Incompatible Changes
====================

This is a list of changes that may require intervention in the form of
changes to scripts or your development environment. Our intent is that
all other changes should not affect existing scripts.

Note that setting :var:`config.script_version` will cause many of
these changes to be reverted, at the cost of losing access to recent
features.

.. _incompatible-6.13:

6.13
----

The changes to text behavior can affect games in development in many
ways. The biggest change is the introduction of new-style
(square-bracket) text substitutions, and the elimination of old-style
(percent-based) substitutions. These changes can be reverted with the
code::

    init python:
        config.old_substitutions = True
        config.new_substitutions = False

New- and old-style substitutions can coexist in the same game, by
setting both variables to True.

Ren'Py has also changed the default line-wrapping behavior. While
the new behavior should never increase the number of lines in a
paragraph, it may change which words fall on each line. To restore
the old behavior, add the code::

    init python:
        style.default.layout = "greedy"
        style.default.language = "western"

A bug with negative line_spacing was fixed. This fix can cause blocks of
text to shrink in height. To revert to the old behavior, use::

    init python:
        config.broken_line_spacing = True

Finally, the new text code may lead to artifacts when displaying slow
text, especially in conjunction with a negative line spacing. Consider
adjusting :prop:`line_overlap_split` to fix this.
        
.. _incompatible-6.12.1:

6.12.1
------

Image names have changed from being static names to being
attribute-based. This can lead to image names that were previously
distinct becoming ambiguous. To disable attribute-based image names,
set :var:`config.image_attributes` to False.

Showing an image without providing a transform or ATL block will now
continue the previous transform that the image was using. This means
that a moving image may continue moving once it has changed. To revert
to the old behavior, set :var:`config.keep_running_transform` to False.

The `image` argument to :func:`Character` has changed meaning. While
the old meaning was unsupported in the screens-based environment, it
can be restored for compatibility purposes by setting
:var:`config.new_character_image_argument` to False.


.. _incompatible-6.12.0:

6.12.0
------

The definition of the `items` parameter of the :ref:`choice-screen` and
``nvl_choice`` screens has changed. The ``nvl_choice`` screen is
deprecated in favor of the :ref:`nvl-screen` screen.

Screens may be invoked at any time, in order to allow for image
prediction, unless they have a predict property of False. When the
predict property is not False, screens should not cause side effects
to occur upon their initial display.

For performance reason, Ren'Py now ignores the position properties of
ImageReferences. This means that the position properties of
style.image_placement are now ignored. To revert to the old behavior,
set :var:`config.imagereference_respects_position` to True.

.. _incompatible-6.11.1:

6.11.1
------

MoveTransition has been modified to respect the xoffset and yoffset
parameters of the displayables it is moving. The factory functions
that are used for movement now take `xoffset` and `yoffset`
parameters.  While the built-in movement factories take these
parameters without problem, user-defined factories may need to
be upgraded to use or ignore these additional parameters.


.. _incompatible-6.11.0:

6.11.0
------

* The transform specified by the :var:`config.default_transform`
  variable is used to initialize the transform properties of images
  shown using the show and hide statements. The default value of this
  transform sets :propref:`xpos` and :propref:`xanchor` to 0.5, and
  :propref:`ypos` and :propref:`yanchor` to 1.0.

  This represents a change in the default value of these style
  properties, which were previously uninitialized and hence defaulted
  to 0. 

  By including the :var:`reset` transform in ATL transforms, these
  properties can be reset back to 0. Alternatively, one can stop using
  the default transform, and revert to the old behavior, using the
  code::

    init python:
        style.image_placement.xpos = 0.5
        style.image_placement.ypos = 1.0
        style.image_placement.xanchor = 0.5
        style.image_placement.yanchor = 1.0

        config.default_transform = None

* If a transform does not define one of the position properties
  :propref:`xpos`, :propref:`ypos`, :propref:`xanchor`, or
  :propref:`yanchor`, that property will be taken from the transform's
  child, if the defines that property.

  This makes it possible to have one transform control a displayable's
  vertical motion, and the other control the horizontal. But this is
  incompatible with previous behavior, and so can be disabled with the
  :var:`config.transform_uses_child_position` variable. ::

    init python:
        config.transform_uses_child_position = False
  
.. _incompatible-6.10.1:

6.10.0
------

* The default positions (left, right, center, truecenter,
  offscreenleft, and offscreenright) are now defined as ATL
  transforms. This means that showing an image at such a position will
  cause the position to be remembered. If you do not want this
  behavior, you need to redefine these positions, by adding the code::

    define left = Position(xalign=0.0)
    define center = Position(xalign=0.5)
    define truecenter = Position(xalign=0.5, yalign=0.5)
    define right = Position(xalign=1.0)
    define offscreenleft = Position(xpos=0.0, xanchor=1.0)
    define offscreenright = Position(xpos=1.0, xanchor=0.0)

.. _incompatible-6.9.2: 
    
6.9.2 
-----

* To migrate your game from Ren'Py 6.9.2 or later, copy the directory
  containing your game into your projects directory. You can choose a
  projects directory by clicking "Options", "Projects Directory" in the
  Launcher. Please see the
  `Ren'Py 6.9.2 release notes <http://www.renpy.org/wiki/renpy/releases/6.9.2>`_
  for information about migrating from older releases.
