1:
2: # The LearningOnline Network with CAPA
3: # image click response style
4: #
5: # $Id: imageresponse.pm,v 1.47 2004/02/11 21:59:34 albertel Exp $
6: #
7: # Copyright Michigan State University Board of Trustees
8: #
9: # This file is part of the LearningOnline Network with CAPA (LON-CAPA).
10: #
11: # LON-CAPA is free software; you can redistribute it and/or modify
12: # it under the terms of the GNU General Public License as published by
13: # the Free Software Foundation; either version 2 of the License, or
14: # (at your option) any later version.
15: #
16: # LON-CAPA 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.
20: #
21: # You should have received a copy of the GNU General Public License
22: # along with LON-CAPA; if not, write to the Free Software
23: # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
24: #
25: # /home/httpd/html/adm/gpl.txt
26: #
27: # http://www.lon-capa.org/
28: #
29: #FIXME LATER assumes multiple possible submissions but only one is possible
30: #currently
31:
32: package Apache::imageresponse;
33: use strict;
34: use Image::Magick;
35: use Apache::randomlylabel;
36: use Apache::londefdef;
37: use Apache::Constants qw(:common :http);
38:
39: BEGIN {
40: &Apache::lonxml::register('Apache::imageresponse',('imageresponse'));
41: }
42:
43: sub start_imageresponse {
44: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
45: my $result;
46: #when in a radiobutton response use these
47: &Apache::lonxml::register('Apache::imageresponse',
48: ('foilgroup','foil','text','image','rectangle',
49: 'polygon','conceptgroup'));
50: push (@Apache::lonxml::namespace,'imageresponse');
51: my $id = &Apache::response::start_response($parstack,$safeeval);
52: if ($target eq 'meta') {
53: $result=&Apache::response::meta_package_write('imageresponse');
54: } elsif ($target eq 'analyze') {
55: my $part_id="$Apache::inputtags::part.$id";
56: push (@{ $Apache::lonhomework::analyze{"parts"} },$part_id);
57: }
58: return $result;
59: }
60:
61: sub end_imageresponse {
62: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
63: &Apache::response::end_response;
64: pop @Apache::lonxml::namespace;
65: &Apache::lonxml::deregister('Apache::imageresponse',('foilgroup','foil','text','image','rectangle','conceptgroup'));
66: my $result;
67: if ($target eq 'edit') { $result=&Apache::edit::end_table(); }
68: return $result;
69: }
70:
71: %Apache::response::foilgroup=();
72: sub start_foilgroup {
73: %Apache::response::foilgroup=();
74: $Apache::imageresponse::conceptgroup=0;
75: &Apache::response::setrandomnumber();
76: return '';
77: }
78:
79: sub getfoilcounts {
80: my ($parstack,$safeeval)=@_;
81:
82: my $max = &Apache::lonxml::get_param('max',$parstack,$safeeval,'-2');
83: # +1 since instructors will count from 1
84: my $count = $#{ $Apache::response::foilgroup{'names'} }+1;
85: if (&Apache::response::showallfoils()) { $max=$count; }
86: return ($count,$max);
87: }
88:
89: sub whichfoils {
90: my ($max)=@_;
91: if (!defined(@{ $Apache::response::foilgroup{'names'} })) { return; }
92: my @names = @{ $Apache::response::foilgroup{'names'} };
93: my @whichopt =();
94: while ((($#whichopt+1) < $max) && ($#names > -1)) {
95: &Apache::lonxml::debug("Have $#whichopt max is $max");
96: my $aopt;
97: if (&Apache::response::showallfoils()) {
98: $aopt=0;
99: } else {
100: $aopt=int(&Math::Random::random_uniform() * ($#names+1));
101: }
