added multiple regions support

common/lib/capa/capa/responsetypes.py

@@ -23,6 +23,7 @@ import abc
 import os
 import subprocess
 import xml.sax.saxutils as saxutils
+from shapely.geometry import Polygon, Point
 
 # specific library imports
 from calc import evaluator, UndefinedVariable
@@ -1720,12 +1721,20 @@ class ImageResponse(LoncapaResponse):
     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>
     should contain one or more <imageinput> stanzas. Each <imageinput> should specify
-    a rectangle, given as an attribute, defining the correct answer.
+    a rectangle(s) or region(s), given as an attribute, defining the correct answer.
+
+    Rectangle(s) are more prioritized over regions due to simplicity and backward compatibility.
+    In this example regions will be ignored:
+    <imageinput src="/static/images/Lecture2/S2_p04.png" width="811" height="610"  rectangle="(10,10)-(20,30);(12,12)-(40,60)" regions='[[[10,10], [20,30], [40, 10]], [[100,100], [120,130], [110,150]]]'/>
+
+    Regions is list of lists [region1, region2, region3, ...] where regionN is ordered list of points: [[1,1], [100,100], [50,50], [20, 70]].
     """
     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)" />
+      <imageinput src="image3.jpg" width="210" height="130" rectangle="(10,10)-(20,30);(12,12)-(40,60)" />
+      <imageinput src="image4.jpg" width="811" height="610"  rectangle="(10,10)-(20,30);(12,12)-(40,60)" regions='[[[10,10], [20,30], [40, 10]], [[100,100], [120,130], [110,150]]]'/>
+      <imageinput src="image5.jpg" width="200" height="200" regions='[[[10,10], [20,30], [40, 10]], [[100,100], [120,130], [110,150]]]' />
     </imageresponse>'''}]
 
     response_tag = 'imageresponse'
@@ -1753,8 +1762,10 @@ class ImageResponse(LoncapaResponse):
                                 'error grading %s (input=%s)' % (aid, given))
             (gx, gy) = [int(x) for x in m.groups()]
 
+            rectangles, regions = expectedset
+            if rectangles[aid]:  # rectangles part - for backward compatibility
                 # Check whether given point lies in any of the solution rectangles
-            solution_rectangles = expectedset[aid].split(';')
+                solution_rectangles = rectangles[aid].split(';')
                 for solution_rectangle in solution_rectangles:
                     # parse expected answer
                     # TODO: Compile regexp on file load
@@ -1770,12 +1781,18 @@ class ImageResponse(LoncapaResponse):
                     if (llx <= gx <= urx) and (lly <= gy <= ury):
                         correct_map.set(aid, 'correct')
                         break
-
+            else:  # rectangles are more prioretized for same id
+                if regions[aid]:
+                    parsed_region = json.loads(regions[aid])
+                    for region in parsed_region:
+                        if Polygon(region).contains(Point(gx, gy)):
+                            correct_map.set(aid, 'correct')
+                            break
         return correct_map
 
     def get_answers(self):
-        return dict([(ie.get('id'), ie.get('rectangle')) for ie in self.ielements])
-
+        return (dict([(ie.get('id'), ie.get('rectangle')) for ie in self.ielements]),
+                dict([(ie.get('id'), ie.get('regions')) for ie in self.ielements]))
 #-----------------------------------------------------------------------------
 # TEMPORARY: List of all response subclasses
 # FIXME: To be replaced by auto-registration