library tester for painting methods

These are the first and second parts of a library to create the image generators for the Commentary project. The first part are the basic function to create lines, straight and circular ones. The second part are the painting methods.
In the third script section of the page this is tested.

Note: the thrird part of the library is not included in the code above.
It will be compiled from the files mentioned below.

the painting methods are:

• pastel like, the animation variations are
  • straight line
  • curve, circle
  pastelWaterLineCurve.html contains both methods
  
• brushstrokes, the animation directions are
  • linear rotated,
  • circular,
  • vertical/horizontal (most simple)
  brush7a_circle_ani.html contains the circular method
  comments_2.html contains vertical/horizontal method
  
• dripdrop
  dripdrop_scribble7struct.html contains this painting method
• scratch layers ^**
• ...
• sketch "pencil" ^**

All painting methods can be animated. They are not "static" functions, like the prior used oilpaint filter (or pencil sketch filter).

The paint method differ into one of the following categories:
Simple point based ones and the more complex and special one namely the brushstroke method.
The first group draws a sinple particle, dripdrop, or line, which are animated on the point aka in one frame. Whereas the brushstroke is an object with in itself, that needs to be animated along the stroke line in multiple frames. The simplification here is to animate along the main orientation of the figure in many frames, so the mask has not to be rotated.
Brushstrokes need to be collected in groups to fill shapes like rectangles. The other paint methods fill those shapes with particles instead.

The third part of the library, the figures to paint, are structures in

1. dripdrop_scribble7struct.html, (blocks)
2. formal-in-formal, (blocks)
3. gallery.html, (linear pattern variations)
4. bezierLeaf_g2.html (bezierLeaf variations), (circular, round, layers)
5. hesse-variations, (circular, round)bezier-leaf and hesse-variants can be viewed here
6. nay-variations (circular, round, waves)

contains the scratch layers and sketch pencil variations

** not needed/implemented | *** optional