[example] fiddling

1 files changed, 52 insertions, 45 deletions

diff --git a/examples/11-canvas-geometry.lisp b/examples/11-canvas-geometry.lisp
index 7103663..c144c10 100644
--- a/examples/11-canvas-geometry.lisp
+++ b/examples/11-canvas-geometry.lisp
@@ -13,6 +13,56 @@
       (when (eql :scancode-q scancode)
         (ww::stop))))
 
+(ww:defhandler clear-and-draw
+    (ww::on-perframe (canvas time)
+      (ww::clear-canvas canvas)
+      (draw-stuff canvas time)
+      (ww::blit canvas)))
+
+(defun draw-stuff (canvas &optional time)
+  ;; draw a circle
+  (ww::with-grid-circle (x y) (350 100 90 :interiorp t)
+    (ww::with-pixel (r g b a) (ww::pixel canvas x y)
+      (setf r (mod (* 3 x y time) 256)
+            g (mod x 256)
+            b (mod y 256))))
+  
+  ;; draw a bunch of circles
+  (loop
+    for cx from 0 to 50  
+    for cy from 0 to 50 do
+      (ww::with-grid-circle (x y) ((+ 300 cx) (+ 300 cy) 80)
+        (ww::with-pixel (r g b a) (ww::pixel canvas x y)
+          (setf r (mod (* x y) 256)
+                g (mod time 256)
+                b (mod (* y x) 256)))))
+  
+  ;; draw a random thing
+  (let ((path
+          (loop repeat 7
+                collect (list (+ 10 (random 240))
+                              (+ 10 (random 240))))))
+    (ww::with-grid-path (x y) (path :autoclosep t :interiorp t)
+      (ww::with-pixel (r g b a) (ww::pixel canvas x y)
+        (setf r (mod (* 2 y) 256)
+              g (mod (* 3 x) 256)
+              b (mod (* x y) 256)))))
+  
+  (let ((control-points
+          `((100 250)
+            (,(+ (mod time 20) -10 -100) 490)
+            (,(+ (mod time 20) -10 300) 490)
+            (100 250)))
+        (path nil))
+    ;; collect the points along the curve
+    (ww::with-grid-bezier (x y) (control-points :count 16)
+      (push (list x y) path))
+
+    ;; and then treat them as a closed path, which is filled.
+    (ww::with-grid-path (x y) (path :interiorp t)
+      (ww::with-pixel (r g b a) (ww::pixel canvas x y)
+        (setf r 200 b 120 g 30)))))
+
 (defmethod ww:boot ((app geo-demo))
   (let ((canvas
           (make-instance 'ww:canvas
@@ -25,51 +75,8 @@
     ;; add it to the display tree
     (ww:add-unit app canvas)
 
-    (ww::with-pixels-rect (x y r g b a) (canvas)
-      (ww::setf-many r g b 0))
-
-    ;; draw a circle
-    (ww::with-grid-circle (x y) (350 100 90 :interiorp t)
-      (ww::with-pixel (r g b a) (ww::pixel canvas x y)
-        (setf r (mod (* 3 x y) 256)
-              g (mod (+ x x) 256)
-              b (mod (* y y) 256))))
-
-    ;; draw a bunch of circles
-    (loop
-      for cx from 0 to 50  
-      for cy from 0 to 50 do
-        (ww::with-grid-circle (x y) ((+ 300 cx) (+ 300 cy) 80)
-          (ww::with-pixel (r g b a) (ww::pixel canvas x y)
-            (setf r (mod (* x y) 256)
-                  g (mod (* x x) 256)
-                  b (mod (* y x) 256)))))
-
-    ;; draw a random thing
-    (let ((path
-            (loop repeat 7
-                  collect (list (+ 10 (random 240))
-                                (+ 10 (random 240))))))
-      (ww::with-grid-path (x y) (path :autoclosep t :interiorp t)
-        (ww::with-pixel (r g b a) (ww::pixel canvas x y)
-          (setf r (mod (* 2 y) 256)
-                g (mod (* 3 x) 256)
-                b (mod (* x y) 256)))))
-
-    (let ((control-points
-            '((10 490)
-              (200 300)
-              (0 400)
-              (40 250))))
-      (ww::with-grid-bezier (x y) (control-points :count 80)
-        (ww::with-grid-rect (rx ry) ((- x 2) (- y 2) (+ x 2) (+ y 2)) 
-          (ww::with-pixel (r g b a) (ww::pixel canvas rx ry)
-            (setf g 255)))))
-
-    ;; blit the canvas
-    (ww::blit canvas)
-
-    ;; quit handler
+    ;; handlers
+    (ww::add-handler canvas #'clear-and-draw)
     (ww:add-handler app #'quit)
     (ww:add-handler canvas #'quit)))