Feature Request: Drawing Primitives

[anthonyfinch]

FRAG should support drawing primitives. Use cases are:

• for simple game prototypes (or just games with a very simple visual style)
• for debug and "editor" gui systems - eg. drawing bounding boxes, "handles" to resize, move objects etc.

As a list of possible primitive to start with, I would suggest something like that supported by sdl2, ie:

• lines
• points
• rects
  with filled and non-filled variants.

See the discussion on the forum here: http://community.fragworks.io/t/possible-feature-request-drawing-primitives/19 ( @zacharycarter has some implementation suggestions here. )

[zacharycarter]

This is going to require porting :
https://github.com/bkaradzic/bgfx/tree/master/examples/common/nanovg
and more specifically :
https://github.com/bkaradzic/bgfx/blob/master/examples/common/nanovg/nanovg_bgfx.cpp

[zacharycarter]

Implemented with 0b46c89