bqn-fenster/README.org

• Minimal graphical applications in BQN
  • Setup
  • API
  • Example

Minimal graphical applications in BQN

Bindings for Fenster, providing a set of functions for displaying a window and setting the color of individual pixels inside.

Setup

Clone the repository recursively (git clone --recurse-submodules) and run make to build the shared library. The Makefile should work on Linux and macOS.

API

High-level API:

• F _display width‿height creates a window of the given dimensions and displays its left operand. F should be a function returning a color as an RGB triplet in the (0,1) range, and taking a list of two elements x‿y, where x and y are the pixel coordinates.

Low-level API:

• OpenWindow w‿h‿t opens a window of width w and height h, with title t. Returns a window handle.
• CloseWindow w closes a window given its handle w.
• F _render w runs the function F at each coordinate of the window w and set the corresponding pixel color. F is a function with the same arguments as for _display.

Example

See example.bqn.

f←•Import"fenster.bqn"

size←500

Rainbow←{𝕊x‿y:
  x‿y↩x‿y÷size
  h←(x+y)÷2
  f.HSVtoRGB⟨360×h,1,1⟩
}

Rainbow f._display size‿size