Update README.

1 files changed, 13 insertions, 14 deletions

diff --git a/README b/README
index fe201d8..b478a57 100644
--- a/README
+++ b/README
@@ -29,21 +29,22 @@ Sly differentiates itself from most other game engines by encouraging
   #+BEGIN_SRC scheme
     (use-modules (sly))
 
-    ;; Create OpenGL context and do other setup.
-    (sly-init)
-
-    ;; Load a GNU head sprite.
-    (define gnu
-      (load-sprite "gnu.png"))
-
     ;; The way we see the world.
     (define camera
       (2d-camera #:area (make-rect 0 0 640 480)))
 
+    ;; Load a GNU head sprite when the game starts.  Until the game
+    ;; starts, this "signal" holds the null sprite.
+    (define-signal gnu
+      (on-start (load-sprite "gnu.png")
+                null-sprite))
+
     ;; View the sprite from the perspective of the camera.
     (define-signal scene
-      (with-camera camera
-        (move (vector2 320 240) (render-sprite gnu))))
+      (signal-let ((gnu gnu))
+        (with-camera (2d-camera #:area (make-rect 0 0 640 480))
+          (move (vector2 320 240)
+                (render-sprite gnu)))))
 
     (with-window (make-window #:title "Hello, world!")
       (run-game-loop scene))
@@ -70,7 +71,7 @@ Sly differentiates itself from most other game engines by encouraging
    #+BEGIN_SRC scheme
      (with-window (make-window #:title "Best Game Ever"
                                #:resolution #(640 480))
-       (run-game-loop))
+       (run-game-loop scene))
    #+END_SRC
 
 ** Functional Reactive Programming
@@ -160,8 +161,7 @@ Sly differentiates itself from most other game engines by encouraging
 
   #+BEGIN_SRC sh
     guix environment -l guix.scm
-    ./bootstrap && ./configure \
-        --with-libgslcblas-prefix=$(guix build gsl)
+    ./bootstrap && ./configure
   #+END_SRC
 
 * Running Examples
@@ -193,10 +193,9 @@ Sly differentiates itself from most other game engines by encouraging
 
 * Dependencies
 
-  - GNU Guile >= 2.0.11
+  - GNU Guile >= 2.0.11 (Guile 2.2.x recommended for best performance)
   - [[http://www.gnu.org/software/guile-opengl/][guile-opengl]] >= 0.1.0
   - [[https://dthompson.us/pages/software/guile-sdl2.html][guile-sdl2]] >= 0.1.0
-  - GNU Scientific Library (GSL)
 
 * Releases