From: Javier Sancho <jsf@jsancho.org>
Date: Thu, 20 Apr 2017 23:39:14 +0000 (+0200)
Subject: Moving scenes
X-Git-Url: https://git.jsancho.org/?p=gacela.git;a=commitdiff_plain;h=a586780bf88efb2a54df1e2af26600a549f7113d

Moving scenes
---

diff --git a/gacela/image.scm b/gacela/image.scm
index 278a7d7..e6c8f4e 100644
--- a/gacela/image.scm
+++ b/gacela/image.scm
@@ -24,9 +24,14 @@
   #:use-module ((sdl2 surface) #:prefix sdl2:)
   #:use-module (gl)
   #:export (image
-            move-xy
+            move
             scale))
 
+(define (calculate proc-or-value)
+  (if (procedure? proc-or-value)
+      (proc-or-value)
+      proc-or-value))
+
 (define (image filename)
   (make-scene
    "image"
@@ -52,15 +57,14 @@
          (gl-vertex (- w/2) (- h/2) 0))
        (gl-disable (oes-framebuffer-object texture-2d))))))
 
-(define (move-xy x y scene)
-  (define (to-integer n)
-    (inexact->exact (round n)))
+(define* (move scene x y #:optional (z 0))
   (make-scene
-   "move-xy"
+   "move"
    (lambda ()
-     (let ((xy (list (to-integer (if (procedure? x) (x) x))
-                     (to-integer (if (procedure? y) (y) y)))))
-       (display-scene scene #:xy xy)))))
+     (gl-translate (calculate x)
+                   (calculate y)
+                   (calculate z))
+     (display-scene scene))))
 
 (define* (scale scene x #:optional (y x) (z y))
   (make-scene