1:
2: # The LearningOnline Network with CAPA
3: # image click response style
4: #
5: # $Id: imageresponse.pm,v 1.67 2005/04/22 14:03:56 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: use Apache::lonlocal;
39: use Apache::lonnet;
40:
41: BEGIN {
42: &Apache::lonxml::register('Apache::imageresponse',('imageresponse'));
43: }
44:
45: sub start_imageresponse {
46: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
47: my $result;
48: #when in a radiobutton response use these
49: &Apache::lonxml::register('Apache::imageresponse',
50: ('foilgroup','foil','text','image','rectangle',
51: 'polygon','conceptgroup'));
52: push (@Apache::lonxml::namespace,'imageresponse');
53: my $id = &Apache::response::start_response($parstack,$safeeval);
54: undef(%Apache::response::foilnames);
55: if ($target eq 'meta') {
56: $result=&Apache::response::meta_package_write('imageresponse');
57: } elsif ($target eq 'analyze') {
58: my $part_id="$Apache::inputtags::part.$id";
59: push (@{ $Apache::lonhomework::analyze{"parts"} },$part_id);
60: }
61: return $result;
62: }
63:
64: sub end_imageresponse {
65: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
66: &Apache::response::end_response;
67: pop @Apache::lonxml::namespace;
68: &Apache::lonxml::deregister('Apache::imageresponse',('foilgroup','foil','text','image','rectangle','conceptgroup'));
69: my $result;
70: if ($target eq 'edit') { $result=&Apache::edit::end_table(); }
71: undef(%Apache::response::foilnames);
72: return $result;
73: }
74:
75: %Apache::response::foilgroup=();
76: sub start_foilgroup {
77: %Apache::response::foilgroup=();
78: $Apache::imageresponse::conceptgroup=0;
79: &Apache::response::pushrandomnumber();
80: return '';
81: }
82:
83: sub getfoilcounts {
84: my ($parstack,$safeeval)=@_;
85:
86: my $max = &Apache::lonxml::get_param('max',$parstack,$safeeval,'-2');
87: # +1 since instructors will count from 1
88: my $count = $#{ $Apache::response::foilgroup{'names'} }+1;
89: #if (&Apache::response::showallfoils()) { $max=$count; }
90: return ($count,$max);
91: }
92:
93: sub whichfoils {
94: my ($max)=@_;
95: if (!defined(@{ $Apache::response::foilgroup{'names'} })) { return; }
96: my @names = @{ $Apache::response::foilgroup{'names'} };
97: my @whichopt =();
98: while ((($#whichopt+1) < $max) && ($#names > -1)) {
99: &Apache::lonxml::debug("Have $#whichopt max is $max");
100: my $aopt;
101: # if (&Apache::response::showallfoils()) {
102: # $aopt=0;
103: # } else {
104: $aopt=int(&Math::Random::random_uniform() * ($#names+1));
105: # }
106: &Apache::lonxml::debug("From $#names elms, picking $aopt");
107: $aopt=splice(@names,$aopt,1);
108: &Apache::lonxml::debug("Picked $aopt");
109: push (@whichopt,$aopt);
110: }
111: return @whichopt;
112: }
113:
114: sub prep_image {
115: my ($image,$mode,$name)=@_;
116: my $part=$Apache::inputtags::part;
117: my $respid=$Apache::inputtags::response['-1'];
118: my $id=&Apache::loncommon::get_cgi_id();
119: my (%x,$i);
120: $x{"cgi.$id.BGIMG"}=&Apache::lonnet::escape($image);
121: my ($x,$y)=split(/:/,$Apache::lonhomework::history{"resource.$part.$respid.submission"});
122: #draws 2 xs on the image at the clicked location
123: #one in white and then one in red on top of the one in white