102: &Apache::lonxml::debug("From $#names elms, picking $aopt");
103: $aopt=splice(@names,$aopt,1);
104: &Apache::lonxml::debug("Picked $aopt");
105: push (@whichopt,$aopt);
106: }
107: return @whichopt;
108: }
109:
110: sub prep_image {
111: my ($image,$mode,$name)=@_;
112: my $part=$Apache::inputtags::part;
113: my $respid=$Apache::inputtags::response['-1'];
114: my $id=&Apache::loncommon::get_cgi_id();
115: my %x;
116: $x{"cgi.$id.BGIMG"}=&Apache::lonnet::escape($image);
117: my ($x,$y)=split(/:/,$Apache::lonhomework::history{"resource.$part.$respid.submission"});
118: #draws 2 xs on the image at the clicked location
119: #one in white and then one in red on top of the one in white
120: if (defined($x) && defined($y)) {
121: $x{"cgi.$id.LINECOUNT"}=4;
122: my $length = 6;
123: my $width = 1;
124: my $extrawidth = 2;
125: $x{"cgi.$id.LINE0"}=
126: join(':',(($x-$length),($y-$length),($x+$length),($y+$length),
127: "FFFFFF",($width+$extrawidth)));
128: $x{"cgi.$id.LINE1"}=
129: join(':',(($x-$length),($y+$length),($x+$length),($y-$length),
130: "FFFFFF",($width+$extrawidth)));
131: $x{"cgi.$id.LINE2"}=
132: join(':',(($x-$length),($y-$length),($x+$length),($y+$length),
133: "FF0000",($width)));
134: $x{"cgi.$id.LINE3"}=
135: join(':',(($x-$length),($y+$length),($x+$length),($y-$length),
136: "FF0000",($width)));
137: }
138: if ($mode eq 'answer') {
139: my $width = 1;
140: my $extrawidth = 2;
141: my @areas = @{ $Apache::response::foilgroup{"$name.area"} };
142: foreach my $area (@areas) {
143: if ($area=~/^rectangle:/) {
144: my ($x1,$y1,$x2,$y2)=
145: ($area=~m/rectangle:\(([0-9]+),([0-9]+)\)\-\(([0-9]+),([0-9]+)\)/);
146: my $i=$x{"cgi.$id.BOXCOUNT"}++;
147: $x{"cgi.$id.BOX$i"}=join(':',($x1,$y1,$x2,$y2,"FFFFFF",
148: ($width+$extrawidth)));
149: $i=$x{"cgi.$id.BOXCOUNT"}++;
150: $x{"cgi.$id.BOX$i"}=join(':',($x1,$y1,$x2,$y2,"00FF00",$width));
151: } elsif ($area=~/^polygon:(.*)/) {
152: my $i=$x{"cgi.$id.POLYCOUNT"}++;
153: $x{"cgi.$id.POLYOPT$i"}=join(':',("FFFFFF",($width+$extrawidth)));
154: $x{"cgi.$id.POLY$i"}=$1;
155: $i=$x{"cgi.$id.POLYCOUNT"}++;
156: $x{"cgi.$id.POLYOPT$i"}=join(':',("00FF00",$width));
157: $x{"cgi.$id.POLY$i"}=$1;
158: }
159: }
160: }
161: &Apache::lonnet::appenv(%x);
162: return $id;
163: }
164:
165: sub displayfoils {
166: my ($target,@whichopt) = @_;
167: my $result ='';
168: my $name;
169: my $temp=1;
170: foreach $name (@whichopt) {
171: $result.=$Apache::response::foilgroup{"$name.text"};
172: &Apache::lonxml::debug("Text is $result");
173: if ($target eq 'tex') {$result.="\\vskip 0 mm \n";} else {$result.="<br />\n";}
174: my $image=$Apache::response::foilgroup{"$name.image"};
175: &Apache::lonxml::debug("image is $image");
176: if ( $target eq 'web' && $image !~ /^http:/ ) {
177: $image=&clean_up_image($image);
178: }
179: &Apache::lonxml::debug("image is $image");
180: if ( &Apache::response::show_answer() ) {
181: if ($target eq 'tex') {
182: $result.=$Apache::response::foilgroup{"$name.image"}."\\vskip 0 mm \n";
183: } else {
184: my $token=&prep_image($image,'answer',$name);
185: $result.="<img src=\"/adm/randomlabel.png?token=$token\" /><br />\n";
186: }
187: } else {
188: if ($target eq 'tex') {
189: $result.=$Apache::response::foilgroup{"$name.image"}."\\vskip 0 mm \n";
190: } else {
191: my $id=$Apache::inputtags::response['-1'];
192: my $token=&prep_image($image);
193: my $temp=1;
194: $result.="<input type=\"image\" name=\"HWVAL_$id:$temp\" ".
