Here is a short description of the shapes.
A simple rectangle shape. You can set its width and height.
A rectangle with rounded corners. You can set its width, height and the radius of each corner separately.
PolygonA regular polygon. You can set the radius and the number of sides (up to 20).
StarA star shape. You can set the dimensions, the number of spikes (up to 40), a X/Y aspect.
A Shift parameters allows you to change the spike direction.
SpiralA arithmetic or geometric spiral. You can set the number of turns, a start value for radius and width.
The Add Radius and Add Width value are used to make the radius and width grow by the given value, each turn.
The Mult Radius and Mult Width value are used in the construction of a geometric spiral. They act like factors.
WormA sinus wave shape. You can set the number of cycles, the start and end values for the height and the width.
Height and width can be considered as amplitude and wavelength.
PetalA flower shape. You can set the inner and outer radius, the number of petal (up to 40) and their roundness.
SunSame as petal but the shape looks more like a sun. The petal can be made more sharp.
You can set the inner and outer radius, the number of petal (up to 40) and their roundness.
MoonTwo arcs of circle. You can set the radius, the X/Y aspect and the shape of both arcs.
LeafA shematic leaf. You can set the size, the X/Y aspect, the spike size and density.
The shape value defines the overall roundness.
CogA simple cog shape. You can set the inner radius, the number (up to 100) and dimension of the spikes.
FlareA random spiky shape. You can set two inner and outer radius, the spike count and a random seed.
OvoidRound shape defined by two arcs.You can set the radius and the roundness and ratio for the top and bottom arcs.
AngleTwo rectangles joined with an arc of circle. You can set the length of the start and end rectangle, their common width and the curve radius.
RuleA rule build with small rectangles. You can set the length (up to 1000) of the shape and the ticks dimensions and frequency. There are two levels of ticks.
JointA shape defined by two curves, looks like a vase profile. You can set the top and bottom length, their relative position, the height and the curve shape.
SpirangularSegments of lines placed to form a spiral. You can set the width of the segment and its variation, the radiuse and its variation, the angle between two consecutive segments and the segment count (up to 500).
Don't raise the count value too fast, the resulting shape ca become very big. You can get strange moire effects with some values.
A rectangle with a bumpy edge. You can set the length, the minimum and maximum height, the frequency and phase for the bumps and their style.