1 files changed, 83 insertions, 0 deletions
diff --git a/subprojects/libhandy/src/hdy-animation.c b/subprojects/libhandy/src/hdy-animation.c
new file mode 100644
index 0000000..ce5bf64
--- /dev/null
+++ b/subprojects/libhandy/src/hdy-animation.c
@@ -0,0 +1,83 @@
+/*
+ * Copyright (C) 2019 Purism SPC
+ *
+ * SPDX-License-Identifier: LGPL-2.1+
+ */
+
+#include "config.h"
+
+#include "hdy-animation-private.h"
+
+/**
+ * SECTION:hdy-animation
+ * @short_description: Animation helpers
+ * @title: Animation Helpers
+ *
+ * Animation helpers.
+ *
+ * Since: 0.0.11
+ */
+
+/**
+ * hdy_get_enable_animations:
+ * @widget: a #GtkWidget
+ *
+ * Returns whether animations are enabled for that widget. This should be used
+ * when implementing an animated widget to know whether to animate it or not.
+ *
+ * Returns: %TRUE if animations are enabled for @widget.
+ *
+ * Since: 0.0.11
+ */
+gboolean
+hdy_get_enable_animations (GtkWidget *widget)
+{
+  gboolean enable_animations = TRUE;
+
+  g_assert (GTK_IS_WIDGET (widget));
+
+  g_object_get (gtk_widget_get_settings (widget),
+                "gtk-enable-animations", &enable_animations,
+                NULL);
+
+  return enable_animations;
+}
+
+/**
+ * hdy_lerp: (skip)
+ * @a: the start
+ * @b: the end
+ * @t: the interpolation rate
+ *
+ * Computes the linear interpolation between @a and @b for @t.
+ *
+ * Returns: the linear interpolation between @a and @b for @t.
+ *
+ * Since: 0.0.11
+ */
+gdouble
+hdy_lerp (gdouble a, gdouble b, gdouble t)
+{
+  return a * (1.0 - t) + b * t;
+}
+
+/* From clutter-easing.c, based on Robert Penner's
+ * infamous easing equations, MIT license.
+ */
+
+/**
+ * hdy_ease_out_cubic:
+ * @t: the term
+ *
+ * Computes the ease out for @t.
+ *
+ * Returns: the ease out for @t.
+ *
+ * Since: 0.0.11
+ */
+gdouble
+hdy_ease_out_cubic (gdouble t)
+{
+  gdouble p = t - 1;
+  return p * p * p + 1;
+}