195: "src=\"/adm/randomlabel.png?token=$token\" /><br />\n";
196: }
197: }
198: $temp++;
199: }
200: return $result;
201: }
202:
203: sub clean_up_image {
204: my ($image)=@_;
205: if ($image =~ /\s*<img\s*/) {
206: ($image) = ($image =~ /src\s*=\s*\"([^\"]+)\"/i);
207: if ($image !~ /^http:/) {
208: $image=&Apache::lonnet::hreflocation('',$image);
209: }
210: if (!$image) {
211: $image='/home/httpd/html/adm/lonKaputt/lonlogo_broken.gif';
212: }
213: } else {
214: $image=&Apache::lonnet::filelocation($Apache::lonxml::pwd[-1],$image);
215: if (&Apache::lonnet::repcopy($image) ne OK) {
216: $image='/home/httpd/html/adm/lonKaputt/lonlogo_broken.gif';
217: }
218: }
219: return $image;
220: }
221:
222: sub gradefoils {
223: my (@whichopt) = @_;
224: my $x;
225: my $y;
226: my $result;
227: my $id=$Apache::inputtags::response['-1'];
228: my $temp=1;
229: foreach my $name (@whichopt) {
230: $x=$ENV{"form.HWVAL_$id:$temp.x"};
231: $y=$ENV{"form.HWVAL_$id:$temp.y"};
232: &Apache::lonxml::debug("Got a x of $x and a y of $y for $name");
233: if (defined($x) && defined($y) &&
234: defined(@{ $Apache::response::foilgroup{"$name.area"} })) {
235: my @areas = @{ $Apache::response::foilgroup{"$name.area"} };
236: my $grade="INCORRECT";
237: foreach my $area (@areas) {
238: &Apache::lonxml::debug("Area is $area for $name");
239: $area =~ m/([a-z]*):/;
240: &Apache::lonxml::debug("Area of type $1");
241: if ($1 eq 'rectangle') {
242: $grade=&grade_rectangle($area,$x,$y);
243: } elsif ($1 eq 'polygon') {
244: $grade=&grade_polygon($area,$x,$y);
245: } else {
246: &Apache::lonxml::error("Unknown area style $area");
247: }
248: &Apache::lonxml::debug("Area said $grade");
249: if ($grade eq 'APPROX_ANS') { last; }
250: }
251: &Apache::lonxml::debug("Foil was $grade");
252: if ($grade eq 'INCORRECT') { $result= 'INCORRECT'; }
253: if (($grade eq 'APPROX_ANS') && ($result ne 'APPROX_ANS')) { $result=$grade; }
254: &Apache::lonxml::debug("Question is $result");
255: $temp++;
256: }
257: }
258: $Apache::lonhomework::results{"resource.$Apache::inputtags::part.$id.submission"}="$x:$y";
259: $Apache::lonhomework::results{"resource.$Apache::inputtags::part.$id.awarddetail"}=$result;
260: return '';
261: }
262:
263: sub end_foilgroup {
264: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
265: my $result='';
266: my @whichopt;
267: if ($target eq 'web' || $target eq 'grade' || $target eq 'tex' ||
268: $target eq 'analyze') {
269: my ($count,$max) = &getfoilcounts($parstack,$safeeval);
270: if ($count>$max) { $count=$max }
271: &Apache::lonxml::debug("Count is $count from $max");
272: @whichopt = &whichfoils($max);
273: if ($target eq 'web' || $target eq 'tex') {
274: $result=&displayfoils($target,@whichopt);
275: } elsif ($target eq 'grade') {
276: if ( defined $ENV{'form.submitted'}) { &gradefoils(@whichopt); }
277: } elsif ( $target eq 'analyze') {
278: &Apache::response::analyze_store_foilgroup(\@whichopt,
279: ['text','image','area']);
280: }
281: } elsif ($target eq 'edit') {
282: $result=&Apache::edit::end_table();
283: }
284: return $result;
285: }
286:
287: sub start_conceptgroup {
288: $Apache::imageresponse::conceptgroup=1;
289: %Apache::response::conceptgroup=();
290: return '';
291: }
292:
293: sub end_conceptgroup {
294: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
295: $Apache::imageresponse::conceptgroup=0;
296: my $result;
297: if ($target eq 'web' || $target eq 'grade' || $target eq 'tex' ||
298: $target eq 'analyze') {
299: &Apache::response::pick_foil_for_concept($target,
300: ['area','text','image'],
301: \%Apache::hint::image,
302: $parstack,$safeeval);
303: } elsif ($target eq 'edit') {
304: $result=&Apache::edit::end_table();
305: }
306: return $result;
307: }
308:
309: sub insert_foil {
310: return '
311: <foil>
312: <image></image>
313: <text></text>
314: <rectangle></rectangle>
315: </foil>
316: ';
317: }
318:
319: $Apache::imageresponse::curname='';
320: sub start_foil {
321: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
322: if ($target eq 'web' || $target eq 'grade' || $target eq 'tex' ||
323: $target eq 'analyze') {
324: my $name = &Apache::lonxml::get_param('name',$parstack,$safeeval);
325: if ($name eq '') { $name=$Apache::lonxml::curdepth; }
326: if ( $Apache::imageresponse::conceptgroup
327: && !&Apache::response::showallfoils()) {
328: push(@{ $Apache::response::conceptgroup{'names'} }, $name);
329: } else {
330: push(@{ $Apache::response::foilgroup{'names'} }, $name);
331: }
332: $Apache::imageresponse::curname=$name;
333: }
334: return '';
335: }
336:
337: sub end_foil {
338: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
339: my $result;
340: if ($target eq 'edit') {
341: $result=&Apache::edit::end_table();
342: }
343: return $result;
344: }
345:
346: sub start_text {
347: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
348: my $result='';
349: if ($target eq 'web' || $target eq 'tex' || $target eq 'analyze') {
350: &Apache::lonxml::startredirection;
351: } elsif ($target eq 'edit') {
352: my $descr=&Apache::lonxml::get_all_text('/text',$parser);
353: $result=&Apache::edit::tag_start($target,$token,'Task Description').
