Fix for the WithinImageBorderUP1D predicate not working with a ViewEdge such that

none of the SVertices are within the image boundary but an FEdge intersects with
the image boundary.

The problem was reported by edna through the BA Freestyle thread, with a .blend
file for reproducing the bug.  Thanks!

1 files changed, 57 insertions, 0 deletions

diff --git a/source/blender/freestyle/intern/stroke/Predicates1D.h b/source/blender/freestyle/intern/stroke/Predicates1D.h
index 6461f6428ab..b1159a8332e 100755
--- a/source/blender/freestyle/intern/stroke/Predicates1D.h
+++ b/source/blender/freestyle/intern/stroke/Predicates1D.h
@@ -358,6 +358,63 @@ namespace Predicates1D {
     }
   };
   
+  // WithinImageBoundaryUP1D
+  /*! Returns true if the Interface1D is (partly) within the image boundary.
+   */
+  class WithinImageBoundaryUP1D: public UnaryPredicate1D
+  {
+  private:
+    real _xmin, _ymin, _xmax, _ymax;
+  public:
+    /*! Builds the Predicate.
+     *  \param xmin
+     *    The X lower bound of the image boundary.
+     *  \param ymin
+     *    The Y lower bound of the image boundary.
+     *  \param xmax
+     *    The X upper bound of the image boundary.
+     *  \param ymax
+     *    The Y upper bound of the image boundary.
+     */
+	WithinImageBoundaryUP1D(const real xmin, const real ymin, const real xmax, const real ymax) :
+		_xmin(xmin), _ymin(ymin), _xmax(xmax), _ymax(ymax) {}
+    /*! Returns the string "WithinImageBoundaryUP1D"*/
+    string getName() const {
+      return "WithinImageBoundaryUP1D";
+    }
+    /*! The () operator. */
+    int operator()(Interface1D& inter) {
+	  // 1st pass: check if a point is within the image boundary.
+	  Interface0DIterator it = inter.verticesBegin(), itend = inter.verticesEnd();
+	  for (; it != itend; ++it) {
+		real x = (*it).getProjectedX();
+		real y = (*it).getProjectedY();
+		if (_xmin <= x && x <= _xmax && _ymin <= y && y <= _ymax) {
+		  result = true;
+		  return 0;
+		}
+	  }
+	  // 2nd pass: check if a line segment intersects with the image boundary.
+	  it = inter.verticesBegin();
+	  if (it != itend) {
+		Vec2r pmin(_xmin, _ymin);
+		Vec2r pmax(_xmax, _ymax);
+		Vec2r prev((*it).getPoint2D());
+		++it;
+		for (; it != itend; ++it) {
+		  Vec2r p((*it).getPoint2D());
+		  if (GeomUtils::intersect2dSeg2dArea (pmin, pmax, prev, p)) {
+			result = true;
+			return 0;
+		  }
+		  prev = p;
+		}
+	  }
+	  result = false;
+      return 0;
+    }
+  };
+
   //
   //   Binary Predicates definitions
   //