diff options
| -rw-r--r-- | examples/12-canvas-drawing-language.lisp | 31 |
1 files changed, 24 insertions, 7 deletions
diff --git a/examples/12-canvas-drawing-language.lisp b/examples/12-canvas-drawing-language.lisp index 24008c2..bece8c8 100644 --- a/examples/12-canvas-drawing-language.lisp +++ b/examples/12-canvas-drawing-language.lisp @@ -19,6 +19,7 @@ (draw-stuff canvas) (ww::blit canvas))) +;; draw a triangle, each side is a different color (defun triangle-at (x y) (ww::move-to x y) (ww::canvas-pen-color (list 0 200 200 255)) @@ -28,28 +29,39 @@ (ww::canvas-pen-color (list 0 200 0 255)) (ww::stroke-rel -100 -100)) + +;; draw a filled triangle using the current pen (defun filled-triangle-at (x y) (ww::move-to x y) (ww::fill-rel-path '((100 100) (100 -100)))) +;; a pen function - gets more blue the closer x y is to 0 0 (defun lower-the-bluer (x y) (list (* 256 (/ x 500)) (* 256 (/ y 500)) 255 255)) +;; a pen function - makes a plaid like pattern (defun plaid1 (x y) (list (mod (* x x) 256) (mod (* y y) 256) (mod (* x y) 256) 255)) +;; draws a "flower" like pinwheel using bezier curves (defun flower (&optional (petals 5)) (ww::canvas-pen-width 1) - (let ((r (sqrt (+ (* 25 25) (* 100 100)))) - (psw (* pi 0.08))) + (let ((r ; radius + (sqrt (+ (* 25 25) (* 100 100)))) + (psw ; petal semi-width + (* pi 0.08))) + ;; for each angle a between 0 and 2π draw a petal as a bezier + ;; curve. the curve uses two control points that are R away from + ;; the starting point and PSW radians on either side of the line + ;; at angle a (loop for a from 0 to (* 2 pi) by (/ (* 2 pi) petals) do (ww::stroke-rel-bezier (list (list (* r (sin (- a psw))) @@ -61,17 +73,22 @@ (defun draw-stuff (canvas) (ww::with-canvas canvas + ;; set canvas color. (ww::canvas-pen-color #'plaid1) (filled-triangle-at 250 200) - (ww::canvas-pen-width 2) - ;; temporarily use a different pen - (ww::with-pen-color #'lower-the-bluer + ;; temporarily use a different pen configuration + (ww::with-pen (:color #'lower-the-bluer :width 2) + ;; draw a flower stem (ww::stroke-bezier '((0 0) (200 120) (50 350) (200 100) (300 400)) - 12)) ;; back to plaid pen after this + 12) + ;; draw a flower + (flower 28)) + + - (flower 28) + ;; draw a bunch of triangles (ww::canvas-pen-width 1) (dotimes (x 50) (when (evenp x) |