124: if (defined($x) && $x=~/\S/ && defined($y) && $y =~/\S/ && !&Apache::response::show_answer()) {
125: my $length = 6;
126: my $width = 1;
127: my $extrawidth = 2;
128: my $xmin=($x-$length);
129: my $xmax=($x+$length);
130: my $ymin=($y-$length);
131: my $ymax=($y+$length);
132:
133: $x{"cgi.$id.OBJTYPE"}.='LINE:';
134: $i=$x{"cgi.$id.OBJCOUNT"}++;
135: $x{"cgi.$id.OBJ$i"}=join(':',(($xmin),($ymin),($xmax),($ymax),
136: "FFFFFF",($width+$extrawidth)));
137: $x{"cgi.$id.OBJTYPE"}.='LINE:';
138: $i=$x{"cgi.$id.OBJCOUNT"}++;
139: $x{"cgi.$id.OBJ$i"}=join(':',(($xmin),($ymax),($xmax),($ymin),
140: "FFFFFF",($width+$extrawidth)));
141: $x{"cgi.$id.OBJTYPE"}.='LINE:';
142: $i=$x{"cgi.$id.OBJCOUNT"}++;
143: $x{"cgi.$id.OBJ$i"}=join(':',(($xmin),($ymin),($xmax),($ymax),
144: "FF0000",($width)));
145: $x{"cgi.$id.OBJTYPE"}.='LINE:';
146: $i=$x{"cgi.$id.OBJCOUNT"}++;
147: $x{"cgi.$id.OBJ$i"}=join(':',(($xmin),($ymax),($xmax),($ymin),
148: "FF0000",($width)));
149: }
150: if ($mode eq 'answer') {
151: my $width = 1;
152: my $extrawidth = 2;
153: my @areas = @{ $Apache::response::foilgroup{"$name.area"} };
154: foreach my $area (@areas) {
155: if ($area=~/^rectangle:/) {
156: $x{"cgi.$id.OBJTYPE"}.='RECTANGLE:';
157: $i=$x{"cgi.$id.OBJCOUNT"}++;
158: my ($x1,$y1,$x2,$y2)=
159: ($area=~m/rectangle:\(([0-9]+),([0-9]+)\)\-\(([0-9]+),([0-9]+)\)/);
160: $x{"cgi.$id.OBJ$i"}=join(':',($x1,$y1,$x2,$y2,"FFFFFF",
161: ($width+$extrawidth)));
162: $x{"cgi.$id.OBJTYPE"}.='RECTANGLE:';
163: $i=$x{"cgi.$id.OBJCOUNT"}++;
164: $x{"cgi.$id.OBJ$i"}=join(':',($x1,$y1,$x2,$y2,"00FF00",$width));
165: } elsif ($area=~/^polygon:(.*)/) {
166: $x{"cgi.$id.OBJTYPE"}.='POLYGON:';
167: $i=$x{"cgi.$id.OBJCOUNT"}++;
168: $x{"cgi.$id.OBJ$i"}=join(':',("FFFFFF",($width+$extrawidth)));
169: $x{"cgi.$id.OBJEXTRA$i"}=$1;
170: $x{"cgi.$id.OBJTYPE"}.='POLYGON:';
171: $i=$x{"cgi.$id.OBJCOUNT"}++;
172: $x{"cgi.$id.OBJ$i"}=join(':',("00FF00",$width));
173: $x{"cgi.$id.OBJEXTRA$i"}=$1;
174: }
175: }
176: }
177: &Apache::lonnet::appenv(%x);
178: return $id;
179: }
180:
181: sub displayfoils {
182: my ($target,@whichopt) = @_;
183: my $result ='';
184: my $name;
185: my $temp=1;
186: foreach $name (@whichopt) {
187: $result.=$Apache::response::foilgroup{"$name.text"};
188: &Apache::lonxml::debug("Text is $result");
189: if ($target eq 'tex') {$result.="\\vskip 0 mm \n";} else {$result.="<br />\n";}
190: my $image=$Apache::response::foilgroup{"$name.image"};
191: &Apache::lonxml::debug("image is $image");
192: if ( $target eq 'web' && $image !~ /^http:/ ) {
193: $image=&clean_up_image($image);
194: }
195: &Apache::lonxml::debug("image is $image");
196: if ( &Apache::response::show_answer() ) {
197: if ($target eq 'tex') {
198: $result.=$Apache::response::foilgroup{"$name.image"}."\\vskip 0 mm \n";
199: } else {
200: my $token=&prep_image($image,'answer',$name);
201: $result.="<img src=\"/adm/randomlabel.png?token=$token\" /><br />\n";
202: }
203: } else {
204: if ($target eq 'tex') {
205: $result.=$Apache::response::foilgroup{"$name.image"}."\\vskip 0 mm \n";
206: } else {
207: my $id=$Apache::inputtags::response['-1'];
208: my $token=&prep_image($image);
209: my $temp=1;
210: $result.="<input type=\"image\" name=\"HWVAL_$id:$temp\" ".