354: &Apache::edit::editfield($token->[1],$descr,'Text',60,2).
355: &Apache::edit::end_row();
356: } elsif ($target eq "modified") {
357: $result=$token->[4].&Apache::edit::modifiedfield('/text',$parser);
358: }
359: return $result;
360: }
361:
362: sub end_text {
363: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
364: my $result;
365: if ($target eq 'web' || $target eq 'tex' || $target eq 'analyze') {
366: my $name = $Apache::imageresponse::curname;
367: if ( $Apache::imageresponse::conceptgroup
368: && !&Apache::response::showallfoils() ) {
369: $Apache::response::conceptgroup{"$name.text"} = &Apache::lonxml::endredirection;
370: } else {
371: $Apache::response::foilgroup{"$name.text"} = &Apache::lonxml::endredirection;
372: }
373: } elsif ($target eq 'edit') {
374: $result=&Apache::edit::end_table();
375: }
376: return $result;
377: }
378:
379: sub start_image {
380: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
381: my $result='';
382: if ($target eq 'web' || $target eq 'tex' || $target eq 'analyze') {
383: &Apache::lonxml::startredirection;
384: } elsif ($target eq 'edit') {
385: my $bgimg=&Apache::lonxml::get_all_text('/image',$parser);
386: $Apache::edit::bgimgsrc=$bgimg;
387: $Apache::edit::bgimgsrcdepth=$Apache::lonxml::curdepth;
388:
389: $result=&Apache::edit::tag_start($target,$token,'Clickable Image').
390: &Apache::edit::editline($token->[1],$bgimg,'Image Source File',40);
391: $result.=&Apache::edit::browse(undef,'textnode').' ';
392: $result.=&Apache::edit::search(undef,'textnode').
393: &Apache::edit::end_row();
394: } elsif ($target eq "modified") {
395: $result=$token->[4].&Apache::edit::modifiedfield('/image',$parser);
396: }
397: return $result;
398: }
399:
400: sub end_image {
401: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
402: my $result;
403: my $name = $Apache::imageresponse::curname;
404: if ($target eq 'web') {
405: my $image = &Apache::lonxml::endredirection;
406: &Apache::lonxml::debug("original image is $image");
407: if ( $Apache::imageresponse::conceptgroup
408: && !&Apache::response::showallfoils()) {
409: $Apache::response::conceptgroup{"$name.image"} = $image;
410: } else {
411: $Apache::response::foilgroup{"$name.image"} = $image;
412: }
413: } elsif ($target eq 'analyze') {
414: my $image = &Apache::lonxml::endredirection;
415: if ( $Apache::imageresponse::conceptgroup
416: && !&Apache::response::showallfoils()) {
417: $Apache::response::conceptgroup{"$name.image"} = $image;
418: } else {
419: $Apache::response::foilgroup{"$name.image"} = $image;
420: }
421: } elsif ($target eq 'edit') {
422: $result=&Apache::edit::end_table();
423: } elsif ($target eq 'tex') {
424: my $src = &Apache::lonxml::endredirection;
425: $src=&Apache::lonnet::filelocation($Apache::lonxml::pwd[-1],$src);
426: my $width_param = '';
427: my $height_param = '';
