Test 'additive' and 'accumulate' attributes.

Eight animations have been defined. For each animation, ruler lines and text are provided to help show what the correct behavior is. The red text shows the values for attributes 'additive' and 'accumulate'. The black text and ruler lines help show the change in height of the rectangles over time.

In the first row, a single animation which changes the height of the rectangle is defined for each picture. The height changes from 10 to 25, and the animation repeats (total of two loops). The four pictures show the effect with the four possible combinations of 'additive' (either 'replace' or 'sum') and 'accumulate' (either 'none' or 'sum').

In the second row, two identical animations change the height of the rectangle, with each animation exactly the same as the corresponding animation in the first row. Again, the four pictures show the effect with the four possible combinations of 'additive' (either 'replace' or 'sum') and 'accumulate' (either 'none' or 'sum'). Because two animations are animating the height, the effects of 'additive' and 'accumulate' are sometimes different than when there is only a single animation.