211: "src=\"/adm/randomlabel.png?token=$token\" /><br />\n";
212: }
213: }
214: $temp++;
215: }
216: return $result;
217: }
218:
219: sub clean_up_image {
220: my ($image)=@_;
221: if ($image =~ /\s*<img\s*/) {
222: ($image) = ($image =~ /src\s*=\s*[\"\']([^\"\']+)[\"\']/i);
223: if ($image !~ /^http:/) {
224: $image=&Apache::lonnet::hreflocation('',$image);
225: }
226: if (!$image) {
227: $image='/home/httpd/html/adm/lonKaputt/lonlogo_broken.gif';
228: }
229: } else {
230: $image=&Apache::lonnet::filelocation($Apache::lonxml::pwd[-1],$image);
231: &Apache::lonxml::debug("repcopying: $image");
232: if (&Apache::lonnet::repcopy($image) ne 'ok') {
233: $image='/home/httpd/html/adm/lonKaputt/lonlogo_broken.gif';
234: }
235: }
236: return $image;
237: }
238:
239: sub gradefoils {
240: my (@whichopt) = @_;
241: my $x;
242: my $y;
243: my $result;
244: my $id=$Apache::inputtags::response['-1'];
245: my $temp=1;
246: foreach my $name (@whichopt) {
247: $x=$env{"form.HWVAL_$id:$temp.x"};
248: $y=$env{"form.HWVAL_$id:$temp.y"};
249: &Apache::lonxml::debug("Got a x of $x and a y of $y for $name");
250: if (defined($x) && defined($y) &&
251: defined(@{ $Apache::response::foilgroup{"$name.area"} })) {
252: my @areas = @{ $Apache::response::foilgroup{"$name.area"} };
253: my $grade="INCORRECT";
254: foreach my $area (@areas) {
255: &Apache::lonxml::debug("Area is $area for $name");
256: $area =~ m/([a-z]*):/;
257: &Apache::lonxml::debug("Area of type $1");
258: if ($1 eq 'rectangle') {
259: $grade=&grade_rectangle($area,$x,$y);
260: } elsif ($1 eq 'polygon') {
261: $grade=&grade_polygon($area,$x,$y);
262: } else {
263: &Apache::lonxml::error("Unknown area style $area");
264: }
265: &Apache::lonxml::debug("Area said $grade");
266: if ($grade eq 'APPROX_ANS') { last; }
267: }
268: &Apache::lonxml::debug("Foil was $grade");
269: if ($grade eq 'INCORRECT') { $result= 'INCORRECT'; }
270: if (($grade eq 'APPROX_ANS') && ($result ne 'APPROX_ANS')) { $result=$grade; }
271: &Apache::lonxml::debug("Question is $result");
272: $temp++;
273: }
274: }
275: my $responsestr="$x:$y";
276: my $part=$Apache::inputtags::part;
277: my %previous=&Apache::response::check_for_previous($responsestr,$part,$id);
278: if ($result
279: && $Apache::lonhomework::type eq 'survey') { $result='SUBMITTED'; }
280: &Apache::response::handle_previous(\%previous,$result);
281: $Apache::lonhomework::results{"resource.$part.$id.submission"}=$responsestr;
282: $Apache::lonhomework::results{"resource.$part.$id.awarddetail"}=$result;
283: return '';
284: }
285:
286: sub end_foilgroup {
287: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
288: my $result='';
289: my @whichopt;
290: if ($target eq 'web' || $target eq 'grade' || $target eq 'tex' ||
291: $target eq 'analyze') {
292: my ($count,$max) = &getfoilcounts($parstack,$safeeval);
293: if ($count>$max) { $count=$max }
294: &Apache::lonxml::debug("Count is $count from $max");
295: @whichopt = &whichfoils($max);
296: if ($target eq 'web' || $target eq 'tex') {
297: $result=&displayfoils($target,@whichopt);
298: } elsif ($target eq 'grade') {
299: if ( defined $env{'form.submitted'}) { &gradefoils(@whichopt); }
300: } elsif ( $target eq 'analyze') {
301: &Apache::response::analyze_store_foilgroup(\@whichopt,
302: ['text','image','area']);
303: }
304: } elsif ($target eq 'edit') {
305: $result=&Apache::edit::end_table();
306: }
307: &Apache::response::poprandomnumber();
308: return $result;
309: }
310:
311: sub start_conceptgroup {
312: $Apache::imageresponse::conceptgroup=1;
313: %Apache::response::conceptgroup=();
314: return '';
315: }
316:
317: sub end_conceptgroup {
318: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
319: $Apache::imageresponse::conceptgroup=0;
320: my $result;
321: if ($target eq 'web' || $target eq 'grade' || $target eq 'tex' ||
322: $target eq 'analyze') {