428: my $scaling = .3;
429: my $image = Image::Magick->new;
430: my $current_figure = $image->Read($src);
431: $width_param = $image->Get('width') * $scaling;;
432: $height_param = $image->Get('height') * $scaling;;
433: undef $image;
434: my $epssrc = $src;
435: $epssrc =~ s/(\.gif|\.jpg)$/\.eps/i;
436: if (not -e $epssrc) {
437: my $localfile = $epssrc;
438: $localfile =~ s/.*(\/res)/$1/;
439: my $file;
440: my $path;
441: if ($localfile =~ m!(.*)/([^/]*)$!) {
442: $file = $2;
443: $path = $1.'/';
444: }
445: my $signal_eps = 0;
446: my @content_directory = &Apache::lonnet::dirlist($path);
447: for (my $iy=0;$iy<=$#content_directory;$iy++) {
448: my @tempo_array = split(/&/,$content_directory[$iy]);
449: $content_directory[$iy] = $tempo_array[0];
450: if ($file eq $tempo_array[0]) {
451: $signal_eps = 1;
452: last;
453: }
454: }
455: if ($signal_eps) {
456: my $eps_file = &Apache::lonnet::getfile($localfile);
457: } else {
458: $localfile = $src;
459: $localfile =~ s/.*(\/res)/$1/;
460: my $as = &Apache::lonnet::getfile($src);
461: }
462: }
463: my $file;
464: my $path;
465: if ($src =~ m!(.*)/([^/]*)$!) {
466: $file = $2;
467: $path = $1.'/';
468: }
469: my $newsrc = $src;
470: $newsrc =~ s/(\.gif|\.jpg|\.jpeg)$/\.eps/i;
471: $file=~s/(\.gif|\.jpg|\.jpeg)$/\.eps/i;
472: #do we have any specified size of the picture?
473: my $TeXwidth = &Apache::lonxml::get_param('TeXwidth',$parstack,$safeeval);
474: my $TeXheight = &Apache::lonxml::get_param('TeXheight',$parstack,$safeeval);
475: my $width = &Apache::lonxml::get_param('width',$parstack,$safeeval);
476: if ($TeXwidth ne '') {
477: $width_param = $TeXwidth;
478: } elsif ($TeXheight ne '') {
479: $width_param = $TeXheight/$height_param*$width_param;
480: } elsif ($width ne '') {
481: $width_param = $width*$scaling;
482: }
483: #where can we find the picture?
484: if (-e $newsrc) {
485: if ($path) {
486: $Apache::response::foilgroup{"$name.image"} ='\vskip 0 mm \noindent\graphicspath{{'.$path.'}}\includegraphics[width='.$width_param.' mm]{'.$file.'} ';
487: }
488: } else {
489: #care about eps dynamical generation
490: $Apache::response::foilgroup{"$name.image"}='\vskip 0 mm '.&Apache::londefdef::eps_generation($src,$file,$width_param);
491: }
492: }
493: return $result;
494: }
495:
496: sub start_rectangle {
497: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
498: my $result='';
499: if ($target eq 'web' || $target eq 'grade' || $target eq 'tex' ||
500: $target eq 'analyze') {
501: &Apache::lonxml::startredirection;
502: } elsif ($target eq 'edit') {
503: my $coords=&Apache::lonxml::get_all_text('/rectangle',$parser);
504: $result=&Apache::edit::tag_start($target,$token,'Rectangle').
505: &Apache::edit::editline($token->[1],$coords,'Coordinate Pairs',40).
506: &Apache::edit::entercoord(undef,'textnode',undef,undef,'box').
