Support for multiple rectangle hitboxes in imageresponse

common/lib/capa/capa/responsetypes.py

@@ -1717,7 +1717,7 @@ class ImageResponse(LoncapaResponse):
     """
     Handle student response for image input: the input is a click on an image,
     which produces an [x,y] coordinate pair.  The click is correct if it falls
-    within a region specified.  This region is nominally a rectangle.
+    within a region specified.  This region is a union of rectangles.
 
     Lon-CAPA requires that each <imageresponse> has a <foilgroup> inside it.  That
     doesn't make sense to me (Ike).  Instead, let's have it such that <imageresponse>
@@ -1727,6 +1727,7 @@ class ImageResponse(LoncapaResponse):
     snippets = [{'snippet': '''<imageresponse>
       <imageinput src="image1.jpg" width="200" height="100" rectangle="(10,10)-(20,30)" />
       <imageinput src="image2.jpg" width="210" height="130" rectangle="(12,12)-(40,60)" />
+      <imageinput src="image2.jpg" width="210" height="130" rectangle="(10,10)-(20,30);(12,12)-(40,60)" />
     </imageresponse>'''}]
 
     response_tag = 'imageresponse'
@@ -1743,20 +1744,10 @@ class ImageResponse(LoncapaResponse):
         for aid in self.answer_ids:	 # loop through IDs of <imageinput> fields in our stanza
             given = student_answers[aid]	 # this should be a string of the form '[x,y]'
 
+            correct_map.set(aid, 'incorrect')
             if not given: # No answer to parse. Mark as incorrect and move on
-                correct_map.set(aid, 'incorrect')
                 continue
 
-            # parse expected answer
-            # TODO: Compile regexp on file load
-            m = re.match('[\(\[]([0-9]+),([0-9]+)[\)\]]-[\(\[]([0-9]+),([0-9]+)[\)\]]',
-                         expectedset[aid].strip().replace(' ', ''))
-            if not m:
-                msg = 'Error in problem specification! cannot parse rectangle in %s' % (
-                    etree.tostring(self.ielements[aid], pretty_print=True))
-                raise Exception('[capamodule.capa.responsetypes.imageinput] ' + msg)
-            (llx, lly, urx, ury) = [int(x) for x in m.groups()]
-
             # parse given answer
             m = re.match('\[([0-9]+),([0-9]+)]', given.strip().replace(' ', ''))
             if not m:
@@ -1764,11 +1755,24 @@ class ImageResponse(LoncapaResponse):
                                 'error grading %s (input=%s)' % (aid, given))
             (gx, gy) = [int(x) for x in m.groups()]
 
-            # answer is correct if (x,y) is within the specified rectangle
-            if (llx <= gx <= urx) and (lly <= gy <= ury):
-                correct_map.set(aid, 'correct')
-            else:
-                correct_map.set(aid, 'incorrect')
+            # Check whether given point lies in any of the solution rectangles
+            solution_rectangles = expectedset[aid].split(';')
+            for solution_rectangle in solution_rectangles:
+                # parse expected answer
+                # TODO: Compile regexp on file load
+                m = re.match('[\(\[]([0-9]+),([0-9]+)[\)\]]-[\(\[]([0-9]+),([0-9]+)[\)\]]',
+                             solution_rectangle.strip().replace(' ', ''))
+                if not m:
+                    msg = 'Error in problem specification! cannot parse rectangle in %s' % (
+                        etree.tostring(self.ielements[aid], pretty_print=True))
+                    raise Exception('[capamodule.capa.responsetypes.imageinput] ' + msg)
+                (llx, lly, urx, ury) = [int(x) for x in m.groups()]
+
+                # answer is correct if (x,y) is within the specified rectangle
+                if (llx <= gx <= urx) and (lly <= gy <= ury):
+                    correct_map.set(aid, 'correct')
+                    break
+
         return correct_map
 
     def get_answers(self):

common/lib/capa/capa/tests/test_files/imageresponse.xml

@@ -8,8 +8,14 @@ Hello</p></text>
 <text>Click on the image where the top skier will stop momentarily if the top skier starts from rest.</text>
 <imageinput src="/static/Physics801/Figures/Skier-conservation of energy.jpg" width="560" height="388" rectangle="(242,202)-(296,276)"/>
 <text>Click on the image where the lower skier will stop momentarily if the lower skier starts from rest.</text>
+<imageinput src="/static/Physics801/Figures/Skier-conservation of energy.jpg" width="560" height="388" rectangle="(490,11)-(556,98);(242,202)-(296,276)"/>
+<text>Click on either of the two positions as discussed previously.</text>
+<imageinput src="/static/Physics801/Figures/Skier-conservation of energy.jpg" width="560" height="388" rectangle="(490,11)-(556,98);(242,202)-(296,276)"/>
+<text>Click on either of the two positions as discussed previously.</text>
+<imageinput src="/static/Physics801/Figures/Skier-conservation of energy.jpg" width="560" height="388" rectangle="(490,11)-(556,98);(242,202)-(296,276)"/>
+<text>Click on either of the two positions as discussed previously.</text>
 <hintgroup showoncorrect="no">
 <text><p>Use conservation of energy.</p></text>
 </hintgroup>
 </imageresponse>
-</problem>
\ No newline at end of file
+</problem>

common/lib/capa/capa/tests/test_responsetypes.py

@@ -53,12 +53,22 @@ class ImageResponseTest(unittest.TestCase):
         imageresponse_file = os.path.dirname(__file__) + "/test_files/imageresponse.xml"
         test_lcp = lcp.LoncapaProblem(open(imageresponse_file).read(), '1', system=test_system)
         correct_answers = {'1_2_1': '(490,11)-(556,98)',
-                           '1_2_2': '(242,202)-(296,276)'}
+                           '1_2_2': '(242,202)-(296,276)',
+                           '1_2_3': '(490,11)-(556,98);(242,202)-(296,276)',
+                           '1_2_4': '(490,11)-(556,98);(242,202)-(296,276)',
+                           '1_2_5': '(490,11)-(556,98);(242,202)-(296,276)',
+                          }
         test_answers = {'1_2_1': '[500,20]',
                         '1_2_2': '[250,300]',
+                        '1_2_3': '[500,20]',
+                        '1_2_4': '[250,250]',
+                        '1_2_5': '[10,10]',
                         }
         self.assertEquals(test_lcp.grade_answers(test_answers).get_correctness('1_2_1'), 'correct')
         self.assertEquals(test_lcp.grade_answers(test_answers).get_correctness('1_2_2'), 'incorrect')
+        self.assertEquals(test_lcp.grade_answers(test_answers).get_correctness('1_2_3'), 'correct')
+        self.assertEquals(test_lcp.grade_answers(test_answers).get_correctness('1_2_4'), 'correct')
+        self.assertEquals(test_lcp.grade_answers(test_answers).get_correctness('1_2_5'), 'incorrect')
 
 
 class SymbolicResponseTest(unittest.TestCase):