-(defun min-pxcor () (getf (clnl-model:world-dimensions *model*) :xmin))
-(defun max-pxcor () (getf (clnl-model:world-dimensions *model*) :xmax))
-(defun min-pycor () (getf (clnl-model:world-dimensions *model*) :ymin))
-(defun max-pycor () (getf (clnl-model:world-dimensions *model*) :ymax))
+(defun min-pxcor () (getf *dimensions* :xmin))
+(defun max-pxcor () (getf *dimensions* :xmax))
+(defun min-pycor () (getf *dimensions* :ymin))
+(defun max-pycor () (getf *dimensions* :ymax))
+
+(defvar *cached-sins*
+ (loop
+ :for i :from 0 :to 360
+ :collect
+ (let
+ ((potential-sin (strictmath:sin (strictmath:to-radians i))))
+ (if (< (abs potential-sin) 3.2d-15) 0d0 potential-sin))))
+
+(defun using-cached-sin (n)
+ (if (= (floor n) n) (nth (floor n) *cached-sins*) (strictmath:sin (strictmath:to-radians n))))
+
+(defvar *cached-coses*
+ (loop
+ :for i :from 0 :to 360
+ :collect
+ (let
+ ((potential-cos (strictmath:cos (strictmath:to-radians i))))
+ (if (< (abs potential-cos) 3.2d-15) 0d0 potential-cos))))
+
+(defun using-cached-cos (n)
+ (if (= (floor n) n) (nth (floor n) *cached-coses*) (strictmath:cos (strictmath:to-radians n))))