+WVTEST_MAIN("auxiliary angle between three points")
+{
+ double a;
+ a = angle_between_three_points(1, 0, 0, 0, 0, 1);
+ WVPASSEQ_DOUBLE(a, M_PI/2, 0.00001);
+ a = angle_between_three_points(0, 1, 0, 0, 1, 0);
+ WVPASSEQ_DOUBLE(a, M_PI/2, 0.00001);
+ a = angle_between_three_points(2, 2, 1, 1, 0, 0);
+ WVPASSEQ_DOUBLE(a, 0, 0.00001);
+ a = angle_between_three_points(-2, 2, -1, 1, -1, 2);
+ WVPASSEQ_DOUBLE(a, M_PI/4, 0.00001);
+ a = angle_between_three_points(-1, 2, -1, 1, -2, 2);
+ WVPASSEQ_DOUBLE(a, M_PI/4, 0.00001);
+}
+