Geometric Algorithms

In order to do anything of any worth with vector graphics (drawn on an area), such as drag and drop, there is a need to calculate the following:
- If a point (like a mouse click) is inside a shape whether it is a filled arc, polygon, or closed figure with bezier curves.
- If a point (like a mouse click) lies at the edge of a shape whether it is a stroked arc, a polyline, or an open figure with bezier curves

As such, it only makes sense that the GUI library would provide such algorithms just like [Java AWT](https://docs.oracle.com/javase/7/docs/api/java/awt/geom/package-summary.html) does; it includes algorithms for testing if a shape contains a point in all shapes. I already make great use of it in [Glimmer DSL for SWT](https://github.com/AndyObtiva/glimmer-dsl-swt).

Since you already make use of such algorithms to render the vector graphics in the GUI, I would imagine that exposing them as part of libui would be a small step from there.

I would greatly appreciate you making such algorithms available.

Thank you again for libui. I have been able to build apps very productively with it using [Glimmer DSL for LibUI](https://github.com/AndyObtiva/glimmer-dsl-libui) in Ruby.