323: &Apache::response::pick_foil_for_concept($target,
324: ['area','text','image'],
325: \%Apache::hint::image,
326: $parstack,$safeeval);
327: } elsif ($target eq 'edit') {
328: $result=&Apache::edit::end_table();
329: }
330: return $result;
331: }
332:
333: sub insert_foil {
334: return '
335: <foil>
336: <image></image>
337: <text></text>
338: <rectangle></rectangle>
339: </foil>
340: ';
341: }
342:
343: $Apache::imageresponse::curname='';
344: sub start_foil {
345: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
346: my $result;
347: if ($target eq 'web' || $target eq 'grade' || $target eq 'tex' ||
348: $target eq 'analyze') {
349: my $name = &Apache::lonxml::get_param('name',$parstack,$safeeval);
350: if (!$name) {
351: &Apache::lonxml::error("Foils without names exist. This can cause problems to malfunction.");
352: $name=$Apache::lonxml::curdepth;
353: }
354: if (defined($Apache::response::foilnames{$name})) {
355: &Apache::lonxml::error(&mt("Foil name <b><tt>[_1]</tt></b> appears more than once. Foil names need to be unique.",$name));
356: }
357: $Apache::response::foilnames{$name}++;
358: if ( $Apache::imageresponse::conceptgroup
359: #&& !&Apache::response::showallfoils()
360: ) {
361: push(@{ $Apache::response::conceptgroup{'names'} }, $name);
362: } else {
363: push(@{ $Apache::response::foilgroup{'names'} }, $name);
364: }
365: $Apache::imageresponse::curname=$name;
366: } elsif ($target eq 'edit') {
367: $result = &Apache::edit::tag_start($target,$token);
368: $result .= &Apache::edit::text_arg('Name:','name',$token);
369: $result .= &Apache::edit::end_row().
370: &Apache::edit::start_spanning_row();
371: } elsif ($target eq 'modified') {
372: my $constructtag=&Apache::edit::get_new_args($token,$parstack,
373: $safeeval,'name');
374: if ($constructtag) { $result = &Apache::edit::rebuild_tag($token); }
375: }
376: return $result;;
377: }
378:
379: sub end_foil {
380: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
381: my $result;
382: if ($target eq 'edit') {
383: $result=&Apache::edit::end_table();
384: }
385: return $result;
386: }
387:
388: sub start_text {
389: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
390: my $result='';
391: if ($target eq 'web' || $target eq 'tex' || $target eq 'analyze') {
392: &Apache::lonxml::startredirection;
393: } elsif ($target eq 'edit') {
394: my $descr=&Apache::lonxml::get_all_text('/text',$parser);
395: $result=&Apache::edit::tag_start($target,$token,'Task Description').
396: &Apache::edit::editfield($token->[1],$descr,'Text',60,2).
397: &Apache::edit::end_row();
398: } elsif ($target eq "modified") {
399: $result=$token->[4].&Apache::edit::modifiedfield('/text',$parser);
400: }
401: return $result;
402: }
403:
404: sub end_text {
405: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
406: my $result;
407: if ($target eq 'web' || $target eq 'tex' || $target eq 'analyze') {
408: my $name = $Apache::imageresponse::curname;
409: if ( $Apache::imageresponse::conceptgroup
410: #&& !&Apache::response::showallfoils()
411: ) {
412: $Apache::response::conceptgroup{"$name.text"} = &Apache::lonxml::endredirection;
413: } else {
414: $Apache::response::foilgroup{"$name.text"} = &Apache::lonxml::endredirection;
415: }
416: } elsif ($target eq 'edit') {
417: $result=&Apache::edit::end_table();
418: }
419: return $result;
420: }
421:
422: sub start_image {
423: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
424: my $result='';
425: if ($target eq 'web' || $target eq 'tex' || $target eq 'analyze') {
426: &Apache::lonxml::startredirection;
427: } elsif ($target eq 'edit') {
428: my $bgimg=&Apache::lonxml::get_all_text('/image',$parser);
429: $Apache::edit::bgimgsrc=$bgimg;
430: $Apache::edit::bgimgsrcdepth=$Apache::lonxml::curdepth;
431:
432: $result=&Apache::edit::tag_start($target,$token,'Clickable Image').
