/* * Clutter. * * An OpenGL based 'interactive canvas' library. * * Authored By Matthew Allum * Jorn Baayen * * Copyright (C) 2006 OpenedHand * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library 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 * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the * Free Software Foundation, Inc., 59 Temple Place - Suite 330, * Boston, MA 02111-1307, USA. */ /** * SECTION:clutter-alpha * @short_description: A class for calculating an alpha value as a function * of time. * * #ClutterAlpha is a class for calculating an alpha value as a function * of time. */ #include "clutter-alpha.h" #include "clutter-main.h" #include "clutter-marshal.h" G_DEFINE_TYPE (ClutterAlpha, clutter_alpha, G_TYPE_OBJECT); struct ClutterAlphaPrivate { ClutterTimeline *timeline; guint timeline_new_frame_id; guint32 alpha; ClutterAlphaFunc func; }; enum { PROP_0, PROP_TIMELINE, PROP_FUNC, PROP_ALPHA }; /* Alpha funcs */ guint32 clutter_alpha_ramp_inc_func (ClutterAlpha *alpha) { int current_frame_num, nframes; current_frame_num = clutter_timeline_get_current_frame (alpha->priv->timeline); nframes = clutter_timeline_get_n_frames (alpha->priv->timeline); return (current_frame_num * CLUTTER_ALPHA_MAX_ALPHA) / nframes; } guint32 clutter_alpha_ramp_dec_func (ClutterAlpha *alpha) { int current_frame_num, nframes; current_frame_num = clutter_timeline_get_current_frame (alpha->priv->timeline); nframes = clutter_timeline_get_n_frames (alpha->priv->timeline); return ((nframes - current_frame_num) * CLUTTER_ALPHA_MAX_ALPHA) / nframes; } guint32 clutter_alpha_ramp_func (ClutterAlpha *alpha) { int current_frame_num, nframes; current_frame_num = clutter_timeline_get_current_frame (alpha->priv->timeline); nframes = clutter_timeline_get_n_frames (alpha->priv->timeline); if (current_frame_num > (nframes/2)) { return ((nframes - current_frame_num) * CLUTTER_ALPHA_MAX_ALPHA) / (nframes/2); } else { return (current_frame_num * CLUTTER_ALPHA_MAX_ALPHA) / (nframes/2); } } /* Object */ static void timeline_new_frame_cb (ClutterTimeline *timeline, guint current_frame_num, ClutterAlpha *alpha) { ClutterAlphaPrivate *priv; priv = alpha->priv; /* Update alpha value */ if (priv->func) { priv->alpha = priv->func(alpha); g_object_notify (G_OBJECT (alpha), "alpha"); } } static void clutter_alpha_set_property (GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec) { ClutterAlpha *alpha; ClutterAlphaPrivate *priv; alpha = CLUTTER_ALPHA(object); priv = alpha->priv; switch (prop_id) { case PROP_TIMELINE: clutter_alpha_set_timeline (alpha, g_value_get_object (value)); break; case PROP_FUNC: priv->func = g_value_get_pointer (value); break; default: G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); break; } } static void clutter_alpha_get_property (GObject *object, guint prop_id, GValue *value, GParamSpec *pspec) { ClutterAlpha *alpha; ClutterAlphaPrivate *priv; alpha = CLUTTER_ALPHA(object); priv = alpha->priv; switch (prop_id) { case PROP_TIMELINE: g_value_set_object (value, priv->timeline); break; case PROP_FUNC: g_value_set_pointer (value, priv->func); break; case PROP_ALPHA: g_value_set_uint (value, priv->alpha); break; default: G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); break; } } static void clutter_alpha_finalize (GObject *object) { G_OBJECT_CLASS (clutter_alpha_parent_class)->finalize (object); } static void clutter_alpha_dispose (GObject *object) { ClutterAlpha *self = CLUTTER_ALPHA(object); clutter_alpha_set_timeline (self, NULL); G_OBJECT_CLASS (clutter_alpha_parent_class)->dispose (object); } static void clutter_alpha_class_init (ClutterAlphaClass *klass) { GObjectClass *object_class; object_class = (GObjectClass*) klass; object_class->set_property = clutter_alpha_set_property; object_class->get_property = clutter_alpha_get_property; object_class->finalize = clutter_alpha_finalize; object_class->dispose = clutter_alpha_dispose; g_type_class_add_private (klass, sizeof (ClutterAlphaPrivate)); g_object_class_install_property (object_class, PROP_TIMELINE, g_param_spec_object ("timeline", "Timeline", "Timeline", CLUTTER_TYPE_TIMELINE, G_PARAM_READWRITE)); g_object_class_install_property (object_class, PROP_FUNC, g_param_spec_pointer ("func", "Alpha function", "Alpha function", G_PARAM_READWRITE)); g_object_class_install_property (object_class, PROP_ALPHA, g_param_spec_uint ("alpha", "Alpha value", "Alpha value", 0, CLUTTER_ALPHA_MAX_ALPHA, 0, G_PARAM_READABLE)); } static void clutter_alpha_init (ClutterAlpha *self) { self->priv = G_TYPE_INSTANCE_GET_PRIVATE(self, CLUTTER_TYPE_ALPHA, ClutterAlphaPrivate); self->priv->func = CLUTTER_ALPHA_RAMP_INC; } /** * clutter_alpha_get_alpha: * @alpha: A #ClutterAlpha * * Query the current alpha value. * * Return Value: The current alpha value for the alpha */ gint32 clutter_alpha_get_alpha (ClutterAlpha *alpha) { g_return_val_if_fail (CLUTTER_IS_ALPHA (alpha), FALSE); return alpha->priv->alpha; } /** * clutter_alpha_set_func: * @alpha: A #ClutterAlpha * @func: A #ClutterAlphaAlphaFunc * */ void clutter_alpha_set_func (ClutterAlpha *alpha, ClutterAlphaFunc func) { alpha->priv->func = func; } /** * clutter_alpha_set_timeline: * @alpha: A #ClutterAlpha * @timeline: A #ClutterTimeline * * Binds @alpha to @timeline. */ void clutter_alpha_set_timeline (ClutterAlpha *alpha, ClutterTimeline *timeline) { if (alpha->priv->timeline) { g_signal_handler_disconnect (alpha->priv->timeline, alpha->priv->timeline_new_frame_id); g_object_unref (alpha->priv->timeline); alpha->priv->timeline = NULL; } if (timeline) { alpha->priv->timeline = g_object_ref (timeline); alpha->priv->timeline_new_frame_id = g_signal_connect (alpha->priv->timeline, "new-frame", G_CALLBACK (timeline_new_frame_cb), alpha); } } /** * clutter_alpha_get_timeline: * @alpha: A #ClutterAlpha * * Return value: The #ClutterTimeline */ ClutterTimeline * clutter_alpha_get_timeline (ClutterAlpha *alpha) { return alpha->priv->timeline; } /** * clutter_alpha_new: * @timeline: #ClutterTimeline timeline * @func: #ClutterAlphaFunc alpha function * * Create a new #ClutterAlpha instance. * * Return Value: a new #ClutterAlpha */ ClutterAlpha* clutter_alpha_new (ClutterTimeline *timeline, ClutterAlphaFunc func) { return g_object_new (CLUTTER_TYPE_ALPHA, "timeline", timeline, "func", func, NULL); }