#!/usr/bin/clisp ;;;; ;;;; Terra Nostra is a Minecraft-like survival game for the commandline. ;;;; ;;;; (c) 2018 Daniel Vedder ;;;; (defvar *world* NIL) (defstruct patch (pos '(0 0)) ;position (alt 0) ;altitude (streams-in NIL) (streams-out NIL)) (defun init-matrix (size) "Create a square matrix of empty patches" (do ((y 0 (1+ y)) (world NIL) (row NIL NIL)) ((= y size) world) (dotimes (x size) (setf row (append row (list (make-patch :pos (list x y)))))) (setf world (append world (list row))))) (defun coord (x y &optional (world *world*)) "Return the patch at the given coordinates or NIL if out of bounds" (unless (or (< x 0) (< y 0) (> x (length world)) (> y (length world))) (nth x (nth y world))))