Logo functionality in Common Lisp. Inspired by the book Turtle Geometry.
Tested with SBCL.
Get quicklisp.
cd ~/quicklisp/local-projects/
git clone https://github.com/hahahahaman/qua.git
git clone https://github.com/hahahahaman/turtle-geometry.git
In the REPL use quicklisp to install all dependencies and to build the package:
(ql:quickload :turtle-geometry)
In order to save on typing, I run the commands while I'm inside the turtle-geometry package
REPL:
(in-package :turtle-geometry)
(run)
(dotimes (x 100) (square x));; create a turtle in the world
;; movement and rotation
(forward distance)
(fw d)
(back distance)
(bk d)
(left radians)
(lt r)
(right radians)
(rt r)
(roll radians) # x-axis rotation
(pitch radians) # y
(yaw radians) # z
;; pen
(pen-down)
(pen-up)
(pen-toggle)
(color)
;; misc.
(clear)
(clr)
The interface is a hybrid graphical text interface. A graphical windows is created with SDL2, which acts as a first person explorer of the 3D space. Using Emacs and Slime the Logo commands are inputted.
shapes.lisp stores code from the book.
Hotkeys in main.lisp:
`ESC` - quit
`LALT+r` - clear
`LCTRL+MOUSE Move` - change camera direction
`LCTRL+{w,a,s,d}` - move up, down, left, right
`LCTRL+MOUSE_WHEEL` - zoom in and out
`LSHIFT+TAB` - get camera to face the turtle
`z` - decrease camera speed
`x` - increase camera speed
`c` - print camera info to console
In the book Mindstorms, Papert presents the idea of microworlds, which resonates with me as a compelling way to interact with mathematical behavior. I am particularly interested in the connection between building a idealized thought experiment in the mind vs. the machine. Thought experiments (Gedankenexperiment) are typically used in physics in order to reason about nature. The idea of microworlds is similar, in that it tries to distill and elaborate upon a important feature of a system, but the act of creation used to build a microworld seems to give the idea a powerful nuance.
The turtle is an immutable map of attributes, which includes: position, color, rotation, and pen up/down.