examples: Add sprite batch example.

* examples/sprite-batch.scm: New file.
* examples/images/shot.png: New file.
* Makefile.am (EXTRA_DIST): Add them.

1 files changed, 66 insertions, 0 deletions

diff --git a/examples/sprite-batch.scm b/examples/sprite-batch.scm
new file mode 100644
index 0000000..c31ffbf
--- /dev/null
+++ b/examples/sprite-batch.scm
@@ -0,0 +1,66 @@
+(use-modules (chickadee)
+             (chickadee math matrix)
+             (chickadee math rect)
+             (chickadee math vector)
+             (chickadee render)
+             (chickadee render font)
+             (chickadee render sprite)
+             (chickadee render texture)
+             (chickadee scripting)
+             (ice-9 format)
+             (ice-9 match)
+             ((sdl2) #:select (sdl-ticks))
+             (srfi srfi-1)
+             (statprof))
+
+(define texture #f)
+(define start-time (sdl-ticks))
+(define avg-frame-time 16)
+(define num-sprites 5000)
+(define sprites
+  (list-tabulate num-sprites
+                 (lambda (n)
+                   (list (rect (* (random:uniform) 640.0)
+                               (* (random:uniform) 480.0)
+                               16.0 16.0)
+                         (vec2 (* (- (random:uniform) 0.5) 0.5)
+                               (* (- (random:uniform) 0.5) 0.5))))))
+(define matrix (make-identity-matrix4))
+
+(define (stats-message)
+  (format #f "sprites: ~d   fps: ~1,2f"
+          num-sprites
+          (/ 1000.0 avg-frame-time)))
+
+(define stats-text (stats-message))
+
+(define (load)
+  (set! *random-state* (random-state-from-platform))
+  (set! texture (load-image "images/shot.png"))
+  (script
+   (forever
+    (sleep 60)
+    (set! stats-text (stats-message)))))
+
+(define stats-text-pos (vec2 4.0 464.0))
+(define (draw alpha)
+  (with-batched-sprites
+   (for-each (match-lambda
+               ((r v)
+                (set-rect-x! r (+ (rect-x r) (vec2-x v)))
+                (set-rect-y! r (+ (rect-y r) (vec2-y v)))
+                (draw-sprite* texture r matrix)))
+             sprites))
+  (draw-text stats-text stats-text-pos)
+  (let ((current-time (sdl-ticks)))
+    (set! avg-frame-time
+          (+ (* (- current-time start-time) 0.1)
+             (* avg-frame-time 0.9)))
+    (set! start-time current-time)))
+
+(define (update dt)
+  (update-agenda 1))
+
+(gcprof
+ (lambda ()
+   (run-game #:load load #:draw draw #:update update)))