
Precision test for linear animateMotion with separated path fragments, mpath element, rotate auto.
The main indication for a failed test is the appearence of the red fill of the test circle. The circle has to follow exactly the paths given in gray.
A linear animateMotion of a blue stroked square with a centered circle is compared with four animateMotion of a red square with a centered circle. The motion of the red square is following the combination of four animateMotion following on each other and is the same as the motion of the blue square, because the timing is choosen in such a way. Therefore the blue square covers always the red one completely.
The path is given in gray. The red fill of the circle is always covered with the gray path. Eight gray stroked markers are lightened, when the circle is exactly above the marker. The red fill of the marker is exactly covered by the blue stroked circle. If something red gets visible, an error is occured and the animateMotion is not linear.
The exact timing is calculated using an analytical integration of the path length of the sub paths (this is available for quadratic or linear curves). With this method the path position and the time can be determined as functions of the usual parametrisation of the used Bézier curves.