Add a primitive:
You choose primitive in drop-down list.
You can modify parameters for primitive.
Effect of filter apply in real time.
Modify a primitive:
Click on modify button.
You can modify all parameters.
Remove a primitive:
Click on remove button.
Primitive is removed
Others primitives are reorganized.
See intermediate effects:
Click on see button.
Intermediate effect is draw.
Click on last see button to retrieve final effect.
Get SVG code:
PHP server send SVG code only for filter effect.
You can save it on your disk.