507: &Apache::edit::end_row();
508: } elsif ($target eq "modified") {
509: &Apache::edit::deletecoorddata();
510: $result=$token->[4].&Apache::edit::modifiedfield('/rectangle',$parser);
511: }
512: return $result;
513: }
514:
515: sub grade_rectangle {
516: my ($spec,$x,$y) = @_;
517: &Apache::lonxml::debug("Spec is $spec");
518: my ($x1,$y1,$x2,$y2)=($spec=~m/rectangle:\(([0-9]+),([0-9]+)\)\-\(([0-9]+),([0-9]+)\)/);
519: &Apache::lonxml::debug("Point $x1,$y1,$x2,$y2");
520: if ($x1 > $x2) { my $temp=$x1;$x1=$x2;$x2=$temp; }
521: if ($y1 > $y2) { my $temp=$y1;$y1=$y2;$y2=$temp; }
522: if (($x >= $x1) && ($x <= $x2) && ($y >= $y1) && ($y <= $y2)) {
523: return 'APPROX_ANS';
524: }
525: return 'INCORRECT';
526: }
527:
528: sub end_rectangle {
529: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
530: my $result;
531: if ($target eq 'web' || $target eq 'grade' || $target eq 'tex' ||
532: $target eq 'analyze') {
533: my $name = $Apache::imageresponse::curname;
534: my $area = &Apache::lonxml::endredirection;
535: &Apache::lonxml::debug("out is $area for $name");
536: if ( $Apache::imageresponse::conceptgroup
537: && !&Apache::response::showallfoils()) {
538: push @{ $Apache::response::conceptgroup{"$name.area"} },"rectangle:$area";
539: } else {
540: push @{ $Apache::response::foilgroup{"$name.area"} },"rectangle:$area";
541: }
542: } elsif ($target eq 'edit') {
543: $result=&Apache::edit::end_table();
544: }
545: return $result;
546: }
547:
548: sub start_polygon {
549: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
550: my $result='';
551: if ($target eq 'web' || $target eq 'grade' || $target eq 'tex' ||
552: $target eq 'analyze') {
553: &Apache::lonxml::startredirection;
554: } elsif ($target eq 'edit') {
555: my $coords=&Apache::lonxml::get_all_text('/polygon',$parser);
556: $result=&Apache::edit::tag_start($target,$token,'Polygon').
557: &Apache::edit::editline($token->[1],$coords,'Coordinate list',40).
558: &Apache::edit::entercoord(undef,'textnode',undef,undef,'polygon').
559: &Apache::edit::end_row();
560: } elsif ($target eq "modified") {
561: $result=$token->[4].&Apache::edit::modifiedfield('/polygon',$parser);
562: }
563: return $result;
564: }
565:
566: sub grade_polygon {
567: my ($spec,$x,$y) = @_;
568: &Apache::lonxml::debug("Spec is $spec");
569: $spec=~s/^polygon://;
570: my @polygon;
571: foreach my $coord (split('-',$spec)) {
572: my ($x,$y)=($coord=~m/\(([0-9]+),([0-9]+)\)/);
573: &Apache::lonxml::debug("x $x y $y");
574: push @polygon, {'x'=>$x,'y'=>$y};
575: }
576: #make end point start point
577: push @polygon, $polygon[0];
578: # cribbed from
579: # http://geometryalgorithms.com/Archive/algorithm_0103/algorithm_0103.htm
580: my $crossing = 0; # the crossing number counter
581:
582: # loop through all edges of the polygon
583: for (my $i=0; $i<$#polygon; $i++) { # edge from V[i] to V[i+1]
584: if ((($polygon[$i]->{'y'} <= $y)
585: && ($polygon[$i+1]->{'y'} > $y)) # an upward crossing
586: ||
587: (($polygon[$i]->{'y'} > $y)
588: && ($polygon[$i+1]->{'y'} <= $y))) { # a downward crossing
589: # compute the actual edge-ray intersect x-coordinate
590: my $vt = ($y - $polygon[$i]->{'y'})
591: / ($polygon[$i+1]->{'y'} - $polygon[$i]->{'y'});
592: if ($x < $polygon[$i]->{'x'} + $vt *
593: ($polygon[$i+1]->{'x'} - $polygon[$i]->{'x'})) { # x<intersect
594: $crossing++; # a valid crossing of y=P.y right of P.x
595: }
596: }
597: }
598:
599: # 0 if even (out), and 1 if odd (in)
600: if ($crossing%2) {
601: return 'APPROX_ANS';
602: } else {
603: return 'INCORRECT';
604: }
605: }
606:
607: sub end_polygon {
608: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
609: my $result;
610: if ($target eq 'web' || $target eq 'grade' || $target eq 'tex' ||
611: $target eq 'analyze') {
612: my $name = $Apache::imageresponse::curname;
613: my $area = &Apache::lonxml::endredirection;
614: &Apache::lonxml::debug("out is $area for $name");
615: if ( $Apache::imageresponse::conceptgroup
616: && !&Apache::response::showallfoils()) {
617: push @{ $Apache::response::conceptgroup{"$name.area"} },"polygon:$area";
618: } else {
619: push @{ $Apache::response::foilgroup{"$name.area"} },"polygon:$area";
620: }
621: } elsif ($target eq 'edit') {
622: $result=&Apache::edit::end_table();
623: }
624: return $result;
625: }
626: 1;
627: __END__
628:
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