433: &Apache::edit::editline($token->[1],$bgimg,'Image Source File',40);
434: $result.=&Apache::edit::browse(undef,'textnode').' ';
435: $result.=&Apache::edit::search(undef,'textnode').
436: &Apache::edit::end_row();
437: } elsif ($target eq "modified") {
438: $result=$token->[4].&Apache::edit::modifiedfield('/image',$parser);
439: }
440: return $result;
441: }
442:
443: sub end_image {
444: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
445: my $result;
446: my $name = $Apache::imageresponse::curname;
447: if ($target eq 'web') {
448: my $image = &Apache::lonxml::endredirection();
449: &Apache::lonxml::debug("original image is $image");
450: if ( $Apache::imageresponse::conceptgroup
451: #&& !&Apache::response::showallfoils()
452: ) {
453: $Apache::response::conceptgroup{"$name.image"} = $image;
454: } else {
455: $Apache::response::foilgroup{"$name.image"} = $image;
456: }
457: } elsif ($target eq 'analyze') {
458: my $image = &Apache::lonxml::endredirection();
459: if ( $Apache::imageresponse::conceptgroup
460: #&& !&Apache::response::showallfoils()
461: ) {
462: $Apache::response::conceptgroup{"$name.image"} = $image;
463: } else {
464: $Apache::response::foilgroup{"$name.image"} = $image;
465: }
466: } elsif ($target eq 'edit') {
467: $result=&Apache::edit::end_table();
468: } elsif ($target eq 'tex') {
469: my $src = &Apache::lonxml::endredirection();
470: my ($path,$file) = &Apache::londefdef::get_eps_image($src);
471: my ($height_param,$width_param)=
472: &Apache::londefdef::image_size($src,0.3,$parstack,$safeeval);
473: $Apache::response::foilgroup{"$name.image"} ='\vskip 0 mm \noindent\graphicspath{{'.$path.'}}\includegraphics[width='.$width_param.' mm]{'.$file.'} ';
474: }
475: return $result;
476: }
477:
478: sub start_rectangle {
479: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
480: my $result='';
481: if ($target eq 'web' || $target eq 'grade' || $target eq 'tex' ||
482: $target eq 'analyze') {
483: &Apache::lonxml::startredirection;
484: } elsif ($target eq 'edit') {
485: my $coords=&Apache::lonxml::get_all_text('/rectangle',$parser);
486: $result=&Apache::edit::tag_start($target,$token,'Rectangle').
487: &Apache::edit::editline($token->[1],$coords,'Coordinate Pairs',40).
488: &Apache::edit::entercoord(undef,'textnode',undef,undef,'box').
489: &Apache::edit::end_row();
490: } elsif ($target eq "modified") {
491: &Apache::edit::deletecoorddata();
492: $result=$token->[4].&Apache::edit::modifiedfield('/rectangle',$parser);
493: }
494: return $result;
495: }
496:
497: sub grade_rectangle {
498: my ($spec,$x,$y) = @_;
499: &Apache::lonxml::debug("Spec is $spec");
500: my ($x1,$y1,$x2,$y2)=($spec=~m/rectangle:\(([0-9]+),([0-9]+)\)\-\(([0-9]+),([0-9]+)\)/);
501: &Apache::lonxml::debug("Point $x1,$y1,$x2,$y2");
502: if ($x1 > $x2) { my $temp=$x1;$x1=$x2;$x2=$temp; }
503: if ($y1 > $y2) { my $temp=$y1;$y1=$y2;$y2=$temp; }
504: if (($x >= $x1) && ($x <= $x2) && ($y >= $y1) && ($y <= $y2)) {
505: return 'APPROX_ANS';
506: }
507: return 'INCORRECT';
508: }
509:
510: sub end_rectangle {
511: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
512: my $result;
513: if ($target eq 'web' || $target eq 'grade' || $target eq 'tex' ||
514: $target eq 'analyze') {
515: my $name = $Apache::imageresponse::curname;
516: my $area = &Apache::lonxml::endredirection;
517: $area=~s/\s//g;
518: &Apache::lonxml::debug("out is $area for $name");
519: if ( $Apache::imageresponse::conceptgroup
520: #&& !&Apache::response::showallfoils()
521: ) {
522: push @{ $Apache::response::conceptgroup{"$name.area"} },"rectangle:$area";
523: } else {
524: push @{ $Apache::response::foilgroup{"$name.area"} },"rectangle:$area";
525: }
526: } elsif ($target eq 'edit') {
527: $result=&Apache::edit::end_table();
528: }
529: return $result;
530: }
531:
532: sub start_polygon {
533: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
534: my $result='';
535: if ($target eq 'web' || $target eq 'grade' || $target eq 'tex' ||
536: $target eq 'analyze') {
537: &Apache::lonxml::startredirection;
538: } elsif ($target eq 'edit') {
539: my $coords=&Apache::lonxml::get_all_text('/polygon',$parser);
540: $result=&Apache::edit::tag_start($target,$token,'Polygon').
