipLineNormalizedCoords (x1, y1, x2, y2))
775 // convert standard pelem coordinates back to phantom coordinates
776 xform_mtx2 (m_xformObjToPhm, x1, y1);
777 xform_mtx2 (m_xformObjToPhm, x2, y2);
784 * pelem_clip_line Clip pelem against an arbitrary line
787 * pelem_clip_line (pelem, x1, y1, x2, y2)
788 * PhantomElement& pelem; Pelem to be clipped
789 * double *x1, *y1, *x2, *y2 Endpoints of line to be clipped
792 * true if line passes through pelem
793 * (x1, y1, x2, y2 hold coordinates of new line)
794 * false if line do not pass through pelem
795 * (x1, y1, x2, y2 are undefined)
799 PhantomElement::clipLineNormalizedCoords (double& x1, double& y1, double& x2, double& y2) const
804 case PELEM_RECTANGLE:
806 rect[0] = -1.0; rect[1] = -1.0;
807 rect[2] = 1.0; rect[3] = 1.0;
808 accept = clip_rect (x1, y1, x2, y2, rect);
811 accept = clip_circle (x1, y1, x2, y2, 0.0, 0.0, 1.0, 0.0, 0.0);
814 accept = clip_triangle (x1, y1, x2, y2, 1.0, 1.0, true);
817 accept = clip_segment (x1, y1, x2, y2, m_u, m_v);
820 accept = clip_sector (x1, y1, x2, y2, m_u, m_v);
823 sys_error (ERR_WARNING, "Illegal pelem type %d [pelem_clip_line]", m_type);
831 // METHOD IDENTIFICATION
832 // PhantomElement::isPointInside Check if point is inside pelem
835 // is_point_inside (pelem, x, y, coord_type)
836 // double x, y Point to see if lies in pelem
837 // int coord_type Coordinate type (PELEM_COORD or PHM_COORD)
840 // true if point lies within pelem
841 // false if point lies outside of pelem
844 PhantomElement::isPointInside (double x, double y, const CoordType coord_type) const
846 if (coord_type == PHM_COORD) {
847 xform_mtx2 (m_xformPhmToObj, x, y);
848 } else if (coord_type != PELEM_COORD) {
849 sys_error(ERR_WARNING, "Illegal coordinate type in pelem_is_point_inside");
854 case PELEM_RECTANGLE:
855 if (x > 1. || x < -1. || y > 1. || y < -1.)
861 if (y < 0. || y > 1. - x || y > 1. + x)
867 if (x > 1. || x < -1. || y > 1. || y < -1.)
869 if (x * x + y * y > 1.) // check if inside unit circle
875 // for clipping segments & sectors, must NOT scale by (1/u, 1/v)
876 // because this destroys information about size of arc component
879 if (x > 1. || x < -1. || y > 0.)
880 return (false); // clip against y > 0
881 x *= m_u; // put back u & v scale
883 if (x * x + (y-m_v) * (y-m_v) > m_u * m_u + m_v * m_v)
884 return (false); // clip against circle, r = sqrt(@)
889 if (x > 1. || x < -1. || y > 1.) // extent
891 if (y > 1. - x || y > 1. + x) // triangle
892 return (false); // clip against triangle
893 x *= m_u; // circle: put back u & v scale
895 if (x * x + (y-m_v) * (y-m_v) > m_u * m_u + m_v * m_v)
896 return (false); // clip against circle
901 sys_error (ERR_WARNING, "Illegal pelem type in pelem_is_point_inside()");