render: Add vector path rendering module.

1 files changed, 80 insertions, 0 deletions

diff --git a/examples/path.scm b/examples/path.scm
new file mode 100644
index 0000000..0223864
--- /dev/null
+++ b/examples/path.scm
@@ -0,0 +1,80 @@
+(use-modules (chickadee)
+             (chickadee graphics color)
+             (chickadee graphics font)
+             (chickadee graphics path)
+             (chickadee math)
+             (chickadee math vector)
+             (chickadee scripting))
+
+(set! *random-state* (random-state-from-platform))
+
+(define (stats-message)
+  (format #f "fps: ~1,2f"
+          (/ 1000.0 avg-frame-time)))
+(define start-time 0.0)
+(define avg-frame-time 16)
+(define stats-text (stats-message))
+(define stats-text-pos (vec2 4.0 464.0))
+(define last-update start-time)
+(define canvas (make-empty-canvas))
+(define rss-orange (string->color "#FF8800"))
+
+(define rss-feed-logo
+  (superimpose
+   (with-style ((fill-color rss-orange))
+     (fill
+      (rounded-rectangle (vec2 0.0 3.0) 95.0 95.0 #:radius 15.0)))
+   (with-style ((fill-color white))
+     (fill
+      (circle (vec2 18.0 18.0) 9.0)))
+   (with-style ((stroke-color white)
+                (stroke-cap 'round)
+                (stroke-width 15.0))
+     (stroke
+      (path
+       (arc (vec2 18.0 18.0) 30.0 30.0 0.0 pi/2))
+      (path
+       (arc (vec2 18.0 18.0) 60.0 60.0 0.0 pi/2))))))
+
+(define polylines
+  (with-style ((stroke-color tango-plum)
+               (stroke-width 6.0))
+    (stroke
+     (apply polyline (map (lambda (i)
+                            (vec2 (* (+ i 1) 30) (+ (random 240) 100)))
+                          (iota 20))))))
+
+(define (make-example-painter s)
+  (superimpose (translate (vec2 30.0 10.0)
+                 (scale s rss-feed-logo))
+               polylines))
+
+(define (load)
+  (script
+   (forever
+    (tween 60 1.0 4.0
+           (lambda (s)
+             (set-canvas-painter! canvas (make-example-painter s))))
+    (tween 60 4.0 1.0
+           (lambda (s)
+             (set-canvas-painter! canvas (make-example-painter s)))))))
+
+(define (draw alpha)
+  (draw-canvas canvas)
+  (draw-text stats-text stats-text-pos)
+  (let ((current-time (elapsed-time)))
+    (set! avg-frame-time
+          (+ (* (- current-time start-time) 0.1)
+             (* avg-frame-time 0.9)))
+    (set! start-time current-time)
+    (when (>= (- current-time last-update) 1000)
+      (set! stats-text (stats-message))
+      (set! last-update current-time))))
+
+(define (update dt)
+  (update-agenda 1))
+
+(run-game #:window-title "Vector paths"
+          #:load load
+          #:draw draw
+          #:update update)