From: Javier Sancho <jsf@jsancho.org>
Date: Thu, 20 Apr 2017 23:40:35 +0000 (+0200)
Subject: Merge branch 'feature/animations' into develop
X-Git-Url: https://git.jsancho.org/?p=gacela.git;a=commitdiff_plain;h=d5e6b96df9710217483559f367132f2e3c84119c;hp=e1e0e1c4a98a9b27391eeef40dea40a59d983710

Merge branch 'feature/animations' into develop
---

diff --git a/examples/05-animations/05-animations.scm b/examples/05-animations/05-animations.scm
new file mode 100644
index 0000000..eea8812
--- /dev/null
+++ b/examples/05-animations/05-animations.scm
@@ -0,0 +1,34 @@
+#!/usr/bin/env guile
+!#
+
+;;; Gacela, a GNU Guile extension for fast games development
+;;; Copyright (C) 2017 by Javier Sancho Fernandez <jsf at jsancho dot org>
+;;;
+;;; This program is free software: you can redistribute it and/or modify
+;;; it under the terms of the GNU General Public License as published by
+;;; the Free Software Foundation, either version 3 of the License, or
+;;; (at your option) any later version.
+;;;
+;;; This program is distributed in the hope that it will be useful,
+;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;;; GNU General Public License for more details.
+;;;
+;;; You should have received a copy of the GNU General Public License
+;;; along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+(use-modules (gacela))
+
+(define (tick) (* 3000000 (get-internal-real-time)))
+(define (waggle) (* 200 (cos (* pi (tick)))))
+(define (wiggle) (* 300 (sin (* pi (tick)))))
+
+(display-scene
+ (window ((resolution '(640 480)))
+   (move (image "homer.png")
+         wiggle 0)))
+
+(display-scene
+ (window ((resolution '(640 480)))
+   (move (image "marge.png")
+         0 waggle)))
diff --git a/examples/05-animations/homer.png b/examples/05-animations/homer.png
new file mode 100644
index 0000000..485e01e
Binary files /dev/null and b/examples/05-animations/homer.png differ
diff --git a/examples/05-animations/marge.png b/examples/05-animations/marge.png
new file mode 100644
index 0000000..576092b
Binary files /dev/null and b/examples/05-animations/marge.png differ
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