attic/fluttr/src/fluttr-behave.c

   1 /*
   2  * Copyright (C) 2007 Neil J. Patel
   3  * Copyright (C) 2007 OpenedHand Ltd
   4  *
   5  * Author: Neil J. Patel  <njp@o-hand.com>
   6  */
   7
   8
   9 /* This is a utility ClutterBehaviour-derived class, in which you can set the
  10    alphanotify function. It is useful for situations where you do not need the
  11    full capabilities of the ClutterBehvaiour class, you just want a function to
  12    be called for each iteration along the timeline
  13 */
  14
  15 #include "fluttr-behave.h"
  16
  17 #include "math.h"
  18
  19 G_DEFINE_TYPE (FluttrBehave, fluttr_behave, CLUTTER_TYPE_BEHAVIOUR);
  20
  21 #define FLUTTR_BEHAVE_GET_PRIVATE(obj) (G_TYPE_INSTANCE_GET_PRIVATE ((obj),\
  22         FLUTTR_TYPE_BEHAVE, \
  23         FluttrBehavePrivate))
  24
  25 struct _FluttrBehavePrivate
  26 {
  27         FluttrBehaveAlphaFunc     func;
  28         gpointer                data;
  29 };
  30
  31 guint32
  32 alpha_sine_inc_func (ClutterAlpha *alpha,
  33                      gpointer      dummy)
  34 {
  35         ClutterTimeline *timeline;
  36         gint current_frame_num, n_frames;
  37         gdouble x, sine;
  38
  39         timeline = clutter_alpha_get_timeline (alpha);
  40
  41         current_frame_num = clutter_timeline_get_current_frame (timeline);
  42         n_frames = clutter_timeline_get_n_frames (timeline);
  43
  44         x = (gdouble) (current_frame_num * 0.5f * M_PI) / n_frames ;
  45         /* sine = (sin (x - (M_PI / 0.5f)) + 1.0f) * 0.5f; */
  46
  47         sine = (sin (x - (M_PI / 0.5f))) ;
  48
  49         return (guint32)(sine * (gdouble) CLUTTER_ALPHA_MAX_ALPHA);
  50 }
  51
  52 guint32
  53 alpha_linear_inc_func (ClutterAlpha *alpha,
  54                        gpointer      dummy)
  55 {
  56         ClutterTimeline *timeline;
  57         gint current_frame_num, n_frames;
  58         gdouble x;
  59
  60         timeline = clutter_alpha_get_timeline (alpha);
  61
  62         current_frame_num = clutter_timeline_get_current_frame (timeline);
  63         n_frames = clutter_timeline_get_n_frames (timeline);
  64
  65         x = (gdouble) (current_frame_num) / n_frames ;
  66         /* sine = (sin (x - (M_PI / 0.5f)) + 1.0f) * 0.5f; */
  67
  68         return (guint32)(x * (gdouble) CLUTTER_ALPHA_MAX_ALPHA);
  69 }
  70
  71 static void
  72 fluttr_behave_alpha_notify (ClutterBehaviour *behave, guint32 alpha_value)
  73 {
  74         FluttrBehave *fluttr_behave = FLUTTR_BEHAVE(behave);
  75         FluttrBehavePrivate *priv;
  76
  77         priv = FLUTTR_BEHAVE_GET_PRIVATE (fluttr_behave);
  78
  79         if (priv->func != NULL) {
  80                 priv->func (behave, alpha_value, priv->data);
  81         }
  82 }
  83
  84 static void
  85 fluttr_behave_class_init (FluttrBehaveClass *klass)
  86 {
  87         GObjectClass        *gobject_class = G_OBJECT_CLASS (klass);
  88         ClutterBehaviourClass *behave_class = CLUTTER_BEHAVIOUR_CLASS (klass);
  89
  90         behave_class->alpha_notify = fluttr_behave_alpha_notify;
  91
  92         g_type_class_add_private (gobject_class, sizeof (FluttrBehavePrivate));
  93 }
  94
  95 static void
  96 fluttr_behave_init (FluttrBehave *self)
  97 {
  98         FluttrBehavePrivate *priv;
  99
 100         priv = FLUTTR_BEHAVE_GET_PRIVATE (self);
 101
 102         priv->func = NULL;
 103         priv->data = NULL;
 104 }
 105
 106 ClutterBehaviour*
 107 fluttr_behave_new (ClutterAlpha                 *alpha,
 108                  FluttrBehaveAlphaFunc   func,
 109                  gpointer                data)
 110 {
 111         FluttrBehave *behave;
 112         FluttrBehavePrivate *priv;
 113
 114         behave = g_object_new (FLUTTR_TYPE_BEHAVE,
 115                                "alpha", alpha,
 116                                NULL);
 117
 118         priv = FLUTTR_BEHAVE_GET_PRIVATE (behave);
 119
 120         priv->func = func;
 121         priv->data = data;
 122
 123         return CLUTTER_BEHAVIOUR(behave);
 124 }