Generating one image from several small ones inside a silhouette shape (see img inside)

I have a big shape of some figure and some set of symbols.

I'm looking for some way to fill the shape with symbols so that they're trying to fill all the space inside a shape. Symbols can be scaled, rotated and repeated.

As there are a lot of shapes making all by hands is too expensive so I need to automatize the process.

At least I need some pattern generator and after getting a pattern I will cut the rest symbols that don't lay inside a shape.

Any ideas are highly appreciated!