UI: transitions - use existing ease functions

Author: eruvanos

arcade/gui/__init__.py

@@ -28,7 +28,6 @@
 )
 from arcade.gui.widgets import UIDummy, Rect
 from arcade.gui.transition import (
-    EaseFunctions,
     TransitionBase,
     EventTransitionBase,
     TransitionAttr,
@@ -100,7 +99,6 @@
     "Rect",
     "NinePatchTexture",
     # Transitions
-    "EaseFunctions",
     "TransitionBase",
     "EventTransitionBase",
     "TransitionAttr",

arcade/gui/transition.py

@@ -1,20 +1,11 @@
-import math
 from abc import ABC, abstractmethod
 from typing import Callable, Any, Optional, List, TypeVar
 
 from pyglet.event import EventDispatcher
 
-T = TypeVar("T", bound="TransitionBase")
-
+from arcade import linear
 
-class EaseFunctions:
-    @staticmethod
-    def linear(x: float):
-        return x
-
-    @staticmethod
-    def sine(x: float):
-        return 1 - math.cos((x * math.pi) / 2)
+T = TypeVar("T", bound="TransitionBase")
 
 
 class TransitionBase(ABC):
@@ -109,7 +100,7 @@ def __init__(
         attribute,
         duration: float,
         start=None,
-        ease_function=EaseFunctions.linear,
+        ease_function=linear,
         delay=0.0,
         mutation_function: Callable[[Any, str, float], None] = setattr,
     ):
@@ -149,7 +140,7 @@ def __init__(
         increment: float,
         attribute,
         duration: float,
-        ease_function=EaseFunctions.linear,
+        ease_function=linear,
         delay=0.0,
         mutation_function: Callable[[Any, str, float], None] = setattr,
     ):

doc/programming_guide/gui/concept.rst

@@ -60,7 +60,7 @@ Transitions
 
 To animate a UIWidget, use :meth:`UIWidget.add_transition` and add a :class:`Transition`.
 A :class:`Transition` can be used to manipulate a value over time.
-:class:`EaseFunctions` provides a few easing functions.
+Arcade provides a few easing functions listed below.
 
 .. code-block::
 
@@ -83,6 +83,25 @@ Arcade provides following transitions:
 > Be aware, that transitions may interfere with :class:`UILayout` positioning.
 
 
+Easing functions
+................
+
+You can check out all of these functions using `python -m arcade.examples.easing_example_1`
+
+- :meth:`arcade.linear`
+- :meth:`arcade.smoothstep`
+- :meth:`arcade.ease_in`
+- :meth:`arcade.ease_out`
+- :meth:`arcade.ease_in_out`
+- :meth:`arcade.ease_out_elastic`
+- :meth:`arcade.ease_out_bounce`
+- :meth:`arcade.ease_in_back`
+- :meth:`arcade.ease_out_back`
+- :meth:`arcade.ease_in_sin`
+- :meth:`arcade.ease_out_sin`
+- :meth:`arcade.ease_in_out_sin`
+
+
 UILayout
 ========