541: &Apache::edit::editline($token->[1],$coords,'Coordinate list',40).
542: &Apache::edit::entercoord(undef,'textnode',undef,undef,'polygon').
543: &Apache::edit::end_row();
544: } elsif ($target eq "modified") {
545: $result=$token->[4].&Apache::edit::modifiedfield('/polygon',$parser);
546: }
547: return $result;
548: }
549:
550: sub grade_polygon {
551: my ($spec,$x,$y) = @_;
552: &Apache::lonxml::debug("Spec is $spec");
553: $spec=~s/^polygon://;
554: my @polygon;
555: foreach my $coord (split('-',$spec)) {
556: my ($x,$y)=($coord=~m/\(([0-9]+),([0-9]+)\)/);
557: &Apache::lonxml::debug("x $x y $y");
558: push @polygon, {'x'=>$x,'y'=>$y};
559: }
560: #make end point start point
561: push @polygon, $polygon[0];
562: # cribbed from
563: # http://geometryalgorithms.com/Archive/algorithm_0103/algorithm_0103.htm
564: my $crossing = 0; # the crossing number counter
565:
566: # loop through all edges of the polygon
567: for (my $i=0; $i<$#polygon; $i++) { # edge from V[i] to V[i+1]
568: if ((($polygon[$i]->{'y'} <= $y)
569: && ($polygon[$i+1]->{'y'} > $y)) # an upward crossing
570: ||
571: (($polygon[$i]->{'y'} > $y)
572: && ($polygon[$i+1]->{'y'} <= $y))) { # a downward crossing
573: # compute the actual edge-ray intersect x-coordinate
574: my $vt = ($y - $polygon[$i]->{'y'})
575: / ($polygon[$i+1]->{'y'} - $polygon[$i]->{'y'});
576: if ($x < $polygon[$i]->{'x'} + $vt *
577: ($polygon[$i+1]->{'x'} - $polygon[$i]->{'x'})) { # x<intersect
578: $crossing++; # a valid crossing of y=P.y right of P.x
579: }
580: }
581: }
582:
583: # 0 if even (out), and 1 if odd (in)
584: if ($crossing%2) {
585: return 'APPROX_ANS';
586: } else {
587: return 'INCORRECT';
588: }
589: }
590:
591: sub end_polygon {
592: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
593: my $result;
594: if ($target eq 'web' || $target eq 'grade' || $target eq 'tex' ||
595: $target eq 'analyze') {
596: my $name = $Apache::imageresponse::curname;
597: my $area = &Apache::lonxml::endredirection;
598: $area=~s/\s*//g;
599: &Apache::lonxml::debug("out is $area for $name");
600: if ( $Apache::imageresponse::conceptgroup
601: #&& !&Apache::response::showallfoils()
602: ) {
603: push @{ $Apache::response::conceptgroup{"$name.area"} },"polygon:$area";
604: } else {
605: push @{ $Apache::response::foilgroup{"$name.area"} },"polygon:$area";
606: }
607: } elsif ($target eq 'edit') {
608: $result=&Apache::edit::end_table();
609: }
610: return $result;
611: }
612: 1;
613: __END__
614:
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