** License

Permission is hereby granted, free of charge, to any person obtaining a copy

of this software and associated documentation files (the "Software"), to deal

:license "MIT"

:depends-on (#:alexandria

#:cl-geometry

#:glkit

#:mathkit

#:md5

:keyboard-event

:other-event

:close-window)

(:export :sketch

:setup

:draw

:with-font

:set-font

:text

))

(defun point (x y)

(declare (type real x y))

(with-pen (make-pen :fill (pen-stroke (env-pen *env*)))

(rect x y 1 1)))

(let* ((a (atan (- y2 y1) (- x2 x1)))

(w (/ (or (pen-weight (env-pen *env*)) 1) 2))

(dx (* 2 (sin a) w))

(cdar (last lines)))

nil)))

(multiple-value-bind (d+ d-)

(div2-inexact (pen-weight (env-pen *env*)))

(let* ((lines (edges (group coordinates) nil))

(t (with-pen (flip-pen (env-pen *env*))

(funcall (apply #'make-polyline coordinates))))))

(if (and (plusp w) (plusp h))

(lambda ()

(draw-shape

y (* radial (- y (* x tangential)))))

(nreverse vertices)))

(let ((vertices (ngon-vertices n cx cy rx ry angle)))

(lambda ()

(draw-shape :triangle-fan vertices vertices))))

(type real cx cy rx ry angle))

(funcall (make-ngon n cx cy rx ry angle)))

(let ((vertices (mix-lists (ngon-vertices n cx cy ra ra (+ 90 angle))

(ngon-vertices n cx cy rb rb (- (+ 90 angle) (/ 180 n))))))

(lambda ()

(when (not (zerop r))

(ellipse x y (abs r) (abs r))))

(list

:triangles

(triangulate coordinates)